Impact of surgical maxillomandibular advancement upon pharyngeal airway volume and the apnoea-hypopnoea index in the treatment of obstructive sleep apnoea: systematic review and meta-analysis

A simple method to characterize upper airway in orthognatic surgery patients

Orthognathic surgery is used to treat dentofacial deformities and causes upper airway dimension changes. Surgical planning includes the study of the upper airway in CT images. The most common geometry-associated parameters used for the analysis are the total volume and the minimal cross-sectional area. However, these measurements do not provide information about the entire airway, potentially allowing irregularities and shape changes to go unnoticed. As a result, obtaining measurements of the cross-sectional areas along the entire upper airway is desirable. This information will prove useful for clinicians to compare changes after surgery and between patients. In this work, we introduce a simple technique for quantifying the cross-sectional area of the upper airway. We began by segmenting CT images of the upper airway. Later, we established its central axis and defined oblique slices perpendicular to this axis for measuring the cross-sectional area. Furthermore, we propose plotting these areas along the central axis, providing clinicians with an easily interpretable overview of the airway. The method was applied to nine patients, comparing pre-operative and post-operative images, clearly demonstrating changes in the cross-sectional areas after surgery. This method will allow for a better understanding of the effects and has the potential to improve the planning of orthognathic surgery. Further research will show how the movements of the jaw and maxilla influence the dimensions of the upper airway.

Cone beam computed tomography based upper airway measurement after orthognathic surgery: a comparative evaluation of different imaging software

Cone-beam computed tomography (CBCT) enhances understanding of the upper airway (UA). This study compared three software products' abilities in visualizing and quantifying specific upper airway changes using CBCT. We conducted a retrospective analysis of pre- and post-operative CBCT images from 29 patients using Dolphin (Do), Romexis 5 (Ro5), and Romexis 6 (Ro6) software, focusing on alterations in oropharyngeal volume and minimum cross-sectional area as key indicators of orthognathic surgery outcomes. ANOVA analysis showed significant differences in volume measurements between Do/Ro5 (p = 0.034) and Do/Ro6 (p = 0.047), but no difference between Ro5 and Ro6 (p = 0.685). No significant differences were found in minimum cross-sectional area parameters. Despite standardized protocols, interpretation discrepancies exist between Do and Ro 5/6, possibly due to program-specific properties. Further studies on threshold value comparability are needed for data standardization. Direct comparisons of clinical data from Do, Ro5, and Ro6 are limited due to methodological disparities. Nonetheless, these programs allow reproducible and quantifiable measurements for clinical assessments of these specific airway changes following orthognathic surgery.

The effect of mandibular advancement on pharyngeal airway space in patients with oral squamous cell carcinoma: A monocentric prospective study with computed tomography

OBJECTIVES

The presented study aimed to evaluate the effect of mandibular protrusion with a temporarily applied mandibular advancement device (MAD) on the posterior airway space and to determine a reliable metric constant based on a three-dimensional computed tomography (CT) evaluation.

MATERIALS AND METHODS

The study population consisted of patients with oral squamous cell carcinoma who were treated at least six months prior to the follow-up CT in supine position. Each patient received an individually adjusted MAD that was temporarily applied with three different protrusion distances (P0 = 0 mm, P4 = 4 mm, and P8 = 8 mm) during follow-up CT. The open-source software Slicer was used to calculate three parameters: minimum cross-sectional area (minCSA), mean cross-sectional area (meanCSA), and volume.

RESULTS

The results showed a significant increase for all three parameters. The minCSA increased as follows: P0 = 236.4 mm2 ± 192.2; P4 = 309.2 mm2 ± 235.4; and P8 = 430.6 mm2 ± 265.3. The meanCSA increased significantly (p < 0.001) in all protrusion steps and all parts of the pharynx. The volume changed as follows: P0 = 24.0 cm3 ± 5.0; P4 = 29.6 cm3 ± 18.1; and P8 = 33.6 cm3 ± 19.0. The minCSA increased by 24.9 mm2 ± 13.0 per millimeter mandibular protrusion. CONCLUSION AND CLINICAL RELEVANCE: The results are interesting for both conservative and surgical therapy and could find future application in dental, orthodontic, and combined oral surgical therapy. With the results of this study, surgeons and dentists may better predict the change of PAS parameter in order to better prepare for orthognathic surgery. They also could ensure the right protrusion distance for mandibular advancement devices in the case of obstructive sleep apnea.

Impact of tumor localization and choice of microvascular flap on posterior airway changes following ablative surgery in primary oral squamous cell carcinoma: A monocentric cross-sectional study

BACKGROUND

The aim of this study was to determine the influence of intraoral reconstructions following oral squamous cell carcinoma (OSCC) resection with a free microvascular flap on the posterior airway space (PAS) and to correlate these results with the potential risk of developing an obstructive sleep apnea syndrome (OSAS).

