SummaryIn an effort to explain the aetiology of early temporomandibular joint (TMJ) injuries, their incidence in children born by vaginal breech delivery and possible correlation with such deliveries were investigated.The study covered 156 children aged from 4 to 6 years, eighty‐three of them born by vaginal breech delivery under application of the classical Mauriceau manoeuvre in seventeen cases and the Bracht manoeuvre in sixty‐six. Seventy‐three children delivered spontaneously in vertex presentation served as the control group.Signs of TMJ injury were found in 59.6% of the total group, the by‐birth percentages being 67.5 in those after breech delivery and 50.7 in those after spontaneous delivery—the difference is statistically significant.The difference was even more significant for the more severe TMJ disorders, their percentages being in two groups respectively 48.2 and 29.7. In the children born by breech delivery the TMJ disorders were invariably attended by severe forms of distocclusion, among which the unilateral form deserves particular attention.The authors conclude that vaginal breech delivery is probably among the factors responsible for early TMJ abnormalities. They call the attention of paediatricians and obstetricians to this fact and urge examination of this joint as a very important part of oral examination in children born by vaginal breech