Anatomic relations of the medial aspect of the temporomandibular joint

Complete pterygoidectomy--a novel method for the topographical investigation of the deep masticator space and its contents

The complexity of the topographical anatomy of the infratemporal fossa (=masticator space) remains underappreciated because of limitations of the methods used to expose it; these methods are described and critiqued. The disposition of the lateral pterygoid (LPt) muscle in the masticator space obscures the anatomical relations of clinically significant neurovascular structures. Controversies regarding the nerve supply and actions of the two LPt heads are summarized. Since the LPt has been implicated in temporomandibular (joint) dysfunction (TMD), its precise relationships to the mandibular neurovascular structures is essential in understanding its role in TMD. We recently developed a method involving the en bloc removal of the LPt-tensor veli palatini complex along with all vital neurovascular structures. Further investigations using our method--in conjunction with contemporary imaging techniques (CT, MRI)--should help describe the detailed topography of masticatory structures. This information should help in understanding, differential diagnosis, and treatment of TMD.

The distribution of the auriculotemporal nerve around the temporomandibular joint

OBJECTIVE

The purpose of this cadaver dissection was to study the position of the auriculotemporal nerve in relation to the mandibular condyle, capsular tissues, articular fossa, and lateral pterygoid muscle and to evaluate the anatomic possibility of nerve impingement or irritation by the surrounding structures.

STUDY DESIGN

Eight cadaveric heads (16 sides) were dissected. The auriculotemporal nerve was identified by following its course around the middle meningeal artery. The course of the nerve trunk was dissected from the middle meningeal artery to the terminal branches within the temporomandibular disk. The horizontal distance between the auriculotemporal nerve and the medial portion of the condyle/condylar neck was measured. The vertical distance from the most superior portion of the articular condyle to the superior border of the auriculotemporal nerve was measured.

RESULTS

The auriculotemporal nerve was identified on each side, and a single trunk was evident along the medial aspect of the condylar neck. At the posterior border of the lateral pterygoid muscle, the nerve trunk was in direct contact with the condylar neck in every specimen. The average vertical distance between the superior condyle and the nerve was 7.06 mm (+/- 3.21 mm); the range was 0 to 13 mm. The vertical distance between the nerve and the superior condyle on one side of the specimen did not correlate with the distance on the contralateral side.

CONCLUSION

The auriculotemporal nerve trunk has a close anatomic relationship with the condyle and the temporomandibular joint capsular region, and there is evidence of a possible mechanism for sensory disturbances in the temporomandibular joint region. In all cases, the nerve was in direct contact with the medial aspect of the capsule or condylar neck. Because there is no correlation between the positions of the nerves on the right and left sides, only one side may be affected. The nerve was also observed to course in direct apposition to the lateral pterygoid muscle. The findings support the hypothesis that the anatomic and clinical relationship of the auriculotemporal nerve to the condyle, articular fossa, and lateral pterygoid muscle may be causally related to compression or irritation of the nerve, producing numbness or pain, or both, in the temporomandibular joint region.

Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

Dental research continued to grow during 1988. Unfortunately the quality does not always parallel the quantity of publications. This report obviously does not encompass all of the literature but focuses on studies that are related to trends and to matters that are considered controversial. Likewise the particular interests of the members of the American Academy of Restorative Dentistry were taken into consideration. The subjects covered include periodontics, preventive dentistry, bulp biology, craniomandibular disorders, ceramics, color in restorative dentistry, and dental materials.