Sleep Quality and Comfort Reported by Sleep Bruxism Individuals Wearing the Occlusal Splint and Mandibular Advancement Splint: Revisiting Two Crossover Studies.

PURPOSE: To assess (1) whether an occlusal splint (OS) or mandibular advancement splint (MAS) allowed better sleep quality and was more comfortable in individuals with sleep bruxism (SB); and (2) the relationship between sleep quality, comfort, and reduction in RMMA related to SB. MATERIALS AND METHODS: Polysomnographic data from 21 SB subjects (mean ± SD age 25.6 ± 4.5 years) collected in two previous studies were compared. Morning self-reports on sleep quality and comfort of the oral device, polysomnographic data, and RMMA index data from no-device nights were compared to nights using an OS or MAS. The reduction ratio of the RMMA index was calculated for both devices. A responder to the oral device was identified when the RMMA index was less than 2 and when it showed a reduction of at least 50% from the no-device control night. RESULTS: Self-reports for sleep quality and comfort of the oral device showed a mild advantage of the OS when compared to the MAS (r2 = 0.47, r2 = 0.32; P ≤ .01). In responders, the MAS induced a greater reduction in the RMMA index (P = .03) than the OS. CONCLUSIONS: In the short term, the comfort of the oral device seemed to influence sleep quality in SB individuals. However, despite the slightly higher degree of comfort offered by the OS, the MAS induced a greater effect on the RMMA index. Int J Prosthodont 2022;36:138-147. doi: 10.11607/ijp.7525.

Oral appliances reduce masticatory muscle activity-sleep bruxism metrics independently of changes in heart rate variability.

OBJECTIVES: Sleep bruxism (SB) is associated with physiological activities including sympathetic autonomic system dominance and sleep micro-arousal. While oral appliances (OA) are used to prevent SB harmful effects, the influence of OAs physiological mechanisms during sleep is unknown. The aim of this study is to assess whether heart rate variability (HRV) changes, as a marker of autonomic nervous system activity, would be associated with the OA mechanism of action on SB using occlusal splint (OS) and mandibular advancement splint (MAS). MATERIALS AND METHODS: A retrospective analysis, from data previously collected in 21 participants with SB (25.6 ± 4.5 years) with polysomnographic recordings, was done. HRV data were compared between a reference night (no-device) and ones during which OS or MAS was used in a crossover study design. Rhythmic masticatory muscle activity (RMMA) index was compared between nights. HRV was evaluated using autoregressive model analysis for three sections: baseline (distance from RMMA), immediately before, and after RMMA period. RESULTS: A significant reduction in RMMA index, when wearing OA during sleep, was observed (P < 0.01), but was not associated with HRV parameters change. HRV significantly changed after RMMA onset for nights with OA during non-REM sleep in comparison with baseline (P < 0.02). CONCLUSIONS: The usage of OAs for SB participants reduced RMMA, but most likely independently of changes in HRV linked to the mechanism associated with SB genesis. CLINICAL RELEVANCE: Wearing OA seems to reduce grinding noise and protect from dental injuries but does not seem to influence SB genesis.

Effect of an adjustable mandibular advancement appliance on sleep bruxism: a crossover sleep laboratory study.

PURPOSE: The objective of this experimental study was to assess the efficacy and safety of a reinforced adjustable mandibular advancement appliance (MAA) on sleep bruxism (SB) activity compared to baseline and to a mandibular occlusal splint (MOS) in order to offer an alternative to patients with both tooth grinding and respiratory disorders during sleep. MATERIALS AND METHODS: Twelve subjects (mean age: 26.0 +/- 1.5 years) with frequent SB participated in a short-term (three blocks of 2 weeks each) randomized crossover controlled study. Both brain and muscle activities were quantified based on polygraphic and audio/video recordings made over 5 nights in a sleep laboratory. After habituation and baseline nights, 3 more nights were spent with an MAA in either a slight (25%) or pronounced (75%) mandibular protrusion position or with an MOS (control). Analysis of variance and Friedman and Wilcoxon signed-rank tests were used for statistical analysis. RESULTS: The mean number of SB episodes per hour was reduced by 39% and 47% from baseline with the MAA at a protrusion of 25% and 75%, respectively (P < .04). No difference between the two MAA positions was noted. The MOS slightly reduced the number of SB episodes per hour without reaching statistical significance (34%, P = .07). None of the SB subjects experienced any MAA breakage. CONCLUSION: Short-term use of an MAA is associated with a significant reduction in SB motor activity without any appliance breakage. A reinforced MAA design may be an alternative for patients with concomitant tooth grinding and snoring or apnea during sleep.