Transcript Extract?
Dr. Diana Md Zahid Early loss of deciduous teeth Prolonged retention of deciduous teeth Hypodontia Supernumerary Abnormalities of tooth size Abnormalities of tooth form Abnormalities of tooth structure Abnormalities of eruption Crossbites Skeletal problems 1. EARLY LOSS As a result of Xn due to caries or trauma The degree of space loss and potential occlusal disruption will be influenced by: Age : the earlier tooth is loss, the more potential for crowding Crowding : the more inherent crowding already present, the more potential for space loss Tooth type : position of affected tooth in arch influence subsequent space distribution Time : very early extraction can delay successional tooth eruption, later extraction have opposite effect balancing and compensating • Aim: to preserve arch symmetry and occlusal relationship • Balancing: removal of the tooth from the opposite site of the same arch. Preserve dental midline/centreline. • Compensating: removal of the tooth from the opposite quadrant. Maintain buccal occlussion by allowing molar drift forwards. • The decision will depend on few factors. • Mx:… space maintenance • Removable or fixed appliance that preserves space within dental arches • To prevent the permanent tooth drift to the extraction space Space maintainer 2. PROLONGED RETENTION • Variation can exist in timing of tooth exfoliation and subsequent eruption of permanent successors • 2° erupt having failed to resorb the roots of the overlying 1° • Mx: Usually encouraged for Xn • Crowding , ectopic position of 2° can lead to prolonged retention • Mx: dictated by space available and position of permanent tooth, whether Xn of deciduous alone or traction of permanent tooth needed retained e • Often due to congenital absence of lower 5 • Often have excellent long term prognosis if in good condition • If survived of 20 yrs continued long term function can be anticipated 3. ANKYLOSIS AND INFRAOCCLUSION • Ankylose when pdl is lost and direct fusion occurs between root dentine and surrounding alveolar bone. • Infraocclusion - Consequence of ankylosis. - Submergence of the tooth relative to occlusal plane Mx: • Usually left under observation to exfoliate naturally if the permanent successor is present • If lead to disturbance of occlusion, consider restoring vertical dimension or extract affected tooth. 4. HYPODONTIA Most commonly: -Third molars (8), followed by mandible 2nd premolars (5),maxillary upper lateral incisors (2) and mandibular central incisors (1). -Excluding the 8’s: -If lack of 1-6 teeth: Hypodontia -if lack of >6 teeth: Oligodontia -complete absence of teeth in one or both dentition : Anodontia Mx; • space closure, • maintain space • open space Absence of upper right lateral incisor and very diminutive of upper left lateral incisor. The bridge was designed for replacement the teeth. Congenital absence of upper lateral incisors and the spase close using fixed appliance Severe hypodontia Using fixed appliance to upright the teeth 5. SUPERNUMERARIES • Supernumerary teeth are seen more commonly in permanent dentition. • Can cause dental problem such as: • Failure of eruption, crowding, spacing, cystic formation Supernumeraries in upper labial segment: - Conical supernumeraries. - Tuberculate supernumeraries. - Supplemental teeth. Conical supernumeraries -Close to the mid-line between central incisors. -Usually 1 or 2. -Do not prevent eruption of incisors, but may cause diastema. An erupted conical mid-line supernumerary Tuberculate supernumeraries -Main cause of failure of eruption of upper permanent incisors. -Early detection improves the prognosis. -A central incisor which fails to erupt before the lateral incisors should be radiographed. -Should be removed surgically as soon as possible. Failure of eruption permanent upper central incisors due to presence of two tuberculate supernumerary teeth. Supplemental teeth of normal morphology -Cause localized crowding unless there is generalized spacing in arch. -Should be extracted. Supplemental lateral incisor causing localized crowding • Mx: • Generally, if did not interfere with occlusion and asymptomatic; can be left in situ, under periodic radiographic review 6. ABNORMALITIES OF TOOTH SIZE Megadontia -Extract or reduce the enamel interdentally for aesthetic reason Microdontia -commonly associated with hypodontia - Upper lateral incisor one of the commonest, peg shape Mx: • Extract? Need for prosthesis. • Retain- restorative build up 7. ABNORMALITIES OF TOOTH FORM • Generally affect the permanent more commonly than deciduous. • Double teeth – slightly enlarged tooth to almost complete separation of two normally formed teeth. Xn rarely indicated in deciduos, permanent manage restoratively • Accessory cusps –usually cusp removal • Invaginated teeth – presence of enamel lined cavity • Evaginated teeth – external enamel covered projection • Dilaceration – abnormal angulation between the crown and tooth • Taurodont – bull like teeth, have pulp chamber enlarged at the xpense of the tooth 8. ABNORMALITIES OF TOOTH STRUCTURE Enamel defects AI –Amelogenesis imperfecta