MATERIALS AND METHODS

Only primary OSCC cases of the tongue or floor of the mouth which were operated and reconstructed. The PAS displayed in computed tomography (CT) scans at three time points were analyzed: t0 = preoperative, t1 = first postoperative CT, and t2 = most recent situation. The following three PAS parameters were calculated: minimum cross-sectional area (minCSA), mean cross-sectional area (meanCSA), and volume.

RESULTS

MinCSA increased from t0 to t2: t0 = 86.9 cm2 (0.0 - 251.8), t1 = 106.6 cm2 (1.0 - 483.4), and t2 = 124.8 cm2 (0.5 - 395.6). MeanCSA increased from t0 to t2: t0 = 225.1 cm2 (79.0 - 500.2), t1 = 247.8 cm2 (102.8 - 674.3), and t2 = 272.2 cm2 (92.2 - 668.4). The volume increased from t0 to t2: t0 = 21.5 cm3 (8.0 - 63.2), t1 = 24.1 cm3 (9.6 - 67.3), and t2 = 26.9 cm3 (6.2 - 67.4).

CONCLUSIONS

Posterior airway space PAS values became higher than preoperatively. In particular, flap type had a significant influence on the three PAS parameters.

Maxilla management in "phase II" skeletal surgery for obstructive sleep apnea

This study investigates the management of patients with obstructive sleep apnea (OSA) who have previously undergone palatal surgery and subsequently undergo maxillomandibular advancement (MMA). The research entails a retrospective analysis of phase II MMA cases from 2017 to 2022. Data encompassing demographics, clinical profiles, pre- and post-operative polysomnographic and radiological findings, surgical techniques, and complications were collected. Out of the 14 patients studied, conservative vestibular approaches were applied universally, with four cases necessitating the sectioning of descending palatine arteries. Results indicate an average maxillary sagittal advancement of 10.07 mm, a mean counterclockwise rotation of the maxillary occlusal plane at 9.35°, and a decline in apnea-hypopnea index from 45.5 to 4.5 events per hour. Surgical success and cure rates were 93.3% and 40%, respectively, with no major complications observed throughout the 45-month follow-up. This study underscores the safe and efficacious application of MMA in OSA patients with prior palatal surgery, offering valuable insights into their management.

Effects of distraction osteogenesis with Le Fort osteotomies on upper airway volumes: a systematic review and meta-analyses

OBJECTIVE

Distraction osteogenesis is one of the treatment options in patients with severe maxillomandibular abnormalities to treat morphological and respiratory problems (obstructive sleep apnea syndrome). The study aimed to evaluate the effect of Le Fort I, II and III distraction osteogenesis (DO) on upper airway dimensions and respiratory function.

METHODS

Electronic search was performed in PubMed, Scopus, Embase, Google Scholar and Cochrane databases. Studies that only involved two dimensional analyses were excluded. Besides, studies that performed DO in conjunction with orthognathic surgery were not considered. NIH quality assessment tool was used to evaluate the risk of bias. Meta-analyses were performed to assess sleep apnea indices and the mean differences in the airway dimensions before and after DO. Gradings of Recommendations, Assessment, Development and Evaluation were used to analyze the evidence level.

RESULTS

Among the 114 studies that went under full-text analyses, 11 articles met the inclusion criteria. Results of the quantitative analyses showed that maxillary Le Fort III DO significantly increased the amounts of oropharyngeal, pharyngeal and upper airway volumes. However, apnea-hypopnea index (AHI) showed a non-significant improvement after this procedure. Besides, the dimensions of the airways increased with Le Fort I and II DO, according to a qualitative analysis. Considering the design of the included studies, our results had a low level of evidence.

CONCLUSION

Maxillary Le Fort DO does not significantly impact AHI, while it significantly increases the airway dimensions. Meanwhile, multicentric studies with standardized evaluation are still required to confirm the effects of maxillary Le Fort DO on airway obstruction.

The Assessment of Upper Airway Volume Changes Following Bimaxillary Advancement Surgery: A Radiological Evaluation in the Supine Position at Multiple Intervals

Background: Bimaxillary surgeries (BiMax) are an essential part of the craniomaxillofacial specialty. The osteotomies and subsequent spatial rearrangement of the maxilla and the mandible enable the correction of facial deformities, asymmetry, and malocclusion. Moreover, the movements performed during the procedure affect the morphology of surrounding soft tissues, including the upper airway (UA). Objectives: The objective of this study was to radiologically assess the potential volumetric alterations of the UA in the supine position at various intervals following BiMax advancement surgeries. Methods: A group of 31 patients who underwent BiMax advancement surgery were included in the study. Medical computed tomography (CT) of the head and neck region was performed 2 weeks preoperatively, 1 day postoperatively, and 6 months postoperatively. The UA volumes were calculated and analyzed based on the acquired Digital Imaging and Communications in Medicine (DICOM) files using different software applications. The sella-nasion-A point (SNA) and sella-nasion-B point (SNB) angles were evaluated to measure the achieved maxillomandibular advancement. Results: When comparing the volume of the UA before surgery, post-surgery, and 6 months post-surgery, the p-value was <0.001, indicating statistically significant differences in UA volume between the successive examinations. A statistically significant difference was found between UA volume before surgery and 6 months post-surgery and between UA volume after surgery and 6 months post-surgery, with the obtained p-values being <0.001 and 0.001, respectively. A significantly larger UA volume was observed 6 months post-surgery (mean ± SD: 27.3 ± 7.3) compared to the volume before surgery (mean ± SD: 22.2 ± 6.4), as well as 6 months post-surgery compared to the volume assessed shortly after surgery (mean ± SD: 24.2 ± 7.3). Conclusions: BiMax advancement surgeries result in the significant enlargement of the UA. The volume of the UA does not diminish immediately following the procedure and is not constant; it increases significantly during the postoperative observation period.

