Abstract

AIM OF STUDY. The objective of this investigation was to estimate the need for orthodontic treatment in a sample of 6 – 9-yearold schoolchildren of Tartu (South-Estonia).
METHODS. The study populations were defined as all children (459 subjects) in their first year of primary school, i. e. age 6-9 years in nine schools in Tartu. Examinations were conducted in each school, using a dental chair with standardized lighting. No radiographs, study casts, or previous written records of the children were used. The IOTN was calculated from direct examination over a period of 3 months ( from October 2005 to December 2005). The Index of Orthodontic Treatment Need incorporates both the Aesthetic Component and the Dental Health Component. The Dental Health Component (DHC) has five grades: grades 1 and 2 indicate no/little need for treatment, grade 3 indicates borderline need for treatment, and grade 4 and 5 indicate high priority treatment. In practice, 10 features or traits of malocclusion are considered: class II and class III buccal occlusion, overjet, overbite, open bite, anterior crossbite, lateral crossbite, displacement of teeth, impeded eruption of teeth, clefts of the lip and/or palate, and hypodontia. The Aesthetic Component (AC) consists of a scale of 10 colour photographs showing different levels of dental attractiveness, grade 1 representing the most attractive and grade 10, the least  attractive dentitions. These grades are grouped to represent the need for orthodontic treatment on aesthetic grounds, from grade 1 indicating no aesthetic need through grade 10 indicating high aesthetic need for treatment.
RESULTS. Using the DHC, 53.2 per cent of the children were assigned to the no/little need, 36.1 per cent to the borderline need and 10.7 per cent to the need for orthodontic treatment. Using the AC, 73.4 per cent of the children were assigned to the no/little need, 20 per cent to borderline need and 6.6 per cent to the need for orthodontic treatment. There was no statistical difference between the genders according to IOTN DHC and AC grade.
The occlusal features in the children considered to be in need for treatment according to the DHC were increased overbites, increased overjet and crowding.
CONCLUSION. Compared with the dental appearance of Caucasian Americans and other European children, the studied Estonian schoolchildren were found to have almost the same need for orthodontic treatment (10.7 per cent). The DHC was found to be reliable, quick, easy to use, and well adapted. The AC alone failed to identify children in need for orthodontic treatment. For all these reasons, the IOTN may be adequate for public health planning and epidemiological purposes.