management of anomalis in tooth number

1. 1 Management of anomalies Management of anomalies I In tooth numbers n tooth numbers Prepared by Prepared by D Dr: Mohammed Alruby r: Mohammed Alruby ءاملا هرثك نم تومي درولاف مهقح نم رثكا سانلا يطعت لا Management of anomalies in tooth number Management of anomalies in tooth number Dr. Mohammed Alruby Dr. Mohammed Alruby

2. 2 Anomalies in number of teeth One of the factors that lead to malocclusion: 1-Supernumerary teeth: = Occurs most commonly in maxilla, sometimes these teeth is well formed so it is difficult to determine which one are the extras a-Supplemental: close to the original site, commonly seen in premolar or lateral b-Mesiodens: occurs in midline palatal to maxillary central incisors, they are conical in shape, occurs in pairs or single = supernumerary teeth lead to delayed eruption or prevent eruption of permanent teeth as incisors which may become cystic after time 2-Missing teeth: Congenital missing teeth are more frequent than the supernumerary teeth Common teeth missing frequency are: -Third molars -Maxillary lateral incisors -Mandibular second premolars -Mandibular incisors -Maxillary second premolars 3-Early loss of permanent teeth: May be due to trauma or caries of permanent dentition as in male patient with excessive overjet, this patient is more liable to trauma, and 1st molar permanent is commonly affected by caries Treatment modalities of each case: 1-Supernumerary teeth: Tooth or tooth like structure which develops in dentition to the normal Incidence: 1-2 % 80% in maxillary anterior, 10% of midline diastema due to supernumerary Etiology: division of tooth bud, hyperactive dental lamina, genetic influences Types: ==Conical: -Small peg shaped tooth -Root usually well developed -May be inverted -In midline known as mesiodens == tuberculate: -No roots and remain unerupted -Often in pairs -Delayed or prevent eruption of central incisors == supplemental: -Resemble the crown morphology of adjacent tooth -Most common in lower incisors or lateral maxillary -Most commonly in primary dentition -TTT: extraction is most appropriate one: always check root from radiograph == odontomes: -Complex: diagnosed as round mass of dentine, pulp, and enamel Management of anomalies in tooth number Management of anomalies in tooth number Dr. Mohammed Alruby Dr. Mohammed Alruby

3. 3 -Compound: mass of discrete denticles each containing dentine, pulp, and enamel -4 times more common than complex Diagnosis: clinical investigation, and radiographs to localized teeth using parallax technique Treatment: depend on type and position of supernumerary teeth for removal and monitoring Tuberculate one need to remove to allow eruption of teeth with maintaining of space Some cases recommend bracket attachment or only exposure of crown depend on position of tooth and amount of root formed Surgical removal of supernumerary tooth prior to orthodontic treatment to avoid resorption of permanent roots Follow all procedures for fixed appliances until good alignment is occur, for all teeth and good occlusion 2-Missing teeth: hypodontia: Dental anomalies associated with hypodontia: -Generalized reduction in crown and root size -Conical crown shape -Enamel hypoplasia -Delayed eruption -Prolonged retention of primary teeth -Infra-occlusion of primary teeth -Tooth impaction -Ectopic eruption – transposition -Lack of alveolar bone -Reduction of vertical dimension -Increased overbite Lateral incisors: 2% of population, with familial tendency for both peg shaped and missing Associated with palatally ectopic canines Premolars: lower 2nd premolar: more frequent than upper Treatment options: -Open space -Close space -Distribute space Advantages of space opening: -Improved esthetics -Good occlusion and intercuspation -Little ability to close all spaces completely Disadvantage: commits the patient to permanent prosthesis Treatment mechanics for missing lateral: 1-Space opening: Fixed appliance for tooth control, using push pull mechanics to open space, using open coil spring and lace back to retract canine Once appropriate space is opened use acrylic tooth to maintained the space Use Hawley type of retainer incorporating prosthetic teeth and stops Take in consideration the need long time of retention 2-Space closing: Invert canine bracket or bond bracket lateral to canine, this will: Management of anomalies in tooth number Management of anomalies in tooth number Dr. Mohammed Alruby Dr. Mohammed Alruby

