Mandibular Rami Projections and Foramina Variability in African American and Caucasian Populations of Male and Female Skulls

Salim, Faddi, Tone Shamon, Robert Trecapelli, and Mary Tracy-Bee

The mandible of the human skull presents numerous projections. Our research investigated variability of these projections in male and female populations, as well as in Caucasian and African-American populations.  One hundred skulls from the Hammaan-Todd collection at the Cleveland Museum of Natural History were digitally photographed and analyzed.  The condyloid process serves as an articulating surface in the temporomandibular joint (TMJ) while the coronoid process has a muscular attachment that allows for closure of the jaw.  While variation was not found to occur in the size of the coronoid process, the height of the condyloid process was significantly higher in the Caucasian skulls compared to African American skulls (F=9.95, p=0.002).  A multiple analysis of variance (MANOVA) was used to identify an overall significant difference related to race (F=2.529, p=0.032) but not sex (F=0.401, p=0.847).  Understanding this variability provides clinical insight when approaching this area for treatment and manipulation of the TMJ.