Sleep-disordered breathing following mandibular setback: a systematic review of the literature

Exploring the relationship between the number of systematic reviews and quality of evidence: an orthognathic surgery-based study

OBJECTIVE

We analyzed the quality and quantity of systematic reviews (SRs) of orthognathic surgery, the most frequently published topic in maxillofacial surgery.

STUDY DESIGN

We searched the PubMed database for SRs of orthognathic surgery with no restriction on the language of publication date. We assessed the certainty of evidence presented according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol and the Leiden Manifesto using the Grading of Recommendations Assessment, Development, and Evaluation approach. We analyzed the data using descriptive statistics, Pearson´s correlation test, and linear regression.

RESULTS

Of the 171 SRs evaluated, approximately one fifth presented evidence with a high level of certainty. The number of orthognathic surgery SRs has been increasing, and many SRs were published after very similar topics had already been published. There is no relationship between the impact factor and the certainty of evidence.

CONCLUSIONS

An excessive number of SRs of orthognathic surgery are published, and many SRs are superfluous, simply reporting previous findings. Clinicians should not base treatment decisions solely on the evidence presented in SRs, and journal editors and reviewers should evaluate these SRs more critically, particularly when they address topics that have already been covered in the literature.

Upper Airway Changes and OSAS Risk in Patients after Mandibular Setback Surgery to Treat III Class Skeletal Malocclusion

INTRODUCTION

Mandibular setback surgery (MSS) is one of the treatment options to resolve mandibular prognathism in patients suffering from skeletal class III malocclusion, which cannot be treated with simple orthodontic treatment. The mandibular setback surgical operation can involve changes in the pharyngeal morphology, resulting in a narrowing of the posterior airway space (PAS). This aspect is associated with an increase in airflow resistance, which increases the risk of developing snoring or obstructive sleep apnea syndrome (OSAS). The aim of this study is to evaluate the medium- and long-term effects of mandibular setback surgery on the upper airways and its possible association with OSAS in patients suffering from class III skeletal malocclusion.

MATERIAL AND METHODS

A total of 12 patients (5 males and 7 females) were enrolled in this study. The statistical tests highlighted a significant change in the PAS and BMI values in relation to T0, before surgery (PAS: 12.7 SD: 1.2; BMI: 21.7 SD: 1.2), and T1, after surgery (PAS: 10.3 SD: 0.6, p < 0.01; BMI: 23.8 SD: 1.2, p < 0.05). Sample size was calculated to detect an effect size of 0.9, with statistical power set at 0.8 and the significance level set at 0.05.

RESULTS

No statistically significant correlation was found between the extent of mandibular setback, PAS and BMI change.

CONCLUSION

This study confirms the effects of mandibular setback surgery on the upper airways, reporting a statistically significant PAS reduction in the medium- and long-term follow-up. On the other hand, no direct correlation was identified with OSAS risk, at least for the small mandibular setback (<8 mm), despite the statistically significant increase in BMI.

What Is the Effect of Maxillary Impaction Orthognathic Surgery on Voice Characteristics? A Quasi-Experimental Study

Background

Regarding the impact of orthognathic surgery on the airway and voice, this study was carried out to investigate the effects of maxillary impaction surgery on patients' voices through acoustic analysis and articulation assessment.

Methods

This quasi-experimental, before-and-after, double-blind study aimed at examining the effects of maxillary impaction surgery on the voice of orthognathic surgery patients. Before the surgery, a speech therapist conducted acoustic analysis, which included fundament frequency (F0), Jitter, Shimmer, and the harmonic-to-noise ratio (HNR), as well as first, second, and third formants (F1, F2, and F3). The patient's age, sex, degree of maxillary deformity, and impaction were documented in a checklist. Voice analysis was repeated during follow-up appointments at one and six months after the surgery in a blinded manner. The data were statistically analyzed using SPSS 23, and the significance level was set at 0.05.

Results

Twenty two patients (18 females, 4 males) were examined, with ages ranging from 18 to 40 years and an average age of 25.54 years. F2, F3, HNR, and Shimmer demonstrated a significant increase over the investigation period compared to the initial phase of the study (P <0.001 for each). Conversely, the Jitter variable exhibited a significant decrease during the follow-up assessments in comparison to the initial phase of the study (P< 0.001).

Conclusion

Following maxillary impaction surgery, improvements in voice quality were observed compared to the preoperative condition. However, further studies with larger samples are needed to confirm the relevancy.

