Non-sleep related outcomes of maxillomandibular advancement, a systematic review.

Maxillomandibular advancement has been shown to be an effective treatment for obstructive sleep apnea; however, the literature focuses mainly on sleep-related parameters such as apnea-hypopnea index, respiratory disturbance index and Epworth sleepiness scale. Other factors that may be important to patients, such as esthetics, patient satisfaction, nasality, swallowing problems and so forth have been reported in the literature but have not been systematically studied. Together with an information specialist, an extensive search in Medline, Embase and Scopus yielded 1592 unique articles. Titles and abstracts were screened by two blinded reviewers. In total, 75 articles were deemed eligible for full-text screening and 38 articles were included for qualitative synthesis. The most common categories of non-sleep related outcomes found were surgical accuracy, facial esthetics, functional outcomes, quality of life, patient satisfaction, and emotional health. All categories were reported using heterogenous methods, such that meta-analysis could not be performed. There was lack of consistent methods to assess these outcomes. This work is the first to systematically review non-sleep related outcomes of maxillomandibular advancement. Despite growing interest in evaluating surgical outcomes through patient subjective experiences, this review points to the need of standardized, validated methods to report these outcomes.

Orodental injury and mouthguard usage in Dutch and international field hockey.

Background: Mouthguards are used to prevent players from orodental injuries in field hockey. However, such injuries are still a common problem. This study describes the prevalence of orodental injury and the related mouthguard usage in field hockey. Material and Methods: A 19-item questionnaire was distributed in the Dutch field hockey competition and at the international Master World Cup. In total, 1213 questionnaires were collected. Standard descriptive statistics were used to describe the samples. Associations between data were determined using the Pearson Chi-Square test. Results: The prevalence of orodental injuries during the career of hockey players was 20% in Dutch players, and 29% in international players. Mouthguard usage among Dutch players was 95%, and among international players 88%. There was no significant association between wearing a mouthguard or not with respect to whether or not treatment was requested as a result of an orodental injury (Dutch p=0.43; international p=0.22). Conclusions: This study showed that the prevalence of orodental injuries in field hockey are high, while the majority of the players use a 'protective' mouthguard. These results imply that the current mouthguards may not provide enough protection against the forces used in field hockey. Key words:Mouthguard, prevention, sports, dental injury.

Association of indications for mandibular third molar coronectomy and the Pell and Gregory and the Winter classification systems.

PURPOSE: The purpose of this study was to determine how the surgeon's decision to perform a mandibular third molar coronectomy or surgical removal is associated with the impaction pattern as classified using Pell and Gregory or Winter's system. METHODS: This observational, cross-sectional study was conducted on 813 mandibular third molars belonging to 565 patients. All patients were referred for removal of the mandibular third molar and had radiographic signs indicating a close relationship with the inferior alveolar nerve. Panoramic images were classified according to the impaction pattern. RESULTS: A coronectomy was performed on 492 (60.5%) mandibular third molars. Most impacted mandibular third molars were class IIB with a mesioangular inclination. A significant association was found between the Pell and Gregory classification and the surgeon's choice (p = 0.002). Winter's classification was not significantly associated with surgeon choice (p = 0.425). CONCLUSION: Mandibular third molar coronectomy is chosen more frequently than surgical removal if molars are class III and position B. TRIAL REGISTRATION NUMBER: Not applicable.

Upper airway morphology in adults with positional obstructive sleep apnea.

