The effect of different hybrid rigid internal fixation techniques on the postoperative stability following a mandibular advancement using a bilateral sagittal split ramus osteotomy: A retrospective three-dimensional comparative study.

OBJECTIVE: To three-dimensionally evaluate post-operative mandibular stability following bilateral sagittal split ramus osteotomies between hybrid and non-hybrid rigid internal fixation techniques. MATERIALS AND METHOD: Seventy adults with skeletal class II deformity who underwent bilateral split sagittal osteotomy with mandibular advancement were included. Patients were divided into four groups based on their fixation techniques: hybrid technique (HT) groups I, II, and IV received a 4-hole 2 mm miniplate with either a bicortical screw (BS), additional 2 mm 4-hole miniplate, or two-hole miniplate, while non-HT group III received a 4-hole 2 mm miniplate with four mini-screws (MS). Measurements were taken pre-operatively (T0), immediately postoperatively (T1), and ≥1 year after surgery (T2) using 3D Slicer software. RESULTS: Age, sex, and follow-up period did not correlate significantly with postoperative relapse or stability. Significant differences were observed in the advancement on the right side between groups II, III, and IV and on the left side between groups I, III, and IV. However, the type of surgical intervention showed no significant effect on postoperative relapse and stability. All groups of fixations showed satisfactory stability with irrelevant relapse (< 2 mm or 2°). CONCLUSION: The study demonstrated satisfactory and comparable stability among different fixation groups on patients undergoing mandibular advancement following bilateral split sagittal osteotomy. The results highlighted the importance of considering the degree of advancement when planning orthognathic surgery and managing postoperative outcomes.

Does adjunctive fixation in conjunction with miniplate affect condylar position and morphology after mandibular advancement through bilateral sagittal split ramus osteotomy? A retrospective 3-dimensional CT comparative study.

To minimize condylar positional and morphological changes after mandibular advancement through bilateral sagittal split ramus osteotomy (BSSRO), surgeons add either a bicortical screw or a two-hole plate distal to the conventional single miniplate. Since there have been no previous studies investigating the effect of this combination, our study aimed to evaluate the short- and long-term effects of these adjunctive fixation methods (AFM) on condylar positional and morphological changes after mandibular advancement through BSSRO. This retrospective cohort study included consecutive patients with retruded mandibles who were treated in the Department of Orthognathic and TMJ Surgery at West China Hospital of Stomatology, Sichuan University. The patients were divided into two groups based on the primary predictor variable, which was the addition of AFM - either a single bicortical screw or a two-hole plate in addition to the single miniplate. The primary outcome variable was the condylar positional and morphological changes after mandibular advancement through BSSRO. Three-dimensional facial CT scans were obtained at three different time points (preoperatively - T0, 1 week postoperatively - T1, and 1 year postoperatively - T2) and analyzed using ITK-SNAP, 3D Slicer, and SlicerSALT software. Intergroup comparisons were conducted with an independent t-test, with a p-value of <0.05 considered significant. Correlations between the variables were estimated by Pearson correlation. The study comprised 51 patients (32 females, 19 males; mean age 25.13 ± 4.24 years), involving a total of 81 condyles (21 unilateral and 60 bilateral). There was a significant difference in long-term condylar displacement in favor of AFM along with a single miniplate (p < 0.001). The bicortical screw group recorded less condylar displacement than the two-hole plate group horizontally (0.11 mm vs 0.22 mm) and sagittally (0.03 mm vs 0.17 mm), but more vertically (0.85 mm vs 0.03 mm). Bone formation associated with AFM occurred on all condylar surfaces, compared with only three surfaces in the single miniplate group. The adjunctive method in addition to the single miniplate fixation method showed less condylar displacement and more bone apposition after mandibular advancement through BSSRO. The follow-up duration variable was the only significant determinant for volumetric changes in the condyle.

Exploring long-term changes and influencing factors of the upper airway in patients with a skeletal Class II relationship after mandibular advancement with maxillary setback surgery: A comprehensive 2-year follow-up investigation.

