Oral appliance (OA_m) therapy has demonstrated efficacy in treating obstructive sleep apnea (OSA). The aim of this systematic review was to clarify the efficacy of device designs (Mono-block or Bi-block) in OA_m therapy for OSA patients. We performed a meta-analysis using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Two studies (Mono-block OA_m versus Bi-block OA_m) remained eligible after applying the exclusion criteria. When comparing Mono-block OA_m and Bi-block OA_m, Mono-block OA_m significantly reduced the apnea–hypopnea index (2.92; 95% confidence interval (95%CI), 1.26 to 4.58; p = 0.0006), and patient preference for Mono-block OA_m was significantly higher (2.06; 95%CI, 1.44 to 2.06; p < 0.0001). Lowest SpO₂, arousal index, non-REM stage 3, sleep efficiency, Epworth Sleepiness Scale (ESS), Snoring Scale, and side effects were not significantly different between the two groups (lowest SpO₂: −11.18; 95%CI, −26.90 to 4.54; p = 0.16, arousal index: 4.40; 95%CI, −6.00 to 14.80; p = 0.41, non-REM stage 3: −2.00; 95%CI, −6.00 to 14.80; p = 0.41, sleep efficiency: −1.42, 95%CI, −4.71 to 1.86; p = 0.40, ESS: 0.12; 95%CI, −1.55 to 1.79; p = 0.89, Snoring Scale: 0.55; 95%CI, −0.73 to 1.83, p = 0.55, side effects: 1.00, 95%CI, 0.62 to 1.61, p = 1.00). In this systematic review, the use of Mono-block OA_m was more effective than Bi-block OA_m for OSA patients.

This systematic review clarifies the amount of effective protrusion in mandibular advancement devices of oral appliances required for obstructive sleep apnea (OSA). The systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Review Manager 5 and GRADEpro were used to combine trials and analyze data. The present review included three studies. In mild to moderate OSA cases, measured using the apnea–hypopnea index (AHI), 50% protrusion was more effective than 75% protrusion. However, 75% protrusion was more effective for severe cases. Sleep stage, Epworth Sleepiness Scale (ESS), snoring index, and side effects significantly differed between the groups. Additionally, 75% protrusion was more effective (AHI: 0.38, 95% CI: −0.89 to 1.65, p = 0.56; sleep stage 3: −1.20, 95% CI: 9.54–7.14, p = 0.78; ESS: 1.07, 95% CI: −0.09 to 2.24, p = 0.07; snoring index: 0.09, 95% CI: 0.05–0.13, p < 0.05; side effects: RR: 1.89, 95% CI: 0.36–9.92, p = 0.45). As per the AHI, 75% protrusion was effective in severe cases, whereas 50% protrusion was effective in moderate cases. Analysis of different surrogate outcomes indicated that 75% protrusion was more effective. Further, well-designed, larger trials should determine the benefits for patients. Additionally, investigations of adherence and side effects with long-term follow-up are needed.

There are no studies on the prevention of temporomandibular joint and/or masticatory muscle pain (TMD pain) associated with oral appliance (OA) therapy in patients with obstructive sleep apnea (OSA). The aim of this study was to determine the effect of jaw-opening exercise on TMD pain associated with OA therapy in OSA patients. Twenty-five OSA patients without pain-related TMD were consecutively enrolled into a two-arm, randomized, double-blind, placebo-controlled trial. One group performed jaw-opening exercise (JE, n=13), and the other group performed placebo exercise (PE, n=12) for 1-month, and had started 2-weeks prior to insertion of an adjustable OA. TMD sign using the Research Diagnostic Criteria for Temporomandibular Disorders and TMD pain intensity using a visual analog scale (VAS) in the morning and daytime were evaluated at baseline (pre-exercise) and at 2-weeks, 1-month, and 3-months after OA insertion. Pain-related TMD was not observed in the JE-group at all evaluation periods, although one subject in the PE-group was diagnosed with arthralgia at the 1-month evaluation. The JE-group showed lower morning and daytime VAS scores than the those of the PE-group at all evaluation periods, and significant group differences were found in terms of chewing pain and jaw-opening pain in the morning at the 1-month evaluation, and of jaw-opening pain during daytime at the 3-month evaluation (P<0.05). Within the limitations of the study, jaw-opening exercise prior to OA therapy reduced the risk of TMD pain associated with OA use. Therefore, jaw-opening exercise may contribute to the prevention of TMD pain.

