Marcos Pérez-Riffo; Marión Verdugo-González & Enrique Olave

SUMMARY: The precondylar tubercle (PCT) is a small, uncommon bony projection located ventrally to the occipital condyles. It is described as a small, non-articular tubercle of varied morphology, which can be unilateral or bilateral and is located on the anterior margin of the foramen magnum. In this study, the anterior portion of the basiocciput of 150 skulls from the cranial collection of the Department of Anatomy at the Universidad Católica del Maule in Talca, Chile, was examined. A descriptive analysis of its morphological characteristics was performed and its dimensions were measured using an electronic Vernier caliper. Among the specimens analyzed, 15 (10%) skulls were identified as having a PCT. Of these, 6 (40%) were female, 8 (53.33%) were male, and 1 (6.66%) was of undetermined sex. The average sagittal diameter of the TPCs found was 2.45 ± 0.89 mm, while the transverse diameter was 2.04 ± 1.32 mm. By explaining their embryological genesis, the data provided will complement the morphopathological knowledge of the presence of a TPC in the foramen magnum.

KEY WORDS: Craniovertebral joint; Foramen magnum; Precondylar tubercle; Basilar tubercle.

PÉREZ-RIFFO, M.; VERDUGO-GONZÁLEZ, M. & OLAVE, E. Precondylar tubercle at the anterior margin of the foramen magnum: Morphological and etiological analysis. Int. J. Morphol., 43(5):1742-1746, 2025.