Postsurgical stability of oropharyngeal airway changes following counter-clockwise maxillo-mandibular advancement surgery

Evaluation of Minimum Axial Airway Area and Airway Volume in Orthognathic Surgery Patients

The aim of this study was to compare preoperative and postoperative linear, planar, and volumetric measurements in the pharyngeal airway in orthognathic surgery patients. Preoperative and postoperative cone beam computed tomography (CBCT) images of 60 patients, who underwent maxillary advancement with mandibular setback (Group I, n=25) and bimaxillary advancement (Group II, n=35), were compared. The airway was divided into 3 regions as nasopharynx, oropharynx, and hypopharynx. Linear and planar measurements were made on the reference sections of each region. The minimum axial airway area, the volume of 3 regions, and total airway volume were also measured. Regarding the linear, planar, and volumetric measurements, while there was a statistically significant increase in the measurements for all three regions in Group II, in Group I only the measurements in the nasopharyngeal region demonstrated a statistically significant increase postoperatively ( P <0.05). There was an increase in minimum axial airway areas in both groups; however, it was only statistically significant in Group II ( P <0.05). There was a statistically significant increase in total airway volumes in both groups ( P <0.05). A positive and good correlation was found between the percent increase in the minimum axial area and the percent increase in the total volume ( P <0.05). While bimaxillary advancement surgery results in a significant increase in the pharyngeal airway, mandibular setback with maxillary advancement caused an increase in the total airway. Changes that may occur in the airway should be considered while planning orthognathic surgery.

Maxillomandibular Advancement Efficacy in Obstructive Sleep Apnea Patients With Class 2 Versus 3 Dentofacial Deformity

OBJECTIVE

To compare the efficacy of maxillomandibular advancement (MMA) for patients with obstructive sleep apnea (OSA) with class 2 versus 3 dentofacial deformities (DFDs).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary sleep surgery center.

METHODS

Patients with OSA and DFD class 2 versus 3 undergoing MMA at Stanford Sleep Surgery between 2014 and 2021 were matched by preoperative body mass index (BMI), age, and sex. Postoperative outcome was compared with polysomnography measures and patient-reported outcome measures (PROMs).

RESULTS

Twenty-eight matched subjects, 14 in each deformity group were identified and assessed. The mean age (standard deviation) was 34.29 (10.21) and 33.86 (10.23) for classes 2 and 3, respectively. The apnea-hypopnea index (AHI) decreased from 43.42 (28.30) to 9.6 (5.29) (p < .001) and 37.17 (35.77) to 11.81 (15.74) (p = .042) in class 2 and 3 subjects, respectively. The oxygen desaturation index (ODI) changed from 30.48 (24.02) to 6.88 (3.39) (p = .024) and 11.43 (11.40) to 5.44 (7.96) (p = .85) in class 2 and 3 subjects, respectively. The Epworth sleepiness scale changed from 8.93 (5.28) to 3.91 (2.70) (p = .018) and 10.23 (4.38) to 4.22 (3.07) (p = .006) in class 2 and 3 subjects, respectively.

CONCLUSION

Among age, sex, and BMI-matched subjects, MMA is equally effective in both dentofacial class 2 and 3 groups, both objectively and subjectively. Preoperatively, dentofacial class 2 patients with OSA presented with the more severe disease with higher AHI and ODI. Dentofacial class 3 patients with OSA may require additional attention to improve nasal function outcomes.

Does Clockwise Rotation of Maxillomandibular Complex Using Surgery-First Approach to Correct Mandibular Prognathism Affect Surgical Movement and Stability?

PURPOSE

Orthognathic surgery (OGS) using the surgery-first approach (SFA) can decrease treatment time and increase patient satisfaction. Clockwise rotation (CWR) of the maxillomandibular complex to correct mandibular prognathism leads to optimized functional, aesthetic, and stable outcomes. This study examined the combined effect of SFA and CWR of the maxillomandibular complex to correct mandibular prognathism by comparing the surgical movement before (T0) and immediately after OGS (T1) and the stability between T1 and 12 months after OGS (T2).

METHODS

This prospective cohort study enrolled patients with skeletal Class III malocclusion who underwent SFA involving Le Fort I osteotomy and bilateral sagittal split osteotomy, with or without genioplasty. Based on the occlusal plane (OP) change at T0-T1, the patients were divided into CWR (OP > 4°) and control (C) groups (OP ≤ 4°). The predictor variable was OP change at T0-T1. The primary outcome variable was the stability of pogonion (Pog) at T1-T2. The covariates included demographic factors, cephalometric measurements (anterior facial height, posterior facial height, OP, mandibular plane angle, incisor mandibular plane angle, overjet, and overbite), and 3-dimensional landmark displacement (anterior nasal spine, A-point, upper central incisor, upper first molar, lower central incisor, lower first molar, Pog, gonion, and condylion). An independent t-test was used to compare between these 2 groups when appropriate. The level of significance was set at P < .05.

RESULTS

The sample included 28 patients (17 females) in the C group and 36 (24 females) in the CWR group; the mean ages were 23.89 ± 3.35 and 24.08 ± 4.02 years, respectively. For the surgical movement at T0-T1, the CWR group showed an association with vertical movement of the maxilla at posterior nasal spine (P = .005), anterior nasal spine (P < .001), and A-point (P < .001) and horizontal backward movement of the mandible at B-point (P < .001), Pog (P < .001), and gonion (P = .042). At T1-T2, all landmarks remained stable without clinically significant difference between the 2 groups.

