Unit 6 Habits And Disorders PDF

UNIT 6 HABITS AND DISORDERS Orthodontics I Bachelor’s degree in Dentistry Professor: Elena Muñoz García HABIT, concept: Is a repeated, permanent, automatic and uncontrolled movement along the time that can cause a modification on teeth position and jaws shape, altering the gro...

UNIT 6 HABITS AND DISORDERS Orthodontics I Bachelor’s degree in Dentistry Professor: Elena Muñoz García HABIT, concept: Is a repeated, permanent, automatic and uncontrolled movement along the time that can cause a modification on teeth position and jaws shape, altering the growth and function of the orofacial muscles. Habit is defined as something you do regularly that produces a mechanical action that will cause a deformity. CRANIOFACIAL GROWTH unctional matrix theory The origin, growth and maintenance of skeletal tissues is always due to secondary and compensatory answers to previous functional events that occurs in non-skeletal tissues and organs. The functional matrix hypothesis rejects that the genotype in skeletal cells has enough information to regulate the type, velocity, direction and duration of the skeletal tissue growth. All FUNCTIONS that take place at oral cavity during childhood (breathing, suction, swallowing, mastication, phonation) stimulate the jaws growth. Everything that alters this function can produce an alveolar bone deformity, and change the teeth position and in long term, the bone base. Genetic control theory: The genotype provides all the information needed to express the phenotype. What the followers of this genetic control theory defend is that the morphology of facial structures is strictly governed by hereditary genetic factors. The organic matrix has a hereditary origin and the functional matrix is the consequence of the organic matrix. (bone growth responds to a functional reaction). A disfunction cannot be produced if there is not an organic matrix disharmony. ORAL FUNCTIONS 1. Breathing: nasal or oral. 2. Suction. 3. Swallowing. 4. Chewing. BREATHING NASO RESPIRATORY FUNCTION Nasal functions are conditioning the inspired air, olfactory function and the function as the auxiliary organ of speech. When we breathe through our nose, we filter, warm and humidify the air. The nose is a great defense of the paranasal cavities and also of the lower respiratory system. This is possible due to the mucus and vascularized lining of the nasal cavity. This mucosa is lined on its surface by a ciliated vibratory cells layer that suffers modifications due to infections, age, allergic reactions, tobacco, inhalation of irritant substances… The other innermost layer has cells that produce mucus for lubrication of the nasal cavity, also having a bactericidal action. Filtering and purification also occurs through the mechanical action of the hairs of the nasal vestibule. Warming is ensured by heat radiation from veins and arteries and from the intense vascularization of the nasal mucosa. In healthy individuals, arterial oxygenation is higher during nasal breathing compared to oral breathing. THE WALDEYER’S RING: Is a ring of lymphoid tissue that surrounds the naso and oropharynx. This ring is about 3% - 5% of the lymphatic system and is of great relevance for the respiratory process, because the hypertrophy of two of their structures can modify the naso respiratory function. The largest volume of lymphatic tissue in relation to body size, occurs around 5 years old. Consist of: - Pharyngeal tonsil (Adenoids). - Palatine tonsils. - Lingual tonsil. - Tubal tonsils. ADENOIDS They grow with repetitive nasal infections. Its removal does not have to cause a decrease in the child's defenses, because when removed, other lymphatic tissues of the body supply their function. Those infections are usually recurrent, and hypertrophic adenoids cause high respiratory distress. PALATINE TONSILS They are located on the lateral part of the oropharynx, between the palatoglossus and palatopharyngeal muscles, closely related to the soft palate, tongue and oral cavity. Irregular folds and crypts contained in the tonsils increase the surface area for antigenic stimulation. They are really active between 4 to 10 years old, and they regress after puberty. Tonsils may grow and the hypertrophy degree has been determined in order to assess the magnitude of the obstruction at oropharyngeal level. LINGUAL TONSIL They are located at the base of the tongue. They are a non-encapsulated lymphatic aggregate of variable size. During the nasal breathing is necessary for the mouth to be closed at some point. Usually this happens due to lip sealing. This closure can also occur in the medial part of the tongue, with the back of the tongue in contact with the hard palate and posteriorly with the base of the tongue in contact with the soft palate. In case that there is no sealing at any of these points, we will have mouth breathing or mixed breathing, that is, through the nose and through the mouth. ORAL BREATHING. ETIOLOGY Nasal obstruction: Nose shape and nostrils dimensions, nasal septum deviation. Obstruction due to hyperplasia of the mucosa: The hyperplasia of the mucosa could be produced due to allergic rhinitis, sinusitis or irritation due to pollution. Laxity of the perioral muscles: The laxity of the facial muscles can also lead to the mouth opening and the consequent mouth breathing. Habit: some people breathe through their mouths without any apparent cause. EVALUATION Good anamnesis. Observe natural body posture and head in relation to shoulders. Anatomical facial examination. Functional examination. ANATOMICAL