Impact of clear aligner therapy on tooth pain and masticatory muscle soreness

Abstract

Background: Clinical findings suggest that orthodontic treatment with clear aligners (clear aligner therapy/CAT) may cause masticatory muscle soreness in some patients. Objective: This multi-site prospective study investigated tooth pain and masticatory muscle soreness and tenderness in patients undergoing CAT and explored whether psychological traits affected these outcomes. Methods: Twenty-seven adults (22F, 5M; mean age ± SD=35.3 ± 17.6 years) about to start CAT were recruited at three clinics. During CAT, they reported on 100-mm visual analogue scales their tooth pain, masticatory muscle soreness and stress three times per day over 4 weeks (week 1 = baseline; week 2 = dummy aligner; week 3 = first active aligner; week 4 = second active aligner). Pressure pain thresholds (PPTs) were measured at the masseter and temporalis at baseline and after week 4. Mixed models were used to evaluate the outcome measures over time. Results: Clear aligner therapy caused mild tooth pain, which was greater with the passive than the first and second active aligners (both P < .001). Mild and clinically not relevant masticatory muscle soreness was produced by all aligners (all P < .05), with the first active aligner producing less soreness than the dummy aligner (P < .001). PPTs did not change significantly after 4 weeks. Both tooth pain and masticatory muscle soreness were affected by stress and trait anxiety, whilst muscle soreness was affected also by oral behaviours. Conclusions: In the short term, CAT produces tooth pain and masticatory muscle soreness of limited significance. Frequent oral behaviours are related to increased masticatory muscle soreness during CAT. The medium-and long-term effects of CAT should be further explored.

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

“…In agreement with past research, the wearing of PCAs was sufficient to cause OD, with both groups experiencing an increase in OD after insertion of the PCAs on Aligner Day 1 40 . By Aligner Day 8, reductions in OD were recorded in all participants, indicating that some form of habituation to the aligners was taking place over time 3,40 …”

“…No significant change in reported TMD symptoms occurred in either group in response to the PCAs. Transient increases in muscle tenderness without progression to TMD development have been reported in response to CAT 40 . Although masticatory muscle pain was not objectively assessed in our study, the lack of change in TMD symptom scores over time indicates the PCAs did not influence TMD development in the short‐term.…”

“…Finally, the decrease in episode amplitude after insertion of the PCAs could be related to the parallel increase in OD in all participants. OD and pain in response to clear aligners have been reported by others, 3,40 with reduced MMA in response to discomfort recognised as a form of tooth contact avoidance behaviour. 37,41 The possibility of a negative association between OD and MMA is reinforced by the significantly greater rise in OD in the HPF group, which corresponds to a larger fall in episode amplitude in these individuals.…”

“…40 By Aligner Day 8, reductions in OD were recorded in all participants, indicating that some form of habituation to the aligners was taking place over time. 3,40 The HPF participants had significantly higher SQ scores than the LPF group. This suggests that individuals with high self-reported oral parafunction also had a greater tendency towards somatisation-a finding supported by others.…”

The association between orthodontic treatment and temporomandibular disorders diagnosis and disease characteristics

“…57 A recent study also found that clear aligners use may cause temporary jaw pain, but no patient developed TMD and the effect was transient. 58…”