CONCLUSION

Surgical movement in the CWR group could vertically displace the maxilla and setback mandible more than that in the C group. Postoperative skeletal stability remained the same between the 2 groups at 1 year after OGS.

The Effects of Occlusal Plane Inclination and Dental Decompensation on the Overall Result of Surgical Correction of Class II Malocclusion

PURPOSE

To evaluate the effects of upper occlusal plane (UOP) inclination and incisor decompensations on the outcome of surgical Class II patients.

MATERIALS AND METHODS

Pretreatment (T0), preoperative (T1), and posttreatment (T2) cephalograms of 30 surgical Class II patients were included. Cephalometric measurements were performed using the Dolphin Imaging Software in this retrospective study. The differences between time points were analyzed with repeated measures ANOVA. Spearman correlation test was used to determine any correlations between either the UOP alterations or incisor decompensations and the cephalometric variables.

RESULTS

A significant improvement was obtained in the sagittal skeletal, dental variables, and soft tissue B point. Significant correlations were found between the decompensation achievement ratio and the change of the convexity angle. The relative percentage ratio (RPR) of the lower incisor was correlated with Wits appraisal, ANB, and Convexity Angle at the T2 stage. The RPR of the upper incisor was found to be correlated with lip strain. The relative surgical correction ratio of the UOP angle was found to be correlated with the surgical change of Wits appraisal and convexity angle. The RPR of the UOP angle was correlated with the SNB, ANB, and SN-GOGN angles at the T2 stage.

CONCLUSIONS

Significant improvement in the incisor inclinations was achieved, but the incisors were inadequately decompensated at the preoperative phase. Surgical correction was limited by the inadequate presurgical decompensation. The surgical alteration of the UOP should be taken into consideration for the surgical planning to obtain better outcomes for Class II patients.

Comparison of oropharyngeal airway dimensional changes in patients with skeletal Class II and Class III malocclusions after orthognathic surgery and functional appliance treatment: A systematic review

Objective

To compare the dimensional changes in the oropharyngeal airway in patients with skeletal Class II and Class III malocclusion before and after orthognathic surgery and treatment with a functional appliance.

Methods

The protocol was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and was registered to the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42020170901. Furthermore, the reporting of the present SR was performed based on the PRISMA checklist.

Results

The use of removable functional appliances increased the volume of the oropharyngeal airway in patients with skeletal Class II malocclusion. Furthermore, the increase in the volume of the oropharyngeal airway following the removable functional appliance treatment was more than that observed after fixed functional appliance treatment in growing patients. For patients with skeletal Class III malocclusion, who underwent the bimaxillary orthognathic surgery, resulted in no change in the dimensions of the oropharyngeal airway.

Conclusion

Growing patients who receive removable functional appliance treatment have a more favorable long-term prognosis with regard to the oropharyngeal airway when compared with those who receive fixed functional appliance. Alternatively, in patients aged from (18–22) years with skeletal class III malocclusion Bimaxillary orthognathic surgery was found to be the recomended and superior method of treatment.

Does Combined Temporomandibular Joint Reconstruction With Patient-Fitted Total Joint Prosthesis and Orthognathic Surgery Provide Stable Skeletal and Occlusal Outcomes in Juvenile Idiopathic Arthritis Patients?

PURPOSE

To determine skeletal and occlusal surgical changes and long-term stability outcomes for patients diagnosed with juvenile idiopathic arthritis (JIA) after TMJ reconstruction with TMJ Concepts patient-fitted total joint prostheses (TJP) and concomitant maxillary orthognathic surgery.

MATERIAL/METHODS

A retrospective cohort study was conducted of all patients diagnosed with JIA, receiving TJP, and concomitant maxillary orthognathic surgery between 1991 and 2019, at Baylor University Medical Center treated by 1 surgeon. Patient evaluations presurgery (T1), immediate postsurgery (T2), and at longest follow-up (LFU) (T3) were analyzed using 20 cephalometric landmarks to compute 29 linear and angular measurements to determine surgical changes, long-term skeletal and occlusal stability, as well as oropharyngeal airway changes. Comparative data were tested for significance (α = 0.05) using paired and unpaired t tests.

RESULTS

Forty-two patients met the JIA inclusion criteria, with a median age of 17.5 years and median postsurgical follow-up of 26 months. There were significant surgical changes (T1-T2) (P ≤ .05) for all parameters associated with mandibular linear and angular surgical changes, except for the horizontal position of posterior nasal spine and the vertical/horizontal position of gonion, indicating highly stable surgical outcomes. There were significant improvements in the oropharyngeal airway dimensions.

CONCLUSIONS

This study suggests that TMJ Concepts patient-fitted TJP for TMJ reconstruction in conjunction with maxillary orthognathic surgery for counterclockwise rotation of the maxillo-mandibular complex for the JIA patients provides long-term skeletal and occlusal stability as well as dimensional improvement in the oropharyngeal airway.

