Orthodontics Answers PDF

Machine Translated by Google 1. Study of jaws using a gnathostat. Obtaining gnathostatic models. Diagnostic value. The gnathostatic method was proposed by P. Simon. Gnathostat - a device by means of which the position of models is determined in relation to three mutually perpendicular...

Machine Translated by Google 1. Study of jaws using a gnathostat. Obtaining gnathostatic models. Diagnostic value. The gnathostatic method was proposed by P. Simon. Gnathostat - a device by means of which the position of models is determined in relation to three mutually perpendicular planes: the midsagittal plane passes along the palatine suture and divides the face in half; the ear- orbital or Frankfurt plane, the horizontal passes through the orbital point and the upper edge of the external auditory opening; the frontal or orbital plane, perpendicular to the first two, passes through both orbital points. The P.Simon device consists of a facial bow connected to an impression tray and has four moving arrows installed on the ear and lower orbital points. Using a gnathostat, the base of the model is formed in accordance with the above-mentioned planes, thereby simulating the spatial orientation of the patient's dental arches, allowing a clear representation of the location of the jaws in the skull. Method: The upper jaw impression tray is filled with the impression mass and inserted into the mouth. After the impression has hardened, the assistant holds the tray in this position, the handle of which is fastened to the rod. The face bow is placed on the latter, orienting it with arrows at the level of the Frankfurt horizontal at the orbitale and tragion points. These points are first marked on the patient's face with a grease pencil or black paper circles are glued on. After placing and securing the arrows and the bow with screws, the sliding sleeve is moved close to the bow and everything is fixed. Then the bow with the rod is disconnected from the impression tray, the impression is removed from the mouth and reconnected in the previous position. The line connecting the ends of the two middle arrows is the line of intersection of the Frankfurt horizontal with the orbital plane. To transfer this line to the surface of the impression, use a ruler, which is applied to the sharp ends of the two arrows of the orbital arch. From the middle of the ruler, arrows with a pointed end depart at a right angle, which can move up and down and around the axis within one plane. The ruler is placed so that the point of the arrow reaches the surface of the impression. When the arrow moves up and down and to the sides, the point leaves a trace on the surface of the impression in the form of an engraved line. Then replace the orbital arch with a platform and cast the upper model. After releasing the model from the impression, find the drawn transverse line that passes through the tops of both canines, and the median plane is installed along the palatine suture. Gnathostatic models produced in this way have the following features: The upper base surface of the upper model corresponds to the Frankfrut horizontal, and the lower one is parallel to it; the distance between them is 8 cm; the back surfaces of the models are parallel to the orbital plane and are 4 cm from it. The models are drawn and studied using a symmetrograph. When comparing gnathostatic models with conventional ones, it is clear that the occlusion curve does not pass equally. On gnathostatic models, it decreases forward, i.e., it goes with an inclination in relation to the Frankfrut horizontal. If the upper canines coincide with the orbital plane, it is normal; if they are in front of it, it is prognathism and treatment should be aimed at the upper jaw. If the upper canines are displaced beyond the frontal plane, therapeutic manipulations are performed on the lower jaw. 2. "Progenic" bite (mesial occlusion). Classification, etiology, clinical picture, forms, differential diagnostics. Mesial bite is an anomaly of the closure of the dental arches in the sagittal direction, which is characterized by the following intraoral symptoms: the mesial buccal tubercle of the upper first permanent molar when the dental arches are closed is located behind the intertubercular fissure of the same name Machine Translated by Google lower tooth, the upper canine (permanent or temporary) is located behind the space between the third and fourth teeth of the lower jaw. Mesial occlusion refers to sagittal bite anomalies, characterized by the closure of the molars according to Angle's class III. According to various sources, there are various terms that characterize the mesial occlusion. Class III closure according to Angle Progenia progenic bite lower prognathism anterior occlusion mesial bite mesial occlusion mandibular macrognathia maxillary micrognathia maxillary retrognathia, etc. Etiology of mesial bite. Most often, mesial bite is a genetically determined disease: lower macrognathia or upper micrognathia is inherited. In addition, the cause the formation of such pathology may be congenital disorders, for example, clefts of the maxillofacial areas, birth trauma. Among the acquired factors, the following should be noted: adentia, the presence of supernumerary teeth on the lower jaw, macroglossia, bad habits (sucking in the upper lip, habitual protrusion of the lower jaw, incorrect sleeping position), impaired abrasion of the tubercles of temporary teeth, inflammatory processes (osteomyelitis), early loss of teeth on the upper jaw. Morphologically, the following forms of mesial occlusion can be distinguished : a) dentoalveolar - is the result of incorrect placement of teeth in the alveolar processes, gnathic - is the result of incorrect development of the bones of the facial skeleton; combined; b) with and without displacement of the lower jaw. Depending on the etiological factor, L.V. Ilyina-Markosyan distinguishes between true and false progeny. True - the morphological structure of which is based on a true increase in the size of the body, the branch of the lower jaw. The author classifies frontal progenia and forced progenia as false forms of progenial bite. According to the author's description, frontal progenia can also be called a protrusion of the alveolar process of the lower jaw in the frontal area. That is, the lower frontal teeth are tilted forward (vestibularly), there are tremas and a diastema between them, the dental row of the lower jaw is elongated, however, the ratio of the first permanent molars is according to Angle's first class. Forced progenia (articular form of false progenia) occurs in the absence of abrasion of the tubercles of the temporary canines of the lower jaw with normal rows of the upper and lower jaws. In a state of physiological rest, neither facial nor dental signs of anomaly are observed, however, as soon as the child closes his teeth, the lower jaw shifts forward to the progenial ratio. According to Betelman's classification, mesial bite belongs to anomalies in the sagittal plane and has the following clinical forms: 1-micrognathia of the upper jaw; 2-macrognathia of the lower jaw; 3- macrognathia of the lower jaw and micrognathia of the upper jaw. Facial signs of mesial bite. The facial profile of a patient with mesial bite is concave, the chin protrudes, the upper lip sinks, the lower part of the face is often enlarged (in case of deep reverse incisor overlap it can be reduced), the subnasal fold is deepened, the lower lip is thickened. Morphological disorders of the dental system, characteristic of mesial bite: Machine Translated by Google 1) at the jaw level: posterior position of the upper jaw (retrognathia), reduction in the size of the upper jaw jaws (micrognathia); forward position of the lower jaw (prognathia), increase in the size of the lower jaws (macrognathia); 2) at the level of the dental arches: shortening of the upper dental arch in the anterior section, lengthening of the lower dental arch in the anterior section; 3) at the level of the teeth: mesial displacement of the lower lateral teeth. Functional disorders of the dental system with mesial bite. With mesial bite, biting and chewing food is difficult, the function of swallowing, articulation of the tongue, and pronunciation of sounds are impaired. Differential diagnostics For differential diagnostics of the dentoalveolar and gnathic forms of mesial occlusion, a functional test is carried out: if, when the patient tries to move the lower jaw back to the marginal closure of the anterior teeth, the ratio of the first permanent molars approaches class 1 according to Engel, then the dentoalveolar form of progenia or forced false prognathism is diagnosed. The diagnosis of true progenia is based on anamnesis data (including genetic data), facial examination, study of occlusal relationships in the oral cavity and on diagnostic models, anthropometric measurements on the face and on models. During the examination, it is necessary to accurately distinguish the position of the central occlusion and the posterior (synonyms: retrocuspid, posterior contact position) - when the articular heads of the lower jaw are in the upper, mid-sagittal position, which is called the central relationship. When choosing a treatment method, especially surgical, this position should be the initial one. 3. "Progenic" bite (mesial occlusion). Treatment methods depending on the form of the anomaly and age. Prevention. Treatment of mesial bite begins at the age of 3-4 years with the elimination of acquired etiological factors that contributed to the occurrence of bite anomalies. The period of temporary bite. The main task of the doctor - orthodontist: creating optimal conditions for the growth of the upper jaw, restraining excessive growth of the lower jaw. Treatment methods: the main one is hardware, additional - myotherapy. Less often, complex treatment method. The choice of treatment method depends on the depth of the reverse incisor overlap and the severity of the sagittal discrepancy (the size of the sagittal gap): 1. With a reverse incisor overlap of up to 1/2 the height of the crown of the temporary incisor, the cutting cusps of the canines and incisors of both jaws are ground down in one or several visits, depending on contact with the patient and the sensitivity of the teeth. After completing the grinding of the teeth, complex remineralizing therapy must be carried out. The most effective device for restraining the growth of the lower jaw during the period of temporary occlusion is a cap with a chin sling and sagittal rubber traction (Fig. 48). With a combination of mesial occlusion with protrusion of the lower incisors and dysfunction of the dentoalveolar system, the following is recommended: systems, additionally use individual and standard vestibular plates. 