A possible association between medial depression of mandibular ramus and maximum bite force

Medial depression of the mandibular ramus (MDMR) is an anatomical depression with unknown aetiology and described as a result of a slender mandibular ramus in the area of the mandibular notch. It is suggested that MDMR may be due to variations in muscle functions. The aim of this study is to compare the bite force of patients with and without MDMR detected on panoramic radiographs.

One hundred and ten patients (55 women and 55 men; mean age 22.69 ± 2.85 years) participated in this study. Patients were divided into two groups based on the presence of MDMR. Bite force of 55 patients with MRMD and 55 patients without MDMR were determined using a bite force sensor. Non-parametric tests were used to assess differences between groups.

Measurements showed statistically significant differences in bite force between genders (p = 0.00) with men having higher values (535.98 ± 187.85 N) than women (363.59 ± 139.56 N). The mean bite force in the sides with and without MDMR was 538.19 ± 196.94 N and 396.22 ± 157.69 N, respectively. There was a statistically significant difference between groups with and without MDMR (p = 0.00). There was no statistically significant difference in bite force between groups according to Angle's classification (p = 0.581).

This study suggests that the presence of MDMR may be an indicator of high muscle activity. Patients with MDMR should be carefully examined for the risk of relapse prior to any surgical intervention.