Treacher Collins syndrome: Orthodontic treatment with mandibular distraction osteogenesis and orthognathic surgery

Interdisciplinary treatment for patients with Treacher Collins syndrome is challenging because of the rarity of the condition and the wide variety of phenotypic expression. A 23-year-old male was diagnosed with Treacher Collins syndrome with a history of severe obstructive sleep apnea. He presented with a Pruzansky-Kaban classification grade I mandible, skeletal type II pattern with a hyperdivergent mandibular plane, severe convex profile, and Class II malocclusion with a missing mandibular incisor. Improvement of facial esthetics was achieved by a combination of orthodontics, mandibular distraction osteogenesis, and 2-jaw maxillomandibular advancement surgery. Presurgical orthodontic treatment involved permanent tooth extraction to relieve severe crowding, and Class III mechanics were employed to increase overjet. Correction of mandibular hypoplasia by increasing ramal height and the mandibular length was done by intraoral mandibular distraction osteogenesis. Counterclockwise rotation of the mandibular plane angle and a Class III occlusion with negative overjet were achieved after mandibular distraction osteogenesis. A postdistraction posterior open bite was maintained with a biteplane during the consolidation period. Subsequently, 2-jaw orthognathic surgery was performed. LeFort I osteotomy was done for maxillary advancement to correct an anterior crossbite, eliminate canting, and reestablish occlusal contact at the mandibular occlusal plane. Bilateral sagittal split ramus osteotomy was done to correct the residual mandibular deviation. A genioplasty was also performed to improve chin projection. Postoperatively, the oropharyngeal airway was enlarged. The patient's facial profile and obstructive sleep apnea problem were improved as a result of advancement and counterclockwise rotation of the maxillomandibular complex.

Immediate three-dimensional changes in the oropharynx after different mandibular advancements in counterclockwise rotation orthognathic planning

Background

A retrospective cohort study was performed to evaluate the immediate effect on the oropharynx dimensions from different mandibular advancements in patients undergone counterclockwise rotation (CCW) of the maxillomandibular complex.

Material and Methods

138 CBCT images of patients, who had undergone orthognathic surgery, were identified from Dolphin Imaging archive according to pre- (T0) and post-operative (T1) times. Each pre-operative CBCT image was selected considering retrognathic mandible. Superimpositions of CBCT images were performed to measure mandibular advancement at B point in millimeters (mm) and divided into three groups: G1 (< 5 mm), G2 (between 5 and 10 mm) and G3 (> 10 mm). For evaluating oropharynx dimension at T0 and T1 for each group, medial sagittal area (MSA), volume, and minimum cross-sectional axial area (CSA) were measured on Dolphin Imaging. Pearson correlation verified reliability of method. Paired t-test were applied to compare values of measurements between T0 and T1 (p ≤ 0.05).

Results

88 CBCT images were included. Method was reliable (r ≥ 0.93). According to MSA, volume and CSA values from G1, there was no significant difference between T0 and T1. CSA values presented significant difference comparing T0 and T1 in G2 (p ≤ 0.05). In subjects of G3, measurements increased in T1 significantly affecting oropharynx dimension.

Conclusions

MSA, volume and CSA values showed a significant increase affecting upper airway in advancements higher than 10 mm. Mandibular advancement range showed different effects in the airway space and should be considered to achieve favorable post-operative results in the oropharynx dimensions.

Key words:Retrognathia, orthognathic surgery, three-dimensional imaging, oropharynx, airway.

Craniofacial and airway morphology of individuals with oculoauriculovertebral spectrum

OBJECTIVES

The objectives of this study were to characterize the craniofacial and airway morphology of oculo-auriculo-vertebral spectrum (OAVS) individuals using computed tomography (CT) examination.

SETTING AND SAMPLE POPULATION

This sample included individuals in the age range from 5 to 14 years, consisted of a group of 18 OAVS individuals (12 females and 6 males), Pruzansky-Kaban¹ IIB and III and by a paired control group matched by age and sex for comparison of morphometric and airway variables.

MATERIALS AND METHODS

Through the CT examination, airway analysis was performed using Dolphin Imaging® Software, and seven morphometric measurements were performed to evaluate craniofacial morphology by Materialize Mimics® Software. To compare airway and morphometric variables, the control group was used. Student's t test and Mann-Whitney U test were performed to compare differences between the groups.

RESULTS

Statistically significant differences were showed between the control and OAVS groups for the variables: total airway (TA) area, volume and MAA, RP area, RP volume, RP MAA, RG volume, RG MAA, total posterior height diff, Md incl and y-axis asymmetry. Pearson and Spearman's correlation showed mostly moderate correlations between Mand Occlusal canting AS with TA area and RP volume, Ax-Gn with TA area and Hy-C3 with TA volume.

CONCLUSIONS

The OAVS's airway was altered and worse than the control group. Our results suggest that the contralateral side of OAVS individuals is unaffected; however, longitudinal assessments are needed to confirm it. Hyoid bone and postural measures play an important role in interpreting airway features of individuals with and without OAVS.

Evaluation of Changes in the Pharyngeal Airway Space as a Sequele to Mandibular Advancement Surgery: A Cephalometric Study

PURPOSE

To evaluate effect of mandibular advancement on pharyngeal airway space using lateral cephalogram.

MATERIALS AND METHODS

Twenty patients who were diagnosed with class II skeletal malocclusion and underwent surgical intervention for the correction of their dentofacial deformity following orthodontic treatment were included. The soft tissue changes in the pharyngeal space were brought about by the surgical intervention, and the changes that had occurred in increasing the airway were evaluated by using cephalogram.