2. In the treatment of mesial bite in combination with deep reverse incisor overlap (more than 1/2 the height of the crown) along with grinding the cutting tubercles of the canines and incisors of both jaws it is advisable to use disengaging devices (a plate on the upper jaw with occlusal pads). To restrain the growth of the lower jaw, a cap with a chin sling and sagittal rubber traction is used (Fig. 48). In children with reduced adaptation to orthodontic devices, a complex treatment method is used (V.P. Nespryadko's method): the lower temporary incisors and canines that block the growth of the upper jaw are removed. After removing the block, the child is recommended to wear a cap with a chin sling and sagittal rubber traction to restrain the growth of the lower jaw. 3. With a significant sagittal gap between the upper and lower incisors (more than 5 mm) in patients aged 4-5 years, a stable positive result can be achieved using the device proposed at the Department of Pediatric Dentistry at Moscow State Medical Institute (Fig. 49). The device consists of intraoral and extraoral parts. The intraoral part is a plate on the upper jaw with occlusal pads, into the base of which in the anterior section two sections of the Angle arch with screw threads and nuts are fixed (Fig. 49 a), which protrude from the oral cavity along the line of lip closure. Machine Translated by Google The extraoral part is a head cap with a chin sling and sagittal rubber traction to restrain the growth of the lower jaw (Fig. 49 b, c). The intraoral part of the device, using a flexible metal (steel) tape and sections of Angle's arches are connected to the extraoral (Fig. 49 b, c). Due to the properties of the flexible metal tape, the growth of the upper jaw is optimized. Modern analogues of the above-described device are facial masks - the Delaire mask (Fig. 50 a), the Petit mask (Fig. 50 b). Facial masks are used in combination with a plate on the upper jaw with occlusal pads (to remove the blockage of the upper jaw by the lower jaw) and ensure optimization of the growth of the upper jaw and containment of the growth of the lower jaw. Fig. 50. Facial masks: a – Delaire mask; b – Petit mask The optimal duration of wearing the above-mentioned devices is 8-10 hours per day. The rest of the time, it is recommended to continue wearing the plate on the upper jaw with occlusal pads. For the treatment of mesial bite with significant sagittal discrepancy in children aged 4–5 years, it is possible to use the Frenkel clasp activator. Machine Translated by Google Fig. 51. Frenkel clasp activator The use of a plate on the upper jaw with a sectoral cut for vestibular deviation of the upper incisors, as well as the Bruckl apparatus (a plate on the lower jaw with an inclined plane) in the temporary bite is inappropriate. Despite the fairly rapid positive result of treatment, in most cases a relapse is possible in mixed and permanent bite. It occurs due to the effect of the above-mentioned devices not on the dental arches, but on the position of the upper incisors. The temporary upper incisors deviate vestibularly, with the apices of the roots they exert pressure on the rudiments of the permanent incisors, facilitating their oral eruption. Mixed occlusion period. The main task of the orthodontist is to optimize the growth of the upper jaw and restrain the growth of the lower jaw in the sagittal direction. Treatment methods: the main one is hardware, the additional one is myotherapy. In some cases, a complex method is used. Mesial occlusion in this period of dental arch formation is often combined with buccal-crossbite, which is caused by upper retrognathia or, much less often, narrowing of the upper dental arch. One of the common medical errors in the treatment of such disorders is the expansion of the upper dental arch with a plate with a screw or a spring. Such manipulations lead to aggravation of disorders in the sagittal plane. Therefore, it is advisable to eliminate the narrowing of the upper dental arch only after the completion of the treatment of sagittal disorders or in dental varieties of Angle's class III. The choice of an orthodontic device for eliminating the dental type of mesial bite should be made depending on the depth of the reverse incisor overlap and the severity of the sagittal inconsistencies: 1. In case of reverse incisor overlap of less than 1/2 the height of the crown of the lower incisor, grinding of the incisal tubercles of the temporary canines is performed. To lengthen the anterior segment of the upper dental arch and normalize the incisor overlap, a plate is used on the upper jaw with occlusal pads, a screw and a sectoral cut for lengthening for vestibular deviation of the upper incisors. 2. In case of deep reverse incisor overlap (more than 1/2 the height of the crown) and the absence of a sagittal gap, the Bruckl appliance is effective, providing vestibular deviation of the upper incisors and their intrusion. The patient should be taught to correctly position the upper incisors on the inclined plane of the device, without pushing the lower jaw forward, and to talk without opening the teeth. The habitual pushing of the lower jaw can be eliminated by using a cap with a chin sling and sagittal rubber traction simultaneously with the Bruckl device. The extraoral device is worn 8-10 hours a day, the Bruckl device - around the clock. Fig. 52. Reichensbach-Brückl apparatus: a – view of the apparatus; b - apparatus on diagnostic models After the vestibular deviation of the upper incisors and achievement of incisal overlap, the round-the-clock wearing of the Bruckl appliance is discontinued and it is recommended to use it as a retention appliance. 3. Treatment of mesial bite with a significant sagittal gap between the upper and lower incisors during the period of tooth change is recommended to be carried out using a Frenkel clasp activator or a Wunderer activator with a Weise screw. Machine Translated by Google Fig. 53. Wunderer activator with Weise screw To decide on the choice of an orthodontic appliance, it is necessary to evaluate the patient's ability to place the lower jaw in marginal closure of the incisors. If the patient can place the lower jaw in marginal closure of the incisors, it is possible to use functionally acting appliances: closed Andresen-Hoipl activator, open Klammt type III activator, Frenkel function regulator type III (Fig. 54), Bimler bite former type III. The most widely used is the open Klammt activator, due to its simplicity in manufacture and fairly rapid adaptation of patients to it. Fig.54. Frenkel function regulator type III Patients with mesial bite and significant sagittal discrepancy in the position and size of the jaws (large sagittal gap between the incisors of the upper and lower jaws) should undergo teleradiographic examination. In cases where such an anomaly of the bite is caused by the lower prognathism and/or upper micrognathia, upper retrognathia – it is advisable to use a comprehensive treatment method. During the initial mixed bite period (patients aged 6 to 9 years), the above-mentioned dental occlusion disorders can be eliminated using the Hotz method. Permanent bite period. The main task of the orthodontist: reducing the size of the lower dental arch to normalize the dental arch ratio (for the complex method). Treatment methods: hardware, complex, surgical. In case of minor sagittal disorders (the size of the sagittal gap is up to 5 mm), formed due to the retroposition of the upper jaw or its underdevelopment, it is possible to use the hardware method of treatment. The most effective devices for patients with such disorders are the clasp Frenkel activator or Wunderer activator with Weise screw. The average duration of treatment of mesial permanent bite in such patients is the same as in patients during the period of tooth change. One of the most common complications is the formation of an open bite in the lateral sections, which resolves itself 6-12 months after the removal of the device. In case of significant sagittal disorders formed due to lower prognathism, the method of choice is a complex one. When using a complex treatment method, individual teeth are removed on the lower jaws. It is most appropriate from a functional and aesthetic point of view to remove the first premolars. Less often, the second premolars, incisors or canines are removed. When making a final decision on the choice of a complex method for correcting mesial bite, it is necessary to pay attention to the size of the tongue and its position, the position of the lower incisors and the presence spaces between them. The use of a complex method in the treatment of mesial bite is not indicated in the following cases: Machine Translated by Google 1. Macroglossia – as a result of the removal of teeth on the lower jaw, the volume of the oral cavity will be significantly reduced and the tongue, exerting increased pressure on the lower jaw, will cause a relapse of the disorder. 2. The presence of a gap and/or diastema between the lower front teeth – may be a sign of both macroglossia and mandibular macrognathia. Elimination of macrognathia by reducing the size of the lower dental arch is ineffective. In such cases, it is advisable to use surgical treatment method. 3. Significant oral inclination of the lower incisors - after the extraction of teeth on the lower jaw and further oral inclination of the lower incisors, these teeth will not withstand the axial load when biting off food and can be dislocated. Correction of mesial bite using a comprehensive treatment method is carried out using mechanically acting, functionally guiding and combined devices. The multibonding system is most often used. With mesial bite combined with significant sagittal discrepancy caused by mandibular macrognathia or maxillary micrognathia, it is advisable to use a surgical method of treatment. The task of the orthodontist in such cases is to normalize the position of individual teeth and the shape of the dental arches using the multibonding system before surgery and postoperative correction of the relationship of the dental arches. After completion of active orthodontic treatment during the period of permanent bite, to prevent relapse, it is recommended to remove the rudiments of the third molars on the lower jaw. The removal of the third lower molars is done to prevent the growth of the lower jaw, and their eruption can also be the cause of relapse of crowding of the anterior group of teeth. 4. Diastema. Etiology, clinical picture, prevention, treatment methods. Diastema is an abnormal position of the central incisors, characterized by the presence of a free space between them. The interdental gap with diastema can reach a size of 1 to 10 mm (on average 2-6 mm). Diastema occurs during the formation of the dental arch and is often a family trait. It is also formed as a result of thickening of the frenulum of the upper lip, the fibers of which are woven into the interalveolar septum and the apex of the interdental papilla. Diastemas and tremas are observed with excessive development of the jaws or with normally developed jaws and microdontia. Based on clinical examination, study of diagnostic models of the jaws, radiographs of the incisor area and the alveolar process, F.Ya. Khoroshilkina suggests distinguishing the following types of diastemas: 1) lateral deviation of the crowns of the central incisors with the correct location of the root apices; 2) corpus deviation of the incisors; 3) medial inclination of the crowns of the central incisors and lateral deviation of the roots. First of all, a distinction is made between false and true diastema. False diastema is typical for the period of changing the temporary bite to a permanent one. This is a normal, natural condition for childhood. Usually, by the time the change of teeth ends, the diastema closes on its own. True diastema is observed in the permanent bite and does not disappear without special dental care. Etiology: The causes of diastema are often supernumerary teeth, the eruption of which preceded the eruption of the central incisors, the bad habit of biting a nail, pencil or other objects is often the cause of not only diastema, but also rotation of the upper central incisors along the axis. Incorrect position of the lower central incisor in the dental row can be the cause of the diastema between the upper incisors, partial adentia (absence of the rudiments of one or two upper lateral incisors), significant compaction of bone tissue in the area of the median interalveolar septum, low attachment of the frenulum of the upper lip, loss of a lateral incisor, canine or anomalies in their position, with odontoma, multiple adentia. Sometimes diastema occurs under the influence of not one, but several reasons. The first and second types of diastema are more common than the third. Treatment of diastema should be carried out during the period of mixed dentition before the eruption of permanent canines. Treatment begins with the removal of supernumerary teeth, elimination of bad habits, and normalization of swallowing function. It is advisable to eliminate type 1 diastema using removable or non-removable devices with mechanically acting devices for medial inclination of incisors: plates with hand-shaped springs, a plate with a vestibular arch and springy processes (Schwartz device). Non-removable devices include Machine Translated by Google Korkhauz device (metal rings for central incisors with vertical bars soldered closer to their medial surface and rubber traction). Reduction of rubber rings stretched between bars helps to bring the incisors closer together. It is possible to eliminate diastema of the first type independently. For treatment of diastema of the 2nd type, rail structures are used: crowns with horizontal tubes on central incisors. The tubes are sawn lengthwise and an arc is inserted, after which the tubes are compressed with pliers to reduce their clearance. The incisors are brought closer together using rubber traction. For treatment of diastema of the 3rd type, a multibonding system is used. Plastic surgery of the frenulum of the lip is performed after hardware elimination of the diastema. If after its elimination the lateral incisors are installed close to the central ones, there is no relapse of the anomaly. It is possible to eliminate diastema using a prosthetic method (veneers, crowns) in the presence of microdontia, anomalies in the shape and structure of the hard tissues of the incisors. 