In the present study, 1,869 skulls from the Hamann-Todd Collection were examined (macroscopically and by radiographs) for closure of the petroexoccipital articulation (jugular synchrondrosis). The results demonstrated the the petroexoccipital articulation underwent closure between 20 and 50 years of age in most human skulls evaluated. Approximately 7-10% of the human skulls underwent complete union of the petroexoccipital articulation before 20 years of age. In 5-9% of the population, the joint remained completely open. After 50 years of age, there was no increase in the frequency of individuals with incomplete closure. The frequency of "partial closure" was similar (4-8%) for all age groups (20-25, 30-35, 40-45, 50-55, 60-65, and 70+), excluding the 30-35 year old group (17.5%). The time interval necessary for closure to occur appeared to be very short. No significant differences in closure rates due to ethnic origin, gender, or laterality were noted. The utility of the pteroexoccipital articulation as an age estimator is discussed.