The effect of passive clear aligners on masticatory muscle activity in adults with different levels of oral parafunction

BackgroundThere is limited knowledge of the possible side‐effects of clear aligners on jaw function.ObjectivesTo determine the short‐term effect of passive clear aligners (PCAs) on masticatory muscle activity (MMA), occlusal discomfort (OD) and temporomandibular disorder (TMD) symptoms in adults with different levels of self‐reported oral parafunction.Materials and MethodsParticipants were screened for oral parafunctional behaviours using the oral behavioural checklist. Respondents in ≥85th and ≤15th percentiles were invited to participate and allocated to a high (HPF: N = 15) or low (lower parafunction [LPF]: N = 16) parafunction group. Participants underwent a TMD clinical examination; somatisation and somatosensory amplification were assessed by questionnaires; OD and stress were assessed by visual analogue scales. While wearing PCAs, awake‐time MMA was assessed three times over 9 days using a wearable electromyography device, along with OD, stress and TMD symptoms.ResultsThe wearing of PCAs was associated with a significant decrease in mean contraction episode amplitude in both groups (p = 0.003). OD levels increased and remained raised in all participants after insertion of the PCAs (p