Quantitative changes of upper airway in class III patients undergoing bimaxillary surgery after one-year follow-up: a retrospective study

Background

Bimaxillary surgery is often performed for class III malocclusion, and its complex influence on the upper airway has been well considered. The aim of this research was to provide a scaled formula between upper airway volume changes and bone movements in Class III patients after orthognathic surgery.

Materials and methods

Using a retrospective study design, the investigators enrolled a total of 30 class III malocclusion patients who were undergoing bimaxillary surgery as the study subjects. The subjects included 15 males and 15 females, and their average age was 23.3 ± 3.4 years. CBCT (cone beam tomography) was performed both before and one year after the surgery for each patient. The changes in the soft palate, tongue and upper airway were measured by using CBCT data that was collected before and after surgery. 3D superimposition of CBCT was performed to calculate three-dimensional jaw movements. A multiple regression analysis was used to calculate the quantitative relationship between airway volume changes and jaw movements.

Results

The nasopharynx airway volume was observed to be increased by 1064.0 ± 1336.2 mm³, whereas the retropalatal and retroglossal airway volumes were observed to be decreased by 1399.0 ± 2881.6 mm³ and 1433.8 ± 3043.4 mm³, respectively, after the surgery. One millimetre forward and downward movements of the PNS resulted in increases of 626.90 mm³ and 392.18 mm³ in nasopharynx airway volume, respectively. Moreover, one millimetre retrogression of the B point caused decreases of 314.6 mm³ and 656.6 mm³ in the retropalatal and retroglossal airway volume, respectively. The changes in the soft palate contributed to the decrease in the retropalatal airway volume, whereas the tongue compensated for the decrease in the retroglossal airway volume.

Conclusion

The movements of the PNS and B points could be used to predict upper airway volumetric changes in Class III patients after maxillary advancement and mandibular setback.

Effect of Mandibular Setback Surgery on Tongue Length and Height and Its Correlation with Upper Airway Dimensions

Introduction

The changes in length and height of tongue following mandibular setback (MS) surgery may affect pharyngeal airway dimensions. There is limited literature correlating tongue dimensional changes with linear and volumetric airway changes following MS with bilateral sagittal split ramus osteotomy (BSSRO) in skeletal class III patients.

Materials and Methods

Treatment records of 18 patients who underwent MS with BSSRO were evaluated for changes in tongue and linear airway dimensions, mean airway volume and area at T1 (1-week pre-surgery), T2 (6-month post-surgery) and T3 (2-year post-surgery). Amount of MS was recorded from case sheets of patients. Mean tongue length reduced, whereas mean tongue height increased at T2 compared to T1 (P value = 0.001 for both). Linear, area and volumetric airway parameters at T2 were significantly reduced (P value = 0.001). All parameters showed statistically nonsignificant increase from T2 to T3 (P value > 0.05). Correlation analysis showed that change in tongue length at T3 did not show statistically significant correlation with amount of MS, changes in linear, area and volumetric airway parameters (P value > 0.05). However, the change in tongue height at T3 showed a significant (P value < 0.05) negative correlation (r value = - 0.742) with change in posterior airway space (PAS).

Conclusions

The appraisal of tongue length and height after MS surgery should be an integral part of diagnosis and treatment planning. The retro-positioning of tongue and increase in its height after MS surgery may compromise pharyngeal airway especially PAS. Additional options such as bi-jaw surgery, debulking of tongue volume and genioplasty should be explored to minimize adverse effects post-surgically.

Multislice computed tomography assessment of airway patency changes in the supine position following mandibular setback surgery for mandibular prognathism: A prospective 1-year follow-up study

Objectives:

The purpose of this study was to perform a three-dimensional analysis on the pharyngeal airway of supine patients who have undergone mandibular setback surgery, using multislice computed tomography (MSCT). We also measured the respiratory disturbance index pre- and post-surgery, using a portable sleep monitor.

Materials and Methods:

The subjects included two males and nine females who were diagnosed with mandibular prognathism at Hiroshima University Hospital and were scheduled to undergo the bilateral sagittal split osteotomy. Using a CT scanner, baseline MSCT images were obtained from the subjects before surgery for morphological analysis, and then the two further scans were obtained after mandibular setback surgery. All patients were provided with at-hoeme sleep monitor to use it both at baseline and approximately 1 year after surgery.