The Incidence of Obstructive Sleep Apnea in Patients with Dento-Skeletal Malformation

Purpose: The aim of this article is to analyze the incidence of undiagnosed obstructive sleep apnea (OSA) in patients affected by dento-skeletal malformation. We also evaluated the patterns most affected by the condition and calculated the post surgical changes. Methods: We conducted a retrospective cohort study on 71 patients including 35 men and 36 women. The patients studied were affected by dento-skeletal class II and III malformations and underwent bimaxillary orthognathic surgery in all cases. Patients were evaluated with polysomnography before surgery and at least 6 months after surgery to assess any improvement or worsening of the apnea hypopnea index (AHI) index. Regarding AHI evaluation criteria, an AHI > 5 was considered indicative of OSA, 4 < AHI < 5 was considered borderline and AHI < 4 was considered indicative of non-OSA. We also considered demographic variables like age at the time of intervention and gender, and anatomical variables like the pattern of the dento-skeletal deformity and the presence or absence of maxillary hypoplasia. Qualitative variables were described as absolute and relative frequencies, while quantitative variables were summarized as mean and standard deviation. To quantitatively express the relationship between two variables, the correlation coefficient was calculated. The covariance array was used to evaluate multiple correlations. Results: Our study shows that there is a significant percentage (33%) of patients who undergo orthognathic surgery with an AHI > 5 and also a percentage of patients (11%) who can be considered to be "borderline." It emerges that the pattern most at risk is the one characterized by retruded maxilla and patients with dento-skeletal class II. Considering the post surgical period, the statistical analysis shows that after surgery, only 8% of malformed patients present an AHI > 5, compared to the 20.5% described in the Italian population. Conclusions: In patients who receive orthognathic surgery, the presence of obstructive sleep apnea is significantly higher than in the general population. When planning the surgical correction of a dento-skeletal malformation, the surgeon must aim not only for the esthetics results, but also for proper stomatognathic and respiratory function; this cannot be achieved without taking polysomnography information into account.

Interdisciplinary Role of Orthodontist in Screening and Managing Obstructive Sleep Apnea in Children and Adults

Obstructive sleep apnea (OSA) can affect children and adults, and, if left untreated, could have a major impact on the general and overall well-being of the patient. Dental health care providers and orthodontists have an interdisciplinary role in screening patients at risk for OSA and make a referral to establish a definitive diagnosis by a sleep physician. The gold standard of diagnostic testing is polysomnography. The adeno-tonsillar hypertrophy is the primary cause of sleep apnea in children; therefore, adeno-tonsillectomy must be the first line of treatment. Post adeno-tonsillectomy, if there is residual OSA due to underlying skeletal discrepancy, the patient may be referred to an orthodontist for appropriate management. Currently the evidence in the literature for prophylactic growth modification in children to prevent OSA is weak. In adults, the gold standard for managing OSA is Positive Airway Pressure (PAP) therapy; however, adherence to this treatment is rather low. The oral appliance (OA) therapy is an alternate for PAP intolerant patients and for mild to moderate OSA patients. The OA therapy has to be administered by a qualified dentist or orthodontist after careful examination of dental and periodontal health as well as any pre-existing joint conditions. The OA therapy could cause OA-associated malocclusion and patients have to be made aware of prior to initiating treatment. In patients with severe OSA, surgical maxilla-mandibular advancement (MMA) is highly effective.

Does Aesthetic Osseous Genioplasty Impact Upper Airway Volume?

BACKGROUND

Although maxillomandibular advancement is the treatment of choice for obstructive sleep apnea syndrome (OSAS) in the presence of underlying maxillomandibular complex hypoplasia, there is still a gap in the literature regarding the impact of genioplasty upon upper airway volume (UAV).

OBJECTIVES

The aim of this study was to evaluate the impact of isolated osseous genioplasty upon UAV.

METHODS

A retrospective analysis of all patients subjected to isolated osseous genioplasty between July 2015 and July 2022 was conducted. Cone-beam computed tomography was performed preoperatively and postoperatively to assess the chin and hyoid 3-dimensional (3D) spatial position and UAV changes after surgery.

