Anatomical study of the retroarticular process in dry human skulls

ABSTRACT

Introduction: The retroarticular process is a bony prominence formed by the thickening of the lateral borderof the mandibular fossa, forming the posterior wall of the temporomandibular joint. Since little is known anddiscussed about the retroarticular process, our aim was to study its presence, shape and size, relating thesefindings to the shape of the skulls according to the horizontal cephalic index.Materials and Methods:Weused 400 dry human skulls of the Institute of Science and Technology–UNESP Anatomy Laboratory. Eachskull was classified in brachycranics, mesocranics or dolichocranics, and then positioned on a craneostat tomeasure the height of the retroarticular process from its lower extremity to the auriculo-orbital plane. Thewidth was obtained by measuring the base of the process on its longer lateral axis.Results:The retroarticularprocess was found bilaterally in 397 skulls (99.25%). All the processes were classified into the following shapespyramidal (35.55%), tubercular (31.78%), mammilar (20.73%), crest-like (9.05%) and molar shape (2.89%);254 skulls (63.50%) showed the same type of process at the right and left sides (Kappa=0.496, moderateagreement). The average height and width were 5.28 mm and 12.81 mm, respectively.Conclusion:Theretroarticular process was found in almost all the skulls examined. There are no significant evidences aboutthe relationship among the presence, shape and size of the retroarticular process and the shape of the skullsaccording to the horizontal cephalic index. However, our findings led us to infer that there would be afunctional relationship between the process and the temporomandibular joint.