Extraction in orthodontics /certified fixed orthodontic courses by Indian dental academy


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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

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  • Location in arch such that space gained by Xn utilized for correction of both anterior and posterior segments.
  • Bimaxillary dento alveolar protrusion.
  • Riedel- treatment time is reduced.
  • Extraction in orthodontics /certified fixed orthodontic courses by Indian dental academy

    1. 1. 1 Extractions in Orthodontics INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
    2. 2. "To extract or not to extract" may not have quite the significance of "To be or not to be," but for 100 years it has been a key question in planning orthodontic treatment. There are two major reasons to extract teeth: (1) To provide space to align the remaining teeth in the presence of severe crowding, (2) To allow teeth to be moved (usually, incisors to be retracted) so protrusion can be reduced or so skeletal Class II or Class III problems can be camouflaged. 2www.indiandentalacademy.com
    3. 3. The Great Extraction Controversy of the 1920s Edward Angle struggled with both facial esthetics and stability of result as potential complications in his efforts to achieve an idealized normal occlusion. Systematized and organized. Suggested extractions in earlier works.(1887). By 1907, strongly opposed extractions. His dogmatic views dominated for next 30yrs in America Calvin case argued in favour of extractions 3www.indiandentalacademy.com
    4. 4. The Re-introduction of Extraction in Mid-Century By the 1930s, relapse after non-extraction treatment was frequently observed. At this time soon after Angle's death, one of his last students, Charles Tweed, decided to re-treat with extraction a number of his patients who had experienced relapse. Four first premolar teeth were removed and the teeth were aligned and retracted. Tweed's dramatic public presentation of consecutively treated cases with premolar extraction caused a revolution in American orthodontic thinking and led to the widespread reintroduction of extraction into orthodontic therapy by the late 1940s. Raymond Begg in Australia, also concluded that non-extraction treatment was unstable 4www.indiandentalacademy.com
    5. 5. Breeding experiments with animals, of which Stockard's widely publicized results from crossbreeding dogs were most influential, showed conclusively that malocclusion could be inherited Rather than developing the (non-existent) It appeared that it was necessary for the orthodontist to recognize genetically determined disparities between tooth size and jaw size, or to acknowledge that the lack of proximal wear on teeth produced tooth size-jaw size discrepancies during development. In either case, extraction was frequently necessary. By the early 1960s, more than half the American patients undergoing orthodontic treatment had extraction of some teeth. 5www.indiandentalacademy.com
    6. 6. 6 • Increased ability to move teeth under better control: ever-expanding choice of extraction. Factors affecting choice of extraction 1. Treatment objectives 2. Type of malocclusion 3. Esthetics (large chin button, prominent nose) 4. Growth pattern. 5. Conditions of teeth.(caries, multifilled teeth, impacted, ectopic, severe rotation) 6. Health of supporting tissues. www.indiandentalacademy.com
    7. 7. 7 Facial profile alteration: – Maxi retraction of U&L anteriors: 4s (laterals) – Lesser retraction in lower face: U4s and L5s – Less overall retraction: 5s or 6s. Deep anterior overbite: – Closer.( Mechanically easier to level, as spaces are closed). incisors – min time and effort. Open bite: – 5 or 6 Xn. Accentuate the curve of Spee. GRABER: Removal of 5s in mandibular arch preferable. ‘.’ reduces the tendency of relapse of openbite &lingually inclined incisors seen occasionally with Xn of 4s. www.indiandentalacademy.com
    8. 8. 8 Extraction of Ist premolars. ADVANTAGES : • Erupts before any other post teeth, after 6. • Eruptive sequence : Xn at proper time. • Strategically located close to the incisors. • Center of each half of arch .’. Ant & post crowding. • Protraction of molars not required. • 4 Xn adequate anchorage for retraction of 6 teeth. • Contact b/w canine and 2nd premolar satisfactory. www.indiandentalacademy.com
    9. 9. 9 1. Convex profile with severe crowding. 2. Class II div I with deep anterior bite. 3. Class I with severe crowding. 4. Class I with bimaxillary protrusion. Indications for I st premolar extraction: www.indiandentalacademy.com