DI- Dentinogenesis imperfecta • Ortho mx of AI and DGI: Appearance is often poor, dentine exposure can lead to sensitivity, result in poor oral hygiene and significant caries risk • When considering ortho tx Removable appliances where possible Bracket failure or removal can lead to enamel fracture Bands used where possible Monitor oral hygiene and diet control during tx 9. ABNORMALITIES OF ERUPTION UNERUPTED TOOTH Unerupted permanent maxillary imcisors Unerupted permanent maxillary canines • Ectopic maxillary canines: Prevalence of 2% of population • (85% of canine are palatal and 15% buccal to the line of the upper arch). Unerupted permanent mandibular canines Impacted maxillary first permanent molar transposition INCISOR SPACING-MID-LINE DIASTEMA • Midline diastema can be normal feature of dental development • Will often improve following eruption of permanent canine teeth However can also be Due to: -Generalized spacing. -Diminutive teeth. -Congenital absence of upper lateral incisors. -Fleshy upper labial frenum. -Mx will depend upon the underlying cause. DIGIT-SUCKING HABITS Digit-sucking habits which persist into the mixed dentition may cause: Anterior open bite. Increased overjet. Unilateral posterior cross-bite with displacement. Anterior open bite associated with thumb sucking and upper removable appliance with a steeply inclined anterior bite plane. CROWDING SERIAL EXTRACTION Aims to relieve crowding. It consists of planned sequence of extractions: - Primary canines - First primary molars - First premolars. b. a. c. Serial extractions. (a) Class I occlusion with incisor crowding in the mixed dentition. (b) Improved incisor alignment following extraction of primary canines. The primary first molars are extracted to encourage eruption of first premolars. (c) First premolars are extracted on eruption to relieve crowding of the permanent canines. (d) the result following eruption of the canines. d. Indication for serial extraction: • Significant incisors crowding. • Pt aged about 9 years. • Class I occlusion without a deep overbite. • All permanent teeth are present. • First permanent molars in good condition. Contraindication for serial extraction: • Class I malocclusion where the lack of space is slight and the teeth show only mild crowding. • Where there is a skeletal discrepancy in the dental arches. • When there is a deep overbite or an open bite, these should be treated before undertaking serial extraction. • When there are permanent teeth congenitally absent from the dental arch. Advantage -To minimize or eliminate the need for appliances Disadvantage - Need a space maintainer following extraction of the first premolar if the crowding is severe. - Multiple episodes of extractions. 10. CROSSBITES • Early correction is indicated, particularly when associated with mandibular displacement or periodontal damage. • Can be achieved relatively easily during mixed dentition. ANTERIOR CROSS BITE Can cause ginigival recession with lower incisors if there is displacement on closing, particularly if these teeth are displaced labially. In presence of positive overbite the correction will usually self retaining. Localized gingival recession associated with incisor cross-bite Appliance to procline upper incisor POSTERIOR CROSS-BITE • There is a weak association between posterior crossbite with displacement. • It is considered appropriate to correct a posterior crossbite and eliminate displacement as early as possible. Treated by: -Expansion the upper arch to remove the initial cusp to cusp contact. -Use the midline expansion screw,or fixed expanders such as quadhelix or tri-helix. Unilateral posterior cross-bite with lateral mandibular displacement. Posterior cross-bite has been eliminated after using mid-line expansion screw. 11. SKELETAL PATTERN • Although skeletal discrepancies will often respond well to early intervention, early treatment is also associated with disadvantages of long term treatment. (what are the disadvantages?) Class III skeletal tend to worsen with age. • Treatments are often delayed at this stage to monitor further growth and to better determine the extent of the skeletal problem. • Except for the ‘pseudo Class III malocclusion’ Class II discrepancies is significant to be corrected in the mixed dentition if • Class II females with significant skeletal discrepancy • An increased OJ which is a source of teasing and bullying • An increased OJ which is at risk of trauma (associated with gross lip incompetence and marked maxillary protrusion) • The most effective time is during adolescent growth spurt An 11 year old boy with class II div 1 malocclusion, he had 10 mm overjet and treated with activator Pre and post treatment facial profile 12. OTHERS ORTHODONTICS AND DENTAL TRAUMA Orthodontic brackets are used: • To stabilize loose or reimplanted teeth. • To realign displaced teeth. • To extrude teeth that have been intruded. Orthodontic movement of traumatized teeth • The risk of resorption during tooth movement should be minimized by: - Maintaining a calcium hydroxide dressing in root canal. - The force are as light as possible.