RESULTS

The results of this study showed that following mandibular advancement surgery, the pharyngeal airway space increased along with an increase in the length and thickness of the uvula with a reduction in the angulation. All the changes remained stable in the late postoperative phase.

CONCLUSION

Patients who underwent mandibular advancement showed a significant increase in the pharyngeal airway space and that remained stable during the evaluation period. As a consequence, mandibular advancement seems to be the most stable surgical movement in relation to airway dimensional gains.

Follow-up observation of patients with obstructive sleep apnea treated by maxillomandibular advancement

INTRODUCTION

This study aimed to evaluate the follow-up observation of patients with obstructive sleep apnea treated with maxillomandibular advancement (MMA) procedure with or without genial tubercle advancement (GTA).

METHODS

A total of 25 patients (mean age 37.1 ± 17.3 years) were included in the study. Cone-beam computed tomography scans were taken before treatment; after presurgical orthodontic treatment; immediately after MMA procedure; and follow-up visit. All Digital Imaging and Communications in Medicine files were analyzed using the Dolphin 3D Imaging software program (Dolphin Imaging and Management Solutions, Chatsworth, Calif) to determine the total airway volume (TAV), airway area (AA), and minimal cross-sectional area (MCA). Dolphin 3D voxel-based superimposition was used to determine the amount of skeletal advancement with MMA and changes after surgery.

RESULTS

Significant increase in TAV, AA, and MCA was found with MMA treatment (40.6%, 28.8%, and 56.4%, respectively, P <0.0001). Smaller but significant decrease in TAV, AA, and MCA was found during a follow-up visit (20.0%, 9.7%, and 26.8%, respectively, P <0.0001) giving a net increase of TAV, AA and MCA (35.8%, 27.1%, and 45.9%, respectively). No significant differences were found in any of the airway measurements with or without the GTA procedure. The average forward movements of the maxilla, mandible, and chin were 6.6 mm, 8.2 mm, and 11.4 mm, respectively. A relapse of less than 1 mm was found in each of the variables during the follow-up period. No correlation was found between the magnitudes of skeletal advancement and the change in oropharyngeal airway space (OPAS).

CONCLUSIONS

Significant increase in OPAS can be expected with MMA surgery with or without GTA procedure in patients diagnosed with obstructive sleep apnea. A partial loss in OPAS was found during the follow-up visit. The surgical movements were found to be stable, with less than 1 mm of relapse during the follow-up period, which was not clinically significant.

Independent risk factors for long-term skeletal relapse after mandibular advancement with bilateral sagittal split osteotomy

The purpose of this retrospective cohort study was to identify the independent risk factors for long-term skeletal relapse following mandibular advancement with bilateral sagittal split osteotomy. Univariate and multivariate linear regression analyses were performed including nine common risk factors for relapse as independent variables and horizontal/vertical long-term (≥2 years) skeletal relapse as dependent variables. Ninety-six patients were analyzed; 66 were female (68.8%) and the average age of the patients was 29.7±10.5 years. Over an average follow-up of 3.8±1.8 years after an initial mandibular advancement of 8.8±2.4 mm, long-term skeletal relapse of 1.6±1.0 mm horizontal and 0.9±0.7 mm vertical was found. Multivariate analysis identified age, preoperative mandibular plane angle (MPA), bimaxillary surgery, counterclockwise mandibular rotation, and the magnitude of mandibular advancement to be significantly associated with horizontal long-term skeletal relapse. Preoperative MPA, counterclockwise mandibular rotation, and the magnitude of mandibular advancement were significantly associated with vertical long-term skeletal relapse. Thus preoperative MPA, the magnitude of mandibular advancement, and counterclockwise mandibular rotation of the mandible were found to be independent risk factors for both horizontal and vertical long-term skeletal relapse. Although long-term skeletal relapse cannot be avoided entirely, understanding the independent risk factors and their contributions will optimize treatment planning and long-term stability.

Tomographic Analysis of the Impact of Mandibular Advancement Surgery on Increased Airway Volume

PURPOSE

This study aimed to quantify, using cone-beam computed tomography (CBCT) in patients who underwent a mandibular advancement surgery associated with genioplasty, three-dimensional changes in airway space and to evaluate whether these changes differ between men and women.

MATERIALS AND METHODS

Preoperative and 8-month postoperative CBCT scans of 38 patients aged 18-45 years of either sex and any ethnicity who underwent mandibular advancement surgery associated with genioplasty were analyzed using the Xoran software (Xoran Technologies, Ann Arbor, MI, USA). The linear distances gonion-gnathion (Go-Gn) and condylion-menton (Co-Me) were obtained. Airway volume was measured using the Dolphin Imaging software, version 11.0. Then, data were tabulated and analyzed using Student's t-test.

RESULTS

Mean patient age was 30.3 years; 39.47% were men and 60.63% were women. The mean Go-Gn distance was 72.05 mm before surgery and 78.56 mm after surgery, with a mean gain of 6.51 mm. The mean Co-Me distance was 113.47 mm before surgery and 119.89 mm after surgery, with a mean increase of 6.42 mm. Both differences were statistically significant. The mean volume of airway space was 17,272.92 mm3 before surgery and 24,173.74 mm3 after surgery, with a statistically significant mean increase of 6900.82 mm3. There was no statistically significant difference in mean volumetric gain between men (7566.69 mm3) and women (7456.69 mm3).

