Effect of mandibular advancement splint therapy on cardiac autonomic function in obstructive sleep apnoea.

PURPOSE: This study aimed to evaluate the effect of mandibular advancement splint (MAS) therapy on cardiac autonomic function in patients with obstructive sleep apnoea (OSA) using heart rate variability (HRV) analysis. METHODS: Electrocardiograms (ECG) derived from polysomnograms (PSG) of three prospective studies were used to study HRV of patients with OSA before and after MAS treatment. HRV parameters were averaged across the entire ECG signal during N2 sleep using 2-min epochs shifted by 30 s. Paired t-tests were used to compare PSG and HRV measures before and after treatment, and the percent change in HRV measures was regressed on the percent change in apnoea-hypopnea index (AHI). RESULTS: In 101 patients with OSA, 72% were Caucasian, 54% men, the mean age was 56 ± 11 years, BMI 29.8 ± 5.3 kg/m2, and treatment duration was 4.0 ± 3.2 months. After MAS therapy, there was a significant reduction in OSA severity (AHI, - 18 ± 16 events per hour, p < 0.001) and trends towards increased low-frequency to high-frequency ratio, low-frequency power, and reduced high-frequency power (LF:HF, - 0.4 ± 1.5, p = 0.01; LF, - 3 ± 16 nu, p = 0.02, HF, 3.5 ± 13.7 nu, p = 0.01). Change in NN intervals correlated with the change in AHI (ß(SE) = - 2.21 (0.01), t = - 2.85, p = 0.005). No significant changes were observed in the time-domain HRV markers with MAS treatment. CONCLUSION: The study findings suggest that successful MAS treatment correlates with changes in HRV, specifically the lengthening of NN intervals, a marker for improved cardiac autonomic adaptability.

Mandibular device treatment in obstructive sleep apnea -A structured therapy adjustment considering night-to-night variability night-to-night variability in mandibular devices.

BACKGROUND: Mandibular advancement devices (MAD) are a well-established treatment option for obstructive sleep apnea (OSA). MAD are considered preferably for patients with mild to moderate OSA presenting with a elevated night-to-night variability (NNV). This study aimed to determine the treatment effect of MAD on NNV considering different protrusion distances and patient related outcome (PRO). METHODS: We conducted a prospective cohort analysis of patients before MAD with 60% and 80% of the maximum protrusion. OSA severity was assessed using a home-sleep test for two consecutive nights. PRO contained the Epworth Sleepiness Scale (ESS) and sleep related quality of life (FOSQ). RESULTS: Twenty patients with a median overweight body-mass-index of 27.1 (interquartile range (IQR) 16.3 kg/m²), with a mainly mild to moderate OSA with an apnea -hypopnea index (AHI) of 18.3 / h (IQR 17.7) and elevated ESS of 12.5 (IQR 8.0) were included. As opposed to 80%, 60% protrusion significantly but not 80% relevantly reduced AHI (60%%: 11.2 (IQR 5.5)/h, p = 0.01; 80%: 12.9 (IQR18,0)/h, p = 0.32) and improved the ESS (60%: 8.0 (IQR 10,0); 80%: 10 (IQR 9.0)), with therapy settings. No correlation could be detected between NNV and ESS, and FOSQ changes. Higher baseline NNV was associated with severe OSA (p = 0.02) but not with gender, overweight, or status post-tonsillectomy. CONCLUSIONS: OSA improvement is associated with lower NNV; both OSA and NNV are connected to the degree of protrusion. Therefore, higher NNV does not justify the exclusion of candidates for MAD treatment. PRO changes are not visibly affected by NNV but by general OSA changes. These findings may help to define and optimize future study designs for the primary outcome decision between objective OSA parameters and PRO.

Gender differences in oral appliance treatment of obstructive sleep apnea.