INTRODUCTION: The objective of this study was to investigate the 2-year postoperative change and influencing factors of the upper airway after mandibular advancement with maxillary setback surgery for patients with a skeletal Class II relationship. METHODS: Fifty-seven participants who underwent mandibular advancement with maxillary setback surgery were enrolled consecutively. Cone-beam computed tomography was performed preoperatively, 3 months postoperatively (T1), and 2 years (T2) postoperatively. All parameters were measured using Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). RESULTS: The total volume (V), minimum cross-sectional area (CSAmin), and glossopharynx increased significantly in both the short-term (V, 13.33%; CSAmin, 33.03%; glossopharynx, 26.73%) and long-term (V, 10.19%; CSAmin, 23.18%; glossopharynx, 18.27%) after the surgery. Mandibular advancement, mandibular width increase, preoperative CSAmin, and body mass index (BMI) significantly affected 2-year postoperative V increases. Mandibular advancement and BMI significantly affected 2-year postoperative glossopharynx increases. Backward movement of point PNS may lead to a reduction of the nasopharynx; however, downward movement of point PNS, upward movement of point A, and increased maxillary width may compensate for this effect by increasing the likelihood of the nasopharynx opening. Furthermore, mandibular body length at T1 is positively associated with relapse rate ([T2 - T1] / T1) of V and CSAmin. CONCLUSIONS: Mandibular advancement amount, mandibular width increase, preoperative CSAmin, and BMI are the 4 factors for long-term V changes. Patients with a longer mandibular body length might have a lower relapse rate.

Modified maxillomandibular advancement surgery for the treatment of obstructive sleep apnoea: a scoping review.

Modified maxillomandibular advancement (MMMA) has been proposed as an alternative to the classic maxillomandibular advancement (MMA) in East and Southeast Asian populations in which bimaxillary protrusion is a prevalent trait. The key difference between MMMA and MMA is the inclusion of anterior segmental osteotomies to reduce the protrusion of the perioral region. The aim of this scoping review was to identify the variations in MMMA and treatment outcomes. A search was conducted in the PubMed, Embase, and Cochrane electronic databases for articles published up to January 2023. Ten articles were included in this review. Three variations of MMMA have been reported in the literature. Treatment outcomes have mostly been favourable for all of these variations. Mandibular advancement of >10 mm and a greater than 50% reduction in the apnoea-hypopnoea index (AHI) have been well reported. Improvements in other outcome measures, such as enlargement of the airway dimension on computed tomography and the Epworth Sleepiness Scale score, have also been shown. Despite additional surgical procedures, complications have been uncommon and mostly minor in nature. It is necessary to be cognizant of MMMA and its variations when providing sleep surgery for East and Southeast Asian patients, tailoring this to the patient's profile and needs.

Skeletal stability after mandible bilateral sagittal split osteotomy - comparison of patient-specific implant and mini-plate fixation: A retrospective study.

The aim of the study was to compare the stability of the virtual surgical planning (VSP) and computer-aided design accompanied by patient-specific implants (PSIs) and conventional mini-plates in mandible advancement with bilateral sagittal split osteotomy (BSSO). This retrospective study evaluates the clinical and cephalometric records of 53 patients (12 male, 41 female) treated with BSSO in Helsinki University Hospital. Subjects were divided into two groups: VSP-PSI (21 patients: 4 male and 17 female; mean age 38 years, range 25-53 years); and conventional wafer-based repositioning with mini-plate fixation (32 patients: 8 male and 24 female; mean age 39 years, range 21-56 years). The effect of the amount and direction of the advancement on the stability was also analysed individually. The standardized lateral cephalometric radiographs in three time points were analysed to compare the groups. After surgery (T2), there were no differences between groups in cephalometric variables. During follow-up (T2-T3), the cephalometric variables in both Groups A and B were stable, so there was no difference in stability between the VSP-PSI and the conventional mini-plate groups. During follow-up, the mandibles rotated clockwise or counterclockwise, relapsed towards their original direction, and the changes were statistically significant (jaw relationship; p = 0.018, soft tissue profile; p = 0.025); when the advancement of mandible was >6 mm, the increase in gonial angle compared to mandibles advanced ≤6 mm was statistically significant (p = 0.03). VSP-PSI and conventional mini-plate fixation can be considered equally stable. Large advancements with counterclockwise rotation regardless of fixation method are more susceptible to relapse. VSP-PSI alone cannot solve the relapse-related concerns in mandible osteotomy.