    10. 10. 10 Indications for I st premolar extraction. www.indiandentalacademy.com
    11. 11. 11 Extraction of 2nd premolars: History: Henry(1965) 1.mild degree of crowding & excellent profile. 2.No crowding and fullness of lips. Begg: unless carious or poorly formed. Nance: Ist person.Mild discrepancy. Avoids dished-in-face & less tendency for relapse. Carey: 2.5-5mm www.indiandentalacademy.com
    12. 12. 12 • DEWEL: Xn creates more space in borderline cases, closed by reducing the anchorage value of buccal segments • LOGAN: • U4 more esthetic than 5 • Contact b/w 4 and 6 tended to stay closed. • Reduced possibility of buccal/lingual furrows in Xn site ‘.’ of rapid closure. • Closure of ant open bite, by reducing post vertical dimension. • De CASTRO: 3 independent segments. – 5s Xed only post segment shortened. – 4s Xed, both segments shortened- functional integrity of the dentition. www.indiandentalacademy.com
    13. 13. 13 INDICATIONS FOR 2ND PREMOLAR EXTRACTION 1.Good profile+mild crowding 2.flat profile+moderate crowding 3.Class II div 1 on skeletal class I +mild crowding. 4. Mild Class III inter-arch relation+mild crowding in U arch. 5.Congenitally missing,impacted. 6. Grossly destructed/heavy restn. 7. Abnormal root morphology. 8. Open bite. www.indiandentalacademy.com
    14. 14. 14 Extraction of 2nd premolars: ADVANTAGES: 1. Original facial contours retained without reduction of lip profile. www.indiandentalacademy.com
    15. 15. 15 Ist Molar Extraction: • Avoided: Not provide adequate space in the ant region. 5 & 7 may tip in the Xn space. Deepening of bite. Masticatory efficiency. www.indiandentalacademy.com
    16. 16. 16 Carious- beyond restorationCarious- beyond restoration RC Treated, - than a perfectly good premolar.RC Treated, - than a perfectly good premolar. Multi filled teeth- crown.Multi filled teeth- crown. Premature Xn of 6, to preserve symmetry.Premature Xn of 6, to preserve symmetry. Facial considerations: large chin buttons&/ prominentFacial considerations: large chin buttons&/ prominent nosenose (4- dished-in)(4- dished-in) ((rationale: farther back less facial change)rationale: farther back less facial change) Open bite cases.Open bite cases. Indications: www.indiandentalacademy.com
    17. 17. 17 Ist Molar Extraction: • Not to allow U7 locked behind L7. Horizontal elastics – until danger of locking has passed. • Mesially inclined 7, lesser degree of anchor bend. Wilkinson’s Extraction: 1942 8 ½ to 9 ½ yrs. Extraction of all Ist molars. Basis: •Additional space for eruption of 8s. •Crowding of lower arch minimized. •Disadvantages- www.indiandentalacademy.com
    18. 18. 18 Single arch extraction – U 6 or what to do when non extraction treatment fails. Raleigh Williams. AJO 1979 • Class II div 1 with perfect lower arch alignment but growth expectation inadequate. • Class II div 1 active growth over. Pt non cooperative. • Class II div 1 with good lower arch over basal bone, with some growth expectation. • Class II div 1 with mild open bite. www.indiandentalacademy.com
    19. 19. 19 • Problems with Xn of 4s: • Tipping, opening of space (5 small to fill the space) • Mesial tipping of 6, hanging palatal cusp Avoided with 6 Xn. • Good molar relation. • U 4 occlude with L4 • 8s erupt normally. • Min patient cooperation • Stable results. • Tuberosity not crowded. • Results similar to nonext. • Rx duration is reduced. • Profile maintained. www.indiandentalacademy.com
    20. 20. 20 2nd MOLAR EXTRACTION: • David W.Liddle- AJO 1977 • Malocclusion: potential force by developing 7,8. • Xn of 7s to intercept this forward force. • 4 Xn: treating the effect and not the cause. – 10-12mm of space :satisfies arch length problem, not apparent when patient smiles. – 91% 7 Xn. • 6 move distally in response to pressure. www.indiandentalacademy.com
    21. 21. 21 2nd MOLAR EXTRACTION: ADVANTAGES AND INDICATIONS • Disimpaction of 3rd molars, faster eruption • Prevention of “dished-in” at the end of facial growth • Prevention of late incisor imbrication • Facilitation of 1st molar distalization • Distal movement only as needed to correct the overjet • Fewer “residual”spaces at the end of Rx • Less likelihood of relapse • Good functional occlusion • Good mandibular arch form • Overbite reduction. www.indiandentalacademy.com
    22. 22. 22 Indications: Chipman: • Xn 7 - caries, ectopic, rotated. • Mild – moderate discrepancy with good profile. • Crowding in tuberosity area ,with a need for distal movement of 1st molar. Lehman - preconditions • 8 in favorable angulation 15-30*angle to the long axis of the 1st molar. • Normal in size/shape & root area is sufficient w.r.t 2nd molar. • No congenitally missing teeth. www.indiandentalacademy.com