RESULTS

A total of 44 patients were included in the study. Regarding surgical movements of the chin, almost all patients received a sagittal movement (n = 42; 39 forward and 3 backward), while in 8 patients a vertical movement (5 upward and 3 downward) was applied, and in 6 patients the chin was centered. Statistically significant increases in total UAV (P = .014) and at the level of the oropharynx (P = .004) were observed. Specifically, chin centering, upward and forward movements enlarged the oropharynx volume (P = .006, .043 and .065, respectively). Chin advancement enlarged the hypopharynx volume (P = .032), as did upward movement of the hyoid bone (P < .001).

CONCLUSIONS

Results of the study suggest that aesthetic osseous genioplasty impacts the UAV: each 3D spatial chin movement differently impacts the upper airway by enlarging or narrowing it. However, further studies addressing the apnea-hypopnea index are required to assess its effectiveness in treating OSAS.

LEVEL OF EVIDENCE: 4

Bilateral sagittal split osteotomy with or without concomitant removal of third molars: a retrospective cohort study of related complications and bone healing

PURPOSE

To carry out a comparative evaluation of the intra- and postoperative complications, and bone healing, following bilateral sagittal split osteotomy (BSSO) with or without concomitant removal of third molars.

MATERIAL AND METHODS

A retrospective analysis was performed of two cohorts subjected to BSSO with the intraoperative removal of third molars (test group) versus the removal of third molars at least 6 months prior to BSSO (control group), comprising at least 1 year of clinical and radiographic follow-up. Partially or completely erupted third molars were extracted immediately before completing the osteotomy, whereas impacted third molars were removed after the osteotomy had been performed. Hardware reinforcement was performed in bimaxillary cases where concomitant molar extraction impeded placement of the retromolar bicortical screw of the hybrid technique.

RESULTS

A total of 80 surgical sites were included (40 in each group). Concomitant extraction of the molar represented a mean increase in surgery time of 3.7 min (p < 0.001). No additional complications occurred in the test group (p = 0.476). The gain in bone density was preserved in both groups (p = 0.002), and the increase was of the same magnitude in both (p = 0.342), despite the fact that the immediate and final postoperative bone densities were significantly higher in the control group (p = 0.020).

CONCLUSION

The results obtained support concomitant molar extraction with BSSO as a feasible option.

Does orthognathic surgery have an incidentally beneficial effect on mild or asymptomatic sleep apnoea?

A prospective study was performed to assess the effect of orthognathic surgery on mild obstructive sleep apnoea (OSA) in patients with an underlying dentofacial deformity treated for occlusal and/or aesthetic reasons. As the main outcome variables, changes in upper airway volume and apnoea-hypopnoea index (AHI) were evaluated at 1 and 12 months of follow-up, in patients undergoing orthognathic surgery with widening movements of the maxillomandibular complex. Descriptive, bivariate, and correlation analyses were performed; significance was set at P < 0.05. Eighteen patients diagnosed with mild OSA were enroled (mean age 39.8 ± 10.0 years). An overall upper airway volume widening of 46.7% after orthognathic surgery was observed at 12 months of follow-up. The AHI decreased significantly from a median 7.7 events/hour preoperatively to 5.0 events/h at 12 months postoperative (P = 0.045), and the Epworth Sleepiness Scale score decreased from a median 9.5 preoperatively to 7 at 12 months postoperative (P = 0.009). A cure rate of 50% was obtained at 12 months of follow-up (P = 0.009). Despite the limited sample size, this study provides evidence that in patients with an underlying retrusive dentofacial deformity and mild OSA, a slight decrease in AHI is obtained after orthognathic surgery due to upper airway enlargement, which could be added as a beneficial effect of orthognathic surgery.

Current Trends in Orthognathic Surgery

Orthognathic surgery has evolved significantly over the past century. Osteotomies of the midface and mandible are contemporaneously used to perform independent or coordinated movements to address functional and aesthetic problems. Specific advances in the past twenty years include increasing fidelity with computer-assisted planning, the use of patient-specific fixation, expanding indications for management of upper airway obstruction, and shifts in orthodontic-surgical paradigms. This review article serves to highlight the contemporary practice of orthognathic surgery.

Maxillomandibular advancement is a safe procedure in patients with obstructive sleep apnoea. Results of a retrospective study

Obstructive sleep apnoea (OSA) is a syndrome with a high burden on public health. Maxillomandibular advancement (MMA) has proven to be a highly effective treatment option. This retrospective analysis evaluated the safety of maxillomandibular advancement with rotation in patients with OSA. A total of 63 patients with OSA were included in this study. Surgical treatment by maxillomandibular advancement was virtually planned based on preoperative cone beam computed tomography (CBCT). A 3D printed guide and a customised implant were used for surgical transfer. The safety of MMA was evaluated based on the necessity of postoperative intermediate care unit (IMCU) stay, duration of stay in hospital, and recording of medical complications. A total of 63.5% of the OSA patients treated by MMA (n = 40/63) were postoperatively transferred from the recovery room directly to the regular ward, while 36.5% of the patients (n = 23/63) stayed on IMCU for at least one night. On average, the length of hospitalisation was four days after surgery. One patient from the ward group and one patient from the IMCU group developed a major complication according to Clavian-Dindo classification grade IV. MMA is a safe surgical procedure. The necessity for postoperative monitoring in an IMCU setting should be based on an individual risk evaluation. However, since major complications can occur, MMA should be performed as an inpatient procedure in a hospital with available intensive medicine care. This study underlines the safety of MMA in OSA patients.