PURPOSE: To compare the anatomical balance and shape of the upper airway in the supine position between adults with positional obstructive sleep apnea (POSA) and adults with non-positional OSA (NPOSA). METHODS: Adults diagnosed with OSA (apnea-hypopnea index (AHI) > 10 events/h) were assessed for eligibility. POSA was defined as the supine AHI more than twice the AHI in non-supine positions; otherwise, patients were classified as NPOSA. Cone beam computed tomography (CBCT) imaging was performed for every participant while awake in the supine position. The anatomical balance was calculated as the ratio of the tongue size to the maxillomandibular enclosure size. The upper airway shape was calculated as the ratio of the anteroposterior dimension to the lateral dimension at the location of the minimal cross-sectional area of the upper airway (CSAmin-shape). RESULTS: Of 47 participants (28 males, median age [interquartile range] 56 [46 to 63] years, median AHI 27.8 [15.0 to 33.8]), 34 participants were classified as having POSA (72%). The POSA group tended to have a higher proportion of males and a lower AHI than the NPOSA group (P = 0.07 and 0.07, respectively). After controlling for both sex and AHI, the anatomical balance and CSAmin-shape were not significantly different between both groups (P = 0.18 and 0.73, respectively). CONCLUSION: Adults with POSA and adults with NPOSA have similar anatomical balance and shape of their upper airway in the supine position. TRIAL REGISTRATION: This study was registered with the Australian New Zealand Clinical Trials Registry (ANZCTR Trial ACTRN12611000409976).

Temporomandibular Joint Prosthesis in a Patient with Congenital Infiltrating Lipomatosis of the Face with Bony Ankylosis of the Temporomandibular Joint: A Case Report.

Hemifacial hyperplasia (HFH) is a rare congenital disorder characterized by marked unilateral overgrowth of the facial tissues. A subtype of HFH is congenital infiltrating lipomatosis of the face (CIL-F). This disease is characterized by unilateral diffuse infiltration of mature adipose cells in the facial soft tissue and is associated with skeletal hypertrophy. This work aims to report a case of a CIL-F patient with right facial asymmetry and progressive growth at adolescent age, causing mandibular asymmetry due to signs of concomitant unilateral condylar hyperplasia. At the age of seventeen, a condylectomy was performed to stop the progression of asymmetric mandibular growth. Five years later, the patient developed CIL-F-associated temporomandibular joint ankylosis, manifesting as progressive restricted mouth opening along with temporal facial pain. In this CIL-F patient, a TMJ reconstruction with an alloplastic total joint prosthesis was successfully performed with optimal maximal mouth opening, complete alleviation of temporal facial pain, and stable dental occlusion one year postoperatively. A TMJ reconstruction with a complete alloplastic total joint prosthesis proved to be a predictable, stable, and safe treatment option in a patient with CIL-F-associated TMJ ankylosis who was previously treated with condylectomy due to progressive mandibular asymmetry.

Assessment of Surgical Accuracy in Maxillomandibular Advancement Surgery for Obstructive Sleep Apnea: A Preliminary Analysis.

This retrospective study aimed to: (1) investigate the surgical accuracy of maxillomandibular advancement (MMA) in obstructive sleep apnea (OSA) patients, with a specific focus on maxillary and mandibular advancement and counter-clockwise rotation and (2) investigate the correlation between the amount of achieved advancement and the reduction in the relative apnea hypopnea index (AHI). Sixteen patients, for whom a three-dimensional virtual surgical plan was generated preoperatively and a computed tomography scan (CT) or cone-beam computer tomography (CBCT) was acquired postoperatively, were included. The postoperative CT or CBCT was compared to the virtual surgical plan, and differences in the mandibular and maxillary advancement and counter-clockwise rotation were assessed. Maxillary and mandibular advancement (median 3.1 mm, p = 0.002 and 2.3 mm, p = 0.03, respectively) and counter-clockwise rotation (median 3.7°, p = 0.006 and 4.7°, p = 0.001, respectively) were notably less than intended. A significant correlation was found between the planned maxillary advancement and the difference between the planned and actual maxillary advancement (p = 0.048; adjusted R2 = 0.1979) and also between the planned counter-clockwise rotation and the difference between the planned and actual counter-clockwise rotation for the mandible (p = 0.012; adjusted R2 = 0.3261). Neither the maxilla-first nor the mandible-first surgical sequence proved to be superior in terms of the ability to achieve the intended movements (p > 0.45). Despite a significant reduction (p = 0.001) in the apnea hypopnea index (AHI) from a median of 62.6 events/h to 19.4 events/h following MMA, no relationship was found between the extent of maxillary or mandibular advancement and AHI improvement in this small cohort (p = 0.389 and p = 0.387, respectively). This study underlines the necessity for surgeons and future research projects to be aware of surgical inaccuracies in MMA procedures for OSA patients. Additionally, further research is required to investigate if sufficient advancement is an important factor associated with MMA treatment outcome.

