The effect of a mandibular advancement appliance on cervical lordosis in patients with TMD and cervical pain

Aims: A preliminary study to compare cervical lordosis by means of cervical cephalometric analysis, before and after six months of continuous mandibular advancement appliance (MAA) use, and to show how physical therapy posture re-education would improve the cervical lordosis angle.

Methodology: Twenty-two female patients with temporomandibular disorders (TMD) and cervical pain with lordosis <20° were included. Patients had to have a muscle pain history for at least six months, and with an intensity ≥6, measured by means of a visual analog scale (a horizontal 0–10 numeric rating scale with 0 labeled as ‘no pain’ and 10 as ‘worst imaginable pain’). Patients had to present the angle formed by the posterior tangents to C2 and C7 of equal or less than 20°. Cephalometric and clinical diagnostics were performed initially (baseline) and at the end of the study period (six months). During the third month with MAA treatment, a physical therapist evaluated the postural deficit and performed a program of postural re-education. Angular and linear dimension data presented a normal distribution (P>0.05; Shapiro Wilk Test), so the paired comparison of the cephalometric measurements was made by t-test for dependent samples.

Results: Angle 1 (OPT/7CVT); angle 3 (CVT/EVT) and angle 4 (2CL/7CL) showed a significant increase in the cervical lordosis. Angle 2 (MGP/OP), angle 5 (HOR/CVT) and the distances C0–C2 and Pt–VER, presented no significant changes.

Conclusions: The increase in cervical lordosis implies that six months of continuous MAA use, together with a program of postural re-education, promotes the homeostasis of the craniocervical system.