Mechanical Evaluation of Different Stable Internal Fixation Techniques of Sagittal Osteotomy in Mandibular Advance / Evaluación Mecánica de Diferentes Técnicas de Fijación Interna Estable de Osteotomía Sagital en Avance Mandibular

The mandibular advancements performed in orthognathic surgeries can be stabilized with several techniques when using stable internal fixation. This study aims to comparatively evaluate, in vitro, the mechanical strength in a polyurethane mandibular model for four fixation techniques for sagittal split ramus osteotomy mandibular. 60 samples were divided into 4 groups, with 15 units for each group: group A, group B, group C and group D. Advances of 5 mm were made for each subgroup and fixed with 2.0 mm system plates and monocortical screws in the replicas of human hemimandibles in polyurethane resin. The samples were submitted to mechanical tests of linear loading, being evaluated the peak load and peak deformation. Technique B presented higher peak load (Kgf) and techniques A and B presented higher peak strain (p<0.05). Technique D presented lower peak load and lower peak strain (p<0.05). It is concluded that the study based on the development of new techniques for fixation for sagittal osteotomy of the mandibular ramus is of great importance for the advancement of orthognathic surgery, provided by the technical innovation of more favorable plate models.

Los avances mandibulares realizados en cirugías ortognáticas pueden estabilizarse con varias técnicas cuando se utiliza fijación interna estable. Este estudio tuvo como objetivo evaluar comparativamente, in vitro, la resistencia mecánica en un modelo mandibular de poliuretano para cuatro técnicas de fijación para la osteotomía sagital de la rama mandibular. Se dividieron 60 muestras en 4 grupos, con 15 unidades para cada grupo: grupo A, grupo B, grupo C y grupo D. Se realizaron avances de 5 mm para cada subgrupo y se fijaron con placas de sistema de 2,0 mm y tornillos monocorticales en las réplicas de hemimandíbulas humanas en resina de poliuretano. Las muestras fueron sometidas a pruebas mecánicas de carga lineal, siendo evaluadas la carga máxima y la deformación máxima. La técnica B presentó mayor pico de carga (Kgf) y las técnicas A y B presentaron mayor pico de deformación (p<0,05). La técnica D presentó menor carga máxima y menor tensión máxima (p<0,05). Se concluye que el estudio basado en el desarrollo de nuevas técnicas de fijación para la osteotomía sagital de la rama mandibular es de gran importancia para el avance de la cirugía ortognática, proporcionada por la innovación técnica de modelos de placas más favorables.

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.

Maxillomandibular Advancement for Obstructive Sleep Apnea Syndrome: Long-Term Results of Respiratory Function and Reverse Face-Lift.

PURPOSE: Scientific literature considers maxillomandibular advancement (MMA) as the most effective surgical treatment for the management of adult obstructive sleep apnea syndrome (OSAS). Maxillomandibular advancement enlarges the pharyngeal space by expanding the skeletal framework. Moreover, it projects the soft tissue of the cheeks, the mouth, and the nose in the aging face, which is characterized by multiple signs affecting the middle third and the lower third. The potential of orthognathic surgery (double jaw surgical advancement) of expanding the skeletal foundation to increase the facial drape support and to rejuvenate the face by a "reverse face-lift" is now recognized. The aim of this study was to review the surgical outcomes after MMA in terms of respiratory function and assessment of facial esthetics. METHODS: We retrospectively reviewed the charts of all patients affected by OSAS who underwent maxillomandibular advancement between January 2010 and December 2015 in 2 tertiary hospitals (IRCCS Policlinico San Martino of Genoa and IRCCS Policlinico Ca' Granda of Milan). During the postoperative follow-up examination, all patients underwent polysomnographic examination and esthetic assessment to evaluate the respiratory function and facial rejuvenation after double jaw surgical advancement. RESULTS: The final study sample included 25 patients (5 females, 20 males). The overall success rate of the surgical treatment (apnea/hypopnea index, AHI <20) was 79%; the overall rate of surgical cure (AHI <5) was 47%. Twenty-three patients (92%) showed a degree of rejuvenation after MMA. CONCLUSIONS: Maxillomandibular advancement is currently the most effective surgical treatment for the management of OSAS in adult patients who are not responders to medical treatment. "Reverse face-lift" is the consequence of the double jaw surgical advancement.

