Assessment of mental foramen position in dentate subjects

Mental foramen shares its significance in various fields of dentistry. Being a strategically eminent landmark, an understanding of the variation of its position is important. Aim: To evaluate frequently occurring position of mental foramen and its distance with reference to the lower premolars using panoramic image. Method: Total 215 panoramic image of patients taken for different diagnostic purpose, using Planmeca X-ray unit ProMax, The position of the mental foramen was recorded according to the categories which were put forward by Jasser and Nwoku. Result: The most common position was found to be between the two premolars approximately 60.5% for both gender, followed by below the second premolar approximately 34.9% . conclusion: The most common location was reported to be between the two premolars, with a definite bilateral symmetry on both left and right sides. No gender preferences were observed.


Introduction
The mental foramen (MF) is a bilateral opening localized on an anterior surface of the mandible, The mental nerve a branch of the inferior alveolar nerve together with corresponding arteries and veins exit through the MF  . The mental foramen is a funnel-like opening located on the surface of the anterolateral aspect of mandible (11) The inferior alveolar nerve conducts unilaterally the sensory stimuli to the lower lip, labial mucosa, lower canine, and premolar, whereas blood vessels supply soft tissues of the lower jaw (3,4) . Successful and complication-free dental procedures such as curettage, root canal treatment, periapical surgery, orthognathic surgery, and effective anesthesia during nerve blocks depend on knowledge of an operator (5) . An implant placement in an inter foramina area is strictly related to the location of the MF, because it determines a position of most distal implants. Many studies indicate that a minimum distance between MF and an implant should amount up to 6 mm (6,7). Any invasive procedure performed in this region may damage the neurovascular bundles and cause serious complications such as parenthesis (8) .
human skull, the mental foramen is regarded as a stable landmark on the mandible (10) .
The nerves and vessels transmitting through it provide sensory innervations and blood supply to important facial structures; these nerves are susceptible to injury during administration of local anesthesia and surgery (12) Variation in the position of mental foramen is common, which can result in complications during surgical procedures (13)(14).
In our retrospective study on the variability of mental foramen position using 215 digital panoramic image and to compare the results with those reported for other population.

Material and Method
Total 215 panoramic image of patients taken for different diagnostic purpose at Al_Mahmodia specialized dental center, and examined by two well-practiced examiner. The range age of the selected patients was between 18 -45years old. All

Results and Discussion
The 215 panoramic image which were evaluated, were grouped into those 99 male, and 116 female. The most common position was found to be between the two premolars position 3 approximately 60.5% for both gender, followed by the position 4 below the second premolar approximately 34.9% .
(  amalgam fillings (15) . There are significant differences reported in the location of MF among different ethnic groups Igbigbi and Lebona (16) in Malawians and Mbajiorgu et al. (17) in Zimbabweans mandibles reported position IV as the commonest followed by position V; however, Santini and Land (18) in British and Green (19) in Chinese mandibles observed position III being the commonest followed by position IV. In other studies Ngeow and Y. Yuzawati (20) in Malay populations found the most common position was IV followed by position III, AL-SHAYYAB et al found that The most common horizontal location and shape of the mental foramen on panoramic image in Iraqi population are between the two premolars (23) , in our study The most common position was

Conclusion
The most common location was reported to be between the two premolars, with a definite bilateral symmetry on both left and right sides. No gender preferences were observed.