STRUCTURES ALTERED BY ORAL BREATHING: - BODY ALTERATIONS: o The oral breather keep the mouth open to be able to breath. This imbalance is compensated by changes in the posture of the head in relation to the body, with the consequent alterations in the spine in an attempt to compensate for this poor positioning. o Shoulders leaning forward compressing the chest. o Chest deformities. o Flaccid and distended abdominal muscles. - OTHER POSSIBLE ALTERATIONS: o Frequent sinusitis, recurrent otitis and hearing loss. o Halitosis and decreased senses of smell and taste. o Higher incidence of cavities. o Sleep alteration, snoring, night drooling and insomnia. o Daytime sleepiness o Appetite problems and impaired physical development. o Rapid tiredness when doing physical activities. o Agitation, anxiety, impatience, impulsiveness. o Attention and concentration difficulties, generating school difficulties. - CRANIOFACIAL ALTERATIONS: o When a person is not able to breath correctly through the nose, the nasal breathing is replaced by buccal breathing impairing the whole maxilo/pharynx/buccal system. o The endocrine system induces the rate and amount of growth but its direction and the bone morphology, are the result of the balance between muscle groups in the three dimensions of the space, for example: ▪ Elevator muscles – depressors of the mandible. ▪ Orbicular muscle of the lips – tongue. ▪ Cheeks – tongue.  o If there is balance between different muscle groups during growth, the development would be harmonious. If not, the presence of some imbalance will be evident in the morphogenesis. o Predominantly vertical craniofacial growth. o Goniac angle increased. o Muscular tone alterations with hypofunction of the lips and cheeks. o Hypertrophy, hypotonia and hypofunction of the elevator muscles of the mandible. o Short upper lip and lower lip everted and interposed between the teeth. o Dry and ridged lips with color alterations. o Hypertrophic gums with color alterations and frequent bleeding. o Ojival palate (high arched palate). o Narrow facial dimensions. o Narrow or sloping nostrils. o Less space in the nasal cavity. o Dark circles with asymmetry in the position of the eyes, tired look. o Ear affectation. - “ADENOID FACIES” o Narrow and long face. o Dark circles under the eyes o Flaccid cheeks. o Small nose with narrow pinched nostrils o Sad face. o Short upper lip and thick and everted lower lip. o Upper incisor protrusion. - TONGUE o The tongue participates permanently in the neuromuscular balance of the facial region. o During the mouth breathing the tongue adopts a low position to allow free access to air o The lingual stimulus necessary for the correct upper jaw development disappears, growing in vertical direction but not in an anteroposterior or transverse direction.  - UPPER JAW o The normal tongue position (attached to the palatal vault) will stimulate a good transverse palatal development and therefore of the nasal cavity floor. o The tongue then becomes an important factor in the growth and development of the maxilla. The result will be a harmonious growth of the jaws. o In the case of dysfunction in lingual praxis due to mouth breathing, there will be a dolichocephalic development, characterized by a vertical development of the jaws, with a decrease in the available perimeter for the permanent teeth, so we will have dental crowding. ORAL BREATHING. OCCLUSION ALTERATIONS - Transverse and hypo development of the maxilla. - Facial asymmetries. - Functional lateroposition of the mandible. - Class II 1st division with increased overjet malocclusion. The free space that is between arches due to oral breathing allows the extrusion of the upper posterior teeth and the posterior rotation of the mandible. - Posterior crossbite with upper jaw compression, low position of the tongue with interposition between incisors. - Anterior open bite. - Class III malocclusion: decrease of the perioral pressure. - The chronic presence of hypertrophic tonsils PRODUCE a low and forward position of the tongue, which can produce a forward position of the mandible by mechanical effect and relief of the oropharynx area by decompression. - This causes an excess of mandibular growth.  - The tongue exerts direct posteroanterior pressure on the mandible. In this way, it acts on mandibular growth, increasing the contractile activity of the lateral pterygoid muscles and stimulating also the condylar cartilage. SWALLOWING MATURATOIN OF THE SWALLOWING FUNCTION. - BREAST-FEEDING: o The importance of breast-feeding o The low development of the mandible at the time of birth makes childbirth easier. o Promotes the growth of the maxillofacial complex and muscular and dental development. Breast-feeding conditions the first physiological advance of the occlusion and the exercise of the masticatory and facial muscles. - INFANT SWALLOWING: o It is divided in 3 phases: oral (voluntary), pharyngeal (reflex) and esophageal (involuntary). o The oral pase of the child swallowing, before dental eruption, consist of the following steps: separation of the jaws, tonge thrusting between the gingival rims and swallowing movement controlled by the tongue and the perioral musculature contact. - MATURATION OF THE SWALLOWING FUNCTION o End of breast-feeding: 4th or 6th month? (Desirable until 12th month). o The transition to chewing semi-solid food must be gradual. o With the maturation of the CNS, some oral reflexes disappear. o The sequence will no longer be suction+swallowing but chewing+swallowing. - BEGINNING OF THE TRANSITION TO ADULT SWALLOWING. o