5. Clinical and laboratory stages of manufacturing functional-guiding plate devices (Katz). Appliances with an inclined plane are used to treat dental anomalies in the sagittal direction. The action of the devices is based on the use of chewing pressure and muscle traction. The Bruckl apparatus, the Schwartz apparatus, the Katz plate, the Bynin and Schwartz caps and other devices contain an inclined plane. Indications: deep distal bite with protrusion of the upper incisors Katz plate. Models are cast from impressions of the upper and lower jaws. Model of the upper jaw - combined with anterior teeth made of low-melting metal. A plate of lead foil up to 1-1.5 mm thick is placed on the upper jaw model from the palatal side in the area of the anterior teeth from their necks to the base of the alveolar process. Reversible hooks are made for the incisors from steel strips or flattened wire. The hooks embrace the incisors by the cutting edge, passing slightly onto the vestibular surface (1-1.5 mm). These ends must be polished. The parts of the clasps that will enter the base should be made with notches. Retaining clasps are made for milk or permanent molars and installed on the model. The base of the device is modeled from wax and an inclined plane is made on it in the area of the anterior teeth. The wax template with the model is plastered in a flask using a direct method. The wax is replaced with plastic. The purpose of the Katz plate is to shift the frontal upper teeth backwards and “drive” them in. The lower teeth and jaw are shifted forward (Fig. ). The angle of inclination of the inclined plane is 30-45 degrees The device is a removable plate for the upper jaw, which has a plastic inclined plane and ribbon flip clasps on the central and lateral incisors. It is used to eliminate distal deep bite. The device is made on models fixed in the occluder in the position of the constructive bite, i.e. the desired relationship of the dental arches. An insulating tin lining is placed on the model of the upper jaw in the anterior third of the palatine vault, in the area from the necks of the anterior teeth to the line connecting the distal surfaces of the canines. This is necessary so that the base in the frontal area does not adjoin the mucous membrane, in order to prevent pinching of the mucous membrane of the hard palate as a result of Machine Translated by Google posterior displacement of the teeth with the alveolar process. On the tin gasket and the rest of the area of the vault of the palate, a wax base of the plate is formed for the supporting teeth, then clasps are made for the first molars. Flip-over clasps are bent from sheet steel 1.5-2.0 mm wide and 0.5-0.7 mm thick. Each clasp should tightly embrace the lower third of the vestibular surface of the tooth and the cutting edge. From the palatal side, the clasp is bent so that it follows the relief of the tooth up to the dental tubercle, and then bent away from the tooth. The distance of the clasp from the tooth is determined by the line of closure of the lower teeth with the upper ones. The ends of the processes of the flip clasps are flattened for better retention in the plastic. The manufactured clasps are slightly warmed up, fixed on the teeth, and the processes are immersed in a wax plate. After closing the occluder, the uniformity and density of contact of the flip clasps with the lower teeth is checked and, if necessary, the clasp bend is corrected. The inclined plane is modeled, repeating the bend of the dental arch, from a softened wax roller 1.0-1.5 cm high in the area from canine to canine. The triangular roller is glued to the base wax plate and the occluder is closed before the wax hardens. After opening the occluder, the final modeling of the inclined plane is started so that it is no more than 45° in relation to the occlusal surface of the dental arches. The remaining stages are normal. After finishing the plate, the tin lining is removed from its palatal surface and polished. Ya. S. Khurgina introduced an adjustable screw into the Katz functional bite plate — a source of mechanical force for the purpose of simultaneous expansion of the narrowed upper jaw (Fig. 235). This device is made in two stages: first, a wax reproduction of the Katz plate with all its elements is prepared, and then an orthodontic screw is inserted into the wax, usually in the middle of the plate. After polymerization, finishing and polishing, the plate is sawn in the anteroposterior direction into two halves. 6. Clinical and laboratory stages of manufacturing functional-guiding plate devices (Schwartz) The Schwartz plate with a vestibular arch and an inclined plane moves the lower front teeth and jaw forward, “drives in” the lower front teeth and helps to increase the bite on the lateral teeth. Indications: deep distal bite with protrusion of the upper incisors Models are cast from the impressions of the upper and lower jaws and plastered in an occluder in a constructive bite fixed by the doctor in the oral cavity with wax rollers. In the anterior third of the hard palate from the necks of the front teeth to the line connecting the distal surfaces of the canines, tin or lead foil is placed or an adhesive plaster is glued in two layers. Conventional or reversible clasps are bent on the first molars, installed on the model and the wax base of the plate is formed. From a roller of softened wax 1.5-2 cm high on the base, an inclined plane is modeled in the area from canine to canine, focusing on the impressions of the lower teeth obtained when closing the occluder. The slope of its occlusal plane should not be less than 45°. Along the vestibular surface of the outer front teeth at the level of the middle of the crowns, a vestibular arch is bent from a wire with a diameter of 0.6-0.8 mm with U-shaped loops in the area of the canines, going towards the gum and standing 1.5-2 mm from it. Both ends of the arch are bent along the distal surface of the canines to the oral side and flattened. The arch is installed on the model, fusing its ends into the wax base of the plate. The plate is finally modeled and the wax is replaced with plastic. Fig. Schwartz plate. The plate differs from the Katz bite plate in that instead of flip-over clasps on each front tooth, it has a vestibular retraction (pulling back) arch with semicircular loops for activation. Insulation is also made behind the teeth being moved. The device has arrow-shaped or other clasps for fixation and an inclined plane made of plastic. The vestibular arch is bent as Machine Translated by Google described above. On the labial surface of the crowns of the front teeth, the arc can be located in the middle, closer to the neck or to the cutting edge of the teeth, depending on the degree of inclination of the axis of the teeth being moved. Further work is carried out in the same way as when making the Katz plate. If it is necessary to simultaneously expand the dental arch, a screw is inserted. It should be emphasized that the inclined plane of any device should not be a rough monolith. It is necessary to model its surface facing backwards with a notch for the tip of the tongue, which significantly facilitates mastering the device and using it. 7. "Cross" bite (occlusion). Classification, etiology, clinical picture. Crossbite refers to anomalies in the horizontal plane. Various terms are used to characterize crossbite: oblique, vestibuloocclusion, buccoocclusion, linguoocclusion, lateral forced bite, etc. The development of crossbite can be caused by the following reasons: I. Heredity (the abnormal position of the jaws relative to the base of the skull is inherited). II. Congenital pathology: A. Congenital anomalies in the development of the facial skeleton (cleft lip, alveolar process, hard and soft palate, hemiatrophy of the face). B. Congenital anomalies in the development of the spine (scoliotic deformity of the spine). C. Congenital pathology of the TMJ. G. Birth trauma. D) Incorrect positioning of tooth rudiments and their anerubation; macroglossia. III. Acquired pathology: 1. General factors: rickets, osteomyelitis, poliomyelitis, poor posture; 2. Local factors: dysfunction of the cervical spine, bad habits (supporting the cheeks with the hand; sucking fingers, cheeks, tongue, etc.), incorrect position of the child during sleep, violation of the sequence teething, unworn cusps of temporary teeth, early destruction and loss of temporary molars. Among the etiological factors, special attention should be paid to diseases of the temporomandibular joint, such as ankylosis and arthritis of various etiologies. The causes of arthritis may be different: 1. Traumatic inflammation of the joint. 2. Acute and chronic purulent otitis. 3. Infectious arthritis. 4. Hematogenous osteomyelitis of the articular process. The variety of etiological factors creates difficulties in diagnosis and, consequently, in prevention and orthodontic treatment of crossbite. Classification of crossbite I. Buccal - when the dental arches are closed in central occlusion, the buccal cusps of the lower lateral teeth are located more buccal than the longitudinal fissures of the upper lateral teeth: a) unilateral - disturbances on one side, on the opposite side the relationship of the teeth is normal (Fig. 75); b) bilateral - violations on both sides. II. Lingual - when the dental arches close in central occlusion, the buccal cusps of the lower lateral teeth are located lingually to the longitudinal fissures of the upper lateral teeth a) unilateral - disturbances on one side, on the opposite side – the relationship of the teeth is normal; b) bilateral – disturbances on both sides. ÿ. Combined (buccal-lingual) crossbite. The following morphological forms of crossbite are distinguished : 1) dentoalveolar - narrowing or widening of the dentoalveolar arch on one or both jaws; 2) gnathic – narrowing or widening of the jaw base (underdevelopment, overdevelopment); 3) articular – displacement of the lower jaw to the side (parallel to the midsagittal plane or diagonal). Clinical picture: The clinical picture of each type of crossbite has its own characteristics. Machine Translated by Google With a buccal crossbite without a lateral displacement of the lower jaw, facial asymmetry is possible without a displacement of the midpoint of the chin, which is determined in relation to the median plane. The midline between the upper and lower central incisors usually coincides. However, with a close position of the front teeth, their displacement, asymmetry of the dental arches, it can be displaced. In such cases, the location of the bases of the frenulum of the upper and lower