Research on congenital missing of the third molar in patients with different Angle′s malocclusions

AIM:To study the relationship between the congenital missingthird molar and malocclusion. METHODS: Eight hundred patients aged 13-23 from orthodontic clinic were chosen. Their panoramic radiographs were examined and were classified into three groups according to Angle's classification. The data were analyzed by statistic analysis . RESULTS: The incidence of congenital missing of the third molars was 32.63% by the number of people and 18.72% by the number of tooth germs. In both maxillar and mandible, there was no significant difference in the incidence of congenital missing of the third molars between the right and left side. The incidence of congenital absence of the third molar was much higher in maxilla than in mandible (P0.05). The incidence of third molar missing had no significant difference among classificationⅠ, Ⅱ and Ⅲ in the maxilla or mandible (P0.05). CONCLUSION:Nearly 30% of malocclusion patients have one or more than one tooth missing of the third molars. There is no relationship between malocclusion and the third molar missing.