ABSTRACT

To test the hypothesis that there are no statistically significant differences between mandibular dental crowding and angulation and impaction depth of mandibular third molars.

In this study, the lateral cephalograms, panoramic radiographs, and dental casts of 48 patients (11 boys, 37 girls, mean age 17.10 ± 3.20 years) were evaluated. All patients had class 1 molar relationship, mild and moderate dental crowding, and no tooth loss or size anomaly. Three groups were established according to the mandibular third molar impaction depth on a panoramic radiograph. Group 1 (8 patients, mean age 22.3 ± 2.13 years), the occlusal surface of the impacted tooth is level or nearly level with the second molar; group 2 (16 patients, mean age 17 ± 2.33 years), the occlusal surface is between the occlusal plane and the cervical line of the second molar; and group 3 (24 patients, mean age 15.4 ± 1.76 years), the occlusal surface is below the cervical line of the second molar. Third molar angulation was measured with reference to the anterior angle between the occlusal plane of the first and second premolars and a line drawn through the occlusal surface of the third molar. Angulation and impaction depth of all right and left molars were compared with the mandibular dental crowding. Pearson correlation and 1-way ANOVA statistical analyses were used.

There were no statistically significant differences between impaction depth and total mandibular dental crowding (p> 0.05). In addition, no statistically significant differences were found between both left and right third molar angulation and left or right dental crowding in all groups (p > 0.05).

The present study indicated that mandibular third molar angulation and impaction depth have no effect on mandibular dental crowding.