lips, tongue is determined. The degree of disturbance of the dental arch relationships in the bite may vary. The buccal cusps of the upper lateral teeth may be in cusp contacts with the lower teeth, may be located in longitudinal grooves on their chewing surface, or may not be in contact with the lower teeth. In the case of buccal crossbite with a lateral displacement of the lower jaw, facial asymmetry is observed, caused by a lateral displacement of the chin in relation to the midsagittal plane. The right and left profiles of such patients usually differ in shape, and only in preschoolers is facial asymmetry barely noticeable due to plump cheeks. It progresses with age. The midline between the upper and lower central incisors usually does not coincide as a result of the displacement of the lower jaw, changes in the shape and size of the dental arches and often jaws. In addition to the shift parallel to the midsagittal plane, the lower jaw can shift to the side diagonally. The position of the articular heads of the lower jaw in the joint during its lateral displacement changes, which is reflected in the mesiodistal ratio of the lateral teeth in the bite. On the side of the displacement, a distal ratio of the dental arches occurs, on the opposite side - neutral or mesial. When palpating the area of the temporomandibular joints during opening and closing the mouth, normal or weakly expressed movement of the articular head is determined on the side of the displacement of the lower jaw, on the opposite side - more pronounced. When opening the mouth, the lower jaw can move from the lateral position to the central one, and when closing it, it can return to its original position. Some patients experience an increase in the tone of the masticatory muscle itself on the side of the lower jaw displacement and an increase in its volume, which increases facial asymmetry. Diagnostics: To determine the lateral displacement of the lower jaw, the third and fourth clinical functional tests according to Ilyina-Markosyan and Kibkalo are used; the patient is asked to open his mouth wide and the facial signs of deviations are studied. Facial asymmetry increases, decreases or disappears depending on the underlying cause (third test). After this, the lower jaw is set in the usual occlusion, and then, without the usual displacement of the lower jaw, the harmony of the face is assessed from an aesthetic point of view, the degree of displacement of the lower jaw, the size of the interocclusal space in the area of the lateral teeth, the degree of narrowing (or widening) of the dental arches, the asymmetry of the bones of the facial skeleton, etc. are identified (fourth test). In all forms of crossbite, the chewing function is significantly impaired, which is caused by a decrease in the area of occlusal contacts and biting of the mucous membrane of the cheeks. Morphological abnormalities in crossbite: 1. At the jaw level: a) rotation of the body of the upper jaw relative to the vertical axis to the left or right; rotation of the body of the lower jaw jaws are inadequate to the rotation of the upper one; b) unilateral underdevelopment and/or excessive development of the upper or lower jaw. 2. At the level of the dental arches: a) unilateral lengthening or shortening of the upper or lower dental arch; b) unilateral narrowing or widening of the upper or lower dental arch; c) bilateral narrowing or widening of the upper or lower dental arch. 3. At the level of individual teeth: vestibular position of the lateral teeth on one jaw with an oral position of the lateral teeth of the other jaw. With crossbite, chewing and speech functions are impaired. During external examination of a patient with crossbite, facial asymmetry is often revealed. 8. "Cross" bite (occlusion). Methods of treatment of dentoalveolar forms in different age periods. Prevention. Crossbite refers to anomalies in the horizontal plane. Treatment of crossbite without displacement of the lower jaw: Machine Translated by Google In temporary occlusion, the task of the orthodontist is to normalize the shape of the dental arches by creating optimal conditions for the growth and development of the jaws. The main method of treatment is myotherapy, the additional method is hardware. Treatment includes: eliminating the cause of the anomaly, fighting bad habits, grinding down the unworn tubercles of milk molars and canines, normalizing lip closure, prosthetics in case of early loss of temporary teeth. Standard or individual vestibular plates are used to eliminate the pressure of the cheeks on the underdeveloped areas of the jaws: a - Schonher; b - Muppy with a bite plate, c - Muppy with a wire tongue stop Fig. 78. Standard vestibular plates: a – Schonherr; b – Muppy with a bite plate, c – Muppy with a wire tongue stop In mixed bite, the treatment goal is to normalize the shape of the dentition, which was the cause formation of crossbite. The main method of treatment is hardware, an additional method is myotherapy. In addition to the above-described measures, mechanically acting devices are widely used: plates on the upper jaw with occlusal pads and a screw, sectoral sawing (Fig. 79); a plate with occlusal pads and a screw for uneven expansion of the upper or lower dental arches; rings with hooks on the first permanent molars and cross- traction (Fig. 80); grinding down the tubercles of temporary teeth. Fig. 79. Plate with occlusal pads, screw and sectoral cut for unilateral expansion of the upper dental arch Fig. 80. Molar rings with hooks and cross-tie: a – diagram; b – in the oral cavity Machine Translated by Google During the period of permanent occlusion, the main methods of treatment are complex and hardware. In this period, non-removable mechanically acting devices are more widely used (multibonding system, Derichsweiler device, Quad Helix and Bi Helix devices (Fig. 81), palatal expander). According to indications, compact osteotomy is performed in the area of the teeth being moved, followed by the use of mechanically acting orthodontic devices. Fig. 81. Springs for expanding dental arches: a – Quad Helix; b – Bi Helix Treatment of crossbite with displacement of the lower jaw In temporary bite, the tasks of orthodontic treatment are: 1. Creation of optimal conditions for jaw growth; 2. Restraint of the growth of the lower jaw in combination with crossbite and mesial bite. The main method of treatment is hardware, the additional one is myotherapy. The solution to these problems is achieved by using functionally active (vestibular plates, activators and regulators of functions) (Fig. 82) and functionally guiding devices (plates on the upper or lower jaw with an inclined plane in the lateral areas). Machine Translated by Google Fig. 82. Functionally acting devices: a – Kraus’ vestibulo-oral plate; b – Müllemann propulsor; B – Frenkel function regulator; g – pre-orthodontic trainer; d – bionator Janson Treatment begins with eliminating the cause of the anomaly. For treatment, a cap with a chin sling and one-sided rubber traction is widely used; grinding of tubercles and cutting edges of temporary teeth; myotherapy. In mixed occlusion, the task of orthodontic treatment is to normalize the occlusion by shifting the lower jaw to the correct position. The main method of treatment is hardware, additional– myotherapy. Treatment begins with normalization of the shape of the dental arches. This is achieved by using single-jaw plates with screws and springs. After this, monoblock devices of functional action are used (Frenkel function regulators, Janson bionator, Klammt activator) (Fig. 82). During periods of active jaw growth, in addition to functionally acting devices, functionally guiding devices are also used (plates with an inclined plane and occlusal pads). During the period of permanent bite, the main treatment methods are hardware and complex. In addition to devices used in mixed bite, a multibonding system with an intermaxillary oblique is used rubber traction. The first premolars are removed on the upper jaw on the side of Angle's class II, on the lower jaw on the side of Angle's class III. The prognosis for the treatment of crossbite is favorable, mainly after early elimination of the dentoalveolar forms of crossbite, including those combined with displacement of the lower jaw. When treating in a permanent bite, such an anomaly can be eliminated, but the preservation of facial asymmetry is not excluded. The prognosis for orthodontic treatment of the gnathic form of crossbite is more favorable when starting treatment in a temporary bite. In a permanent bite, with a pronounced pathologies, the anomaly can only be eliminated surgically. When treating crossbite, the following mistakes are made: 1. They expand or narrow the dental row on the side of the crossbite without sufficient separation of the displaced teeth; 2. They do not eliminate the displacement of the lower jaw in gnathic and articular forms of crossbite. Prevention methods Machine Translated by Google 9. Teleradiography. Method of obtaining images, analysis according to Schwartz. Teleradiography. This method of X-ray examination is used to study the structure facial skeleton, its growth, to clarify the diagnosis and prognosis of orthodontic treatment, as well as to identify changes occurring during treatment. Teleradiography is performed in lateral and direct projections from a distance of 1.5 m. The head of the subject is fixed using a cephalostat of various designs, the use of which ensures the receipt of identical images (Fig. 13.28). TRG in a direct projection allows diagnosing anomalies of the dental system in the transverse direction, in a lateral projection - in the sagittal and transverse directions. TRG shows the bones of the facial and cranial skull and the contours of soft tissues, which makes it possible to study their relationships (Fig. 13.29). To decipher the TRG, the image is placed on the screen of a negatoscope, and tracing paper is attached to it, onto which the image is transferred. TRG by the Schwartz method allows the most complete study of the size and position of the jaw bones. Using this method, it is possible to conduct craniometric, gnathometric and profilometric measurements. Craniometry is used to determine: 1) the location of the jaws in the sagittal and vertical directions in relation to the plane of the anterior part of the skull base; 2) the location of the TMJ in relation to the plane of the anterior part of the skull base; 3) the length of the anterior part of the base of the cranial fossa. The following points on the plane are used for TRG analysis : A - subspinal point Downs, the deepest on the anterior contour of the apical base of the upper jaws; B - the supramental Downs point, the most distally located on the anterior contour of the apical base of the lower jaw; Se - in the middle of the entrance to the sella turcica; N — on the anterior superior edge of the nasofrontal suture in the sagittal plane; Or - the lowest point of the lower edge of the orbit; Go is the point of the angle of the lower jaw at the point of its intersection with the bisector of the angle formed by the tangents along the lower edge of the body and the posterior edge of the branch of the lower jaw; C is the highest point on the contour of the head of the lower jaw; Machine Translated by Google Me - the most protruding point of the lower contour of the chin area; N is a point on the skin formed at the intersection with the continuation of the N-Se line; Sna - anterior nasal spine; Snp - posterior nasal spine; Pg - the most anterior point of the chin protrusion; NSe is the plane of the anterior part of the base of the skull (it is drawn through points N and Se); SpP — plane of the base of the upper jaw (passes through points Sna and Snp); ÿn is the nasal vertical, which is drawn perpendicular to the NSe plane through the skin point n; MR - plane of the base of the mandible. On the TRG, the cranial part of the skull is separated from the