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.

Three-dimensional evaluation of postoperative stability: a comparative study between surgery-first and surgery-late protocols

The main objective of this study was to compare the stability of the surgery-first and surgery-late approaches according to the standardized centre protocols, by three-dimensional evaluation after 1 year of follow-up. A retrospective study was designed that included a test group (surgery-first protocol) and a control group (surgery-late protocol), with a follow-up period of at least 1 year (average 14 months; range 12-24 months). Stability was evaluated using linear and angular measurements by superimposing cone beam computed tomography images obtained at specific points in time: preoperatively, 1 month after surgery, and at the end of the orthodontic treatment. A total of 56 patients with a mean age of 32.2 ± 11.1 years were included in the study. After surgery there were significant changes in all of the measurements in at least one dimension in both groups (except for the transverse maxillary dimension), which remained stable at the end of the treatment, with no statistically significant differences between the two groups. At the 1-year follow-up, both groups presented a SNA angle relapse; this relapse was more significant in the surgery-late group (P = 0.031) and was present only in Class III patients (P = 0.013). In conclusion, an equivalent three-dimensional stability between surgery-first and surgery-late protocols was demonstrated after 1 year of follow-up when eligibility criteria were strictly adhered to.

Accuracy of Orthognathic Surgical Planning using Three-dimensional Virtual Techniques compared with Conventional Two-dimensional Techniques: a Systematic Review

Objectives

The objective was to assess the accuracy of orthognathic surgical planning using three-dimensional virtual planning compared with conventional two-dimensional planning.

Material and Methods

MEDLINE (PubMed), Embase and Cochrane Library search combined with hand-search of relevant journals was conducted to identify randomized controlled trials (RCTs) published in English through August 2^nd, 2022. Primary outcomes included postsurgical accuracy of hard and soft tissue. Secondary outcomes included treatment planning time, intraoperative time, intraoperative blood loss, complications, financial expenses, and patient-reported outcome measures (PROMs). Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool and GRADE system.

Results

Seven RCTs characterised by low, high, and unclear risk of bias fulfilled inclusion criteria. Included studies disclosed conflicting results regarding accuracy of hard and soft tissue as well as treatment planning time. The intraoperative time was shortened, and financial expenses were increased with three-dimensional virtual surgical planning (TVSP), while no planning-related complications were revealed. Comparable improvement in PROMs were reported with TVSP and two-dimensional planning.

Conclusions

Future orthognathic surgical planning will indisputable be performed by three-dimensional virtual planning. The financial expenses, treatment planning time, and intraoperative time will therefore probably decrease due to further development of three-dimensional virtual planning techniques. The hard and soft tissue accuracy between planned position and achieved surgical outcome seems to be improved by three-dimensional virtual planning compared with two-dimensional planning, although results are inconsistent. Further development of three-dimensional virtual planning involving cutting guides and patient-specific osteosynthesis plates are therefore needed to improve the accuracy of orthognathic surgical planning.

Efficiency of maxillomandibular advancement for the treatment of obstructive apnea syndrome: a comprehensive overview of systematic reviews

OBJECTIVES

To evaluate the efficiency of maxillomandibular advancement using aggregated individual patient data from multiple studies.

MATERIALS AND METHODS

This overview was structured according to the PICO strategy. It adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist and was recorded on the international prospective register of systematic reviews (PROSPERO-CRD42020206135). Searches were conducted in the PubMed/MEDLINE, Scopus, Embase, Web of Science, LILACS, and Cochrane databases for studies published until January 1, 2021. Data from the included studies were collected by one author, while another reviewed the compilation.

RESULTS

Twelve systematic reviews were included. The outcome measures studied were the apnea-hypopnea index, respiratory disturbance index, mean oxygen saturation, lowest oxygen saturation, sleepiness data, posterior air space, sella-nasion point A angle, sella-nasion point B angle, surgical success, and surgical cure in patients who underwent surgery. The AMSTAR scale presented moderate evaluations, with grades varying between 6 and 10 points. The Glenny scale revealed that the study selection did not include all languages. Only three reviews identified quality assessments conducted by at least two reviewers and only five related possible searches for unpublished data.

CONCLUSIONS

Bimaxillary advancement surgery improved respiratory indicators, sleepiness data, and increased upper airway size. However, it is necessary to standardize the surgical criteria to establish measurable efficiency of the procedure.

CLINICAL RELEVANCE

This overview makes a critical analysis of the results of the selected systematic reviews with the aim of presenting the most clinically relevant data on the maxillomandibular advancement for treating obstructive apnea syndrome, with a focus on improving respiratory, anatomical, and quality of life indices. There are no overviews that approach this theme from a well-structured perspective.

