PASSIVE SPACE CONTROL

1. PASSIVE SPACE CONTROL Dr S.E. Jabbarifar;Isfahan Dental School,Pediatric Dentistry Departement 2009

2. Prerequisite knowledge • Understand that arch length is greatest at age four years • Tooth position is maintained by balance of forces – shift vs. drift • Greatest amount of space closure – within first 6 months of premature tooth loss • Sequence & timing of exfoliation/eruption

3. Space control vs. space maintenance • Space control • Dynamic • Careful ongoing supervision • Space maintenance • Utilization of appliance to preserve existing space • Not always the rule!

4. Variables influencing space control • Oral musculature & habits • Time elapsed since extraction • Dental age, eruption sequence & bony covering • Available space • Interdigitation • Absence of anomalies

5. Considerations in premature 1o tooth loss • Preserve the arch length! • Causes: • Anterior – primarily trauma, caries • Posterior – primarily caries • If space lost: • Space maintenance • Space regaining • No treatment

6. Space loss in primary and mixed dentitions • Unrestored interproximal caries reduce arch circumference! • “first line of defense” = Class II & SSC restorations • Natural tooth is the best space maintainer

7. Planning for space maintenance • No medical contraindications • Patient must be dentally fit • Patient must be able to demonstrate good OH

8. Planning for space maintenance • Parents must all understand costs involved • Parents must understand importance of & be willing to attend regularly for appliance supervision/maintenance – teeth lost in primary dentition stage may cause delayed eruption of succedaneous teeth • Periodic recementation may be required

9. Primary Incisors

10. Primary Incisors

11. Primary Incisors • Why replace primary incisors? • Primarily for esthetic reasons • Rarely see long-term effects on speech development and function • Once 1o cuspids have erupted in occlusion the anterior arch length is established

12. Primary Incisors • Problems with replacement: • Appliances are weak • High maintenance – close monitoring req’d • Frequent alterations as dentition changes • Appliance may enhance caries risk

13. Primary Incisors

14. Primary Incisors

15. Primary Incisors

16. Primary Incisors

17. Primary Canine • Loss due to trauma or caries – rare • Space maintainer: B&L vs. RPD • Must be removed to accommodate lateral • No space maintainer: • Midline shift • Lingual collapse in mandible

18. Premature loss of primary molars

19. Band-loop space maintainer • Indications: • Unilateral loss of the 1st primary molar before eruption of the 1st permanent molar • Unilateral loss of the 1st or 2nd primary molar after eruption of the 1st permanent molar • Bilateral loss of the 1st primary molars before eruption of the permanent incisors and 1st permanent molars • Bilateral loss of the 2nd primary molars after eruption of the 1st permanent molar

20. Early loss of the 1st primary molar

21. Early loss of the 2nd primary molar

22. Other indications Deflection of succedaneous tooth

23. Band-loop space maintainer FABRICATION & DESIGN

24. Band-loop fabrication • Technique: • Properly fitting band on abutment tooth (pg. 389 – Pinkham) • Segmental impression (compound/alginate) • Remove band from tooth & secure in impression • Create working model

25. Band-loop fabrication • Sectional impression tray • Green or red compound

26. Band-loop fabrication

27. Band-loop fabrication

28. Band-loop fabrication

29. Band-loop design • Loop should be wide enough bu-li to allow eruption of bicuspid (8 mm) • Loop should not restrict physiologic movement of adjacent teeth (eg. lateral movement of primary canine)

30. Band-loop design • Loop should not impinge on soft tissue • Loop should be in close approximation to ridge

31. Band-loop cementation • Apply floss ligature • Try-in / seat band completely • Loop should contact abutment below contact point • No soft tissue impingement • Cementation in properly isolated, dry field • Check/adjust occlusion

32. Try it in first!

33. Loop impingement

34. Loop impingement

35. Loop impingement

36. Lingual arch

37. Lingual arch • Indications: • Bilateral single or multiple tooth loss in mandible • Not recommended when primary incisors still present

38. Lingual arch

39. Lingual arch design • Archwire should rest on cingulae of incisors 1-1.5 mm above gingival margin • Removable vs. soldered

40. Lingual arch design • Solder joint should be in mid-third and parallel to band • Wilson loops • Archwire should be below plane of occlusion posteriorly

41. Lingual arch fabrication • Fit molar bands • Compound/alginate impression – accurate especially in lingual sulcus & lower incisor area

42. Lingual arch fabrication Secure bands in impression … …create working model

43. Lingual arch cementation • Check for passivity on the model and in the mouth before cementation • Archwire should be in contact with lower incisor cingulae

44. Lingual arch cementation • Dry field • GI or polycarboxylate cement • No soft tissue impingement

45. Transpalatal arch

46. Transpalatal arch • Rarely recommended for bilateral tooth loss in maxilla • Can prevent mesio-palatal rotation of palatal root of Mx 1st permanent molar but allows mesial tipping of molars & space loss

47. Transpalatal arch • May have an indication for use when one side of the arch is intact but several primary teeth are missing contralaterally • Some designs incorporate omega loop: when active can prevent bodily movement of molars

48. Nance arch

49. Nance arch • Used commonly in maxilla for bilateral tooth loss • Incorporates acrylic button in contact with palate to prevent molars from tipping • Can be very unhygenic

50. Nance arch