gnathic plane of the maxilla (SpP). The options for the arrangement of the jaws are determined by the facial, inclination angle and horizontal angle: 1) the facial angle F is formed at the intersection of the lines N-Se and N-A (inner lower angle). Its size characterizes the position of the upper jaw in relation to the base of the skull in the sagittal direction. An angle smaller than the norm is characteristic of retrognathia, greater than the norm - of prognathia; if it is within the normal range, we speak of normognathia; 2) the horizontal angle H is formed at the intersection of the line H (horizontal line) and Pn (inner upper angle) and determines the position of the articular head of the lower jaw in relation to the base of the skull, which affects the shape of the facial profile; 3) the inclination angle J is formed by the intersection of the lines Pn and SpP (inner upper angle). If the angle J is greater than the average value, the jaws are tilted forward, which Schwartz called anteinclination. If the angle is less than the average value, the jaws are tilted backward. This position of the jaws is called retroinclination. The gnathometric method (according to Schwartz) allows: determine the anomaly that developed as a result of the discrepancy in the size of the jaws (length of the jaw body, height of the branches of the lower jaw), anomalies in the position of the teeth and the shape of the alveolar process; identify the influence of the size and position of the jaw, as well as dental anomalies on the shape of the facial profile; determine the individual shape of the jaw body length and deviations in size. The most important parameters of gnathometry: 1) basal angle B - the angle of inclination of the base of the jaws to each other (SpP - ÿÿ), characterizing the vertical position of the jaws; 2) the length of the body of the lower jaw MT is measured along the plane MP from the projection of the point Pg on MP to the point of its intersection with the tangent to the branch of the lower jaw; 3) the height of the MT branches is measured tangent to the posterior edge of the branch from the point of intersection with the MP plane to the projection of point C on the tangent; 4) the mandibular angle G is measured between the lines MT1 and MT2, i.e. between the tangents to the lower edge of the lower jaw and the posterior surface of its branches; 5) the length of the upper jaw is measured from the point of intersection of the perpendicular dropped from point A to SpP (point A' ) to point Sn. Average individual standards according to Schwartz: 1) the length of the body of the lower jaw, with its normal development, is equal to the length of the base of the anterior cranial fossa (distance N - Se) plus 3 mm; 2) the length of the upper jaw in relation to the length of the anterior part of the base of the skull is 7:10; 3) the length of the body of the lower jaw is related to the length of its branches as 7:5 10. Photostatic images. Method of obtaining. Analysis of images. Diagnostic value. Black and white and color photographs, slides, filmstrips and movies allow us to observe the growth and formation of the face, its changes during orthodontic treatment, both statically and dynamically. Quantitative assessment helps to compare and distinguish qualitative changes in the structure and shape of the face in normal and pathological. Machine Translated by Google To assess the facial profile according to A.M. Schwartz, certain points and lines are used: Jaw profile field. The jaw profile field is formed by the Frankfurt horizontal (line H), Perpendiculare orbitale (Po) and Perpendiculare nasale (Pn). The correct width of the jaw profile field (KPF) is 13-14 mm in children and 15-17 mm in adults. Line H is defined as a horizontal line that passes through the Orbitale and Porion points. Perpendiculare orbitale (perpendicular to the Orbitale point, perpendicular Po) is the perpendicular to the H line from the Orbitale point. Perpendiculare nasale is the perpendicular from the cutaneous Nasion point to the H line (Fig. 1). Profile classification according to A.M. Schwartz A.M. Schwartz defined the average size of the face as follows (Fig. 1): in the case of a straight average face (ideal average size or biometric face), the Subnasale point touches the perpendicular Nasion (Pn). The upper lip at point Ls touches this line. The lower lip is 1/3 of the width of the KPF behind the perpendicular Pn. The soft tissue point of the chin (Rod') is in the middle of the jaw profile field (KPF), the most caudal point of the chin (skin point Gnation Gn') on the perpendicular of the Orbitale point (Ro). The tangent of the mouth T passes through the points Subnasale (Sn) and Pogonion (Genus), divides the red border of the upper lip and touches the lower lip at point C (Fig. 3). With the perpendicular Pn it forms a profile angle (angle T, the correct value is 10°). Variants of facial profile according to the classification of A.M. Schwartz AM. Schwartz identified nine possible variants of the facial profile (Fig. 1 a-i). Depending on the position of the Subnasale point (Sn) to the perpendicular Pp, meso-, cis-, or transfrontal are distinguished face: — Mesofrontal face = point Sn lies perpendicular to point Nasion. — Cis-frontal face = point Sn lies in front of the perpendicular to point Nasion. — Transfrontal face = point Sn lies behind the perpendicular to point Nasion. In the straight cisfrontal or transfrontal facial types, the chin point Rod' is shifted as much as the Subnasale point. The next two subtypes of the facial profile slanted "forward" or "backward" are distinguished depending on the change in the position of the Pogonion point of the soft tissues relative to the Subnasale point of each of the three above-mentioned types. Lip profile analysis according to A.M. Schwartz In the case of a face of average size, the oral tangent divides the upper lip in half. The lower lip touches the tangent and forms an angle of 10° with the perpendicular Pn (Perpendiculare nasale). Prepare photographs of the head in front and profile. It is important to identify the receipt of photographs, that achieved: 1) the same position of the head in space; 2) using the same photographic equipment; +3) the same shooting mode (lighting, distance, exposure time, photographic materials); Machine Translated by Google 4) continuous processing of exposed photographic plates and films (development, fixation, drying, printing); 5) precise orientation of the head relative to the reference points and planes in accordance with the technique used. To position the head in space in a Cartesian coordinate system, photostats of various designs are used: Simon's photostat, Schwartz's orienting cube, and simplified photostat designs - Korkhauz, Mutsi, Schwartz, Schonher, Mirgazizov, Pereverzev, El-Nofeli, etc. Identification points are marked on the subject's face, through which a reference line is drawn on the photograph; the Frankfurt horizontal line is most often used. The head is positioned so that the Frankfurt horizontal plane is parallel to the floor, and the orbital and midsagittal planes are perpendicular to each other and to the Frankfurt plane. To position the head in the photostat, a device in the form of a semicircle or circle is used, which performs the same tasks as the face bow in the Simon gnathostat. The use of a photostat allows one to obtain photographs with the same position of the head and the same distance of the subject from the camera lens. The head photograph is used to judge its shape and type of face (wide, medium, narrow, oval, conical, inversely conical, asymmetrical, etc.). The face photograph reflects some clinical symptoms of dentoalveolar anomalies with functional and morphological deviations in the maxillofacial region, as evidenced by the location of soft tissues caused by functional and age-related changes, for example, a double chin with glossoptosis, a thimble symptom in the chin area, failure of the lips to close and a change in their shape with swallowing and breathing disorders. When studying photographs from the front, lines are drawn on them dividing the face into parts corresponding to its anatomical features (frontal, ocular, nasal, gnathic, chin). For the study, parallel lines are drawn at the level of the trichion point, superciliary arches, corners of the eyes, lower edge of the eye sockets, base of the nose, oral slit, corners of the lower jaw, chin. Connecting individual points of the face allows us to obtain its polygons, study linear and angular dimensions. V. A. Pereverzev proposed a unified method for determining the shape of the face, upper jaw and teeth and established three main face shapes (rectangular, square, triangular) and three additional (rectangular-oval, square- oval and triangular-oval). According to this author, in our country, regardless of gender, square and square-oval faces predominate. In the photometric analysis of the facial profile according to Engle, a "line of harmony" is drawn from the glabellar point to the pogonion point. In the normal development of the dental system, it passes through the wing of the nose. The author studied the position of the facial profile, especially the lips, relative to this line. The degree of convexity of the face according to Campion is judged by the size of the angle formed by the tangent to the forehead and tip of the nose and the tangent to the tip of the nose and chin. The photostatic analysis of the facial profile according to Simon is carried out taking into account the location of the orbital plane. In the case of using this method, an ear-orbital line is drawn on the photograph from the lower orbital edge to the upper edge of the tragus of the ear and an orbital line perpendicular to it. According to Kantorovich, a line is drawn from the glabellar point parallel to the orbital vertical. The listed lines were used for photometry by G. Izard and G. Korkhaus. G. Izard systematized the varieties of facial profiles in the form of a series of typical profiles characteristic of sagittal malocclusion. Dreyfus proposed to apply to photographs the nasal plane (Pn), parallel to the orbital plane (Horn), drawn downwards from the nasion point (the most posterior point on the concavity between the forehead and the nose). A. M. Schwarz recommended connecting the subnasion (sn) and pogonion (pg) points and measuring the profile angle (T) formed by this line and the nasal plane (Pn) to characterize the location of the subnasal and chin points in relation to the nasal plane (Pn) and to determine the degree of convexity or concavity of the face. This angle is equal to 10° on average. With an average angle T, the shape of the facial profile, in the author’s opinion, is ideal in aesthetic terms and is called by him a “straight profile”. If the profile angle is greater than 10°, the profile is designated as slanted backwards, if less than 10°, beveled forward. With a slight change in the value of the angle T, the harmony of the facial features is disturbed insignificantly, but its expression changes: an increase in the angle gives the face an expression of tenderness, and a decrease - energy. The position of the lips is determined in relation to the line T. If this line divides the red border of the upper lip in half and touches the outer surface of the red border of the lower lip, then the position of the lips is called average. If the lips (one or both) are in front of the average position, then this position is called positive, if behind - negative. The shape of the facial profile also depends on Machine Translated by Google thickness of soft tissues. The author recommended studying the position of the lips in relation to the planes of the Horn and Rn and to the oral tangent. Depending on the position of the upper lip and chin in the jaw profile field, nine types of faces are distinguished according to Schwartz with a normal bite: an average face, a face with a forward or backward displacement of the