PURPOSE: Although overall success rates for treating obstructive sleep apnea (OSA) with an oral appliance (OA) are high, they are significantly higher among females. To verify published data, the study's purpose was to evaluate a participant sample after one year of OA use. The primary outcome was treatment response, with responders defined as having an apnea-hypopnea index (AHI) < 10 at follow-up and/or reduced by ≥50% of baseline. Secondary measures were from standardized questionnaires. METHODS: A sample of 314 participants, predominately with moderate-to-severe OSA, were enrolled and instructed to use an OA every night. At baseline and one-year follow-up, polygraphic recordings and questionnaires, including sleepiness (measured using the Epworth sleepiness scale) and quality-of-life (measured using the Functional Outcomes of Sleep Questionnaire), were collected. RESULTS: Among the 314 participants, 192 completed the one-year evaluation: 51 females (27%) and 141 males (73%). Overall, OA treatment resulted in 78% and 77% responders among females and males, respectively. Neither the difference in improvement nor the absolute change in AHI differed significantly based on gender, at any OSA severity level. There were no significant gender differences in sleepiness or quality of life. Treatment-related adverse reactions were more common among females. CONCLUSION: Both females and males with OSA respond well to OA therapy, with nonsignificant gender differences in outcomes. Thus, the hypothesis that females respond better to OA treatment is rejected.

Mandibular advancement devices decrease systolic pressure during the day and night in patients with obstructive sleep apnea: A systematic review and meta-analysis.

The aim of this systematic review and meta-analysis was to analyze whether or not mandibular advancement devices (MADs) produce changes in blood pressure in patients with obstructive sleep apnea (OSA) in relation to use time and if the device is used at night or day. MATERIALS AND METHOD: A systematic review of the literature and meta-analysis was carried out in accordance with PRISMA guidelines. In the bibliographic search, a total of four databases were consulted: PubMed-Medline, Scopus, Web of Science, and Cochrane. Of the 622 articles initially revealed, 160 duplicates were eliminated. After applying the selection criteria, 17 articles were included for the qualitative analysis and 4 for the meta-analysis. The studies were combined using a random effects model with the inverse method of variance, determining the mean differences in systolic and diastolic pressure before and after treatment using the MAD splint as the effect size. Day/night circadian effect and treatment time were analyzed using meta-regression with a mixed-effects model. RESULTS: MAD treatment was not found to affect diastolic pressure. By combining the four studies with the control group in a meta-analysis (I2 = 75%; z = - 0.15; p-value = 0.882), the mean difference in diastolic pressure between the MAD group and the control group was estimated at - 0.06 (- 0.86; 0.74). The meta-regression also showed no significant effect of day/night (p = 0.560) or treatment time (p = 0.854) on diastolic pressure. When combining the four studies with the control group (I2 = 84%%; z = - 1.47; p-value = 0.142), a non-significant mean difference in systolic pressure between the MAD group and the control group of - 0.99 (- 2.31; 0.33) was estimated in the meta-analysis. However, when assessing the effect of day/night or treatment time on systolic blood pressure using a meta-regression, the latter showed significant covariates that reduce systolic blood pressure values in the model at night (p < 0.001) and in relation to treatment time (p < 0.001). CONCLUSIONS: Only systolic pressure appears to be affected by the use of the MAD in patients with OSA, and this decrease in systolic pressure is greater at night and when treatment time is longer.

Effects of mandibular advancement devices on the evolution of obstructive sleep apnea.

PURPOSE: Mandibular advancement devices (MADs) are a treatment for obstructive sleep apnea (OSA). Titration is a necessary component of proper fitting of MADs, yet little is known about what happens at each step of the titration. The objectives of this study were to determine the clinical and paraclinical evolution of OSA at every mm of MAD advancement. METHODS: Volunteers were fitted with MADs set to 50% of maximum advancement. MAD clinical and paraclinical results were recorded at every additional mm-titration, including apnea-hypopnea index (AHI), as well as symptoms of sleepiness and fatigue. RESULTS: In 20 volunteers with OSA, the MAD had a significant effect on every polygraphic parameter at the onset of use. The mean AHI with MAD fell by 15.2/h (p < 0.001). The mean Epworth Sleepiness Score and Pichot Fatigue questionnaire with MAD fell by 2.0 (p = 0.0687) and 2.4 (p = 0.1073) respectively. There was no proportionality between clinical gains (drowsiness and fatigue) and AHI improvements. CONCLUSIONS: MADs led to a significant improvement in AHI and other polygraphic parameters from the onset of use. The decrease of clinical symptoms (drowsiness and fatigue) was more complex to interpret because of the small decreases observed. The absence of concordance between AHI improvement and clinical symptoms was nevertheless objectively quantified and symptoms were alleviated with advancements. The findings suggest that it may be appropriate to use clinical symptoms as a main aim of titration, since the improvement in AHI is reached at the onset of MAD use.

