Trigeminal impingement syndrome: the relationship between atypical trigeminal symptoms and anteromedial disk displacement

Temporomandibular joint innervation: Anatomical study and clinical implications

BACKGROUND

Temporomandibular disorders and related pain are commonly seen in clinical practice. Due to its recurrent nature, they adversely affect a patient's social life. Current knowledge on the temporomandibular joint (TMJ) innervation is debatable and insufficient to ensure optimal treatment for the underlying pathology. This study aimed to elucidate the pathophysiology of temporomandibular pain by revealing the TMJ innervation topography, its variations, and its relationships with the surrounding anatomical structures. This will aid in creating a guide for temporomandibular, infratemporal, and preauricular interventions.

METHODS

A total of 20 cadaver half heads, 10 fresh frozen and 10 embalmed, were used. The TMJ nerves were dissected together with the surrounding anatomical structures.

RESULTS

We showed that the TMJ is mainly innervated by the auriculotemporal nerve posteriorly, the masseteric nerve anteriorly, the posterior deep temporal nerve anteromedially, and the TMJ branch originating directly from the mandibular nerve medially, and that there are variations in these innervation pathways. Additionally, we emphasized how these nerves might be affected in certain clinical conditions based on their anatomical relationships and pathophysiological mechanisms. To our knowledge, this is the first study showing the existence of a branch of the mandibular nerve directly innervating the TMJ.

CONCLUSION

In light of our findings, elucidating TMJ pain based on the anatomical characteristics of the region will allow precise treatment algorithms and better clinical outcomes in these patients. Based on this study, new clinical studies and interventions can be designed to reduce healthcare costs and alleviate the burden of temporomandibular disorders.

Impact of Temporomandibular Joint Complaints on Tinnitus-Related Distress

There is increasing evidence of associations between the presence of temporomandibular joint (TMJ) disorders and tinnitus. It has been recently proposed that tinnitus patients with TMJ complaints could constitute a subtype, meaning a subgroup of tinnitus patients responsive to specific treatments. Tinnitus patients with TMJ complaints are often young women with somatosensory features of their tinnitus. Here, we investigate the socio-economic factors, phenotypic characteristics and psychological variables of tinnitus subjects from the Swedish Tinnitus Outreach Project, with (n = 486) or without (n = 1,996) TMJ complaints. The prevalence of TMJ complaints was greater in tinnitus subjects with severe tinnitus (36%) when compared to those with any tinnitus (19%), strongly indicating the contribution of TMJ problems to the severity of tinnitus. Comparing subgroups with or without TMJ complaints in the whole sample, differences were found regarding a large number of socioeconomic, phenotypic, and psychological characteristics. Subjects with TMJ complaints were more often women, more often reported stress as the cause of tinnitus, were more severely affected by tinnitus, scored worse in measures of psychological well-being and life quality, and were more often affected by problems tolerating sounds, headache, vertigo/dizziness, and neck pain. In addition, they more often reported pulsating and tonal tinnitus, somatic modulation of tinnitus, and aggravation of tinnitus by loud sounds and stress. When focusing the analysis in subjects with tinnitus as a big problem using the Tinnitus Functional Index cut-off ≥ 48, or with severe tinnitus according to the Tinnitus Handicap Inventory cut-off ≥ 58, the impact of somatosensory modulations and stress on tinnitus were greater in subjects with TMJ complaints in comparison to those without. In light of these results, we hypothesize that stress could contribute to the co-occurrence of TMJ problems and tinnitus and also to the development of severe tinnitus. Our study supports the need of involving dental care and stress management in the holistic treatment of patients with severe tinnitus.

Trigeminal Neuralgia, Glossopharyngeal Neuralgia, and Myofascial Pain Dysfunction Syndrome: An Update

Neuropathic pain is a common phenomenon that affects millions of people worldwide. Maxillofacial structures consist of various tissues that receive frequent stimulation during food digestion. The unique functions (masticatory process and facial expression) of the maxillofacial structure require the exquisite organization of both the peripheral and central nervous systems. Neuralgia is painful paroxysmal disorder of the head-neck region characterized by some commonly shared features such as the unilateral pain, transience and recurrence of attacks, and superficial and shock-like pain at a trigger point. These types of pain can be experienced after nerve injury or as a part of diseases that affect peripheral and central nerve function, or they can be psychological. Since the trigeminal and glossopharyngeal nerves innervate the oral structure, trigeminal and glossopharyngeal neuralgia are the most common syndromes following myofascial pain dysfunction syndrome. Nevertheless, misdiagnoses are common. The aim of this review is to discuss the currently available diagnostic procedures and treatment options for trigeminal neuralgia, glossopharyngeal neuralgia, and myofascial pain dysfunction syndrome.