Healthcare costs of different treatment options for condylar fractures.

Objective: As treatment options for condylar fractures have comparable outcomes, getting insight into associated costs is a first step towards implementing value-based healthcare (VBH). Therefore, we described the actual costs of the different treatment options (surgical, conservative, and expectative treatment) for condylar fractures. We expected surgical treatment to be the most expensive treatment. Study design: This is a cost-of-illness study, based on estimates from the literature. Firstly, care pathways of all treatment options were described. Secondly, the costs per step were calculated based on the literature and Dutch guidelines for economic evaluations in health care. Results: The direct treatment costs of surgical treatment (€3721 to €4040) are three to five times higher than conservative treatment (€730 to €1332). When lost productivity costs during the recovery period are included, costs of surgical treatment remain 1.5 times higher (€9511 to €9830 for surgical treatment and €6224 to €6826 for conservative treatment). The costs of expectative treatment (€5436) are lower than both other treatments. Conclusion: The costs for surgical treatment are considerably higher than those for conservative or expectative treatment, mainly related to direct treatment cost. Future research should focus on the patients' perspective, to support implementation of VBH in treating condylar fractures.

Efficacy and Toxicity of Calcitonin Treatment in Children with Cherubism: A Single-Center Cohort Study.

Cherubism is a rare autosomal dominant disease characterized by expansile osteolytic jawbone lesions. The effect and safety of off-label calcitonin treatment during the progressive phase of the disease are not well described. In this retrospective study, we present data on the radiological response and adverse effects of subcutaneously administered calcitonin in a cohort of nine cherubism children (three female, six male). Two of the nine patients underwent two separate treatment courses with a significant off-treatment interval in between; therefore, a total of 11 treatment courses with a mean duration of 17.9 months (range <1 to 35, SD 10.8) were studied. To measure the response, the cumulative volume of cherubism lesions was calculated from available three-dimensional imaging. The primary outcome was the change in the volume of lesions during calcitonin treatment and only assessed for the eight treatment courses with a minimal duration of 6 months. A statistically significant reduction in the mean cumulative volume of lesions was seen regardless of treatment duration. Average volume reduction was highest in the first half year of treatment, with a gradual, ongoing reduction thereafter. For the secondary outcome, the change in the cumulative volume of lesions after treatment cessation was assessed for the seven treatment courses with follow-up imaging available. After six of these seven treatment courses, the cumulative volume increased again but remained undoubtedly smaller than the initial volume at the start of therapy. Adverse effects were assessed for all 11 treatment courses and occurred in 73% of them. Most adverse effects were mild and low grade, with the most severe being one grade 3 symptomatic hypocalcemia requiring hospitalization and early treatment termination. Calcitonin treatment seems effective and tolerable in treating actively progressing cherubism in children. However, further research is required to better understand the pharmacological treatment of cherubism, including also other drugs, dosing, and protocols. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Contact stress distribution after unilateral condylar fracture with angulation of the fractured part: A finite element model study.

After a fracture of the condyle, the head of the condyle is often pulled inwards, which causes the fractured part to angulate medially. This change can cause a disbalance in the masticatory system. The disbalance could lead to contact stress differences within the temporomandibular joints (TMJs) which might induce remodelling within the TMJ to restore the balance. The contact stress in the fractured condyle during open and closing movements is expected to decrease, while the contact stress in the non-fractured condyle will increase. In a clinical situation this is hard to investigate. Therefore, a finite element model (FEM) was used. In the FEM a fractured right condyle with an angulation was induced, which was placed at different degrees, varying from 5° to 50° in steps of 5°. This study shows only minor differences in amount of contact stress between the fractured and the non-fractured condyle. The amount of contact stress in the condyles does not increase with a higher degree of angulation. However, with larger angulations, the contact stress within the fractured condyle is more centralized. Clinically, this more centralized area could be associated with complaints, such as pain. In conclusion, due to the more centralized contact stress in the fractured condyle, one would expect some minor remodelling on the fractured side with more angulation.