Effect of mandibular advancement appliance use on oral and periodontal health in patients with OSA: a systematic review.

STUDY OBJECTIVES: Use of a mandibular advancement appliance (MAA) is an effective treatment option for mild-to-moderate obstructive sleep apnea (OSA). MAA is well-tolerated but undesirable effects may be observed over time. The present systematic review aimed to assess the effect of MAA use on oral and periodontal health in patients with OSA. METHODS: MEDLINE (PubMed), Cochrane, and Scopus were searched for randomized and non-randomized controlled trials (RCTs, NRCTs), cohorts, and case-control studies reporting on side effects of MAA treatment in OSA patients during a follow-up of at least 6 months. RESULTS: From a total of 169 articles screened, 28 were selected. The most frequently reported MAA-related effects on oral health were: hypersalivation (weighted mean prevalence, 33.3%), occlusal changes (30.2%), muscle pain (22.9%), tooth discomfort or pain (20.2%), and xerostomia (18.3%). No MAA-related periodontal effect was reported. The periodontal status prior to MAA treatment was rarely assessed and described, but 5 studies (17.8%) stated that periodontitis was an exclusion criterion for MAA. Only one retrospective study specifically evaluated periodontal parameters and reported no significant changes in periodontally healthy patients with OSA using MAA for over 7 years. CONCLUSION: MAA use is associated with a number of clinical consequences on oral health, but there is no evidence to conclude whether or not MAA affects periodontal health in patients with OSA. This aspect appears to be under-evaluated and should be further investigated in relation to the type of MAA, the duration of treatment, and prior history of periodontitis.

A systematic review on 4D images of the upper airway in patients with OSA.

AIM-BACKGROUND: In the treatment of obstructive sleep apnoea (OSA), oral appliances are now being recognized as a valuable alternative to continuous positive airway pressure (CPAP). Various static imaging techniques of the upper airways allow for assessment of bone and soft tissue structures. However, static images do not capture dynamic airway characteristics. The aim of this paper was to review 4D imaging techniques in patients with OSA. METHODS: PubMed/MEDLINE, Web of Science and Embase were systematically searched for studies published before June 2022. The review was compliant with the PRISMA guidelines. The quality of each eligible study was critically evaluated by all four authors independently. Four unique articles with qualitative analyses were retrieved. All included studies had a clear objective/aim, an appropriate endpoint and sufficiently described eligibility criteria. RESULTS: With dynamic imaging (4D) evaluation of the upper airway, the incidence of upper airway collapsibility due to use of a mandibular advancement device (MAD) was reduced, extraluminal tissue pressure was decreased and the space in the upper airway was increased, notably in the retropalatal and retroglossal areas of the airway. These findings suggest that MADs may be effective for OSA regardless of whether or not the obstruction site is in the velopharynx or oropharynx. However, further investigation of dynamic changes in the upper airway is required to explain the efficacy of OSA treatment and the underlying mechanisms.

Mandibular advancement device in obstructive sleep apnea treatment: what happens to the condyle position and patient response?