4. 4 -torque the canine root palatally -reducing the canine eminence -locate the canine root similar to the position that should have been occupied by lateral canine extrusion to allow the gingiva to be positioned more incisally mimic that of lateral may be need additional palatal root torque for canine retention: bonded retainer. Treatment mechanics for missing 2nd premolars: May be incorporated into extraction pattern if malocclusion have crowding Maintain lower deciduous long term but reduce mesio-distal width and check root morphology Congenitally missing tooth: A tooth that not erupted in the oral cavity and not visible in the radiograph Hypodontia: 1- 6 missing Oligodontia: more than 6 missing Anodontia: complete absence Congenitally missing lateral incisors may be treated as follow: 1-canine substitution: in which the occlusion is: -class II with no crowding -class I with sufficient crowding required lower extraction -achieve proper overjet and overbite in which profile is: - straight profile is ideal -Mild convex may be acceptable Canine shape and color: -Crown width evaluated at CEJ, narrow mesiodistal produce more esthetic than the wide one -Colored should match the centrals: ----- bleaching or veneer -Crown with more convex labial surface need significant amount of reduction -Narrow mid crown buccco-lingual is good -Some cases may require Gingivectomy at the gingival margin 2-Tooth supported restoration: How much space is necessary for missing lateral incisors? a-Golden properties: Should have ratio in anterior segment 1:6 If U1 is 8mm -------------- U2 is 5mm b-Contralateral incisors c-Bolton analysis d-Diagnostic set up Resin bonded fixed partial denture: may land bridge The optimal esthetic depends on: -Position of abutment teeth -Thickness of abutment teeth -Mobility of abutment teeth -Over all occlusion Management of anomalies in tooth number Management of anomalies in tooth number Dr. Mohammed Alruby Dr. Mohammed Alruby

5. 5 -Translucency of abutment teeth Cantilever fixed partial denture Conventional full coverage fixed 3-Implant for single tooth 3-Loss of permanent teeth: A-Early loss of 1st permanent molars: If 1st permanent molars are removed before age of 8 years, there is some complications: -There is no evidence about third molar development -Unerupted mandibular second premolar can drift distally and tip from its position below the apices of primary second molar -Lower labial segment can retroclined, resulting in an increased overbite -Maxillary second molar will often erupt into good position, but space loss can be rapid Treatment planning: ** in class I malocclusion: 1-Minimal to moderate crowding: extraction at time which allow eruption of 2nd molar and relief of crowding at same time 2-Sever crowding: delayed extraction until eruption of 2nd molars and use extraction space for tooth alignment with fixed appliance 3-With lower 1st molar extraction considers compensatory extraction in upper ** in class II division 1 malocclusion: 1-Time of upper 1st molar extraction is important because the need to reduce overjet. For extraction of lower 1st molars, compensatory extraction of upper or using holding appliance as URA or TPA to prevent upper molar extrusion (over eruption) 2-Extraction of upper 1st molar and start process to relief crowding and correction of sagittal discrepancy 3-Extraction of 1st molar upper and wait for second molar to erupt then treated by functional appliances or molar distalization or premolar extraction with fixed appliances- but in case of 1st premolar extraction, the third molars should ideally be present and in good morphology 4-Extraction of upper 1st molar after second molar eruption and use the space for overjet correction with fixed appliances ** class II division 2 malocclusion: Similar to class II division 1 except for overbite reduction can be difficult if there is large extraction space ** class III malocclusion: Used space of extraction to relieve crowding and incisors retraction in mandible and this provided by extraction after second molar erupted N: B: The best occlusal results obtained in the following cases: 1-Child aged around 4 years 2-All permanent teeth including third molar are present 3-There is class I occlusion 4-Minimal or moderate buccal segment crowding Management of anomalies in tooth number Management of anomalies in tooth number Dr. Mohammed Alruby Dr. Mohammed Alruby

6. 6 5-Mandibular second molar roots should be approximately half formed with evidence dentine calcification within bifurcation N: B: Balancing extraction: extraction on other side Compensatory extraction: extraction on opposite arch B-Early loss of maxillary central incisor: = Traumatic loss of maxillary central incisor is seen in around 3% of children = It occurs unilateral in mixed dentition of boys with increased overjet = Long term space maintainer can be achieved with partial denture however this can be associated with loss of alveolar bone height OR: the space can be allowed to close and respond in the permanent dentition prior to prosthetic replacement, this allows preservation of alveolar bone, but will required fixed appliance treatment and often space creation in upper arch = in case of bilateral loss of central incisor, moving lateral to posterior position of central and modify their coronal morphology to obtain good esthetics Management of anomalies in tooth number Management of anomalies in tooth number Dr. Mohammed Alruby Dr. Mohammed Alruby