A Review on Anatomical Variations of Mental Foramen (Number, Location, Shape, Symmetry, Direction and Size)

Mental foramen is located on the anterior aspect of the mandible that permits the terminal branch of the inferior alveolar nerve and blood vessels to exit. The anatomical variations of mental foramen are of considerable importance in local anesthesia, treatment of the fractures in the parasymphysis area, orthognatic surgeries, implant placement, etc. Regarding the importance of mental foramen in dentistry (from local anesthesia to invasive surgical procedures), this study intends to review the anatomical variations of mental foramen in this study. Absence of mental foramen is rare. On the other hand, prevalence of accessory mental foramen has been estimated lower than 15% in the most studies. The position of mental foramen is normally between first and second premolar teeth or under second premolar tooth in different ethnic groups and bilateral symmetry exists in regard with location in most cases. In most studies, the ratio of distance from mental foramen to symphysis to distance from symphysis to posterior border of ramus has been reported about 1/3.5 to 1/3. Mental foramen is oval or circular in shape and its most common direction is usually posterosuperior. Its size in different studies has been estimated about 2 to 5 millimeters and asymmetry in size is possible on both sides of mandible. Due to variations of mental foramen between various ethnic groups and even different individuals in the same ethnic group, using advanced imaging techniques such as CBCT is recommended in order to gain detailed knowledge of anatomy and morphology of mental foramen before applying invasive surgeries

Evaluation the Effect of two Classes of antihypertensive drugs on bone Mineral Density of the Jaws in Males over 50 Years Old in Yazd Using Cone–Beam–Computed Tomography in 2015

Introduction: Aging increases the probability of the concurrent incidence of osteoporosis and hypertension. It is demonstrated that antihypertensive drugs can affect bone metabolism. The object of this study was to evaluate the effects of antihypertensive medication on bone mineral density of maxilla and mandible in males over 50 years old using CBCT. Methods: In this analytical cross-sectional study, 174 CBCT images belong to males over 50 years old were selected according to inclusion and exclusion criteria. According to the history of using antihypertensive drugs by the patients, these images set into three groups: control group who did not have any history of hypertension, beta blocker users group (at least 5 years) and calcium-channel blocker users group (at least 5 years). Bone mineral density in each jaw was obtained in four regions using CBCT and the mean of these four values in each jaw was taken as the mean mineral density of that jaw. One-way ANOVA analysis and Tukey post hoc test were used to compare the mean values. Results: In beta blocker group, the mean of mineral density of all regions of maxilla except for incisor region was significantly greater than that for the control group. The difference between these two groups in mandible was statistically significant only at the mean of lower jaw. There was no statistically significant difference between the control group and the calcium-channel blocker group at all regions of maxilla and mandible. Conclusion: It may be preferred to use beta blockers instead of calcium channel blockers to control hypertension in the patients at risk for osteoporosis