Resistance Training of Inspiratory Muscles After Coronary Artery Disease May Improve Obstructive Sleep Apnea in Outpatient Cardiac Rehabilitation: RICAOS Study

Background

Obstructive sleep apnea (OSA) affects 5% of the adult population and its prevalence is up to 13 times higher in coronary artery disease (CAD) patients. However, OSA in this population is less symptomatic, leading to lower adherence to positive airway pressure (CPAP). While oropharyngeal exercise showed a significant decrease in apnea-hypopnea index (AHI) in patients with moderate OSA, there have been no studies testing the impact of specific inspiratory muscle training (IMT) for these patients. The aim of our study was to assess the effectiveness of IMT on AHI reduction in CAD patients with moderate OSA.

Methods

We included patients with CAD involved in a cardiac rehabilitation program and presenting an AHI between 15 and 30. Patients were randomized in a 1:1 allocation to a control group (CTL – classic training) or an IMT group (classic training + IMT). IMT consisted in 60 deep inspirations a day, 6 days a week, into a resistive load device set at 70% of the maximum inspiratory pressure (MIP). After 6 weeks, we compared AHI, neck circumference, Epworth Sleepiness Scale, Pittsburgh Sleep Quality index, and quality of life with the 12-item Short Form Survey before and after rehabilitation.

Results

We studied 45 patient (60 ± 9 y, BMI = 27 ± 6 kg.m⁻²). The IMT group (n = 22) significantly improved MIP ( p < 0.05) and had a significant decrease in AHI by 25% (−6.5 ± 9.5, p = 0.02). In the CTL group (n = 23), AHI decreased only by 3.5% (−0.7 ± 13.1; p = 0.29). Between groups, we found a significant improvement in MIP ( p = 0.003) and neck circumference ( p = 0.01) in favor of the IMT group. However, we did not find any significant improvement of AHI in the IMT group compared to CTL ( p = 0.09).

Conclusion

A specific IMT during cardiac rehabilitation contributes to reduce significantly AHI in CAD patients with moderate OSA. Magnitude of the decrease in OSA severity could be enhanced according to implementation of specific IMT in this population.

Long-term three-dimensional effects of orthognathic surgery on the pharyngeal airways: a prospective study in 128 healthy patients

OBJECTIVE

To investigate volumetric and circumferential pharyngeal airway space (PAS) changes and stability over time as evaluated with cone beam computed tomography (CBCT) before and after orthognathic surgery 2 years postoperatively.

MATERIALS AND METHODS

One hundred twenty-eight patients underwent bimaxillary orthognathic surgery at the Department of Maxillofacial Surgery of University Hospitals, Leuven, Belgium, were recruited prospectively. Patients were divided into 4 groups based on the amount of mandibular advancement in 5 mm increments (< 0 mm, 0-5 mm, 5-10 mm, or > 10 mm). CBCT data was acquired preoperatively and 1-6 weeks, 6 months, 1 year, and 2 years postoperatively. Patients with a history of maxillofacial trauma or surgery, obstructive sleep apnoea syndrome, or craniofacial anomalies were excluded. Nasopharyngeal, oropharyngeal, and hypopharyngeal PAS volumes and constriction surface areas (mCSA) were measured and compared between each time point with a paired t-test.

RESULTS

The largest significant increase in oropharyngeal volume and mCSA were observed in the 5-10 mm (+ 13.3-21.7%, + 51.3-83.0%)) and > 10 mm (+ 23.3-44.6%, + 92.3-130.0%) mandibular advancement groups. This increase only remained stable 2 years postoperatively in the > 10 mm group. In other mandibular advancement groups, short-term oropharyngeal volume and mCSA increases were noticed, which returned to baseline levels 6 months to 1 year postoperatively.

CONCLUSION

Bimaxillary advancement osteotomy significantly increases oropharyngeal volume and mCSA, which remains stable between 6 months to 1 year postoperatively.

CLINICAL RELEVANCE

Long-term stable volumetric and mCSA enlargements were found with > 10 mm mandibular advancements over a period of 2 years. Return towards baseline levels was observed in the other mandibular advancement groups.

Upper Airway Changes in Diverse Orthodontic Looms: A Systematic Review and Meta-Analysis

Upper airway assessment is particularly important in the daily work of orthodontists, because of its close connection with the development of craniofacial structures and with other pathologies such as Obstructive Sleep Apnea Syndrome (OSAS). Three-dimensional cone-beam computed tomography images provide a more reliable and comprehensive tool for airway assessment and volumetric measurements. However, the association between upper airway dimensions and skeletal malocclusion is unclear. Therefore, the current systematic review evaluates the effects of different surgical movements on the upper airway. Materials and Methods: Medline (PubMed, OVID Medline, and EBSCO), Cochrane Library (Cochrane Review and Trails), Web of Knowledge (social science, and conference abstracts), Embase (European studies, pharmacological literature, and conference abstracts), CINAHL (nursing and allied health), PsycInfo (psychology and psychiatry), SCOPUS (conference abstracts, and scientific web pages), and ERIC (education) databases were searched. Two authors independently performed the literature search, selection, quality assessment, and data extraction. Inclusion criteria encompassed computed tomography evaluations of the upper airway spaces with retrospective, prospective, and randomised clinical trial study designs. To grade the methodological quality of the included studies a GRADE risk of bias tool was used. Results and conclusion: In total, 29 studies were included. Among these, 17 studies had a low risk of bias, whereas 10 studies had a moderate risk of bias. A meta-analysis was performed with the mean differences using a fixed-effects model. Heterogeneity was assessed with the Q-test and the I2 index. The meta-analysis revealed significant (p ≤ 0.001, 95% confidence interval) increases in upper airway volume after rapid maxillary expansion and surgical advancement for the correction of Class II.

