Pathogenesis of post-traumatic ankylosis of the temporomandibular joint: a critical review.

Many factors have been implicated in the development of bony ankylosis following trauma to the temporomandibular joint (TMJ) or ankylosis that recurs after surgical treatment for the condition. Although many reports have been published, to our knowledge very little has been written about the pathogenesis of the process and there are few scientific studies. Over the last 70 years various treatments have been described. Different methods have been used with perceived favourable outcomes although recurrence remains a problem in many cases, and ankylosis presents a major therapeutic challenge. We present a critical review of published papers and discuss the various hypotheses regarding the pathogenesis of the condition.

Communication of the anterior branch of the great auricular nerve with the marginal mandibular nerve: A prospective study of 25 neck dissections.

The great auricular nerve originates from the cervical plexus (C2, 3) and supplies sensation to the lower part of the pinna and the skin overlying the angle of the mandible. We have previously reported an unusual anatomical variant where the anterior division of the great auricular nerve passed into the submandibular triangle and was joined on its deep surface by the marginal mandibular division of the facial nerve. We now report a prospective study of 25 neck dissections in which a meticulous search for this variant resulted in the same communication between the great auricular nerve and the marginal mandibular division of the facial nerve being found in one further patient (an incidence of 2/25 patients in our series). Although communications between the transverse cervical nerve and the cervical branch of the facial nerve are well known, we have found that the marginal mandibular nerve can also be joined by the cervical plexus. This may have clinical implications during operations on the neck, particularly as stimulation of a communicating nerve of the cervical plexus might result in depression of the lip, and could potentially cause the operating surgeon to think that it was a branch of the facial nerve. We think that this finding merits a cadaveric study to evaluate the relation more fully.