A study of the position of the mandibular foramen in adult black Zimbabwean mandibles.

Abstract

To determine the position of the mandibular foramen on dry adult mandibles and hence provide valuable information for dental and other health practitioners for successful inferior alveolar nerve anaesthesia. A cross sectional study. Department of Anatomy, Faculty of Medicine, University of Zimbabwe, Mount Pleasant, Harare, Zimbabwe. 38 dry mandibles from adult black Zimbabweans. The anterior and posterior rameal widths, upper and lower rameal heights and the height of the lingula were measured with respect to the position of the mandibular foramen. The distribution of the foramen in relation to the occlusal plane was determined. The results showed that the position of the mandibular foramen was highly individualistic but on average lies at about 2.56 mm (right) and 2.08 mm (left) behind the midpoint of rameal width and at approximately 3 mm superior to the midpoint of rameal height on both sides. The mean anterior and posterior rameal widths were respectively 18.95 +/- 0.41 and 14.30 +/- 0.35 while the mean rameal heights were respectively 22.50 +/- 0.50 (upper) and 28.44 +/- 0.65 (lower). The distribution of the foramen in relation to the occlusal plane was 47.1% at the same level with the occlusal plane, 29.4% above, and 23.5% below the plane. There was no side variation in the position of the foramen in relation to the occlusal plane, in the dimensions of the ramus and in the size of the mandibular foramen but individual variations exist. The height of the lingula however showed great variation. The mean height was 8.40 +/- 0.39 (right) and 8.36 +/- 0.38 (left). The study has shown similarities and differences between the rameal dimensions and the position of the mandibular foramen in adult black Zimbabwean mandibles and those of other subpopulations. The clinical significance of accurately locating the mandibular foramen during a local anesthetic block of the inferior alveolar nerve is discussed.