Correlation Analysis between Three-Dimensional Changes in Pharyngeal Airway Space and Skeletal Changes in Patients with Skeletal Class II Malocclusion following Orthognathic Surgery

Introduction

Studies on the pharyngeal airway space (PAS) changes using three-dimensional computed tomography (CT) have shed more light on patients with Class III than Class II malocclusion. This paper focuses on analyzing the long-term changes in the PAS and evaluating the postoperative association between these PAS and skeletal changes in patients with skeletal Class II malocclusion who have undergone orthognathic surgery.

Methods

The records of 21 patients with skeletal Class II malocclusion who had undergone orthognathic surgery were included. The anatomical modifications in both jaws, changes in volume, sectional area (SA), minimum sectional area (MSA), and anterior-posterior (AP) and transverse (TV) width in the airway at one month before surgery (T0), and one month (T1) and one year (T2) after surgery were analyzed using CT images. The association between the skeletal and airway changes was evaluated between T0, T1, and T2.

Results

After surgery, the ANS, A point, and PNS demonstrated significant posterior and superior movement. The B point and the pogonion exhibited substantial anterior and superior movement. The total and inferior oropharyngeal volumes (vol 3, vol 4) notably increased, while the nasopharyngeal volume (vol 1) decreased. The anterior-posterior movement at the ANS and PNS after surgery was significantly associated with the total volume, vol 2, vol 3, SA 1, MSA, and TV width 1, while substantial association with the total volume was found at the pogonion.

Conclusion

Thus, an ideal treatment plan can be formulated for patients with skeletal Class II malocclusion by considering the postoperative PAS changes.

Three-dimensional pharyngeal airway space changes after bimaxillary advancement

INTRODUCTION

The probability of improvement in the upper airway space (UAS) with orthognathic surgery should be considered during the surgical-orthodontic treatment decision, providing not only an esthetic, but also a functional benefit for the patient.

OBJECTIVE

The purpose of this study was to evaluate the 3D changes in the upper airway space after maxillomandibular advancement surgery (MMA).

METHODS

A retrospective analysis of 56 patients, 21 male and 35 female, with a mean age of 35.8 ± 10.7 years, who underwent MMA was performed. Pre- and postoperative cone-beam computed tomography scans (CBCT) were obtained for each patient, and the changes in the UAS were compared using Dolphin Imaging 11.7 software. Two parameters of the pharyngeal airway space (PAS) were measured: airway volume (AV) and minimum axial area (MAA). Paired t-test was used to compare the data between T0 and T1, at 5% significance level.

RESULTS

There was a statistically significant increase in the UAS. Bimaxillary advancement surgery increased the AV and the MAA, on average, by 73.6 ± 74.75% and 113.5 ± 123.87%, respectively.

CONCLUSION

MMA surgery tends to cause significant increase in the UAS; however, this increase is largely variable.

Obstructive Sleep Apnea: A Surgeon's Perspective

Obstructive sleep apnea (OSA) is a complex medical disorder with significant impact on mortality, quality of life, and long-term cardiovascular outcomes. The apnea-hypopnea index does not correlate well with either quality-of-life measures or health outcomes, so other outcome measures must be evaluated in treatment of OSA. OSA can be successfully treated through behavioral, nonsurgical, and surgical methods with improvements in quality of life, morbidity, and mortality. Surgical intervention should be considered in patients who are noncompliant with or fail positive airway pressure use. As is true with PAP therapy, surgery for OSA improves mortality and symptoms of OSA even when the polysomnogram does not fully normalize.

Effects of maxillomandibular advancement surgery on a skeletal Class III patient with obstructive sleep apnea: A case report

This case report describes the successful surgical treatment of a patient diagnosed with obstructive sleep apnea (OSA). A 55-year-old Caucasian male patient with a body mass index (BMI) of 25.6 kg/m2 sought treatment with a chief concern of excessive daytime sleepiness and fatigue. An initial polysomnography report showed moderate OSA with an apnea-hypopnea index (AHI) of 21.2 events/h, and Epworth Sleepiness Score (ESS) of 12/24. The patient was initially prescribed with CPAP treatment but was unable to tolerate treatment after a few months. Clinical and radiographic examination revealed a concave facial profile with maxillary retrognathism. Intraoral examination revealed generalized gingival recession, missing upper lateral incisors and lower first premolars, anterior crossbite, and maxillary transverse deficiency with bilateral posterior crossbite. The lateral cephalogram showed a narrow posterior airway space at the level of the base of the tongue. The patient was treated with maxillomandibular advancement (MMA) surgery to improve airway obstruction. Results showed balanced facial esthetic and stable occlusion with a complete resolution of the patient’s OSA and a post-operative improvement of AHI from 21.2 to 0.7 events/h and ESS from 12/24 to 3/24. The lowest oxyhemoglobin saturation during sleep was improved to 97%, and the BMI decreased from 25.6 to 25.2 kg/m2. These results suggest that MMA surgical procedure can be used as a definitive treatment for patients with maxillomandibular deficiency and OSA.