BACKGROUND: This study aims primarily to assess the mandibular condyles and patient response to MAD therapy using cone-beam computed tomography (CBCT). Also, the study proposes to analyze whether variations in condylar position, OSA severity and mandibular protrusion influence patient response. METHODS: 23 patients diagnosed with mild/moderate OSA and treated with MAD comprised the sample. Clinical, CBCT, and PSG assessments were conducted at baseline and with MAD in therapeutic protrusion (4-6 months of MAD use). The condyle position was vertically and horizontally evaluated at baseline and at the therapeutic protrusion. RESULTS: The condyle position significantly changed with MAD, showing anterior (7.3 ± 2.8 mm; p < 0.001) and inferior (3.5 ± 1 mm; p < 0.001) displacement. Patients with mild OSA required more protrusion (p = 0.02) for improvement. Responders exhibited a significantly prominent (p = 0.04) anterior baseline condyle position. A negative modest correlation was found between treatment response and baseline condyle anterior position (p = 0.03; r=-0.4), as well as between OSA severity and the percentage of maximum protrusion needed for therapeutic protrusion (p = 0.02; r=-0.4). The patient protrusion amount did not predict condylar positional changes. Neither condyle position, OSA severity, nor therapeutic protrusion were predictors of MAD treatment response. CONCLUSION: MAD resulted in anterior and inferior condylar displacement, and the amount of protrusion did not predict condylar positional changes. Responders showed a more anterior baseline condyle position. OSA severity and mandibular protrusion did not predict treatment response.

Smart mandibular advancement devices for obstructive sleep apnea: a systematic literature review.

PURPOSE: The goal of this review is to provide sleep physicians, dentists, and researchers with an evidence-based overview of the literature on smart mandibular advancement devices (MADs) for the treatment of obstructive sleep apnea. METHODS: A systematic literature search was conducted by two blinded reviewers and an information specialist. A smart MAD was defined as any MAD with additional functionality besides mandibular protrusion. The bibliographic databases Medline, Embase, and Scopus were used to identify relevant publications. Studies were included if they described any stage of development of smart MADs. A total of 3162 titles and abstracts were screened for their relevance. In total, 58 articles were selected for full-text screening, 26 of which were included in this review. RESULTS: The overall quality of the available literature was low. Most of the studies were observational, clinical or applied-research articles. The authors classified MADs into two main groups: passive and active. Passive MADs measured patient data, most commonly patient compliance. Active MADs adjusted protrusion of the mandible in response to patient data and were found in various phases of technological readiness (in development, demonstration, or deployment). CONCLUSION: Innovations in smart mandibular advancement devices most frequently track patient compliance. Devices measuring other health parameters and active, feedback-controlled, devices are increasingly reported on. However, studies demonstrating their added benefit over traditional methods remain sparse. With further study, smart mandibular advancement devices have the potential to improve the efficiency of obstructive sleep apnea treatment and provide new treatment possibilities.

A finite element study comparing Advansync® and Twin Block in mandibular anterior repositioning.

OBJECTIVE: This study aims to utilize the finite element method (FEM) to compare the dentoalveolar and mandibular effects associated with anterior mandibular repositioning using AdvanSync® (ADV) and Twin Block (TB). METHODS: A patient with Class II skeletal malocclusion and mandibular retrognathism was selected. A TB appliance was subsequently applied. Computed Tomography (CT) scans were acquired at the beginning of treatment (T1) and 8 months later (T2). Concurrently, a numerical TB model was validated through FEM simulations, which were compared with the T2 results. The ADV appliance was virtually simulated to evaluate stress and deformation on the condyle, symphysis, first lower molar and lower central incisors. RESULTS: Both simulations demonstrated significant mandibular advancement. However, ADV led to less incisor proclination and more molar intrusion compared to TB. ADV exhibited increased stress in the lower molar area, while TB had higher stress in the lower incisor region. Stress and deformations in the condyle and mandibular symphysis were similar in both simulations, with the highest stress observed at the condylar neck and the lowest at the upper pole of the condylar head. CONCLUSIONS: Both appliances achieved similar levels of mandibular advancement, with greater proclination of the lower central incisors and more widespread distribution of stress and molar intrusion when using ADV compared to TB.

Polysomnographic phenotypes: predictors of treatment response in Obstructive Sleep Apnea with Mandibular Advancement devices.