Effects of mandibular advancement devices on upper airway dimensions in obstructive sleep apnea: responders versus non-responders.

STUDY OBJECTIVES: To compare the effects of mandibular advancement device (MAD) therapy on upper airway dimensions between responders and non-responders with mild to moderate obstructive sleep apnea (OSA). METHODS: Thirty-one participants (21 men and 10 women) with a mean ± SD apnea-hypopnea index (AHI) of 16.6 ± 6.7 events/h, and aged 48.5 ± 13.9 years, were included in this study. Polysomnographic recordings and cone beam computed tomography (CBCT) scans in supine position were performed for every participant at baseline and at 3-month follow-up with their MAD in situ. Responders were defined as having ≥ 50% reduction in baseline AHI with a residual AHI < 10 events/h. The primary outcome variable was the minimal cross-sectional area of the upper airway (CSAmin). RESULTS: No significant differences were found between responders (n = 15) and non-responders (n = 16) in age, gender distribution, body mass index, and neck circumference (P = 0.06-0.93), nor in AHI and CSAmin (P = 0.40 and 0.65, respectively) at baseline. The changes of the CSAmin with MAD in situ in the responder group were not significantly different compared to those in the non-responder group (P = 0.06). CONCLUSION: Within the limitations of this study, we conclude that the changes of the upper airway dimensions induced by MADs are not significantly different between responders and non-responders with mild to moderate OSA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02724865. https://clinicaltrials.gov/ct2/show/NCT02724865.

Assessing change in quality of life using the Oral Health Impact Profile in patients undergoing orthognathic surgery: A before and after comparison with a minimal follow-up of two years.

PURPOSE: Here we evaluated how orthognathic surgery impacted oral health-related quality of life among patients with dentofacial deformities in the immediate postoperative period and during ≥2 years of follow-up, using the OHIP-14-NL questionnaire. METHODS: This prospective study included 86 patients. Quality of life was assessed using the Dutch version of the Oral Health Impact Profile questionnaire (OHIP-14-NL) preoperatively (T0, baseline), over 7 days postoperatively (T1-T7), and at 4 weeks (T8), 6 months (T9), 1 year (T10), and ≥2 years (T11) postoperatively. Total OHIP score was determined for each patient. Lower OHIP scores indicated higher oral health-related quality of life. Patients also answered questions regarding self-care, discomfort, and experienced pain at all time-points, starting from T1. RESULTS: Compared to baseline (T0), median OHIP scores were significantly higher from T1 to T8. However, at T9 to T11, OHIP scores were significantly lower compared to baseline (T0) (p < 0.01). OHIP scores were not correlated with gender, age, or blood loss; and did not significantly differ according to surgery type or surgery indication (p > 0.01). Pain scores were positively correlated with OHIP scores for all time-points, except T6 and T10. Pain was not correlated with sex, age, blood loss, surgery duration, surgery indication, or surgery type. Compared to at T1, pain was significantly decreased at T9-T11. CONCLUSION: Among patients who underwent orthognathic surgery, oral health-related quality of life was decreased in the immediate postoperative period, but improved at ≥6 months postoperatively. The improvement was significant 2 years after orthognathic surgery.

The Effectiveness of Three-Dimensional Osteosynthesis Plates versus Conventional Plates for the Treatment of Skeletal Fractures: A Systematic Review and Meta-Analysis.