The change in the swallowing pattern is established gradually and is due to neuromuscular maturation and the change in diet. o ADULT SWALLOWING transition: ▪ When sucking activity stops, there is a gradual transition to the acquisition of the adult pattern. As long as the habit of sucking persists, there will not be a complete transition to adult swallowing. ▪ When the primary molars erupt (during 2nd year) the sucking activity of the bottle and breast ceases. Lip activity ceases and moves towards an ADULT SWALLOWING pattern. o Around 8 years old: ▪ 60% adult swallowing ▪ 40% swallowing in transition ▪ Having an open-bite or anterior overjet delays the transition, since the lip seal is needed to maintain a negative pressure inside the mouth. o Can lead to ATYPICAL SWALLOWING: ▪ Anterior open-bite. ▪ Increased anterior overjet. ▪ Low position of the tongue due to oral breathing. - ATYPICAL SWALLOWING It is the persistence of the child swallowing, whose mechanism consist of advancing the tongue and produce its anteroposterior movement. o Etiological factors: ▪ Hypertrophic tonsils.  ▪ Thumb sucking. ▪ Oral breathing. ▪ Increased anterior overjet. ▪ Anterior open bite (a good sealing absence needed to achieve negative pressure forces the tongue or the lower lip to be interposed in the incisor area). ▪ Early loss of primary incisors. - MATURE SWALLOWING, It is divided in 4 phases: o Oral preparatory phase: in the most anterior area. Teeth in contact and labial sealing. The tongue and the hyoid are elevated and, at the same time, the tongue begins to act with lifting movements and peristalsis. o Oral transit phase: Palatal. Soft palate is elevated, makes contact with the posterior wall of the pharynx and closes the upper airway and then the tip of the tongue ascends to the interincisor papilla and peristaltic movement occurs. Contraction of the elevator muscles of the mandible MUST BE present. o Pharyngeal phase: glottis and epiglottis close the lower airway, isolating the digestive tract from the respiratory tract. o Esophageal phase: the transfer of the alimentary bolus through the esophageal sphincter takes place. BOTTLE HABIT During artificial breastfeeding, child does not have to exercise the mandible so vigorously as with breastfeeding to obtain a rapid flow of milk. Consequently, IF THE BOTTLE IS USED FOR A LONG TIME can produce dento-skeletal and muscular alterations: Less protrusive labial, lingual and mandibular posture. The pterygoid and masseter muscles will be also less exercised, since only the lingual pressure could be enough to produce the flow of milk from the bottle. PACIFIER HABIT In most children, the use of the pacifier is frequent before the two years old. If the shape of the pacifier is anatomic, the tongue will be maintained in a low position. The continued use of the pacifier during the primary dentition is almost always associated with the presence of an anterior open bite and a posterior crossbite. The anterior open bite is the result of inhibition of the vertical growth of the anterior portion of the alveolar processes. Posterior crossbite is due to increased cheek muscle activity, combined with a lack of tongue pressure, due to the backward and downward displacement of the tonge by the presence of the pacifier in the oral cavity. The effect is usually transient if the pacifier is carried just until primary incisors eruption. If not, the anterior open bite will persist and that favours the development of a TONGUE THURSTING HABIT. THUMB SUCKING When the pacifier use is dropped, finger suction may appear. It is considered normal during the first year of life and its prevalence in the primary dentition period is relatively low. It might be a sign of anxiety, it could be due to the sudden removal of the pacifier, or it could persist until the time of tooth replacement because the pressure exerted by the finger produces relief from eruption pain. May produce anterior open bite, reversible if the habit is eliminated early. Upper incisor proclination and lower incisors retroclination  Incisor eruption blockage, Molar extrusión due to the absence of contact, Forward displacement of the maxilla, stimulation of sutural growth of the maxilla, palatal elevation with maxillary contraction Tendency to mandibular backwards rotation Posterior crossbite, bilateral or unilateral with mandibular functional deviation Class II molar relationship, overjet Low tongue position, atypical swallowing. LIP SUCKING The lower lip interposition in an habit that many times is presented in oral breathers, because the lower lip rest interposed between incisors. It occurs in malocclusions with a great overjet, although it may appear as a variant of finger sucking. The lower lip is introduced between the incisors, accompanied by a great hypertonia of the mental muscles. Upper incisors protrusion, retroclination and crowding of lower incisors, overjet and open bite. TONGUE THRUSTING Tongue interposition between the dental arches, exerting lateral or forward pressure in the act of swallowing. Protrusion of both upper and lower incisors and lateral or anterior open bite. It is often an adaptive position to achieve correct oral sealing in cases where tooth contact is lacking. MANDIBLE PROTRUSION Etiological factors: discomfort produced by hypertrophic and tender lingual tonsils. Movement of mandibular protrusion will produce a stimulus of mandibular growth with a tendency to class III and dental wear especially in the anterior sector. Etiological factors: discomfort caused by hypertrophic and sensitive lingual tonsils.