PURPOSE: This non-randomized clinical study aims to identify polysomnographic phenotypic characteristics that differentiate responders from non-responders to mandibular advancement devices (MAD) treatment for obstructive sleep apnea (OSA) and to establish a predictive model of treatment response for OSA using oral devices based on the set of anthropometric, demographic, and polysomnographic phenotypic characteristics. METHODS: This study was registered under the identifier number: NCT02724865. It prospectively analyzed patients receiving MAD treatment for six years. The MADs used were two-piece adjustable appliances following a standardized protocol. Treatment response was defined according to the latest International Consensus Statement on OSA severity. The study analyzed polysomnographic phenotypes, categorizing them into positional phenotype, sleep-stage phenotype (REM/NREM-OSA), and airway collapsibility phenotype. A logistic regression model and a classification and regression tree were implemented. RESULTS: A total of 112 patients completed the study (64 responders and 48 non-responders). Positional-OSA patients had higher response rates than non-positional (64.1% vs. 35.9; p 0.032). REM-OSA and apnea-predominant phenotype showed a lower response (p < 0.001). In these phenotypes, most patients were women, with higher body mass index, higher scores in the Epworth Sleepiness Scale, lower minSaO2 in REM-OSA phenotype, and higher T90% in apnea-predominant phenotype. CONCLUSION: This study underscores the importance of hypoxic burden in the severity of OSA. The parameters T90% and POSA formed predictive model. Additionally, MAD appears to be less effective in the REM-OSA phenotype. Moreover, although patients with an apnea-predominant phenotype responded less favorably, there was a conversion from apneas to hypopneas, reducing severity.

Drug induced sleep endoscopy and simultaneous polysomnography to predict the effectiveness of mandibular advancement device in obstructive sleep apnea treatment.

PURPOSES: To evaluate whether mandibular advancement device therapy is recommended in patients affected by obstructive sleep apnea. METHODS: In order to predict oral appliances therapy response, drug induced sleep endoscopy with cardio-respiratory polygraphy and mandibular advancement device simulator was carried out. Patients in which upper airway obstruction was resolved on all levels and AHI was normalized (< 5/h), were referred for oral appliance therapy. At 5 months follow up, a cardio-respiratory polygraphy with MAD was performed. RESULTS: 36 patients who have evidence of resolution of UA collapse and AHI below 5 events per hour, were referred for MAD therapy. At follow up, the mean AHI decreased from 29.1 ± 13.1 to 3.3/h ± 1.9 (p < 0.001). All the patients were responders. CONCLUSION: Combining the evaluation of drug induced sleep endoscopy and cardio-respiratory polygraphy data simultaneously during mandibular protrusion, has the potential to be a useful tool for prediction of MAD therapy response.

Evaluation of condylar and mandibular movements on the upper airway during the use of mandibular advancement device for obstructive sleep apnea treatment.

OBJECTIVES: To evaluate the temporomandibular joint (TMJ), condylar and mandibular movements in obstructive sleep apnea (OSA) patients treated with mandibular advancement device (MAD) and to identify the influence of these anatomic factors on upper airway (UA) volume and polysomnographic outcomes after treatment. MATERIALS AND METHODS: Twenty OSA patients were prospectively treated with MAD. Clinical examinations, cone-beam computed tomography, and polysomnography were performed before MAD treatment and after achieving therapeutic protrusion. Polysomnographic variables and three-dimensional measurements of the TMJ, mandible, and upper airway were statistically analyzed. RESULTS: Condylar rotation, anterior translation, and anterior mandibular displacement were directly correlated with total UA volume, while vertical mandibular translation was inversely correlated with the volume of the inferior oropharynx. MAD treatment resulted in an increase in the volume and area of the superior oropharynx. There was no statistically significant correlation between condylar rotation and translation and polysomnographic variables. With MAD, there was a significant increase in vertical dimension, changes in condylar position (rotation and translation), and mandibular displacement. The central and medial lengths of the articular eminence were inversely correlated with condylar rotation and translation, respectively. The lateral length of the eminence was directly correlated with condylar translation, and the lateral height was directly correlated with condylar rotation and translation. CONCLUSION: Condylar and mandibular movements influenced UA volume. The articular eminence played a role in the amount of condylar rotation and translation. CLINICAL RELEVANCE: Individualized anatomical evaluation of the TMJ proves to be important in the therapy of OSA with MAD.