Results:

Middle and epiglottis pharyngeal space and cross-sectional area were significantly decreased immediately after setback surgery, but did not change further over the 1-year period. Mandibular setback was not associated with the development of sleep breathing disorder (SBD) during the 1-year follow-up period.

Conclusion:

We found no evidence that the reduction in the pharyngeal airway space immediately after mandibular setback surgery recovered significantly during the follow-up period, although mandibular setback was not associated with development of SBD.

The Effect of Bimaxillary Orthognathic Surgery on Voice Characteristics in Skeletal Class 3 Deformity Patients: An Evaluation Using Acoustic Analysis

ABSTRACT

The aim of this study was to analyze the effects of bimaxillary orthognathic surgery on the acoustic voice characteristics of skeletal class 3 patients. All healthy nonsyndromic patients with Class 3 deformity who were eligible for bimaxillary orthognathic surgery, were included in this before and after quasi-experimental study. This experiment's main intervention was mandibular setback surgery by bilateral sagittal split osteotomy plus maxillary advancement using LeFort 1 osteotomy. Age, sex, and intraoperative jaw movements were recorded. Acoustic analysis of voice samples (vowels /a/ and /i/) was performed with Praat software as outcome variables. The formant frequencies (F0, F1, F2, and F3) of these vowels were extracted 1 week preoperatively (T0), 1 and 6 months (T1, T2) postoperatively by a speech therapist. The significance level was set at 0.05 using SPSS 19. The study sample comprised 20 patients including 11 women (55%) and 9 men (45%) with a mean age of 31.95 ± 4.72 years. The average mandibular setback and maxillary advancement were 3.30 ± 0.86 and 2.85 ± 0.74 mm, respectively. The fundamental frequency (F0) and the first, second, and third formants (F1, F2, F3) of vowels /i/ and /a/ were significantly decreased over time intervals, postoperatively (P < 0.05). The finding revealed that bimaxillary orthognathic surgery (maxillary advancement and mandibular setback with bilateral sagittal split osteotomy) might reduce the acoustic formant parameters of voice to the normal frequency ranges, in patients with class 3 skeletal deformities. More clinical trials with greater sample sizes and long-term follow-ups are suggested in the future.

Does Bilateral Gap Arthroplasty Increase the Severity of Obstructive Sleep Apnea in Patients With Temporomandibular Joint Ankylosis?

PURPOSE

Obstructive sleep apnea (OSA) is common in patients with bilateral temporomandibular joint ankylosis (TMJA). The purpose of this study was to compare the preoperative and postoperative apnea-hypopnea index (AHI) in patients with TMJA undergoing bilateral gap arthroplasty (BGA).

METHODS

The investigators implemented a prospective cohort study on patients with bilateral TMJA treated with BGA. The primary predictor variable was time (before and after BGA). The primary outcome variable was AHI and secondary outcome variable included posterior airway space, skeletal changes, Epworth sleepiness scale, minimum oxygen_, average oxygen saturation, and maximal incisal opening at preoperative time (T0), 1 month (T1), and at 6 months (T2). The statistical test used were Greenhouse-Geisser test, repeated measure ANOVA (1 way), followed by post hoc Bonferroni test. The P-value was taken significant when <0.05 at a confidence interval of 95%.

RESULTS

The study sample included 12 (m:f = 1:2) patients of bilateral TMJA with a mean age of 14.9 ± 4.8 years and mean follow-up of 6 months. Mean duration of ankylosis was 10.5 ± 6.9 years (median = 12). Trauma was the main etiological factor in 11 (91.7%) patients followed by infection in 1 (8.3%) patient. The mean increase in AHI was 8.6 (T0 to T1) with P-value = .002 and 23.4 (T1 to T2) and was statistically significant (P = .001). The mean decrease in posterior airway space was 4.5 ± 1.0 to 3.5 ± 0.5 (T0 to T2) and was statistically significant (P = .02). Mean difference in minimum oxygen was 6.8 (P-value = .015). Skeletal changes are consistent with clockwise rotation of the mandible and statistically significant changes in horizontal and vertical dimension. The mean change in average oxygen was statistically insignificant (P = 1.0).

CONCLUSIONS

The present study concludes that gap arthroplasty in patients with bilateral TMJA can lead to development or worsening of pre-existing mild to moderate OSA. Ramus-condyle reconstruction should be performed to prevent the retropositioning of mandible and worsening of OSA.

