[The temporomandibular joint in the newborn infant. Oto-meniscal relations].

Although they are anatomically immature at the time of birth, the temporomandibular joints are able to ensure efficient suction due to the branchial blastema interposed between the two articular nuclei. This conjunctive formation is the principal factor in the constitution of the meniscus and its frena, the articular surfaces, the capsule and the ligaments. This constitutes not only an embryological but also a functional entity. The joint runs the risk of paying heavily for this functional availability, by its relationship with the ear-drum which is a potentially infectious cavity. In fact, at birth there is still evidence of the original branchial continuum between the unknit tympanal and squamosal in the shape of the posterior meniscal frenum, the conjunctivo-vascular isthmus which puts the vascularization of the mucosa of the ear-drum in communication with the very rich vascularization of the neonatal temporo-mandibular articulation. Therefore, 1/3 of the so-called congenital temporo-mandibular ankyloses, apparently without cause, could probably be explained by the otomeniscal relationship existing in the new-born baby and continuing during the first few months of life in the atmosphere in the form of a conjunctivo-vascular link.