jaws, a face with a chin positioned correctly, beveled forward or backward (Fig. 5.3). You can use the Camper horizontal as a guide and study the angles formed by this plane and the lines connecting the glabellar (g) and subnasal (sn) points, as well as the subnasal (sn) and gnathion (gn) points. From the tragion (tr) point, the first semicircle is drawn with the tragion- glabellar radius, and from the subnasal (sn) point, the second semicircle is drawn with the subnasal-glabellar radius. Normally, these semicircles intersect below at the gnathion (gn) point. In the presence of dentoalveolar anomalies and facial shape disorders, the normal location of the gnathion point is found and compared with the existing one. In case of underdevelopment of the lower jaw and distal bite, the gnathion point is usually located behind the calculated one, and in front of the mesial bite. G. Korkhaus emphasized the need to study the features of the shape of the forehead and its slope, the shape of the brow ridges, the cut and position of the eyes, the shape of the bridge of the nose and the location of its root, the shape of the lips and chin. According to C. J. Burstone, the labiomandibular contour is more constant than the maxillomandibular contour. In order to characterize the facial profile, RM Ricketts proposed to determine the location of the lips in photographs in relation to the aesthetic plane - the line connecting the most convex points of the nose and chin. According to the author, with age, during the transition from temporary to permanent bite, their configuration changes due to a change in the angle of inclination of the longitudinal axes of the incisors. Retraction of the cutting edges of the upper incisors by 3 mm leads to a thickening of the upper lip by 1 mm. According to S. J. Burstone et al., beautiful facial profiles are characterized by the location of the labial and chin points on the same line or the presence of an angle between them equal to 0.5 °. However, there are reports that the optimal harmony facial features is observed at an angle of 5.3°. It is recommended to study the location of the contour of the soft tissues of the facial profile in relation to the profile line - tangent to the most protruding points of the upper lip and chin in the profile, and also to measure the size of the angle formed by the Frankfurt horizontal and the profile line (angle r). This angle in adults is on average 80", in men its average value is 82.2°, in women - less than 80.2°, in case of dentoalveolar anomalies at the age of 11 to 15 years - 78°. 11. Anomalies of the shape of dental arches. Etiology, clinical picture, prevention. Treatment methods. In relation to three mutually perpendicular planes, the following anomalies of the dental arches are distinguished: 1) in the sagittal plane: a) lengthening of dental arches; b) shortening of dental arches; 2) in the vertical plane: a) dentoalveolar shortening in individual segments of the dental arches; b) dentoalveolar lengthening in individual segments of the dental arches; 3) in the horizontal plane: a) narrowing of the dental arches; b) expansion of the dental arches. Anomalies of the dental arches in the sagittal direction. Elongation of the dental arches is determined by their overall length (Nance method) and the length of the anterior segment of the dental arch (Korkhaus method). The causes of this anomaly are impaired nasal breathing (oral or mixed breathing), impaired swallowing, incorrect articulation of the tongue, bad habits (sucking a finger, pencil, etc.), macrodontia, supernumerary teeth (located in the dental arch), protrusion of incisors, distal eruption of lateral teeth. The front teeth protrude from under the lip, there are often tremas between them or the teeth are close together, the lip is in the area of the sagittal gap between the incisors. Disorders are usually combined with bite anomalies in the sagittal, vertical and horizontal planes. At a young age, during the period of temporary bite, eliminating bad habits, normalizing the functions of the dental system promotes self-regulation of disorders. Vestibular plates can be used according to indications (Fig. 14). Machine Translated by Google Fig. 14. Standard Schonherr vestibular plate During the period of mixed and permanent occlusion, in addition to the above measures, orthodontic devices of various designs are used; individual teeth are removed as indicated. Shortening of the dental arch is achieved using mechanically acting orthodontic devices, if necessary, combining their action with intermaxillary and extraoral traction. In cases of close positioning of teeth, space is first created in the dental arch for the teeth to be moved. From 6 to 10 years, pre-orthodontic trainers give positive results (Fig. 15). Fig. 15. Pre-orthodontic trainer In case of lengthening of the anterior segment of the dental arch due to protrusion of the incisors and the presence of a diastema and tremas, a plate with Adams clasps on the molars and a vestibular arch with two semicircular bends is used (Fig. 16). Oral movement of the incisors is achieved with simultaneous activation of the vestibular arcs and cutting out the plastic base of the device in the anterior section. Fig. 16. Plate with Adams clasps and a vestibular arch with semicircular bends Shortening of the dental arch is also achieved by mesial displacement of the lateral teeth after the removal of individual premolars (usually the first). In this case, positive results are achieved using non-removable mechanically acting devices, such as the Angle arch and the multibonding system. Shortening of dental arches is determined by their total length (Nance method) and the length of the anterior segment of the dental arch (Korkhaus method). Shortening of the dental arch may be a consequence of anomalies in the shape, size (microdontia), number (adentia) and position of teeth (retrusion of incisors, mesial displacement of lateral teeth), underdevelopment of the jaw, bad habits of sucking or biting the lip, tongue or any objects. Shortening of the dental arch due to mesial displacement of premolars and molars is often caused by not one, but several reasons - carious destruction of the proximal surfaces of the crowns of the teeth, early loss of temporary or permanent teeth, adentia, tooth retention, incorrect positioning of the rudiments of permanent teeth or their eruption outside the dental arch. Machine Translated by Google Often there is a close position of the teeth, combined with a tilt in the vestibular or oral direction, retention of some teeth (usually canines). The disorder can be unilateral or bilateral. There is a recession of the lip, and with a deep bite - shortening of the lower part of the face. Shortening of the lower dentition is often observed with a distal bite; shortening of the upper dentition - with a mesial bite. In order to lengthen the dental arch, orthodontic devices are used: plates with screws, springs, lingual arches and other devices, as well as sectoral cuts (Fig. 18). When a screw is activated in a plate with a sectoral cut for lengthening, vestibular deviation of the incisors and distal movement of the lateral teeth occur (Fig. 19). The screw is positioned parallel to the occlusal plane, its long axis is set in the direction of tooth movement. The cut is made at the level of the middle of the canine crowns. When making cuts, it is necessary to provide conditions for the movement of the movable sector and prevent it from jamming when the screw is activated. Fig. 18. Plates with screws and sectoral cuts for lengthening the upper dental arch Fig. 19. Direction of tooth movement when activating screws in plates with sectoral cuts With reverse incisor overlap, the anterior teeth are separated using occlusal pads. Sectoral cutting in the lateral section of the appliance base allows for lengthening the dental arch by distalizing the premolars and molars. Moving the lateral teeth in the distal direction, i.e. towards a wider parts of the dental arch, contributes not only to the lengthening, but also to the expansion of the dental row. For distal movement of premolars and molars, both removable and non-removable orthodontic devices are used: the Gerling- Gashimov device (Fig. 20, a), the Pendulum device (Fig. 20, b), the Angle device, and the multibonding system. It is important to choose the right design of the orthodontic device, taking into account the biomechanical principles of active and reactive force action. Machine Translated by Google A B Fig. 20. Devices for distalization of lateral teeth: a – Gashimov-Gerling device, b – device Pendulum Lengthening of dental arches is also achieved by using functionally acting devices (Andresen-Hoipl activator, Frenkel function regulator, etc.) (Fig. 21), stimulating jaw growth in the sagittal direction. Screws, springs and other devices are attached to these devices to act on individual teeth or groups of teeth. A B Fig. 21. Functionally acting devices: a – Andresen- Hoepl activator, b – Frankel function regulator Anomalies of dental arches in the vertical direction. Dentoalveolar shortening or dentoalveolar lengthening is observed in individual segments of the dental arches. Such disorders are combined with vertical bite anomalies – open and deep. It should be emphasized that different types of disorders can be combined in different segments of one dental arch. For example, with an open bite in the anterior part of the dental arches, caused by dentoalveolar shortening, dentoalveolar lengthening can be observed in the lateral parts of the upper dental arch, and with a deep bite – vice versa. An important role in the etiology of anomalies of the dental arches in the vertical direction belongs to genetics predisposition. A common cause of dentoalveolar elongation in the anterior segment of the dental arch is carious or non-carious lesions of the hard tissues of the lateral teeth, including their uneven wear, early loss of primary molars, first permanent molars or other lateral teeth, dysfunction of the dental system. Bad habits of sucking or biting fingers, various objects cause the inclination of the front teeth, disruption of their contacts with the opposing teeth, which leads to a decrease in the bite height, the establishment of the first permanent molars at an incorrect occlusal level and underdevelopment of the alveolar processes in the lateral areas. Violation of contacts between the front teeth causes dentoalveolar elongation in this area. Violation of the vertical growth of the alveolar processes is caused by protrusion or retrusion of the front teeth on one or both jaws, displacement of the lower jaw, uneven development of the jaw bases, shortening of the branches of the lower jaw, and a decrease in its angles. Functional disorders in case of dental alveolar elongation are expressed in a decrease in chewing efficiency, overload of the periodontium of the front teeth and, often, trauma to the mucous membrane, which contributes to the emergence and development of periodontal diseases, abrasion of the cutting edges of the incisors and tubercles of other teeth. Mouth breathing, incorrect swallowing and speech impairment contribute to the narrowing of the dental arches, changes in the location of the front teeth and deepening of the incisal overlap. Machine Translated by Google The diagnosis is based on a clinical examination, examination of diagnostic models of the jaws, metric examination of photographs of the face in front and profile, as well as lateral teleradiographs of the head, and assessment of orthopantomographic examination data of the jaws. Treatment of alveolar dentoalveolar elongation in the anterior part of the dental arch is most effective during the period of eruption of the first and second permanent molars, replacement of temporary incisors by permanent ones (periods of physiological increase in bite). The main objectives of the treatment are to eliminate the causes that prevent alveolar dentoalveolar