Effect of surgical mandibular setback on the occurrence of obstructive sleep apnea

The aims were to assess the airway morphologic changes, and to evaluate sleep respiratory function and the occurrence of obstructive sleep apnea (OSA) after mandibular setback. Fifteen prognathism patients underwent bilateral sagittal split ramus (BSSRO) with or without maxilla surgery were grouped by distance of mandibular setback as group A (≤6 mm, n = 7) and group B (>6 mm, n = 8). Morphological changes were assessed using lateral cephalometric radiography and cone-beam computed tomography (CBCT) at preoperative (T0) and 6 months after surgery (T1). Sleep respiratory functions were evaluated using polysomonography. On lateral cephalometric radiography, group B showed significant decreased at Vp (p = 0.028) and PAS-p (p = 0.017). It also significant different between groups (p = 0.011 and p = 0.009 respectively). On CBCT, airway volume and AP width of airway, except Np, decreased in both groups but not significant different between groups. Only group A showed significant different between T0 and T1, cross-sectional area of Vp (p = 0.043), AP width of Vp (p = 0.043), Hp (p = 0.042), and PAS-t (p = 0.043). In group B, apnea hypopnea index increased at T1 (p = 0.043) and REM sleep differed between groups (p = 0.04). In conclusion, mandibular setback decreased the pharyngeal airway dimensions although no OSA occurred. It might be predisposing of OSA.

Is There an Increase in the Risk of Obstructive Sleep Apnea After Isolated Mandibular Setback Surgery? An Evaluation Using the STOP-BANG Questionnaire

PURPOSE

The aim of this study was to assess the impact of isolated mandibular setback surgery on the risk of obstructive sleep apnea (OSA), using the STOP-BANG questionnaire (SBQ).

PATIENTS AND METHODS

The authors implemented a double-blinded prospective quasi-experimental study. All healthy patients with skeletal Class III deformity older than 18 years were included in this study. They were candidates for isolated mandibular setback surgery. The SBQ was completed by the pulmonologist, 1 week preoperatively (T0), and 1 and 6 months postoperatively (T1 and T2, respectively). The mandibular setback displacement was the study intervention. The risk of OSA on the basis of the SBQ was the outcome variable. Descriptive and bivariate statistics were computed and the significance level was set at .05.

RESULTS

The sample comprised 30 patients (15 females, 15 males) with the average age of 25.77 ± 4.76. The mean score of SBQ at T0 was 1.37 ± 0.85, which increased to 2.33 ± 1.52 at T1 interval. However, it decreased significantly to 1.47 ± 1.17 at T2 interval (P < .001). T0-T1 and T0-T2 score differences were observed to be higher in the group with a mandibular setback repositioning greater than or equal to 5 mm (P < .005).

CONCLUSIONS

An isolated mandibular setback surgery less than 5 mm does not increase the risk for OSA in a young healthy nonsmoker Class III patient, according to the SBQ. Moreover, there was a significant increase in the risk for OSA when the setback was greater than or equal to 5 mm, measured at the mandibular incisor edge. Therefore, clinicians should be careful and discuss this potential increased risk with the patients, when this movement is required by the treatment plan. Further clinical trials are needed to support the relevancy.

Why most patients do not exhibit obstructive sleep apnea after mandibular setback surgery?

Maxillomandibular advancement (MMA) is effective for the treatment of obstructive sleep apnea (OSA). In previous studies, the airway was increased in the anteroposterior and transverse dimensions after MMA. However, the effect of the opposite of mandibular movement (mandibular setback) on the airway is still controversial. Mandibular setback surgery has been suggested to be one of the risk factors in the development of sleep apnea. Previous studies have found that mandibular setback surgery could reduce the total airway volume and posterior airway space significantly in both the one-jaw and two-jaw surgery groups. However, a direct cause-and-effect relationship between the mandibular setback and development of sleep apnea has not been clearly established. Moreover, there are only a few reported cases of postoperative OSA development after mandibular setback surgery.

These findings may be attributed to a fundamental difference in demographic variables such as age, sex, and body mass index (BMI) between patients with mandibular prognathism and patients with OSA. Another possibility is that the site of obstruction or pattern of obstruction may be different between the awake and sleep status in patients with OSA and mandibular prognathism. In a case-controlled study, information including the BMI and other presurgical conditions potentially related to OSA should be considered when evaluating the airway. In conclusion, the preoperative evaluation and management of co-morbid conditions would be essential for the prevention of OSA after mandibular setback surgery despite its low incidence.

