Comorbid Insomnia and Sleep-Disordered Breathing in Painful Temporomandibular Disorders: Association With Pain...

Sleep disturbances are common in temporomandibular disorders (TMD), yet insomnia-related complaints are often treated as homogeneous despite frequent co-occurrence with sleep-disordered breathing. This study examined whether sleep-pain relationships differ between insomnia alone and comorbid insomnia and sleep-disordered breathing (COMISA) in patients with chronic TMD-related orofacial pain.

In this cross-sectional study, 50 adults with chronic TMD pain were classified as having insomnia alone (n = 20) or COMISA (n = 30) using validated questionnaires and overnight pulse oximetry. Pain intensity (VAS), pain frequency (days/week), circadian pain patterns, subjective sleep quality (PSQI) and objective nocturnal respiratory and autonomic parameters were assessed. Group comparisons and within-group linear regression analyses were performed.

Pain intensity did not differ between groups (7.45 ± 1.67 vs. 7.33 ± 1.90; p = 0.95). Patients with COMISA reported more frequent pain (3.37 ± 1.35 vs. 2.55 ± 1.19 days/week; p = 0.04) and more frequent morning pain (93.3% vs. 50.0%; p < 0.001). Subjective sleep quality was associated with pain intensity in COMISA (B = 0.200, r = 0.417, p = 0.022) but not in insomnia alone (p = 0.353). In COMISA, lower minimum nocturnal oxygen saturation (p = 0.043) and maximum nocturnal heart rate (p = 0.021) were associated with pain intensity; no such associations were observed in insomnia alone.

Sleep-pain relationships in chronic TMD vary by sleep phenotype. These findings support the need for further investigation of COMISA in relation to pain, particularly in orofacial pain and TMD populations.