Impact of a mandibular advancement device on corticomotor plasticity in patients with obstructive sleep apnea.

BACKGROUND: Neuroplasticity induced by mandibular advancement appliance (MAD) in patients with obstructive sleep apnoea (OSA) is poorly documented. OBJECTIVE: This randomised placebo-controlled crossover mechanistic study assessed the effects of short-term use of a MAD on corticomotor excitability of the masseter and tongue in patients with OSA. METHODS: Adults (n = 28) with mild or moderate OSA were randomly allocated to sleep with a MAD for 2-weeks with 40% of the maximal protrusion (MAD active position) and without any jaw protrusion (MAD placebo position). The outcomes were assessed at baseline, and after 2 and 6 weeks, with a 2-week washout period. The primary outcome was the amplitude of motor evoked potential (MEP) assessed on the right masseter, right side of tongue and right first dorsal interosseous with transcranial magnetic stimulation. Corticomotor map volume of the same muscles was also assessed. Repeated-measures ANOVAs followed by Tukey test were applied to the data (p < .050). RESULTS: There was a significant increase in the MEP amplitude of the masseter and tongue following the MAD active position compared with the baseline and MAD placebo (Tukey: p < .001). There were no significant MEP amplitude differences between the baseline and placebo positions (p > .050). Moreover, there was a significant increase in corticomotor map volume for the masseter and tongue muscles following the MAD active position compared with baseline and MAD placebo (Tukey: p < .003). CONCLUSION: Excitability of the masseter and tongue motor pathways is, at least transiently, increased in patients with OSA following a short-term use of MAD. This novel finding of MAD-induced neuroplasticity in corticomotor pathways may contribute to a further understanding of the mechanisms of oral appliances for treating OSA.

A mandibular advancement device attenuates the abnormal morphology and function of mitochondria from the genioglossus in obstructive sleep apnea-hypopnea syndrome rabbits.

BACKGROUND: Obstructive sleep apnea hypopnea syndrome (OSAHS) is a serious and potentially life-threatening disease. Mandibular advancement device (MAD) has the characteristics of non-invasive, comfortable, portable and low-cost, making it the preferred treatment for mild-to-moderate OSAHS. Our previous studies found that abnormal contractility and fibre type distribution of the genioglossus could be caused by OSAHS. However, whether the mitochondria participate in these tissue changes is unclear. The effect of MAD treatment on the mitochondria of the genioglossus in OSAHS is also uncertain. OBJECTIVE: To examine the morphology and function of mitochondria from the genioglossus in a rabbit model of obstructive sleep apnea-hypopnea syndrome (OSAHS), as well as these factors after insertion of a mandibular advancement device (MAD). METHODS: Thirty male New Zealand white rabbits were randomised into three groups: control, OSAHS and MAD, with 10 rabbits in each group. Animals in Group OSAHS and Group MAD were induced to develop OSAHS by injection of gel into the submucosal muscular layer of the soft palate. The rabbits in Group MAD were fitted with a MAD. The animals in the control group were not treated. Further, polysomnography (PSG) and cone-beam computed tomography (CBCT) scan were used to measure MAD effectiveness. CBCT of the upper airway and PSG suggested that MAD was effective. Rabbits in the three groups were induced to sleep for 4-6 h per day for eight consecutive weeks. The genioglossus was harvested and detected by optical microscopy and transmission electron microscopy. The mitochondrial membrane potential was determined by laser confocal microscopy and flow cytometry. Mitochondrial complex I and IV activities were detected by mitochondrial complex assay kits. RESULTS: OSAHS-like symptoms were induced successfully in Group OSAHS and rescued by MAD treatment. The relative values of the mitochondrial membrane potential, mitochondrial complex I activity and complex IV activity were significantly lower in Group OSAHS than in the control group; however, there was no significant difference between Group MAD and the control group. The OSAHS-induced injury and the dysfunctional mitochondria of the genioglossus muscle were reduced by MAD treatment. CONCLUSION: Damaged mitochondrial structure and function were induced by OSAHS and could be attenuated by MAD treatment.