Application of Computational Fluid Dynamics Analysis after Bimaxillary Orthognathic Surgery

Bimaxillary orthognathic surgery is widely used to treat skeletal class III malocclusion. Changes in jaw position affect the shape of surrounding soft tissues. We used computational fluid dynamics (CFD) simulation to observe changes in airways observed in a patient who underwent bimaxillary orthognathic surgery. For CFD simulation, we performed cone beam computed tomography (CBCT) preoperatively (T0), 3 days postoperatively (T1), and 7 months postoperatively (T2). The values of velocity, pressure drop (ΔP), and wall shear stress all increased 7 months after surgery (Vmax 7.038 m/s to 12.054 m/s, ΔP −7.723 Pa to −53.739 Pa, WSSmax 4.214 Pa to 14.323 Pa). Locations where the velocity and pressure gradients are large included the velopharynx, oropharynx, and epiglottis, with narrow cross-sectional areas. Wall shear stress was also observed at these locations. The velopharynx, oropharynx, and epiglottis are structures most vulnerable to morphological changes, that is, they can easily become obstructed.

Three-Dimensional Morphological Changes of the Upper Airway in Patients With Skeletal Class III Malocclusion After Orthognathic Surgery

OBJECTIVE

To evaluate the morphological changes of the upper airway of patients with skeletal Class III malocclusion after undergoing bilateral mandibular ramus dislocated mandibular retrogression (SSRO) or SSRO combined with Le Fort I maxillary osteotomy and 3-dimensional imaging.

METHODS

All previous studies related to the upper airway in patients with skeletal class III malocclusion and orthognathic surgery were collected from the PubMed, EMB, Cochrane Library, Web of science, ClinicalKey, EBSCO, Weipu, Wanfang, China National Knowledge Infrastructure, and Chinese BioMedical Literature databases. The search date ends in August 2017. RevMan5.3 software was used to perform a meta-analysis related to upper airway morphology. Ten studies were included.

RESULTS

The meta-analysis showed that 6 months after SSRO, CV1, and CV2 did not change significantly (P >0.05), whereas CV3 and CV4 narrowed (P <0.05) and remained narrow after 1 year (P <0.05). (CV1,CV2,CV3,CV4: Plans parallel to the FH plane passing through the most anterior inferior point of the anterior arch of the atlas, the 2nd cervical vertebra, the 3rd cervical vertebra, the 4th cervical vertebra.) There was no significant change in nasopharyngeal volume or laryngeal pharyngeal volume (P >0.05), but oropharyngeal volume and total volume decreased (P ≤0.01). Six months after SSRO combined with Le Fort I maxillary osteotomy, the minimum cross-sectional area of the upper airway was smaller (P <0.05), there was no significant change in nasopharyngeal volume or oropharyngeal volume (P >0.05), and oropharynx volume and total volume decreased (P <0.05).

CONCLUSIONS

Single and double jaw surgery has no significant effect on nasopharynx and oropharynx, but reduces laryngopharynx and total volume; however, whether this will result in postoperative obstructive sleep apnea-hypopnea syndrome or become ameliorated over time requires more in-depth study and a longer period of clinical observation.

Silent Changes in Sleep Quality Following Mandibular Setback Surgery in Patients with Skeletal Class III Malocclusion: A Prospective Study

Mandibular setback surgery (MSS) for skeletal class III patients can result in a relative reduction of pharyngeal airway space (PAS). Consequently, there is a possibility of the decline of sleep quality after surgery. We investigated changes in sleep quality measured by overnight polysomnography (PSG) and the three-dimensional (3D) volumes of PAS following MSS with or without Le Fort I osteotomy (LF I) in class III patients (N = 53). Overnight PSG and cone beam computed tomography were conducted at preoperative stage (T0) and postoperative 3 months (T1). Measurements of PAS volumes were performed, and the subjective symptoms of sleep were evaluated by self-questionnaires. There were significant increases in respiratory disturbance index (RDI) and total respiratory effort-related arousal (RERA) index during T0-T1. The 3D volumes of PAS showed significant decreases in the oropharyngeal airway, hypopharyngeal airway, and total airway spaces. No significant changes were observed in subjective symptoms of sleep. MSS with or without LF I for class III patients could worsen sleep quality by increasing sleep parameters such as the RDI and RERA in PSG, and reduce volumes of PAS at postoperative 3 months. Although subjective symptoms may not show significant changes, objective sleep quality in PSG might decrease after MSS.

