Correlation between the pattern of facial growth and the position of the mandibular third molar

The purpose of this study was to examine the correlation between variables that determine the position of the third molar (M3) and correlation between the pattern of facial growth and examined variables.

Material for the study consisted of 130 panoramic radiographs and lateral radiographs of subjects' heads in whom orthodontic therapy had been started. Analysis of the position of the mandibular M3 and its relation to the bone and other teeth were determined by 4 variables: evaluation of the space for both M3, spatial relation between the second molar and M3, vertical position of the M3 in relation to the alveolar ridge, and inclination of the germ of the M3.

In boys, significant correlation was determined on the right side of the jaw, between the retromolar area and the vertical position of M3. Significant correlation was determined in girls, between the retromolar area and the vertical position of M3 on both sides, retromolar area and M3 inclination on the left side, and retromolar area and spatial relation of M3 on the right side. Analysis of correlation between facial growth pattern and 4 variables that determinate the position of M3 showed positive correlation only for the lower right M3 inclination in subjects with anterior facial rotation.

The present study showed that the amount of retromolar space for the position of the M3 is not a sign of its normal development. No significant differences were determined between the position of M3 and type of facial growth.