elongation in the area of the lateral teeth and to separate them; to create an obstacle to alveolar dentoalveolar elongation in the area of the anterior teeth; correction of the shape of the dental arches, position of individual teeth and their groups; normalization of the position of the lower jaw and growth of the jaws. Existing disorders are eliminated by various methods and techniques, taking into account the causes that caused them, the period of bite formation, its correspondence to the age and gender of the patient. During the period of temporary bite, it is recommended to accustom children to chewing hard food, which stimulates the normal development of the jaws, alveolar processes and dental arches. In case of carious destruction of the crowns of temporary molars, they are subject to restoration, which is achieved with the help of fillings, inlays, restorative crowns. In the presence of bad habits - sucking fingers, lips, various objects, drawing cheeks into the oral cavity and biting with lateral teeth - it is important to wean children from them at an early age; vestibular plates are used for this purpose. In case of incorrect attachment of the frenulum of the tongue, plastic surgery is performed. Prematurely lost temporary molars are subject to replacement with removable dentures in order to prevent the occurrence of deep incisal overlap. Active orthodontic treatment should be started from 5.5 to 9 years. The separation of the lateral teeth in this age period during the eruption of the first permanent molars contributes to the alveolar dentoalveolar elongation in the lateral section, due to which the depth of the incisor overlap decreases. For this purpose, a plate with a bite pad on the upper jaw is used. At the age of 9 to 12 years, they try to use a physiological increase in bite when establishing premolars, canines, and second permanent molars in occlusion. The same orthodontic devices are used as in the previous age period, and some fixed orthodontic devices are also used. Dentoalveolar shortening can be observed in the area of incisors, canines and incisors, less often it has a greater extent, when the incisors, canines, premolars, and sometimes individual molars do not contact. In this case, only the last teeth close. The most common cause of the development of dentoalveolar shortening is the presence of bad habits in children (sucking fingers, tongue, lips, cheeks, pencils and various objects, sleeping with the head thrown back, putting the tongue into the defect of the dental arches after the early loss of temporary or permanent teeth). The gap between the teeth in such patients usually corresponds to the shape of the object that the child sucks. Speech disorders (incorrect articulation of the tongue) contribute to under-eruption of teeth and the formation of an open bite in the anterior part of the dental arches. A shortened frenulum of the tongue hinders its movement, which leads to an incorrect position of its tip. These etiologic factors also cause significant functional disorders: difficulty biting off food, chewing, swallowing, pronouncing dental and hissing sounds of speech (patients lisp); breathing changes to oral, which causes dryness of the mucous membrane of the upper respiratory tract, susceptibility to infectious diseases and predisposition to periodontal diseases. The main tasks of treating alveolar shortening are eliminating bad habits, normalizing the position of the tongue at rest and during function, achieving nasal breathing, lip closure, correct swallowing and pronunciation of speech sounds. To perform these tasks, according to indications, plastic surgery of the shortened frenulum of the tongue and therapeutic myogymnastics are performed. To wean children from the bad habit of sucking the tongue and to normalize the swallowing function, functionally acting devices are used, such as the Kraus vestibulooral plate (Fig. 23), pre-orthodontic trainers. Machine Translated by Google Fig. 23. Kraus' vestibulo-oral plate In the treatment of adolescents and adults, along with mechanically acting single-jaw plates with a tongue rest, springs, arches for dentoalveolar lengthening, fixed devices are often used (Angle's arch, multibonding system using reversible arches). Anomalies of dental arches in the transverse direction. Narrowing of the dental arches can be genetically determined and hereditary. Narrowing of the dental arches is characterized by a change in their shape due to a decrease in the distance between the median plane and the teeth located laterally from it. Anomalies in the shape of the upper dental arch are determined in relation to the median palatine suture, the lower - in relation to the median plane of the face and jaw. The main factors of narrowing of the dental arches and their apical bases are the following: difficult nasal or oral breathing (with this disorder, the tongue occupies an incorrect position in the oral cavity and does not exert sufficient pressure on the alveolar process and teeth of the upper dental arch, which leads to its narrowing); bad habits, such as sucking fingers or objects, increase the pressure of the cheeks on the dental arches as a result of opening the mouth; disruption of the functions of swallowing, speech, parafunction of the facial and chewing muscles, muscles of the tongue lead to the development and consolidation of an incorrect neuromuscular stereotype. Due to the tension of the facial muscles, the pressure of their tendons in the area of the corners of the mouth on the dental arches, deformation of the latter occurs, most pronounced in the area of the canines and premolars. Narrowing of the dental arches and lack of space for the front teeth can be explained by weak pressure on the teeth of a sedentary tongue with its shortened frenulum and the prevailing action of the muscles of the lips and cheeks. Sluggish chewing and chewing food on one side lead to disruption of the normal development and growth of the jaws. Narrowing of the dental arches, in turn, complicates lateral movements of the lower jaw. Early carious destruction of teeth (especially temporary molars) and their loss contributes to the displacement of the lateral teeth in the mesial direction, i.e. towards the narrower part of the dental arch, which causes it narrowing. Narrowing of the dental arches can be observed with a neutral, distal or mesial relationship of the lateral teeth, as well as with vertical bite anomalies. There are dentoalveolar and gnathic forms of narrowing of the dental arches. With the gnathic form of narrowing of the upper dental arch, curvature of the vomer is often determined. Narrowing of the dental, alveolar or basal arches or combined forms are distinguished. The following irregular forms of narrowed dental arches are distinguished: 1) saddle-shaped, when the narrowing is most pronounced in the molar area; 2) V-shaped, when the dental arch is narrowed in the lateral areas, and the anterior area protrudes in the form of an acute angle; 3) trapezoidal, when the anterior area of the dental arch is narrowed and flattened; 4) generally narrowed, when all teeth (anterior and lateral) are located closer to the median plane than normal. The narrowing can be unilateral or bilateral, symmetrical or asymmetrical, on one or both jaws, without or with a violation of the closure of the dental arches. A distinction is made between the narrowing of the dental arch: 1) with protrusion of the anterior teeth without space between them, 2) with protrusion of the front teeth and their close position, 3) with protrusion of the front teeth and gaps between them. The most common are close position of the front teeth, rotation of individual teeth along the axis, tilt of one or more teeth in the vestibular or oral direction, retention of individual teeth. The diagnosis is established on the basis of clinical and radiographic examinations, as well as the study and measurement of diagnostic models of the jaws. Machine Translated by Google The width of the dental arch in the area of premolars and molars (according to Pont, Linder and Harth), and the width of the apical base (according to N.G. Snagina, Howes) are specified. Comparison of the obtained data with the individual norm allows to determine the severity of the narrowing and select a treatment method. In this case, the following is taken into account: 1) the relationship of the lateral teeth (neutral, distal, mesial); 2) the narrowing of the arch (dental, alveolar, basal); 3) the position of the lateral teeth, i.e. whether the close position of the front teeth is a consequence of underdevelopment of the jaw base or other reasons; 4) whether the anomaly can be corrected orthodontically or whether the use of auxiliary treatment methods, including surgical ones, is required. The treatment consists of widening the dental arches and their apical base, setting the teeth in the correct position, and determining orthodontic indications for the extraction of individual teeth or other surgical manipulations (compactosteotomy, decortication, plastic surgery of the shortened frenulum of the tongue, etc.). Widening of the dental arch is achieved using removable or non-removable orthodontic devices. Screws or springs are used to widen the dental arch with removable orthodontic devices. A plate with a screw and a sagittal cut for uniform widening of the dental arch is most often used (Fig. 24). Various screw designs are used: skeletonized (large and small sizes), screws with a closed body, with shock- absorbing springs. Fig. 24. Plate with a skeletonized screw and a cut for uniform expansion of the upper dental arch The greatest narrowing of the upper dental arch is usually observed in the premolar region, so the screw is installed in this region during sagittal cutting of the plate. The distance between the model and the screw should be 0.5-0.7 mm. The cut of the base of the appliance for the upper jaw is made along the line of the median palatine suture. When cutting the plate, the position of the central incisors, the base of the frenulum of the tongue and the attachment point of the frenulum of the lips are used. A plate with a vestibular arch and an expansion screw is used for simultaneous expansion and shortening of the dental arch. Asymmetric expansion of the upper dental arch is achieved using plates with a screw and sectoral cuts. In the area of the lateral teeth subject to vestibular movement, the bite with the help of occlusal pads. In order to unevenly expand the upper dental arch, larger in the anterior section and smaller in the lateral ones, special screws are used (Fig. 25). When expanding them, both halves of the base of the device diverge fan-shaped, which is achieved with the help of a screw with a limiting hinge located in the distal part of the plate on the upper jaw. Plates are used in the periods of temporary, mixed and permanent bite. In addition to single-jaw orthodontic devices, functionally acting monoblock and frame devices (Janson bionator, Frankel Function regulator, etc.) and vestibular plates are used to expand the dental arches. Fig. 25. Plate for uneven expansion of the upper dental arch: a – diagram of the device; b – apparatus on a plaster model of the upper jaw Machine Translated by Google From the group of non-removable mechanically acting devices for expanding the dental arches, the following are used: palatal springs – Quad Helix and Bi-Helix (Fig. 26 a, b), Gozhgorian spring (Fig. 26 c), Derichsweiler device (Fig. 27). A b V Fig. 26. Springs for expansion of dental arches: a – Quad Helix; b – Bi-Helix; c – Gozhgoriana Fig. 27. Derichsweiler apparatus The duration of treatment depends on the period of bite formation, the degree of narrowing and its type (dental alveolar or gnathic form, unilateral or bilateral narrowing, presence of reverse overlap of lateral teeth). Retention of the achieved results is ensured mainly by means of single-jaw plate devices with clasps and other devices for their fixation. The expansion of the dental arches is characterized by an increase in the distance between the median plane and the teeth located laterally from it. The main etiological factors for the expansion of the dental arches and their apical base are the following: in dentoalveolar forms of pathology - bad habits, parafunctions, incorrect formation of tooth rudiments, delayed change of temporary teeth; in gnathic forms - hereditary or acquired macrognathia, tumors (e.g. teratoma), lateral displacement of the lower jaw, abnormal position of the lower lateral teeth. Expansion of the dental arch is much less common than narrowing; it is combined with malocclusion in the sagittal, vertical and horizontal planes. Expansion of the dental arch can be unilateral, bilateral, symmetrical, asymmetrical, on one jaw, on both jaws, without or with abnormal occlusion of the dental arches. Machine Translated by Google Orthodontic treatment or in combination with surgery. To correct the shape of the dental arch, removable and non-removable mechanically acting devices (plates with screws, Angle's arch, multibonding system) are most often used. In the case of using functionally acting devices, such as the Frankel function regulator, on the side of the expansion the lateral shield should fit the teeth and alveolar process. 