Ankylosis & Retained Primary Teeth

1. Ankylosis & Retained Primary Teeth Lecture 5 Ingrid Reed DDS, MS Dept. of Orthodontics & Dentofacial Orthopedics Images: http://www.dditions/dentaentistryportal.com/dental-conl-ankylosis.html

2. Objectives • Be able to diagnose ankylosis • Be able to manage treatment of an ankylosed tooth • Be able to distinguish between delayed eruption and a retained tooth • Guide eruption of permanent dentition

3. ankylosis

5. Definition • Dentoalveolar ankylosis is an eruption anomaly defined as the union of the tooth root to the alveolar bone, with local elimination of the periodontal ligament, and cessation of eruption • Continued vertical alveolar growth and eruption of adjacent teeth

6. Clinical diagnosis • Infraocclusion – marginal ridges uneven • Percussion – different sound on tapping • Ankylosed tooth • Sharp solid sound (>20% of root fused) • Mobility testing • Lack of orthodontic movement • Radiographs

7. Dental implications • Ectopic eruption • Tipping of adjacent teeth • Loss of arch perimeter • Periodontal compromise/problems • Supraeruption • Complications with extraction of ankylosed teeth

8. prevalence • 1.3 % -14% • Ankylosis of anterior primary teeth related only to trauma • The primary second molar is the most commonly ankylosed tooth • Mandibular ankylosis is twice as common as maxillary

9. Causes of ankylosis • Trauma – especially permanent teeth • Unknown – primary teeth • Theories • Familial pattern • Genetics • Metabolic disturbances

10. Treatment options • Observation • Extraction • Orthodontic treatment • Considerations • Absence or presence of successor tooth • Amount of infraocclusion • Dental age /root formation • Complications

11. AH

12. AH

13. Patient AH

14. JH Age 9 years 9 mo

15. JH

16. JH

17. JH

18. JH

19. JH

20. Radiographs

21. JH Extraction complications

22. Extracted teeth

23. 11 months post extraction

24. Brother NH 7 years 1 month

25. DF

27. MC

28. Ankylosed with no successor • Problems • Long term periodontal problems • Loss of alveolar bone • Difficult extraction • Treatment – depends on crowding • Extract – move teeth at least partially into edentulous space – create new bone – reposition later • Extract – close spaces orthodontically

29. Ankylosed 1°- Missing second premolars

32. Consequences of infraocclusion of a deciduous molar

33. Ankylosed primary molar

34. Ankylosis – Permanent tooth pages 671- 673 • Implant planned, can’t align ankylosed tooth • If extract – alveolar atrophy if growth not complete • “Bank” alveolar bone - remove crown, retain root – fill with calcium hydroxide • Root resorbs over 3-5 year • Alveolar bone remains • Implant more successful without need for graft • Pontic placed on archwire or removable appliance • Implant placed when vertical growth is complete

35. Retained primary teeth

36. Age 8 years 1month

37. Chronological age : 13yrs 3mo Dental age : 10.5 – 11 yrs

38. 2nd primary molar Palatal root

40. Over-retained vs. Delayed Eruption

41. Age: 12 years 4 months

43. Retained Primary Tooth

44. Space Maintainers • Distal shoe • Band loop • Hayes Nance • Transpalatal bar • Lower lingual arch

45. Best space maintainer

46. Distal Shoe

47. Band or Crown & Loop

48. Hayes Nance

49. Lower Lingual Arch

50. Space Maintenance Design Factors • Anchorage • Status of succedaneous teeth • Eruption status of other teeth • Medical status • Cleansability • Patient cooperation/abilities • Need to use as active appliance