Morphometric Evaluation of the Mental Foramen Using Cone Beam Computed Tomography in Different Facial Types.

Introduction: The anatomic location of the mental foramen is still a matter of debate. There are variations in the position of mental foramen in different populations. These variations indicate accurate detection of mental foramen position which result in safer dental procedures. Aim: To carry out a morphometric assessment of the mental foramen in patients with different facial types. Material and Methods:Ninety computerized cone beam tomographic scans from brachycephalic (n=30), dolicocephalic (n=30) and mesocephalic (n=30) facial types were used. Computerized cone beam tomographic scans were obtained using a Tomographic I Cat Unit and the Dolphin Imaging 11.0 Program. The mental foramen position was evaluated and compared in the three subgroups. The Bartlett and Shapiro-Wilk ́s tests were used to evaluate the homogeneity of the variances. Influence of the three facial types on cephalometric measurements was evaluated using two way ANOVA and Tukey ́s test. Correlationsbetweenage and some measurements of interest were assessed using Pearson ́s moment correlation test Results:Mental foramen height was slightly smaller in females. Facial types influenced the following measurements: distance from the apex of the second lower bicuspid to the upper border of the mental foramen and distance from the lower border of the mental foramen to thelower border of the mandible. Statistical differences were observed betweenmesocephalic and brachycephalic subjects (p<0.05) and between mesocephalic and dolicocephalic ones (p<0.05). Mental foramen height was smaller in mesocephalic subjects (p<0.05). Mental foramenwidthwas smaller only in the left side in mesocephalic subjects. Distance between the buccal cortical and lingual cortical of the mental foramen was smaller in mesocephalic than in brachycephalic and dolicephalic subjects (p<0.05). A higher number of mental foramina were positioned between bicuspids and along the long axis of the second bicuspids: 74% and 20% respectively. An oval mental foramen was found more frequently: (80.6%) in mesocephalics; (77.4%) in brachycephalics and (86%) in dolicocephalics subjects. A circular shape was observed in 19%; 22%; and 13% in mesocephalic, brachycephalic and dolicocephalic individuals, respectively. Conclusion: Some measurements of the mental foramen may be different among facial type subjects. Distribution and shape of the mental foramen are similar in the three facial types.