Influence of mandibular setback surgery on three-dimensional pharyngeal airway changes

The aim of this study was to investigate the factors influencing three-dimensional changes in pharyngeal airway space after mandibular setback surgery. Airway changes in 48 skeletal class III patients who had undergone mandibular setback surgery alone (n=25, group 1) or with maxillary surgery (n=23, group 2) were analyzed. Linear parameters, cross-sectional area, and volumes of the pharyngeal airway were evaluated before (T0), immediately after (T1), and 1year after surgery (T2) by cone beam computed tomography. Although the reduced airway volume and cross-sectional area recovered slightly in the long term after surgery, the total pharyngeal airway volume (TPV) was significantly reduced compared to baseline, by 15% in group 1 and 12% in group 2. Regression analysis showed that maxillary posterior impaction in two-jaw surgery had a protective effect on preserving TPV. A change in body mass index from T0 to T2 was an important predictor of decreased TPV in one-jaw surgery patients. Maxillary posterior impaction can be a reliable option for compensating the pharyngeal airway reduction after mandibular setback surgery. Postoperative weight gain can increase the risk of postoperative pharyngeal airway reduction. Therefore, these factors need to be considered before and after mandibular setback surgery.

Three-dimensional analysis of changes in airway space after bimaxillary orthognathic surgery with maxillomandibular setback and their association with obstructive sleep apnea

Background

Bimaxillary orthognathic surgery with maxillomandibular setback is often accompanied by changes in airway space. We analyzed the changes in airway space before and after surgery and assessed their association with obstructive sleep apnea.

Methods

This study is based on the cohort of 13 adult patients (9 males, 4 females, average age 23.85 years) who underwent bimaxillary orthognathic surgery with maxillomandibular setback.We performed computed tomography and portable polysomnography before and after the surgery to assess changes in airway space and Apnea-Hypopnea Index (AHI) values (total, supine, non-supine).

Results

The oropharyngeal airway volume decreased by 29% after the surgery, which was statistically significant (p < .05). The upper airway volume and hypopharyngeal airway volume were decreased, but not significantly (4 and 19%, respectively). The changes in airway surface area were statistically significant at all levels examined (p < .05). Changes in the maximum anteroposterior width of the airway were also significant at all levels (p < .05). However, the changes in maximum lateral width were only statistically significant at C2 level (p < .05). AHI values were increased after the surgery but not significantly at any position.

Conclusions

Although bimaxillary surgery with maxillomandibular setback significantly reduces the airway space, it does not affect AHI values or induce obstructive sleep apnea.

Effects of mandibular setback with or without maxillary advancement osteotomies on pharyngeal airways: An overview of systematic reviews

Background

Mandibular setback osteotomies potentially lead to narrowing of the pharyngeal airways, subsequently resulting in post-surgical obstructive sleep apnea (OSA).

Objective

To summarize current evidence from systematic reviews that has evaluated pharyngeal airway changes after mandibular setback with or without concomitant upper jaw osteotomies.

Methodology

PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched with no restriction of language or date. Systematic reviews studying changes in pharyngeal airway dimensions and respiratory parameters after mandibular setback with or without concomitant upper jaw osteotomies have been identified, screened for eligibility, included and analyzed in this study.

Results

Six systematic reviews have been included. While isolated mandibular setback osteotomies result in reduced oropharyngeal airway dimensions, the reduction is lesser in cases with concomitant upper jaw osteotomies. Only scarce evidence exists currently to what happens to naso- and hypo-pharyngeal airways. There is no evidence for post-surgical OSA, even though some studies reported reduced respiratory parameters after single-jaw mandibular setback with or without concomitant upper jaw osteotomies.

Conclusion

Although mandibular setback osteotomies reduce pharyngeal airway dimensions, evidence confirming post-surgical OSA was not found. Nevertheless, potential post-surgical OSA should be taken into serious consideration during the treatment planning of particular orthognathic cases. As moderate evidence exists that double-jaw surgeries lead to less compromised post-surgical pharyngeal airways, they should be considered as the method of choice especially in cases with severe dentoskeletal Class III deformity.

Study registration

PROSPERO (registration number: CRD42016046484).