Palatally impacted canines and the modified index of orthodontic treatment need.

The aim of this study was to assess the severity of any underlying malocclusion in subjects presenting for treatment of a palatally impacted canine (PIC) using a modification of the Dental Health Component (DHC) of the Index of Treatment Need (MIOTN), which does not factor in the impacted canine. The pre-treatment study models of 54 subjects who had previously undergone surgical exposure of a PIC, followed by fixed appliance orthodontic alignment, were scored independently by two examiners on two occasions using the MIOTN system. Unweighted kappa statistics revealed good intraoperator agreement for the two examiners and a moderate level of interexaminer agreement. Forty-six and 41 per cent of the sample still scored either an MIOTN grade 4 or 5 (i.e. a great or very great need of orthodontic treatment). However, 20 and 25 per cent of the subjects were graded with a MIOTN score of 1 or 2, indicating little or no need for treatment when the PIC was not taken into consideration. This finding emphasizes the importance of early diagnosis of an impacted canine and the need to institute interceptive measures where necessary, as up to 25 per cent of patients might otherwise require no other orthodontic treatment.