Atlanto-occipital joint: n. One of two joints, each formed by a superior articular pit of the atlas and a condyle of the occipital bone. [This definition is from Dorland's Illustrated Medical Dictionary © 1994. It is outdated since we now (1985) know that the atlanto-occipital joints are actually two adjacent facet surfaces (one pair per side on both the atlas and the condyles) with separate capsular membranes that pair to create a hinge of the isthmuses. -- Ref: Craton, E. F. (1985). Cranial vertebral junction autopsy. Today's Chiropractic: 14 (4), 29-30. & Craton, E. F. (1985). Cranial - vertebral junction autopsy. The Texas Journal of Chiropractic: October, 21-22.]