PURPOSE: To assess the difference between preformed anatomically shaped osteosynthesis plates and patient-specific implants versus conventional flat plates for the treatment of skeletal fractures in terms of anatomical reduction, operation time, approach, patient outcomes, and complications. MATERIAL AND METHODS: MEDLINE (1950 to February 2023), EMBASE (1966 to February 2023), and the Cochrane Central Register of Controlled Trials (inception to February 2023) databases were searched. Eligible studies were randomised clinical trials, prospective controlled clinical trials, and prospective and retrospective cohort studies (n ≥ 10). Inclusion criteria were studies reporting the outcomes of preformed anatomically shaped osteosynthesis plates and patient-specific implants versus conventional flat plates after treating skeletal fractures. Outcome measures included anatomical reduction, stability, operation time, hospitalisation days, patients' outcomes, and complications. Two independent reviewers assessed the abstracts and analysed the complete texts and methodologies of the included studies. RESULTS: In total, 21 out of the 5181 primarily selected articles matched the inclusion criteria. A meta-analysis revealed a significant difference in operation time in favour of the preformed anatomical plates and patient-specific implants versus conventional plates. Significant differences in operation time were found for the orbital (95% CI: -50.70-7.49, p = 0.008), upper limb (95% CI: -17.91-6.13, p < 0.0001), and lower limb extremity groups (95% CI: -20.40-15.11, p < 0.00001). The mean difference in the rate of anatomical reduction in the lower limb extremity group (95% CI: 1.04-7.62, p = 0.04) was also in favour of using preformed anatomical plates and patient-specific implants versus conventional plates. CONCLUSIONS: This systematic review showed a significant mean difference in surgery time favouring the use of preformed anatomical plates and patient-specific implants for orbital, upper, and lower limb extremity fractures. Additionally, preformed anatomical plates and patient-specific implants in the lower limb group result in a significantly higher rate of anatomical reduction versus conventional flat plates.

Load distribution after unilateral condylar fracture with shortening of the ramus: a finite element model study.

OBJECTIVES: After a fracture of the condyle, the fractured ramus is often shortened, which causes premature dental contact on the fractured side and a contralateral open bite. The imbalance could change the load in the temporomandibular joints (TMJs). This change could lead to remodelling of the TMJs to compensate for the imbalance in the masticatory system. The load in the non-fractured condyle is expected to increase, and the load in the fractured condyle to decrease. MATERIALS AND METHODS: These changes cannot be measured in a clinical situation. Therefore a finite element model (FEM) of the masticatory system was used. In the FEM a fractured right condyle with shortening of the ramus was induced, which varied from 2 to 16 mm. RESULTS: Results show that, with a larger shortening of the ramus, the load in the fractured condyle decreases and the load in the non-fractured condyle increases. In the fractured condyle during closed mouth a major descent in load, hence a cut-off point, was visible between a shortening of 6 mm and 8 mm. CONCLUSIONS: In conclusion, the change of load could be associated with remodelling on both condyles due to shortening of the ramus. CLINICAL RELEVANCE: The cut-off point implies that shortening over 6 mm could present more difficulty for the body to compensate.

Subjective Efficiency Evaluation after Maxillomandibular Advancement Surgery in Obstructive Sleep Apnea Patients.

PURPOSE: To investigate subjective efficiency outcomes after maxillomandibular advancement (MMA) surgery in obstructive sleep apnea (OSA) patients. MATERIAL AND METHODS: A prospective cohort study was carried out between December 2016 and May 2021, including 30 severe or treatment-refractory OSA patients treated by MMA surgery. All patients answered four validated questionnaires: the Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), Mandibular Function Impairment Questionnaire (MFIQ), and EQ-5D-3L (i.e., EQ-5D and EQ-VAS). They also answered one custom-made questionnaire (AMCSQ). Questionnaires were requested to be filled out 1 week before surgery and at least 6 months after surgery. RESULTS: The total preoperative and postoperative scores on the questionnaires were compared. The mean total ESS (p < 0.01), FOSQ (p < 0.01), EQ-5D (p < 0.05), and EQ-VAS (p < 0.01) scores showed significant improvement, which was in accordance with an improvement in the mean postoperative apnea/hypopnea index score (p < 0.01). In contrast, the mean total MFIQ score (p < 0.01) indicated a decline in mandibular function. CONCLUSION: This study confirms the hypothesis that MMA surgery in OSA patients improves outcomes, both objectively and subjectively, with the exception of postoperative mandibular function.

Pre-Chemotherapy Dental Screening: Is There Additional Diagnostic Value for a Panoramic Radiograph?

