— Three hundred and forty‐eight cranial remains from Bronze and Iron Age British, Romano‐British, Anglo‐Saxon, Eastern Coast Australian aborigines, Medieval Christian Norse, Medieval Scarborough, 17–20th century British and German cultures were examined for the presence of osteo‐arthritis in the temporomandibular joints. Cultures exposed to more stringent living conditions and with well‐worn teeth had about twice the incidence of osteo‐arthritis as the more sophisticated cultures. In general, loss of either molar support or occlusal imbalance were potent aetiological factors in this disease.