Neck and jaw dysfunctions in somatosensory tinnitus: Clinical insights and implications

Tinnitus is known to be influenced by many different factors, such as hearing loss and stress or anxiety. In about 25% of tinnitus sufferers, dysfunctions of the cervical spine or temporomandibular area influence the tinnitus percept, then known as somatic or somatosensory tinnitus (ST). Previous research has provided diagnostic criteria for ST that are focused on medical history, but it is not yet clear if we can also recognise patients with ST based on the type of cervical spine or temporomandibular dysfunctions that are present. This cross-sectional study, therefore, aims to investigate which cervical spine and temporomandibular dysfunctions are present in patients diagnosed with ST to aid future diagnosis and treatment of ST.

Patients diagnosed with ST performed a series of assessments for the neck and the jaw, consisting of questionnaires (Neck Bournemouth Questionnaire (NBQ) and Temporomandibular Disorder (TMD) Pain Screener), joint repositioning accuracy (JRA) and range of motion (ROM) tests, strength and coordination tests, and the determination of the presence of active myofascial triggerpoints. In addition, the severity of the tinnitus distress and the hearing level of the ST patients were assessed using the Tinnitus Functional Index (TFI) and Pure Tone Audiometry (PTA) testing, respectively.

In total, 161 ST patients completed the study protocol. The results of the cervical spine assessment indicate that ST patients generally score high on the NBQ and are likely to present cervical dysfunctions on the level of JRA, ROM, or coordination and strength of the DNF, DNE, and scapula stabilizers. The majority (95%) had at least one active myofascial trigger point, and 25% experienced active myofascial trigger points in all tested neck muscles. Half of the sample showed active myofascial trigger points in the jaw muscles. Additionally, ST patients showed a lower ROM of the jaw, especially for protrusion.

Patients with ST present with cervical spine and temporomandibular dysfunctions related to active myofascial trigger points, reduced JRA of the cervical spine, restricted ROM, and decreased coordination or strength of the neck muscles. The presence of these complaints is also reflected in increased scores on the NBQ or TMD pain screener questionnaires. Given the study's substantial heterogeneity in dysfunctions among ST patients, a thorough clinical assessment remains essential to guide the multimodal examination.