This study aimed to analyze the efficacy of maxillary oral appliance (MOA) designs on respiratory variables during sleep. At baseline, 23 participants underwent a sleep test with a portable device for two nights and were categorized as participants with mild obstructive sleep apnea (mild-OSA) (n = 13) and without OSA (w/o-OSA) (n = 10). Three types of MOAs, standard-OA (S-OA), palatal covering-OA (PC-OA), and vertically increasing-OA (VI-OA), were each worn for three nights, and sleep tests with each MOA were performed with a portable device for two nights. Based on the average of the respiratory event index (REI) values for the two nights for each MOA, w/o-OSA participants with an REI ≥ 5.0 were defined as the exacerbation group and those with an REI < 5.0 as the non-exacerbation group. In mild-OSA participants, an REI ≥ 15.0 or REI ≥ baseline REI × 1.5 were defined as the exacerbation group and those with an REI < 15.0 and REI < baseline REI × 1.5 were defined as the non-exacerbation group. The percentage of the exacerbation and non-exacerbation groups with MOA was evaluated in the w/o-OSA and mild-OSA participants. The maxillary and mandibular dental-arch dimension was compared by dentition model analysis. The exacerbation group in w/o-OSA participants (n = 10) comprised 10.0% participants (n = 1) with S-OA, 40.0% (n = 4) with PC-OA, and 30.0% (n = 3) with VI-OA. The exacerbation group in the mild-OSA participants (n = 13) comprised 15.4% subjects (n = 2) with S-OA, 23.1% (n = 3) with PC-OA, and 23.1% (n = 3) in VI-OA. In the model analysis for w/o-OSA, the posterior dental arch width was significantly greater in the exacerbation group than in the non-exacerbation group wearing S-OA (p < 0.05). In addition, the ratio of the maxillary to mandibular dental arch width (anterior dental arch width) was significantly greater in the exacerbation group than in the non-exacerbation group for both PC-OA and VI-OA (p < 0.05). In mild-OSA, the maxillary and mandibular dental arch lengths and the ratio of maxillary to mandibular dental arch width (posterior dental arch width) were significantly smaller in the exacerbation group than in the non-exacerbation group for S-OA (p < 0.05). This study confirmed that wearing an MOA by w/o-OSA and mild-OSA participants may increase the REI during sleep and that PC-OA and VI-OA may increase the REI more than S-OA. The maxillary and mandibular dental-arch dimensions may affect the REI when using an MOA.

This study aimed to evaluate the effects of jaw-opening exercises with and without pain on temporomandibular disorders (TMDs), specifically in relation to pain intensity and range-of-mouth opening in patients with TMDs. Participants were randomly assigned to either the jaw-opening exercise with pain (JE w/pain) or the jaw-opening exercise without pain (JE w/o pain) groups, and each exercise was performed for eight weeks. TMDs pain intensity was assessed using a 100-mm visual analog scale (VAS), and the range-of-mouth opening was evaluated at the baseline (T0), 2 weeks (T1), 4 weeks (T2), and 8 weeks (T3). Of the 61 participants, 57 (JE w/pain group, n = 30; JE w/o pain group, n = 27) were included in the analysis. The range-of-mouth opening and TMDs pain intensity improved from T1 to T3 in both groups. The JE w/pain group showed significant differences at T3 compared to T1 (pain-free unassisted mouth opening, p = 0.006; jaw-opening pain, p = 0.014; chewing pain, p = 0.018). In addition, the JE w/pain group showed significantly greater changes in the maximum unassisted mouth opening at T2 and T3 than the JE w/o pain group (T2, p < 0.001; T3, p = 0.003). Thus, jaw-opening exercises, until the occurrence of pain, may be effective in patients with TMDs.

Background: Awake bruxism involves masticatory muscle activity during wakefulness, potentially leading to clinical concerns. Accurate electromyography (EMG) assessment is challenging with brief durations.Objective: To establish a reliable, short‐term measure for nonfunctional masseter muscle activity during wakefulness.Methods: Thirty‐four healthy participants completed the Oral Behavior Checklist (OBC) and were assessed with an EMG logger (FLA‐500‐SD) across three sessions. On Day 1, participants performed four tasks (reading, bead‐grabbing, video watching and math) for 15 min each in random order. On Day 2, scheduled at least 1 week later, tasks were repeated in a different sequence. On Day 3, participants underwent a 7‐h continuous EMG recording during daily activities while maintaining activity diaries. Main outcomes included the mean number of EMG bursts per hour, burst duration, burst peak value relative to maximum voluntary contraction (%MVC) and integral value (μV.s, %MVC.s).Results: Participants (mean age: 28.0 ± 3.1) scored low on AB likelihood per partial OBC results, contrasting with EMG activity levels. Significant differences in EMG parameters were noted across tasks, with consistent values between Days 1 and 2. The reading, video, and math tasks showed strongest correlations with long‐term EMG measurements (r_s = 0.62–0.66, p < 0.001). Reading task demonstrated high test–retest reliability (ICC > 0.9), with the highest specificity (100%) and positive predictive value, though sensitivity was limited compared with long‐term AB measures.Conclusions: EMG measurements during a 15‐min reading task may correspond to prolonged monitoring, suggesting the potential for short‐task EMG assessments in practice. Integrating such assessments might enhance diagnostic accuracy, although judgement remains essential.