The mandibular foramen in Thais.

ABSTRACT

One hundred twenty-two Thai dry mandibles, 67 males and 55 females, were used in measuring the location of the mandibular foramen, and the position was found to be variable. However, the foramen is predominantly located at the anteroposterior diameter, midpoint of the ramous, halfway between the mandibular notch and the lower border of the mandible and two thirds of the way down a line joining the coronoid process to the angle of mandible. The average distance between the mandibular foramen to the sharp external oblique line of the anterior border of the ramous is 1.976 + 0.388 cm., to the round internal oblique line of the anterior border of the ramous 1.433 + 0.670 cm., to the posterior border of the ramous 1.657 + 0.950 cm., to the mandibular notch 2.360 + 0.562 cm., to the standard basal plane 2.287 + 0.397 cm., to the coronoid process 3.872 + 0.616 cm., to the angle of mandible 2.501 + 0.451 and to the posterior surface of third molar 1.993 + 0.379 cm.. The average minimum width of the ramous is 3.437 + 0.401 cm.. The average height of the lingual is 0.0874 + 0.628 cm.. The majority of the mandibular foramen is located below the occlusal surfaces of the lower molars. It is concluded that the marked variability in the position of the mandibular foramen may be responsible for an occasional failure to block the inferior alveolar nerve.