Radiography in Orthodontics PDF

Radiography in Orthodontic Dr. Shaho Ziyad Al-Talabani B.D.S., M.Sc. , Ph.D. Assistant prof. – P.O.P Dept. College of Dentistry /HMU Specialist Orthodontist –Nova Dental Centre December 2023 Investigating the aetiology of malocclusion Treatment Aims Treatment Opt...

Radiography in Orthodontic Dr. Shaho Ziyad Al-Talabani B.D.S., M.Sc. , Ph.D. Assistant prof. – P.O.P Dept. College of Dentistry /HMU Specialist Orthodontist –Nova Dental Centre December 2023 Investigating the aetiology of malocclusion Treatment Aims Treatment Options Treatment Plan Radiograph  Radiograph Presence or absence of teeth Stage of development of adult dentition Root morphology of teeth Presence of ectopic or supernumerary teeth Presence of dental disease Relationship of the teeth to the skeletal dental bases, and their relationship to the cranial base Radiograph Intra Oral Extra oral  Radiograph Intra Oral Periapical, Bitewing, Occlusal , Paralleling Extra oral OPG, Lateral Ceph, PA ceph 2D  Radiograph Periapical radiographs  Radiograph Paralleling The canine located palatally as the tooth moves with the same direction of the cone.  Radiograph 1- Detect proximal caries 2- Height & contour of inter alveolar bone 3- Detect periodontal changes 4- Detect secondary caries under restoration Bitewing  Radiograph 2) Occlusal radiographs They are particularly useful in the maxillary arch, for assessing root form of the incisors, the presence of midline supernumerary teeth bucco-palatal position of unerupted canine can be determined, either alone or in combination with additional views using parallax.  Radiograph Dental panoramic tomograph [OPG (Orthopantomogram) ]  Advantages of an orthopantomogram: 1. Broad information on facial bone and teeth 2. Convenience for the patient (film are located extraorally),. Ability to be used in patients who cannot open the mouth or when the opening is restricted 3. Short time required for making the image 4. Patient's ready understand ability of panoramic films, making them a useful visual aid in patient education and case presentation. 5. Easy to store compared to the large set of intra oral x-rays which are typically used. Uses of orthopantomogram: Stages of teeth development  Uses of orthopantomogram: Preoperative panoramic x-ray showing radiopacity enlarged right maxillary sinus (Arrow) Uses of orthopantomogram: Impaction- lesion Uses of orthopantomogram: Root Parallelism Maxilla- Mandible bone -Condyle tooth counting - supernumerary teeth- missing teeth Canine Impaction  Radiograph 5) Cephalometric lateral skull radiograph  Radiograph 6) Cone beam computed tomography (CBCT) Cone beam computed tomography (or CBCT) Impaction  Dilaceration deviation or bend in the linear relationship of a tooth crown to its root. Mini screw – surgical guide Cleft cases TMJ Cephalometry is the scientific measurement of the heads of living individuals (Greek kephalē : ‘ a head ’; metron : ‘ a measure ’ or ‘ measurement ’).  Cephalometric radiography is Cephalometric radiography is a radiographic technique for measurement of the craniofacial complex; it is closely patterned after craniometry  Craniometry Craniometry , which is the scientific measurement of dry skulls used in physical anthropology (Greek kranion : skull).  Reserve craniostat The head - positioning device (cephalometer or cephalostat) and the technique of radiographic cephalometry were introduced in 1931 by the orthodontist B Holly Broadbent (1884 – 1977) in the USA and Herbert Hofrath (1899 – 1952) in Germany, simultaneously but independently of one another. Broadbent worked with Todd and helped to modify the craniostat to permit precise standardization of cranial radiographs of dry skulls which led to the adaptation of the Reserve craniostat to permit radiographs of the heads of living subjects, hence the development of the roentgenographic cephalometer. (1948) William Downs is credited with developing the first cephalometric analysis. Over the ensuing years, multiple cephalometric analysis methods have been established,  Cephalometric radiography is a standardised and reproducible method of taking radiographs of the facial skeleton and cranial vault. different cephalometric analyses, which in itself suggests that no single method is sufficient for all purposes and that all have their drawbacks. Cephalometric analysis is also of value in identifying the component parts of a malocclusion it should always be remembered that it is an adjunctive tool to clinical diagnosis 5 feets Types of cephalogram  Uses of cephalometric Aid to diagnosis and treatment planning - Anteroposterior skeletal Assessment Aid to diagnosis and treatment planning –Vertical assessment Aid to diagnosis and treatment planning - Vertical skeletal Assessment Aid to diagnosis and treatment planning - Dental Assessment Growth assessment Impacted teeth  Post Pre Tracing Commonly used cephalometric points