CONCLUSION

Mandibular advancement surgery results in significant increase of airway space, and there is no difference in airway volume between men and women.

Changes in posterior airway space and hyoid bone position after surgical mandibular advancement

OBJECTIVE

To evaluate cephalometric changes in posterior airway space (PAS) and in hyoid bone distance to mandibular plane (MP) 1-3 years after bilateral sagittal split osteotomy (BSSO).

MATERIAL AND METHODS

The sample consisted of 36 females and 16 males who underwent mandibular advancement by BSSO. To observe sagittal changes in PAS and in hyoid bone distance to MP both pre- and postoperative cephalograms were analyzed using WinCeph^® 8.0 software. For the statistical analyses paired T-test and multivariate logistic regression models were used.

RESULTS

By the surgical-orthognathic treatment the sagittal dimension of PAS showed variable changes but it mainly diminished when the mandibular advancement exceeded 6 mm. In most cases the hyoid bone moved superiorly by BSSO. Logistic regression models showed that males, patients with narrow PAS at the baseline, and those with counterclockwise rotation of the mandible by the treatment gained more increase in PAS. However, an increase in sagittal PAS dimension tended to relapse over time. Concerning the movement of the hyoid it was found that the more PAS increased the less hyoid moved superiorly. In males the change in hyoid position was more obvious than in females.

CONCLUSION

Males, patients with narrow PAS at the baseline, and those whose mandible moved in the counterclockwise direction with moderate advancement gained more retrolingual airway patency by BSSO.

Subtypes of Maxillomandibular Advancement Surgery for Patients With Obstructive Sleep Apnea

Maxillomandibular advancement (MMA) surgery, which is the most effective treatment modality for patients with moderate-to-severe obstructive sleep apnea with apparent skeletal discrepancies, has been modified in conjunction with segmental osteotomies, counterclockwise rotation of maxillomandibular complex, and other adjunctive procedures. However, any single type of MMA could not treat or cure all the patients with obstructive sleep apnea showing different dentofacial and pharyngeal patterns. We aimed to suggest critical decision factors for the selective application of MMA subtypes, categorized as straight MMA with genioplasty, rotational MMA, segmental MMA, and segmental-rotational MMA, in the surgical treatment objective process: anteroposterior position of maxilla, upper lip projection, overjet, lower incisor inclination as sagittal factors, and upper incisor exposure and occlusal plane angle as vertical factors. This case series deserves a clinical basis on the way of case-by-case application of the optimal MMA subtype based on the successful treatment outcomes with short-term stability.

Idiopathic intracranial hypertension eliminated by counterclockwise maxillomandibular advancement: a case report

INTRODUCTION

Obstructive sleep apnea (OSA) is a secondary cause of intracranial hypertension (IH). Decreased jugular venous drainage has been seen in patients with idiopathic IH.

CLINICAL PRESENTATION

A complex case of a 48-year-old female whose idiopathic IH was put into remission after counterclockwise maxillomandibular advancement (CC-MMA), despite persistence of her OSA.

CONCLUSION

This case highlights the relationship between OSA and IH and points to the significant morbidity that can result from mild OSA and from what are considered borderline intracranial pressures. This indicates the need for a high index of suspicion for actual underlying pathology that can be surgically corrected when patients manifest symptoms of a somatic syndrome. This is the first report in the medical literature of clinical elimination of IH by CC-MMA. The authors propose that this positive outcome was effected via mandibular advancement producing a decrease in jugular venous resistance, allowing improved absorption of cerebrospinal fluid.

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

INTRODUCTION

A mandibular setback reduces space in the pharyngeal airway, and it has been suggested that it might induce sleep-disordered breathing.

OBJECTIVES

An evidence-based literature review was conducted to identify the effect of mandibular setback on the respiratory function during sleep.

METHODS

The authors performed a systematic review of pertinent literature published up to 2014. A structured search of literature was performed, with predefined criteria. A survey of the PubMed, ScienceDirect, and Cochrane database was performed. A manual search of oral and maxillofacial surgery-related journals was accomplished. Potentially relevant studies then had their full-text publication reviewed.

RESULTS

A total of 1,780 publications were evaluated, through which nine papers (seven case series and two case-control studies) were selected for the final review. No evidence of sleep disorder after six months was related in 223 patients. In one study, two patients developed obstructive sleep apnea syndrome after surgery, and in another two studies, seven patients presented an increase of obstructive apneas/hypopneas events and oxygen desaturation index. Most of the patients analyzed were young and thin.

CONCLUSION

There was no evidence of postoperative sleep apnea syndrome after a mandibular setback surgery. However, one should always consider a potential reduction of the upper airway space during the treatment plan. Obese patients and those submitted to large amounts of mandibular setbacks present a higher chance to develop obstructive sleep apnea syndrome.

