10Somatosensory and TMJ Bedside Assessment

FWhy a sound can be moved by a muscle

Tinnitus is usually thought of as a purely auditory event, yet in many people the percept changes when they clench the jaw, press on the neck or turn the head. This is somatosensory tinnitus: trigeminal and upper-cervical (C1–C3) sensory afferents converge on the dorsal cochlear nucleus and onward auditory pathway, and when that somatic input is altered the auditory percept shifts with it [1999].

Recognising this matters because it reframes the problem. A noise that the patient can modulate by a deliberate movement is, by definition, partly generated outside the ear — and the offending structure (a strained neck, a dysfunctional temporomandibular joint) may itself be treatable [2011].

TThe Levine somatic manoeuvre set

The bedside test is a brief, standardised set of forceful somatic manoeuvres performed against resistance while the patient reports any change in tinnitus loudness, pitch or quality. The classic Levine battery includes: a strong jaw clench; jaw protrusion and lateral excursion; forceful head rotation, flexion and extension against the examiner’s hand; shoulder abduction against resistance; and firm pressure over the temporalis, masseter and suboccipital muscles [2008].

Each contraction is held for several seconds at near-maximal effort — weak movements rarely modulate. A clinically meaningful result is a clear, reproducible increase, decrease or pitch change, not a vague "maybe." Document which manoeuvre worked and in which direction, because that localises the contributing system.

TExamining the TMJ and the cervical spine

If jaw manoeuvres modulate the tinnitus, examine the temporomandibular joint properly: palpate the joint and the muscles of mastication for tenderness, watch for deviation or clicking on opening, and note bruxism wear or malocclusion. TMJ disorders are over-represented among tinnitus patients and define a recognisable subgroup [2011].

If neck manoeuvres modulate it, test cervical range of motion in all planes, palpate the suboccipital and upper-trapezius muscles for tender myofascial points, and look for restricted segmental movement. A panel of clinical cervical-spine tests has measurable diagnostic value for identifying cervicogenic somatic tinnitus [2015].

CFrom a positive test to a treatment plan

A positive somatic modulation test is a referral signal, not an endpoint. Jaw-dominant modulation with TMJ signs points toward dental or orofacial-pain assessment, occlusal management and jaw-relaxation work; neck-dominant modulation points toward physiotherapy, postural correction and manual therapy [2017].

Set expectations honestly: somatic treatment helps a selected subgroup and rarely abolishes long-standing tinnitus completely, but it can reduce intrusiveness and gives the patient an active role [2013]. A negative test does not exclude tinnitus — it simply means the somatosensory lever is not available in this patient.