Anatomical Relations: Discomalleolar Ligament, Temporomandibular Joint and the Middle Ear

The discomalleolar ligament connects the malleus to the medium and posterosuperior portions of the capsule and the articular disk of the temporomandibular joint (TMJ). Some researchers consider that this ligament is part of the anterior malleolar ligament or a superior extension of the sphenomandibular ligament; whereas other authors consider it as being intrinsic to the TMJ. The discussions concerning this ligament are due to the difficulty of performing its dissection. Objective: Thus, this study has the goal of demonstrating this ligament in anatomical material of fetuses and adults, as well as the existing relation between the TMJ and the middle ear. Methods: A total of 4 fetuses (males) and 2 human heads (males, average age 40 years) were fixed in formalin and sectioned in the medial saggital plane. Dissection was done by planes through the lateral region of the head and the middle cranial fossa. The associated structures were removed until reaching the region of the TMJ and middle ear. Results: After dissection, we observed that the discomalleolar ligament is independent from the anterior malleolar ligament and from the sphenomandibular ligament, and is closely related to the TMJ and the middle ear. Conclusion: It is concluded that, in fetuses, there is a mechanical relation between the TMJ and the middle ear, in which the traction of the discomalleolar ligament leads to the movement of the malleus. In adults, the ligament allows the communication of the middle ear with the ATM without any mechanical action. The presence of this ligament, in both fetuses and adults, may be a risk factor in the dissemination of infection from one area to the other.