Role of NF-κB in cardiac changes of obstructive sleep apnoea rabbits treated by mandibular advancement device.

BACKGROUND: Obstructive sleep apnoea (OSA) is an independent risk factor for cardiovascular diseases. We aimed to investigate the role of nuclear factor-kappa B (NF-κB) in the changes of cardiac structures in OSA rabbits treated by mandibular advancement device (MAD). METHODS: Eighteen male New Zealand white rabbits aged 6 months were randomly divided into three groups: control group, group OSA and group MAD. Hyaluronate gel was injected into the soft palate of the rabbits in group OSA and group MAD to induce OSA. The cone beam computer tomography (CBCT) of the upper airway and polysomnography (PSG) was performed to ensure successful modelling. CBCT and PSG were applied again to detect the effects of MAD treatment. All animals were induced to sleep in a supine position for 4-6 h a day for 8 weeks. Then the levels of NF-κB, Interleukin 6 (IL-6), Interleukin 10 (IL-10) and the proportion of myocardial fibrosis (MF) were detected. RESULTS: The higher activation of NF-κB, IL-6 and IL-10 were found in the OSA group than in the control group, leading to the increase of collagen fibres compared with the control group. Furthermore, the apnoea-hypopnea index (AHI) was positively correlated with the above factors. There were no significant differences between group MAD and the control group. CONCLUSION: The NF-κB pathway was activated in the myocardium of OSA rabbits, which accelerated the development of MF. Early application of MAD could reduce the activation of NF-κB in the myocardium and prevent the development of MF.

Comparison of monoblock and twinblock mandibular advancement devices in patiens with obstructive sleep apnea and temporomandibular disorder: effects on airway volume, polysomnography parameters, and sleepiness scale scores.

PURPOSE: This study aimed to compare the effects of two different mandibular advancement devices on the upper airway volume, polysomnographic parameters, and sleepiness scale scores in patients with obstructive sleep apnea and Temporomandibular disorders (TMD). MATERIALS AND METHODS: Monoblock and twinblock mandibular advancement devices were applied to patients with obstructive sleep apnea syndrome for 3 months separated by a wash-out period of 2 weeks. Research Diagnostic Criteria for TMD (RDC/TMD), Polysomnographic parameters and cone-beam computed tomography findings were recorded before and after the use of the mandibular advancement devices. A three-dimensional analysis of the airway was then performed. RESULTS: The use of the monoblock device significantly increased the upper airway volume compared with the use of the twinblock device (p = 0.032). The polysomnographic parameters similarly improved with the use of the twin-block and monoblock devices. The significant reduction in TMD symptoms was observed. CONCLUSION: The use of the monoblock device increased the retropalatal airway volume. This volume increase may be attributed to the fact that the design of the monoblock device allows less mandibular movement than does that of the twinblock device. Indicates the potential benefits of MADS treatment in alleviating TMD-related issues. CLINICAL SIGNIFICANCE: Monoblock MADs have improved effects on respiratory parameters and upper airway dimensions in patients with OSA and mild to moderate TMD.

The development of a novel bidirectional fine-tuning mandibular advancement device.