and reference lines Commonly used landmarks Sella Nasion (N): the most anterior point on the frontonasal suture in the midline. Point A (subspinale): the deepest point on the curved profile of the maxilla between the anterior nasal spine and alveolar crest. Point B (supramentale): the deepest point on the curved profile of the mandible between the chin and alveolar crest. Porion (Po): the upper- and outer-most point on the external auditory meatus. Orbitale (Or): the most inferior and anterior point on the orbital margin. Anterior nasal spine (ANS): the tip of the bony anterior nasal spine in the midline. Posterior nasal spine (PNS): the tip of the posterior nasal spine in the midline (located as a continuation of the base of the pterygopalatine fossa where it intersects with the nasal floor). Incisor superius (Is): the tip of the crown of the most anterior maxillary central incisor. Incisor inferius (Ii): the tip of the crown of the most anterior mandibular central incisor. Menton (Me): the most inferior point of the mandibular symphysis in the midline. Pogonion (Pog): the most anterior point on the bony chin. Gonion (Go): the most posterior and inferior point on the angle of the mandible. Condylion (Cd): the most posterior and superior point on the mandibular condyle.  SN Plane Frankfort Plane Max. Plane Occlusal Plane Man. Plane  Horizontal reference planes In particular, they are used in the evaluation of skeletal relationships and the anteroposterior position of the dentition ▪ relating the jaws to the anterior cranial base; and ▪ superimposing serial lateral skull radiographs. Frankfort horizontal plane  Porion and orbitale are both difficult to locate on a cephalometric head film; Porion and orbitale are bilateral structures, which frequently do not coincide and therefore must be averaged; and The Frankfort horizontal does not lie in the mid- sagittal plane of the skull and can therefore be influenced significantly if the head is not correctly positioned in the cephalostat. Frankfort horizontal plane It is useful for assessing: Vertical jaw relationship: Maxilla to Frankfort plane; Maxilla to SN plane; and Maxilla to mandible. Inclination of the upper incisors to the maxillary skeletal base.  The occlusal plane is constructed using a line connecting the tip of the lower incisor edges to the midpoint between the upper and lower first permanent molar cusps ; and The functional occlusal plane is a line constructed through the point of maximal cuspal interdigitation of the premolars or primary molars and first permanent molars. A problem with both of these planes is the significant error associated with their construction. The mandibular plane is useful for assessing: Vertical jaw relationship: Mandible to Frankfort plane; Mandible to SN plane; and Mandible to maxilla. Inclination of the lower incisors to the mandibular skeletal base. Max. to Cranial base (A.P skeletal pattern) SNA angle 82±3  SNB angle (78±3) Man. to Cranial base(A.P skeletal pattern)  ANB angle (3±2) Max. to Mand.  Wit appraisal 1 (±1.9) Male 0 (±1.77) Female Max. to Mand. AO occlusal plane BO  Vertical skeletal relationship 27+- 5 27+-5 Vertical skeletal The LAFH should be relationship approximately 55% of the TAFH. The TPFH should be approximately UAFH 65% of the TAFH. UPFH TAFH TPFH LPFH LAFH  Max. incisor to max. plane (109±6) Man. incisor to man. Plane (93±6) 135±10  Downs analysis Skeletal pattern  Downs analysis Skeletal pattern  Downs analysis Skeletal pattern  Downs analysis Dental pattern  Downs analysis Dental pattern Skeletal pattern The facial angle represents the degree of recession or protrusion of the chin and is the inferior internal angle between the facial plane (N–Pog) and Frankfort plane; The angle of convexity is a measure of maxillary protrusion in relation to the total profile and is the angle formed between lines running from N–A to A–Pog. It can be positive or negative, depending on the amount of retrognathia or prognathia, respectively; Steiner analysis Steiner analysis Steiner analysis Steiner analysis Steiner analysis  Cephalometric superimposition Most commonly, superimposition is employed to evaluate: Changes in the facial skeleton; Maxillary growth and dentoalveolar change; and Mandibular growth and dentoalveolar change. It is more accurate to use the outline of the cranial base (called de Coster’s line) as little change occurs in the anterior cranial base after 7 years of age the least affected surface is the anterior contour of the zygomatic process. This is the preferred structure for superimposition, however, the maxillary plane registered at the PNS is commonly used as it is easier to identify.  The anterior contour of the chin. The outline of the inferior dental canal. The crypt of the developing third permanent molars from the time of mineralization of the crown until root formation begins. Do we need X ray ??? Which X ray do we need??