A study of the discomalleolar ligament in the adult human.

The discomalleolar ligament (Pinto's ligament) is not described in the anatomy textbooks but was demonstrated by Pinto and others. This is a ligamentous structure connecting the malleus in the tympanic cavity and the articular disc and capsule of the temporomandibular joint. This anatomical relationship between the middle ear and the temporomandibular joint is supposed to be one of the explanations for the aural symptoms associated with temporomandibular joint dysfunction. The objectives of our study were to determine: (1) the frequency of occurrence and morphology of the discomalleolar ligament, (2) its attachments, (3) the morphology of Pinto's ligament in endoscopic visualisation, and (4) whether tension applied to the discomalleolar ligament could elicit movement of the malleus. Fourteen adult human temporomandibular joint and tympanic cavity specimens were examined with the use of an endoscope and then by gross dissection with the superior approach and with the use of the operating microscope. Endoscopic visualisation showed in four cases a band of tissue in the upper temporomandibular joint compartment, known as Pinto's ligament. The dissections exposed a discomalleolar ligament in 11 specimens. We were able to identify two main types of this ligament on the basis of its shape. The discomalleolar ligament was either triangular in shape, as in the first group of seven specimens, or longitudinal in shape, as in the second group of four specimens. We observed that tension applied to the discomalleolar ligament resulted in movement of the malleus in three specimens.