Modified maxillomandibular advancement for obstructive sleep apnoea: towards a better outcome for Asians

Excluding tracheostomy, maxillomandibular advancement (MMA) is the most effective surgical treatment for obstructive sleep apnoea (OSA). However, the anticipated facial changes may prevent acceptance of this procedure by patients with bimaxillary protrusion, a common feature of Asian faces. We therefore developed a modified MMA technique for such cases, consisting of anterior segmental osteotomies together with standard Le Fort I and bilateral sagittal split osteotomies. A prospective study of 20 consecutive Taiwanese adults with moderate-to-severe OSA who underwent modified MMA and postsurgical orthodontics was undertaken to evaluate the efficacy with regard to OSA and the postoperative facial appearance and dental occlusion. After modified MMA, the mean apnoea-hypopnoea index decreased from 41.6±19.2 n/h to 5.3±4.0 n/h (P<0.001). All patients had a successful outcome. No patient was dissatisfied with their postoperative facial appearance. The mean Peer Assessment Rating score decreased from 21.9±14.3 to 1.7±1.6 (P=0.001). The data suggest that the modified MMA is effective in treating patients with moderate-to-severe OSA without negatively affecting facial appearance or dental occlusion. To achieve a better outcome, surgical-orthodontic integration is warranted. The surgery-first approach can achieve early improvement.

Cephalometric and three-dimensional assessment of the posterior airway space and imaging software reliability analysis before and after orthognathic surgery

PURPOSE

This study aimed to compare the reliability of three different imaging software programs for measuring the PAS and concurrently to investigate the morphological changes in oropharyngeal structures in mandibular prognathic patients before and after orthognathic surgery by using 2D and 3D analyzing technique.

MATERIAL AND METHODS

The study consists of 11 randomly chosen patients (8 females and 3 males) who underwent maxillomandibular treatment for correction of Class III anteroposterior mandibular prognathism at the University Hospital in Zurich. A set of standardized LCR and CBCT-scans were obtained from each subject preoperatively (T0), 3 months after surgery (T1) and 3 months to 2 years postoperatively (T2). Morphological changes in the posterior airway space (PAS) were evaluated longitudinally by two different observers with three different imaging software programs (OsiriX(®) 64-bit, Switzerland; Mimics(®), Belgium; BrainLab(®), Germany) and manually by analyzing cephalometric X-rays.

RESULTS

A significant increase in the upper airway dimensions before and after surgery occurred in all measured cases. All other cephalometric distances showed no statistically significant alterations. Measuring the volume of the PAS showed no significant changes in all cases. All three software programs showed similar outputs in both cephalometric analysis and 3D measuring technique.

CONCLUSION

A 3D design of the posterior airway seems to be far more reliable and precise phrasing of a statement of postoperative gradients than conventional radiography and is additionally higher compared to the corresponding manual method. In case of Class III mandibular prognathism treatment with bilateral split osteotomy of the mandible and simultaneous maxillary advancement, the negative effects of PAS volume decrease may be reduced and might prevent a developing OSAS.

Effects of chin advancement surgery in hyoid bone and tongue positions and in the dimension of the oropharynx

INTRODUCTION

Advancement genioplasty has been increasingly indicated for the correction of anterior mandibular deficiency as it balances the patient's profile and generates functional changes.

OBJECTIVE

Thus, the aim of this study was to assess the effects of advancement genioplasty in the oropharyngeal size and in the position of the hyoid bone and tongue.

METHODS

The sample comprised 22 lateral cephalometric radiographs of 11 individuals who had undergone advancement genioplasty alone. Eleven of these radiographs depicted the immediate preoperative period (T0) and the other 11 the postoperative period after at least four months (T1). The radiographs were scanned and exported to the Radiocef Studio 2.0® software (Radio Memory Ltda., Belo Horizonte, MG, Brazil). The landmarks were then identified and automatically measured by the program.

RESULTS

The results showed statistically significant differences between the horizontal position of the hyoid bone and tongue and in the oropharyngeal size. The hyoid bone and tongue were repositioned anteriorly after surgery (p = 0.01), thereby increasing the dimension of the oropharyngeal airspace (p = 0.01).

CONCLUSIONS

The oropharyngeal dimension increased as the tongue base and hyoid bone were repositioned more anteriorly.

Long-term pharyngeal airway changes after bionator treatment in adolescents with skeletal Class II malocclusions

Objective

The aim of this study was to evaluate long-term changes in the pharyngeal airway dimensions after functional appliance treatment in adolescents with skeletal Class II malocclusions.

Methods

Pharyngeal airway dimensions were compared between subjects with skeletal Class II malocclusions (n = 24; mean age: 11.6 ± 1.29 years) treated with a Class II bionator and age-matched control subjects with skeletal Class I occlusions (n = 24; mean age: 11.0 ± 1.21 years) using a series of lateral cephalograms obtained at the initial visit (T0), after treatment (T1), and at the completion of growth (T2).

Results

The length of the nasopharyngeal region was similar between adolescents with skeletal Class I and Class II malocclusions at all time points, while the lengths of the upper and lower oropharyngeal regions and the pharyngeal airway areas were significantly smaller in the skeletal Class II adolescents before treatment when compared to the control adolescents (p < 0.05). However, following treatment with a functional appliance, the skeletal Class II adolescents had increased pharyngeal airway dimensions, which became similar to those of the control subjects.

Conclusions

Functional appliance therapy can increase the pharyngeal airway dimensions in growing adolescents with skeletal Class II malocclusions, and this effect is maintained until the completion of growth.

Changes in the upper airway after counterclockwise maxillomandibular advancement in young Korean women with class II malocclusion deformity

PURPOSE

To evaluate the change in the upper airway in a Class II malocclusion deformity after counterclockwise maxillomandibular advancement.