Clinical and Research Solutions to Manage Obstructive Sleep Apnea: A Review

Obstructive sleep apnea (OSA), a common sleep disorder disease, affects millions of people. Without appropriate treatment, this disease can provoke several health-related risks including stroke and sudden death. A variety of treatments have been introduced to relieve OSA. The main present clinical treatments and undertaken research activities to improve the success rate of OSA were covered in this paper. Additionally, guidelines on choosing a suitable treatment based on scientific evidence and objective comparison were provided. This review paper specifically elaborated the clinically offered managements as well as the research activities to better treat OSA. We analyzed the methodology of each diagnostic and treatment method, the success rate, and the economic burden on the world. This review paper provided an evidence-based comparison of each treatment to guide patients and physicians, but there are some limitations that would affect the comparison result. Future research should consider the consistent follow-up period and a sufficient number of samples. With the development of implantable medical devices, hypoglossal nerve stimulation systems will be designed to be smart and miniature and one of the potential upcoming research topics. The transcutaneous electrical stimulation as a non-invasive potential treatment would be further investigated in a clinical setting. Meanwhile, no treatment can cure OSA due to the complicated etiology. To maximize the treatment success of OSA, a multidisciplinary and integrated management would be considered in the future.

Effects of surgical mandibular advancement on the upper airways of adult class II patients: A systematic review with meta-analysis

AIM

To systematically review the effects of surgical mandibular advancement (SMA) regarding changes of the upper airways in adult patients with skeletal Class II malocclusion.

MATERIALS AND METHODS

Five electronic databases were searched up to April 2020. Human studies focusing on the morphology and dimension of the upper airways after SMA were included. 'Quality assessment for Before-After (Pre-Post) Studies' was used to assess the risk of bias of the individual studies. Standard mean differences (SMD) with 95% confidence intervals (CI) were calculated for random effect model meta-analysis. The certainty of evidence was assessed using the GRADE tool.

RESULTS

Twenty cohort studies of only treated patients without control group were eligible for qualitative synthesis, of which 17 were used for quantitative synthesis. Very low certainty of evidence indicated that SMA resulted in significant increase of the volume and of the smallest cross-sectional area (SMC) of the nasopharynx (volume SMD: 1.43, CI: 0.62, 2.24, P = .001, I²  = 87.8%; SMC SMD: 1.53, CI: 0.59, 2.47, P = .001, I²  = 90.5%) and oropharynx (volume SMD: 1.36, CI: 0.37,2.35, P = .007, I²  = 92.1%; SMC SMD: 1.21, CI: 0.11,2.32, P = .032, I²  = 93.1%). Significant augmentation of the distances between the posterior pharynx wall and the uvala (SMD: 0.73, CI: 0.46,0.98, P < .001, I²  = 72.7%), the posterior border of the tongue (SMD: 0.52, CI: 0.21,0.84, P = .001; I² : 60.5%), the gonion (SMD: 1.24, CI: 0.56,1.91, P < .001; I²  = 88.8%) and the epiglottis (SMD: 0.40, CI: 0.06,0.74, P = .033; I²  = 84.8%) were observed.

CONCLUSIONS

Weak evidence suggests enlargement of the upper airways of adult Class II subjects following SMA, with major increases in the oropharynx.

Stability of fixation methods in large mandibular advancements after sagittal split ramus osteotomy: an in vitro biomechanical study

Sagittal split ramus osteotomy (SSRO) with large mandibular advancements is a common surgical procedure and could be indicated for patients with sleep apnoea. As a large variety of fixation methods is used for the stabilisation of SSRO, a biomechanical test model was used to analyse which fixation technique was most stable. For this in vitro study, 80 polyurethane hemimandibles with a prefabricated SSRO were used as substrates. Loads in Newtons were recorded at displacements of the mandibular incisive edge at 1mm, 3mm and 5mm. The samples were divided into two groups: mandibular advancements of 10mm and 15mm. In both groups, four fixation techniques were used: (A) one four-hole miniplate; (B) two four-hole miniplates; (C) one four-hole miniplate plus one bicortical screw; and (D) three bicortical screws in an inverted-L arrangement. In group 1, three bicortical screws resulted in the best stability, and in group 2, two miniplates resulted in the best stability. The use of two miniplates did not show significant differences between both groups. Other fixation methods showed more stability with 10mm advancements. This study therefore suggests that in SSRO with advancements exceeding 10mm, the use of two miniplates is the optimal means of providing rigid fixation.