    23. 23. 23 Disadvantages: • Too much tooth substance removed in Cl I malocclusion with mild crowding. • Location far from area of concern. • No help in correction of A-P discrepancy without patient cooperation . • Possible impaction of 3rd molars even with 2nd molar Xn • Unacceptable positions of erupted 3rd molars –second, late stage of fixed therapy. • 9-20% missing 3rd molars. www.indiandentalacademy.com
    24. 24. 24 Timing for mandibular 2nd molar extraction: • Kokich: 1. 3rd molar crowns completely formed, Xn before roots begin to develop 2. 30*to the occlusal plane 3. 3rd molars in close proximity to 2nd molar-drift. Halderson, Huggins, Lehman and Smith. Before radiographic evidence of root formn.(12-14yrs) Consensus opinion: as soon as 2nd molar erupts. angulation. www.indiandentalacademy.com
    25. 25. 25 3rd Molar Extraction: • Xn to prevent lower anterior crowding? • Distal movement of 6,7– impaction of 8. • Xn of 8 before retracting. Contraindications: • 1st or 2nd molars are extracted. www.indiandentalacademy.com
    26. 26. 26 Incisor Extraction: • Mandibular incisors- therapeutic value • 1st sign of incipient malocclusion • Difficult to treat as they relapse easily. • Not a new idea. • Jackson (1904) • Riedel : Xn of 2 lower Incisors-arch form without Expn of intercanine width • Angle: Inexcusable.disharmony b/w Occlusal planes, abnormal overbite www.indiandentalacademy.com
    27. 27. 27 Incisor extraction: Indications:- • For mandibular incisors: • Extreme crowding / protrusion. • Gingival recession & loss of overlying bone on labial surface. • Lateral incisors severely # in young children. • Rarely-discrepancy in sizes of U & L incisors themselves, 1 incisor can be removed. • Reidel- Rx time reduced. • min facial change. www.indiandentalacademy.com
    28. 28. 28 Incisor extraction: Advantages: 1. Maintains/ reduces intercanine width 2. General arch form is maintained – greater stability 3. Retention period- less 4. Anterior segments can be retracted readily if need be. 5. Immediate solid tooth support of entire buccal segments. 6. Easy reduction of overbite- intrusion, reshaping 7. Mechanotherapy is simplified. Space closure quick. www.indiandentalacademy.com
    29. 29. 29 Incisor extraction: Disadvantages:- • Reopening of space . Central Incisor. • Danger of creating a tooth size discrepancy. • Reidel- 2 mandi incisors Xed to maintain intercanine width. • 1 incisor Xn- deepbite- if normal tooth size relationship is present before Xn. • Color difference of canine. www.indiandentalacademy.com
    30. 30. 30 Upper Incisor Extraction: • Rarely indicated. • Unfavorable impaction of U incisor. • Bu/Li blocked out lateral, with good contact b/w central and canine. • Congenital missing of 1 lateral incisor • Dilacerated tooth. • Gardiner et al: – U crowding, mesial displacement of root apices of U3 - Xn of lateral incisor. www.indiandentalacademy.com
    31. 31. 31 Summarize: • Incisor Xn rare. • Possibility must always be considered. • Careful planning with diagnostic setup www.indiandentalacademy.com
    32. 32. 32 Extraction of Canines: • Not extracted. Profile. • Long path of eruption. – Conditions where indicated: • Impossible to bring in alignment. • Gross displacement Bu/Li • 4 in contact with 2 & does not show palatal cusp. Decision : position of apex. www.indiandentalacademy.com
    33. 33. 33 The Effect of Different Extraction sites upon incisor retraction. Raliegh Williams et al AJO 1976 • Relation b/w root surface area and Xn site selection upon incisor retraction. • Efficient mechanotherapy. • Diagnostic line. • Larger the root surface area, greater the resistance to movement. www.indiandentalacademy.com
    34. 34. 34 Non extraction 1.5mm 1st molars u&l 6.0mm U4 and L5 8.7mm 1st premolars 9.2mm 1st premolars &1st molars 16.9mm www.indiandentalacademy.com
    35. 35. 35 Conclusion: • Location of the Xn site- –Root surface area. –Predict incisor retraction. • Should be considered in diagnosis, so that a desired Rx goal for the final position of incisors within the facial profile can be achieved. www.indiandentalacademy.com
    36. 36. 36 • Orthodontic treatment may include extractions of any tooth in the arch. • Based on sound diagnosis, treatment objectives. www.indiandentalacademy.com
    37. 37. www.indiandentalacademy.com 37 Thank you For more details please visit www.indiandentalacademy.com