MATERIALS AND METHODS

Seventeen young Korean women with a Class II malocclusion deformity who had undergone Le Fort I and bilateral mandibular ramus sagittal split osteotomy in a counterclockwise rotation were enrolled in the present study. The upper airway was measured at 3 different levels (uvula tip, low C2, and mid C3) using lateral cephalograms at 3 points: preoperatively (T0) and 2 (T2) and 12 (T12) months postoperatively. The changes in the upper airway were then compared.

RESULTS

The mandible advanced an average of 7.0 ± 3.8 mm. The upper airway had widened considerably at all 3 levels at T2 and had decreased slightly at T12, especially at the low C2 level compared with T0. However, the upper airway at T12 remained wider than at T0 at all 3 levels. The mandibular advancement and upper airway width correlated only at T12 at the mid C3 level.

CONCLUSIONS

The upper airway became wider in patients with a Class II malocclusion deformity who had undergone mandibular advancement. However, this might become narrower with time.

Computerized cephalometric study of the pharyngeal airway space in patients submitted to orthognathic surgery

INTRODUCTION

Pharynx is a muscular organ with is sustained by craniofacial bones. It is divided into nasal, oral and hipopharynx, and can be considered as a tube that serves both respiratory and digestive systems. Its anatomical morphology permits that factors facilitate its obstruction, leading to the sleep apnea syndrome. One of the treatment consists of surgical mandibular advancement, increasing pharyngeal dimensions. The aim of this study was evaluate the cephalometric changes in the pharyngeal airway space after orthognathic surgery procedures for correction of mandibular prognathism.

MATERIALS AND METHODS

Pre and post-operative cephalometric analysis was performed on 19 patients submitted to mandibular setback by mandibular bilateral sagittal split osteotomy associated with maxillary advancement by Le Fort I osteotomy, using the Dolphin Imaging 10.0 software.

RESULTS

Results did not reveal statistically significant changes in the upper (nasopharyngeal), middle (oropharyngeal) and lower (hypopharyngeal) airway spaces, but showed increase in the nasal pharynx due the maxillary advancement and a lower position of the hyoid bone due the mandibular setback.

DISCUSSION

Maxillomandibular orthognathic surgery for correction of mandibular prognathism does not seem to statistically significantly change the pharyngeal airway space, but it increases the maxillary airway.

CONCLUSION

It seems to be important to consider the double jaw surgery in cases of mandibular prognathism, aiming prevention of a possible reduction of whole upper airway.

Successful reconstruction of nongrowing hemifacial microsomia patients with unilateral temporomandibular joint total joint prosthesis and orthognathic surgery

PURPOSE

Traditionally, patients with hemifacial microsomia (HFM) and significant ipsilateral hypoplasia or absence of the condyle and ramus undergo reconstruction on the ipsilateral side with autogenous tissues such as rib grafts, often with compromised results. This study analyzed the surgical treatment outcomes of nongrowing patients with HFM and reconstruction of the ipsilateral temporomandibular joint (TMJ) and advancement of the mandible with a patient-fitted TMJ total joint prosthesis (TMJ Concepts, Inc, Ventura, CA), a contralateral mandibular ramus sagittal split osteotomy, and maxillary osteotomies performed in 1 operation.

PATIENTS AND METHODS

All nongrowing patients with HFM treated with this surgical protocol from 1997 to 2010 in a single private practice were included in this study and subjectively evaluated before surgery and at the longest postsurgical follow-up for pain, diet, jaw function, and disability using a visual numerical scale (0 to 10). Surgical changes and postsurgical stability were analyzed using lateral cephalograms before surgery, immediately after surgery, and at the longest follow-up.

RESULTS

Six patients (4 female and 2 male) were included in this study, with an average age at surgery of 23.5 years (range, 14 to 39 yrs) and an average follow-up of 6 years 3 months (range, 1 yr to 11 yrs 4 mo). For all subjective parameters, all patients improved or remained the same. Incisal opening improved or remained the same in 4 of the 6 patients, with 2 patients having decreased opening. Excursive movements decreased. The maxillomandibular complex was surgically rotated counterclockwise, advanced, and transversely leveled, with the anterior maxillary reference points (anterior nasal spine, point A) undergoing relative small movements. The mandibular incisor tips (lower incisor tips) advanced a mean of 8.9 mm, point B 14.8 mm, pogonion 18.6 mm, menton 17.5 mm and the occlusal plane angle decreased -12.3°. Postsurgical long-term stability indicated that the anterior maxillary references changed a significant amount, whereas all horizontal and vertical anterior mandibular measurements (lower incisor tip, point B, pogonion, menton) and the occlusal plane showed no significant changes.

CONCLUSIONS

The TMJ Concepts total joint prosthesis in conjunction with orthognathic surgery for TMJ and jaw reconstruction in nongrowing patients with HFM is highly predictable for skeletal and occlusal stability, comfort, TMJ function, and improved facial balance.