BACKGROUND: The oral cavity is a potential source of infectious complications in patients treated with myelosuppressive chemotherapy (CT). Pre-chemotherapy oral examination to identify foci of infection is recommended, but it is unclear whether this should include panoramic radiography. The present study aimed to evaluate the additional diagnostic merit of panoramic radiography as part of pre-CT oral screening. METHODS: Patients with solid tumors scheduled to receive a myelosuppressive CT were eligible. The foci definition followed the guidelines of the Dutch Association of Maxillofacial Surgery. Oral foci assessed by clinical evaluation and panoramic radiography were compared. RESULTS: In 33 out of 93 patients (35.5%), one or more foci were identified by clinical examination, whereas in 49.5% of patients, panoramic radiography showed pathology. In 19 patients, an oral focus was missed by clinical examination only, whereas in 11 patients, panoramic radiography indicated periodontal bone loss, but advanced periodontitis was not substantiated by clinical examination. CONCLUSIONS: Panoramic radiographs complement clinical examinations and have additional diagnostic value. Nevertheless, the additional merit seems small, and the clinical relevance may vary depending on the anticipated risk of developing oral complications and the need for detailed diagnosis and rigorous elimination of oral foci prior to the start of cancer therapy.

Influence of Surgeon Experience on Surgical Outcome of Maxillomandibular Advancement for Obstructive Sleep Apnea.

The primary aim of this study was to assess the association between clinical efficacy outcomes (i.e., polysomnography (PSG) results) of maxillomandibular advancement (MMA) and surgeons' experience. The second aim was to assess the association between the occurrence of postoperative complications of MMA and surgeons' experiences. Patients treated with MMA for moderate to severe obstructive sleep apnea (OSA) were enrolled in this retrospective study. The patient population was divided into two groups based on two different surgeons performing MMA. The associations between surgeons' experience on the one hand and PSG results and postoperative complications on the other hand were investigated. A total of 75 patients were included. There was no significant difference in baseline characteristics between the two groups. The reductions in apnea-hypopnea index and oxygen desaturation index were both significantly greater in group-B than group-A (p = 0.015 and 0.002, respectively). The overall success rate after MMA was 64.0%. There was a negative correlation between surgeon experience and surgical success (odds ratio: 0.963 [0.93, 1.00], p = 0.031). No significant association was found between surgeon experience and surgical cure. Additionally, there was no significant association between surgeon experience and the occurrence of postoperative complications. Within the limitations of this study, it is concluded that surgeon experience may have little to no influence on the clinical efficacy and safety of MMA surgery in OSA patients.

Development and external validation of prediction models for critical outcomes of unvaccinated COVID-19 patients based on demographics, medical conditions and dental status.

Background: Multiple prediction models were developed for critical outcomes of COVID-19. However, prediction models using predictors which can be easily obtained in clinical practice and on dental status are scarce. Aim: The study aimed to develop and externally validate prediction models for critical outcomes of COVID-19 for unvaccinated adult patients in hospital settings based on demographics, medical conditions, and dental status. Methods: A total of 285 and 352 patients from two hospitals in the Netherlands were retrospectively included as derivation and validation cohorts. Demographics, medical conditions, and dental status were considered potential predictors. The critical outcomes (death and ICU admission) were considered endpoints. Logistic regression analyses were used to develop two models: for death alone and for critical outcomes. The performance and clinical values of the models were determined in both cohorts. Results: Age, number of teeth, chronic kidney disease, hypertension, diabetes, and chronic obstructive pulmonary diseases were the significant independent predictors. The models showed good to excellent calibration with observed: expected (O:E) ratios of 0.98 (95%CI: 0.76 to 1.25) and 1.00 (95%CI: 0.80 to 1.24), and discrimination with shrunken area under the curve (AUC) values of 0.85 and 0.79, based on the derivation cohort. In the validation cohort, the models showed good to excellent discrimination with AUC values of 0.85 (95%CI: 0.80 to 0.90) and 0.78 (95%CI: 0.73 to 0.83), but an overestimation in calibration with O:E ratios of 0.65 (95%CI: 0.49 to 0.85) and 0.67 (95%CI: 0.52 to 0.84). Conclusion: The performance of the models was acceptable in both derivation and validation cohorts. Number of teeth was an additive important predictor of critical outcomes of COVID-19. It is an easy-to-apply tool in hospitals for risk stratification of COVID-19 prognosis.

