Measurement of accessory foramina in the lateral mandibular surface and its clinical significance

Objective: To study the number and distribution of accessory foramina on the medical mandibular surface and the relationship between accessory foramina and tumor spread.Methods:This study involved 74 mandibles and each of them was divided into 2 regions and 6 sections.Under a magnification (×10～×20), the number and distribution of accessory foramina were observed in 2 regions and 6 sections.Results: The number of accessory foramina varied greatly from specimen to specimen.The superior region has fewer formina than the inferior region. In the superior region, the sigmoid section possessed the greatest proportion, followed by the condylar and the coronoid; in the inferior region, the middle third section possessed the greatest proportion, followed by the upper third section and the lower third section. The medial facing wall of the mandibular foramen was found to be the commonest dedicated sites (99.3%), followed by foramina on either of the genial ttubercles (72.8%), the median foramen above the genial tubercles (68.9%) and the digastric fossa (66.2%). Conclusions: Accessory foramina provide a direct path for tumor spread from the cortical surface to the cancellous bone, the occurrence of foramina on the medial facing wall of the mandibular foramen and other sites along the mandibular canal makes this area most vulnerable to tumor spread.