Orthodontic-orthognathic surgical treatment in a patient with Class II subdivision malocclusion: occlusal plane alteration

Despite the different orthodontic treatment options for patients with Class II subdivision malocclusions, the involvement of the skeletal structures is significant. It is desirable to combine orthodontic and surgical treatment to achieve a stable and better esthetic result, as illustrated in this case report. The occlusal plane was canted to the right as a part of the patient's facial asymmetry. Consequently, a 3-mm differential impaction of the maxilla on the left side allowed occlusal plane leveling. Mandibular rotation with advancement on the right side corrected the right Class II malocclusion. The successful attainment of the treatment goals was accomplished through teamwork and integration between the orthodontist and the maxillofacial surgeon.

Treatment of Malocclusion and TMJ Dysfunction Secondary to Condylar Fractures

Unfavorable sequelae from mandibular fractures includes malocclusion and temporomandibular joint dysfunction. The management of these complications is presented in this article and is largely based on the authors' experience. Cases that provide details on treatment methods are shown. Finally, an algorithm for treatment is suggested.

Effects of orthognathic surgery on oropharyngeal airway: a meta-analysis

Oropharyngeal changes caused by orthognathic surgery have been a concern because the sleep quality of patients may be enhanced or worsened by these changes. The purpose of this meta-analysis was to identify, review and compare scientific literature about changes in airway in adult patients undergoing orthognathic surgery to correct anteroposterior osseous discrepancies. An electronic search of four databases was carried out up to July 2010, with supplemental hand searching of the references of the retrieved articles. Quality assessment of the included articles was carried out. Data were extracted and a meta-analysis was performed. Heterogeneity was assessed amongst the studies and results were presented in forest plots. 49 studies met the inclusion criteria. Only studies with moderate or high methodological soundness were included in the review. Moderate evidence was found to support a significant decrease in the oropharyngeal airway in mandibular setback surgery, a milder decrease in bimaxillary surgery to correct Class III and an increase in maxillomandibular advancement surgery. Evidence is lacking on airway volume changes after orthognathic surgery.

Three-dimensional airway changes after Le Fort III advancement in syndromic craniosynostosis patients

BACKGROUND

To investigate the changes of upper airway volume in syndromic craniosynostosis patients following Le Fort III advancement, computed tomographic scans were analyzed and related to the amount of advancement.

METHODS

In this retrospective study, the preoperative and postoperative computed tomographic scans of 19 patients with syndromic craniosynostosis who underwent Le Fort III advancement were analyzed. In four cases, preoperative polysomnography demonstrated obstructive sleep apnea. The airway was segmented using a semiautomatic region growing method with a fixed Hounsfield threshold value. Airway volumes of hypopharynx and oropharynx (compartment A) and nasopharynx and nasal cavity (compartment B) were analyzed separately, as was the total airway volume. Advancement of the midface was recorded using lateral skull radiographs. Data were analyzed for all patients together and for patients with Crouzon/Pfeiffer and Apert syndromes separately.

RESULTS

Airway volume increased significantly in compartment A (20 percent; p = 0.044) and compartment B (48 percent; p < 0.001), as did total airway volume in (37 percent; p < 0.001) in the total study group. No significant differences in volume changes were found comparing Apert with Crouzon/Pfeiffer patients. No distinct relation could be found between advancement of the midface and volume gain either in the total study group or in Apert and Crouzon/Pfeiffer patient groups separately. Postoperative polysomnography showed significant improvement of obstructive sleep apnea in all four patients.

CONCLUSIONS

A significant improvement of the upper airway after Le Fort III advancement in syndromic craniosynostosis patients is demonstrated. No distinct relation could be observed between advancement and airway volume changes.

An orthodontic-surgical approach to Class II subdivision malocclusion treatment

Despite the different orthodontic approaches to Class II subdivision malocclusions one has also to consider the skeletal components before undertaking any treatment protocol. Significant involvement of the skeletal structures may require a combined surgical orthodontic treatment, which has remained stable for more than four years, as illustrated in this case report.

Avaliação cefalométrica do espaço aéreo posterior em pacientes com oclusão Classe II submetidos à cirurgia ortognática

OBJETIVO: o avanço maxilomandibular é um método cirúrgico comumente usado no tratamento de pacientes acometidos pela Síndrome da Apnéia Obstrutiva do Sono (SAOS) e portadores de anormalidades anatômicas identificáveis neste complexo, que estreitam e/ou obstruem o espaço aéreo. O intuito deste estudo foi analisar variações cefalométricas do espaço aéreo faríngeo em indivíduos Classe II de Angle, após a cirurgia ortognática. METODOLOGIA: a amostra consistiu de telerradiografias laterais equivalentes aos períodos pré e pós-operatório de 30 indivíduos, divididos no grupo com avanço cirúrgico mandibular (n=15) e no grupo com avanço maxilomandibular (n=15). Os parâmetros cefalométricos usados permitiram avaliar o espaço aéreo posterior em 3 níveis: a hipofaringe (PFI-V), a orofaringe (PFM-PM, PFM-PO, PFM-U, PFM-Up) e a nasofaringe (PFM-PN, pm-PFS). A análise esquelética foi na base do crânio (N-S-Ba) e na mandíbula (Ar-Go-Me). A média das diferenças entre os valores pré e pós-operatórios das mensurações lineares (mm) e angulares (graus) foi avaliada pelo teste t pareado. RESULTADOS E CONCLUSÕES: estatisticamente, não houve redução do espaço aéreo faríngeo pós-avanço cirúrgico. O que se observou foi que apenas PFM-PO e PFS-pM se mantiveram constantes e na maioria restante os valores aumentaram.