Development of Novel Mandibular Advancement Device for Obstructive Sleep Apnea: Analysing Force Distribution and Deformation Through Finite Element Study.

BACKGROUND

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder involving repeated airway collapse during sleep. Mandibular advancement devices (MADs) serve as an effective alternative treatment for treating mild to moderate OSA, yet many commercially available devices remain unaffordable.

OBJECTIVES

The study aimed to: (1) survey clinicians' and patients' preferences for MAD characteristics, (2) design a novel MAD (KKU-MAD) accordingly, and (3) analyse stress distribution and deformation in the MAD under four simulated scenarios.

METHODS

Preferences were gathered from dental sleep clinicians and OSA patients via survey. A 3D skull model was constructed from dental CBCT data. KKU-MAD, fabricated from polymethyl methacrylate (PMMA), underwent finite element analysis (FEA) in scenarios involving mandibular protrusion, protrusion with clenching, protrusion with lateral grinding at 50% and 100% protrusion under maximal contraction of relevant muscles.

RESULTS

Survey results indicated clinicians preferred custom-made, duobloc, and titratable MADs, while patients prioritised comfort and affordability. FEA revealed consistent von Mises stress concentration at the medial aspect of the lateral fins and anterior corners of the protrusive buttons, peaking during lateral grinding (77.40 MPa) at 100% protrusion. Lower stress levels were recorded during protrusive clenching (61.62 MPa) and protrusion alone (49.46 MPa), with stress reductions of over 50% at 50% protrusion. Deformation was greatest at the lower anterior aspect of the mandibular splint during lateral grinding at 100% protrusion (0.68 mm). Despite elevated stress during complex movements, all values were below PMMA's tensile strength.

CONCLUSIONS

KKU-MAD exhibits favourable biomechanical resilience against clenching and grinding, though further studies on effects to teeth, alveolar bone and temporomandibular joint are necessary before clinical trials in OSA patients.