OBJECTIVE: To develop a novel mandibular advancement device (MAD) with high comfort, good compliance, and bidirectional fine-tuning capability for patients with obstructive sleep apnea hypopnea syndrome (OSAHS), and to evaluate the therapeutic efficacy of the new MAD. METHODS: The MAD, featuring upper and lower dental splints with a fine-tuning mechanism for mandibular adjustment, incorporates improved design elements such as partial dental coverage, shortened baffles, and memory resin lining. The novel MAD was used to treat 30 OSAHS patients in the study, comparing pre- and post-treatment scores on the Epworth Sleepiness Scale (ESS), the Apnea-Hypopnea Index (AHI), and the lowest oxygen saturation (LSO2). RESULTS: The novel MAD reduced size and side effects, enhancing comfort. All patients complied well, using it for an average of 95% over 30 days and ≥ 5 h nightly. After treatment, significant improvements were observed in ESS, AHI, and LSO2 (P < 0.05). CONCLUSIONS: This novel bidirectional adjustable MAD provides high comfort and compliance, improving treatment precision. It is an effective choice for mild to moderate OSAHS patients and an alternative for those intolerant to CPAP or averse to surgery.

Biomechanical effects of functional clear aligners on the stomatognathic system in teens with class II malocclusion: a new model through finite element analysis.

OBJECTIVES: The Functional Clear Aligner (FCA) is a novel orthodontic appliance designed for the treatment of Class II malocclusion with mandibular retrognathia in adolescents. The aim of this study was to investigate the biomechanical characteristics of the masticatory muscles, jawbone, and temporomandibular joint (TMJ) during mandibular advancement using either FCA or Class II elastics combined with clear aligner (Class II elastics) through finite element analysis. MATERIALS AND METHODS: A 3D finite element model of the 'muscle-jawbone-TMJ-appliance' system was constructed based on CBCT and MRI images of a boy with skeletal Class II malocclusion. Masticatory muscles included masseter, temporal, medial pterygoid, and lateral pterygoid muscles. The TMJ consists of the temporal bone's glenoid fossa, disc, and mandibular condyle. To observe the biomechanical characteristics of the muscles and TMJ during orthodontic appliance wearing and the retention phase, two different protocols were used: Model 1: The mandibular advancement using FCA; Model 2: The mandibular advancement using Class II elastics. RESULTS: The FCA group produced greater and more coordinated masticatory muscle forces compared to the Class II elastics group. Temporal and masseter muscles exhibited the most pronounced variation in muscle strength during mandibular advancement. The FCA group exhibited greater TMJ region stress compared to the Class II elastics group. Interestingly, the stress on the articular discs in both models decreased over time. Tensile stresses were observed in both the condyle and the posterior region of the articular fossa. CONCLUSION: During skeletal Class II malocclusion treatment, masticatory muscle forces and stress on the TMJ were higher in the FCA group compared to the Class II elastics group. In both models, stress cushioning was provided by the articular disc.

Effectiveness of mandibular advancement orthodontic appliances with maxillary expansion device in children with obstructive sleep apnea: a systematic review.

BACKGROUND: The current review aims to explore the evidence regarding the effectiveness of mandibular advancement orthodontic appliances with maxillary expansion device in treating pediatric Obstructive Sleep Apnea (OSA). MATERIALS AND METHODS: A systematic literature search was conducted across PubMed, Cochrane Central, Web of Science, Embase, Scopus databases, Chinese Biomedical Database, Chinese National Knowledge Infrastructure, and Wanfang. The research involved children and adolescents (under 16 years old) who received mandibular advancement and maxillary expansion functional orthopedic appliances for OSA treatment. We performed narrative reviews and subsequently amalgamated the findings from the studies. RESULTS: Six articles were included for review. Although a small number of studies were included, the research suggested the potential advantages of mandibular advancement for children with OSA. Following treatment, there was a decrease in AHI/RDI, an improvement in sleep quality, and the increase in oxygen saturation. CONCLUSIONS: The limited quantity and quality of existing studies necessitate caution when drawing conclusions about the effectiveness of mandibular advancement and maxillary expansion for OSA. In the future, larger and well-designed randomized controlled trials (RCTs) are needed to provide more robust evidence. Patients should be carefully selected, and their orthodontic indications should be thoroughly evaluated before inclusion in such trials.We encourage researchers to design studies that monitor patients over several years to provide a comprehensive understanding of the long-term effectiveness. TRIAL REGISTRATION: This study was registered in PROSPERO(CRD42023480407) on November 20, 2023.