Comparison of the upper airway morphology between Dutch and Chinese adults with obstructive sleep apnea.

PURPOSE: The pathogenesis of obstructive sleep apnea (OSA) is complex and may vary between different races. It has been suggested that the anatomical balance between skeletal tissues and soft tissues around the upper airway is a key pathophysiologic factor of OSA. Therefore, the aim of this study was to compare the anatomical balance of the upper airway between Dutch and Chinese patients with OSA based on cone beam computed tomography (CBCT) images. METHODS: This was a cross-sectional study performed in two centers and included Dutch and Chinese adults with OSA. CBCT scans in the supine position were obtained for both Dutch and Chinese OSA groups. The primary outcome variable was the anatomical balance of the upper airway, defined as the ratio of the tongue area and the maxillomandibular enclosure area. RESULTS: A total of 28 Dutch adults (mean age ± SD of 46.6 ± 14.1 years, body mass index [BMI] of 26.8 ± 3.5 kg/m2, and apnea-hypopnea index [AHI] of 15.7 ± 7.1 events/h) and 24 Chinese adults (age 41.0 ± 12.4 years, BMI 26.5 ± 3.3 kg/m2, and AHI 16.5 ± 7.8 events/h). There were no significant differences in AHI, age, BMI, and sex between the two groups (P = 0.14-0.76). The Dutch group had a significantly larger tongue area and tongue length compared to the Chinese group (P = 0.01 and P < 0.01). On the other hand, the Chinese group had a smaller maxilla length compared to the Dutch group (P < 0.01). However, the anatomical balance of the upper airway of both groups was not significantly different (P = 0.16). CONCLUSION: Within the limitations of this study, no significant difference was found in the anatomical balance of the upper airway between Dutch and Chinese patients with mild to moderate OSA. TRIAL REGISTRATION: The present study was registered at the ClinicalTrials.gov identifier NCT03463785.

Comparisons of the effects of two types of titratable mandibular advancement devices on respiratory parameters and upper airway dimensions in patients with obstructive sleep apnea: a randomized controlled trial.

OBJECTIVES: To compare the effects of two types of titratable mandibular advancement devices (MADs), namely MAD-H (allowing limited vertical opening) and MAD-S (allowing free vertical opening), on respiratory parameters and upper airway dimensions in patients with mild to moderate obstructive sleep apnea (OSA). MATERIALS AND METHODS: Patients with mild to moderate OSA (5 ≤ apnea-hypopnea index (AHI) < 30 /h) were randomly assigned to two parallel MAD groups. All MADs were subjectively titrated according to a standardized protocol during a 3-month follow-up. Every patient underwent two polysomnographic recordings, and two cone beam computed tomography scans in supine position: one at baseline and another one after 3 months with the MAD in situ. The primary outcome variables were the AHI in supine position (AHI-supine) and the minimal cross-sectional area of the upper airway in supine position (CSAmin-supine). RESULTS: A total of 49 patients were recruited, and 31 patients (21 men and 10 women) with a mean (± SD) age of 48.5 (± 13.9) years and a mean AHI of 16.6 (± 6.7) /h completed the study. In the per-protocol analysis, there was no significant difference between MAD-H (n = 16) and MAD-S (n = 15) in their effects on AHI-supine (P = 0.14) and CSAmin-supine (P = 0.59). Similar results were found in the intention-to-treat analysis (P = 0.47 and 0.57, respectively). CONCLUSIONS: Within the limitations of this study, we conclude that there is no significant difference in the effects of an MAD allowing limited vertical opening and an MAD allowing free vertical opening on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA. CLINICAL RELEVANCE: MADs allowing limited vertical opening and allowing free vertical opening have similar effects on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02724865. https://clinicaltrials.gov/ct2/show/NCT02724865.