12. "Open" bite. Etiology, clinical forms. An open bite is a vertical bite anomaly and is characterized by the presence of a vertical gaps between teeth when dental arches close; such a gap is most often in the anterior part of the dental arches (symmetrical, asymmetrical, or in the lateral parts – one-sided or two-sided). The absence of contacts between dental arches can be observed in the area of incisors and canines, less often it has a greater extent, when incisors, canines, premolars, and sometimes individual molars do not contact. In this case, only the last teeth close (Fig. 68). Fig. 68. Open bite Etiology of open bite. I. Open bite caused by impaired jaw growth due to unfavorable heredity. II. Congenital (maternal illnesses during pregnancy, abnormal fetal position, birth injury). III. Acquired: a) due to the influence of local factors (sucking fingers, tongue, lips, pencils and other objects, sleeping with the head thrown back, inserting the tongue into a defect in the dental arches after early loss of temporary teeth). Of no small importance is the difficulty of nasal breathing, forcing the mouth to be kept open, and an incorrect position with the tongue inserted between the dental arches. Enlargement of the pharyngeal tonsils contributes to the forward displacement of the tongue, its incorrect position and the development of an open bite. A shortened frenulum of the tongue hinders its movement, which leads to an incorrect position of the tongue, most often interincisal. Speech disorder (incorrect articulation of the tongue with surrounding tissues contributes to under-eruption of teeth and the formation of an open bite in the anterior part of the dental arches). The size and shape of the tongue, present during the period of embryonic development of the oral cavity, can predetermine the development of an open bite, most often in the lateral sections. An open bite can develop at different age periods. It can be observed with a neutral relationship of the dental arches, and also accompany a distal and mesial bite. The degree of severity of the anomalies is determined by the size of the vertical gap: 1 degree - up to 5 mm, 2nd degree – 5-9 mm, 3rd degree – more than 9 mm. Morphological abnormalities in open bite: I. At the jaw level: 1. Rotation of the body of the upper jaw relative to the transverse axis upward and forward. 2. Rotation of the body of the lower jaw downwards and backwards. II. At the level of the dental arches: Machine Translated by Google 1. Extrusion of teeth in the lateral areas of the upper and lower dental arches. 2. Intrusion of incisors and canines. 3. Supraocclusion of the lower lateral teeth. 4. Infraocclusion of the upper lateral teeth. If there is a gap of 8.0 mm or more between the incisors, the shape of the face is usually distorted, its lower part prevails over the middle and upper, the upper lip is shortened, the tongue is visible. The angle of the lower jaw is more than 135 degrees. If the lips are closed, the facial expression is tense. When an open bite is combined with a distal or mesial bite, the facial features are characteristic of both types of bite. An open bite is accompanied by a narrowing of the dental arches, close arrangement of the front teeth, and enamel hypoplasia is often observed. With an open bite, it is difficult to bite off food, chew, swallow, speak, breathing changes, which causes dryness of the mucous membrane. The diagnosis is based on a clinical examination, photometry of the face, orthopantomography of the jaws, lateral teleradiographs of the head; Clinic: Two forms: anterior and lateral open bite Anterior open bite: there is no vertical overlap of the incisors, while the lateral segments are in occlusion. Lateral open bite: while the teeth are in a closed state, there is a space between the occlusal surfaces of the teeth. With an open bite, biting and chewing food is usually difficult, hinge movements of the lower jaw prevail, therefore, when chewing, the tongue takes an active part, helping to knead the food. The pronunciation of labial, lingual-labial and hissing sounds is impaired: "p", "b", "v", "m", "f". It is necessary to pay attention to swallowing, which with an open bite resembles infantile or childish. Breathing changes, becoming predominantly oral, which causes dryness of the mucous membrane. An external examination often reveals an oval face, elongated by the lower third, and often compressed lips due to the patient's desire to hide the existing defect. A study of the structural features of the facial skeleton and soft tissues depending on the shape of the face showed that the severity of an open bite increases precisely with a narrow face. The upper lip can be extended or, on the contrary, shortened and flaccid due to the constant gaping of the oral opening. With an open mouth, the cutting edges of the front teeth and the tongue, which covers the gap between the dental arches, can be seen under the upper lip. The lower lip can be tense and the mental fold smoothed out with the chin seemingly slanted back. Chewing efficiency is significantly reduced. 13. "Open" bite. Treatment methods depending on the form and age. Prevention. An open bite is a vertical bite anomaly and is characterized by the presence of a vertical gaps between teeth when dental arches close; such a gap is most often in the anterior part of the dental arches (symmetrical, asymmetrical, or in the lateral parts - one-sided or two-sided). The absence of contacts between dental arches can be observed in the area of incisors and canines, less often it has a greater extent, when incisors, canines, premolars, and sometimes individual molars do not contact. In this case, only the last teeth close. Etiology of open bite. I. Open bite caused by impaired jaw growth due to unfavorable heredity. II. Congenital (maternal illnesses during pregnancy, abnormal fetal position, birth injury). III. Acquired: a) due to the influence of local factors (sucking fingers, tongue, lips, pencils and other objects, sleeping with the head thrown back, inserting the tongue into a defect in the dental arches after early loss of temporary teeth). Of no small importance is the difficulty of nasal breathing, forcing the mouth to be kept open, and an incorrect position with the tongue inserted between the dental arches. Enlargement of the pharyngeal tonsils contributes to the forward displacement of the tongue, its incorrect position and the development of an open bite. A shortened frenulum of the tongue hinders its movement, which leads to an incorrect position of the tongue, most often interincisal. Machine Translated by Google Speech disorder (incorrect articulation of the tongue with surrounding tissues contributes to under-eruption of teeth and the formation of an open bite in the anterior part of the dental arches). The size and shape of the tongue, present during the period of embryonic development of the oral cavity, can predetermine the development of an open bite, most often in the lateral sections. An open bite can develop at different age periods. It can be observed with a neutral relationship of the dental arches, and also accompany a distal and mesial bite. The degree of severity of the anomalies is determined by the size of the vertical gap: 1 degree - up to 5 mm, 2nd degree – 5-9 mm, 3rd degree – more than 9 mm. Treatment of open bite depends on its type, degree of severity, period of formation, and type of jaw growth. During the temporary bite period, the main task is to eliminate bad habits, normalize the position of the tongue, normalize nasal breathing, lip closure, correct swallowing and pronunciation of sounds. Plastic surgery of the shortened frenulum of the tongue is performed. Individual and standard plates are used to eliminate bad habits. To eliminate tongue sucking and normalize swallowing, a vestibular plate with a plastic tongue support (Fig. 68), a Kraus vestibulo-oral plate (Fig. 69), a chin sling with vertical traction, and grinding of lateral teeth are used. Fig.68. Standard vestibular plate with tongue support Fig. 69. Kraus' vestibulo-oral plate In mixed occlusion, the same treatment measures are used as in the period of temporary occlusion. To eliminate the bad habits of tongue insertion and sucking, a plate is used on the upper jaw with a wire tongue stop (Fig. 70). Fig. 70. Plate for the upper jaw with a wire tongue stop Machine Translated by Google In this period, an open Klammt activator is used, taking into account the main type of pathology (neutral, distal or mesial bite). The tongue is removed from the teeth using wire loops, which are placed in the area of the vertical gap between the incisors. In this period, a plate with a tongue stop is used to treat open bite with a neutral relationship, for the treatment of distal open bite - I and II types of Frankel function regulators (Fig. 71), pre-orthodontic trainers (Fig. 72), and for mesial and open - III type or Frankel clasp activator (Fig. 73). These devices help to expand the dental arches, especially the upper one, which is very important for the treatment of open bite. Fig.71. Frenkel function regulator Fig.72. Pre-orthodontic trainers Fig. 73. Frenkel clasp activator In addition to removable orthodontic devices, non-removable ones are also used. Rings on the supporting teeth with soldered tubes and a U-shaped curved dental vestibular arch. Rings with hooks are attached to the teeth to be moved. Dentoalveolar traction is achieved using rubber traction. In permanent occlusion, open bite treatment should be comprehensive (hardware + surgical method). Extraction of teeth if they are closely spaced, compact osteotomy and the use of removable and non-removable devices. Non-removable structures include the Angle device, the straight arch technique with the use of reversal arches (Fig. 74). Machine Translated by Google Fig. 74. Multibonding system in combination with a non-removable tongue stop. In some cases, a prosthetic treatment method is used for treatment of permanent occlusion. This method is indicated for a sufficient length of the upper lip, moderate size of the mandibular angles and slight lengthening of the lower third of the face. The duration of open bite treatment depends on the period of its formation, type, possibility of eliminating functional disorders, severity of morphological disorders. 14. Clinical and laboratory stages of manufacturing mechanical devices (with a screw, with a Coffin spring, with various wire elements). Mechanically acting orthodontic devices are devices that affect the teeth, dental arches and bite due to an “external” active force (screws, arches, springs, rubber traction). Removable mechanica