Index of Orthodontic Treatment Need modified for use in Epidemiological Surveys : Modified IOTN

1. Index of Orthodontic TreatmentNeed modified for use inEpidemiological Surveys :Modified IOTN

2. Written by Donald Burden and Cynthia Pine with assistance from the BASCD Working Party on Orthodontics

3. Modified IOTN consists of two components: 1. Aesthetic Component 2. Dental Health Component

4. Aesthetic Component Grades 1-7 No Definite Need for treatment Grades 8-10 Definite Need for treatment

6. Recording the Aesthetic Component Ask subject to close on their back teeth Retract lips Grade the dental attractiveness of the anterior teeth

7. Recording the Aesthetic Component The grade awarded is for overall dental attractiveness rather than specific morphological similarity to the photographs First impressions are usually correct Main aim is to differentiate those at 8 - 10

8. Dental Health Component IOTN has been simplified to two categories:  Definite Need for Treatment  No Definite Need for Treatment The subject is examined for specific conditions and if one is found, a Definite Need for Treatment is recorded and no further conditions are sought.

9. Recording the DHC Examine each subject for: Missing teeth Overjets Crossbites Displacement of contact points Overbites =MOCDO

10. Recording the DHC Examine the subject using the ‘MOCDO’ scale As soon as a definite treatment need threshold is reached, then the examination is stopped

11. ‘MOCDO’ Missing teeth Overjets Crossbites Displacement of contact points Overbites

12. Missing Teeth (teeth not visible) • Congenital absence/traumatic loss • Ectopic teeth • Impacted teeth

13. Missing Teeth Palatally ectopic canines Is the canine palpable in the buccalsulcus? If not, it is ectopic = Need for Treatment

14. Missing Teeth IMPACTED if 4mm or less space is available between adjacent teeth Impacted = Need for Treatment

16. Missing Teeth • (Congenital absence/traumatic loss) • In your opinion, is orthodontic treatment required to open or close the space? • If yes = Need for Treatment

17. Original Slide No.15 ‘MOCDO’ Missing teeth Overjets Crossbites Displacement of contact points Overbites

18. Measuring Overjets Increased overjets (Class II) and reverse overjets (Class III) are measured using the metal ruler

19. Second line (red) – 6mm Positive overjets

21. Measuring Overjets Measure to the labial aspect of the most prominentincisor Only record Need for Treatment if the overjet extends beyond the 6mm line

24. Measuring Reverse Overjets All four incisors must be in lingual occlusion

25. Measuring Reverse Overjets If the reverse overjet falls exactly on the 4mm (white line) record in the Definite Need for Treatment category

26. First line (white) – 4mm Crowding Reverse overjets Open bites

28. ‘MOCDO’ Missing teeth Overjets Crossbites Displacement of contact points Overbites

29. Crossbites Can be anterior or posterior, but mostly posterior. Check for displacement on closure. If displacement on closure = Need for Treatment

30. ‘MOCDO’ • Missing teeth • Overjets • Crossbites • Displacement of contact points (crowding) • Overbites

31. Crowding Only applies to crowding between permanent teeth Measure between the contact points of the two most crowded teeth

32. First line (white) – 4mm Crowding Reverse overjets Open bites

34. ‘MOCDO’ Missing teeth Overjets Crossbites Displacement of contact points Overbites

35. Overbite Deep overbite Open bite

36. Deep Overbite Deep overbite causing gingival or palatal traumatic injury = Definite Need for Treatment

38. Other Points of the Modified IOTN Generalised spacing is not recorded in the Dental Health Component