The Efficacy of 3D Virtual Surgery, CAD/CAM, and 3D Printing Technology for Maxillomandibular Advancement in Obstructive Sleep Apnea Patients.

OBJECTIVE: Maxillomandibular advancement (MMA) is the most effective surgical method for treating obstructive sleep apnea, and it moves the maxillomandibular complex forward to increase the entire upper airway volume. By using 3-dimensional (D) virtual surgery, computer-aided design/computer-aided manufacturing, and 3D printing technologies, it is possible to overcome all the limitations of conventional methods. MATERIALS AND METHODS: In this study, (modified) MMA was performed by applying 3D technologies to obstructive sleep apnea patients. Virtual surgery was done as surgical plan, cutting guides, and customized plates were made by computer-aided design/computer-aided manufacturing and 3D printing technologies for surgical procedures. RESULTS: After surgery, all patients improved their appearance, quality of sleep, and sleep apnea level were dramatically improved. Through these results, it was found that there are many advantages in using 3D technologies for preparing and implementing MMA. CONCLUSIONS: It was confirmed that the accuracy and efficiency of surgery were increased by applying 3D technologies. This suggests that 3D technologies are very useful tools in surgical area.

Australasian Sleep Association position statement on consensus and evidence based treatment for primary snoring.

Primary snoring impacts a significant portion of the adult population and has the potential to significantly impair quality of life. The purpose of these guidelines is to provide evidence-based recommendations to assist Australasian practitioners in the management of adult patients who present with primary snoring without significant obstructive sleep apnoea. The Timetable, Methodology and Standards by which this Position Statement has been established is outlined in the Appendix S1. The main recommendations are: Weight loss, and reduced alcohol consumption should be recommended, where appropriate If clinical judgement dictates, benzodiazepine and opioid reduction or avoidance may be advised Positional therapy should be considered in supine dominant snorers In dentate patients, Mandibular advancement devices (MAD) should be recommended as a first line treatment following assessment by both an appropriate Dentist and Sleep physician Continuous positive airway pressure (CPAP) devices may be recommended in patients with primary snoring in those already committed to their use or willing to try Surgical treatment of primary snoring by an appropriately credentialled surgeon may be advised and includes nasal (adjunctive), palatal and other interventions This position statement has been designed based on the best available current evidence and our combined expert clinical experience to facilitate the management of patients who present with primary snoring. It provides clinicians with a series of both non-surgical and surgical options with the aim of achieving optimal symptom control and patient outcomes. This is the first such set of recommendations to be established within Australasia and has also been reviewed and endorsed by the Australasian Sleep Association.

Segmental mandibular advancement for moderate-to-severe obstructive sleep apnoea: a pilot study.

Segmental mandibular advancement (SMA) consists of a combination of bilateral sagittal split osteotomy, anterior subapical osteotomy with extraction of the first premolars, and genioplasty, to allow an extended advancement of the mandible for the improvement of tongue base obstruction in moderate-to-severe obstructive sleep apnoea (OSA) and to minimize any unfavourable aesthetic change due to the large jaw advancement. The aim of this pilot study was to evaluate the surgical outcomes and complications following SMA in OSA patients. Twelve patients (nine male, three female) underwent SMA as part or whole of their skeletal advancement procedure for OSA. The apnoea-hypopnoea index (AHI) improved from a mean± standard deviation 42.4 ± 22.0/hour preoperatively to 9.0 ± 17.4/hour at 1 year postoperative. Surgical success (50% reduction in AHI) was achieved in 11 of the 12 patients (91.7%) at 1 year postoperative, while seven patients (58.3%) attained surgical cure (AHI<5/hour). The lowest oxygen saturation (LSAT) increased from a mean 73.3% preoperatively to 78.7% at 1 year postoperative. The airway volume increased from a mean 2.4 ± 1.7 cm3 at baseline to 6.7 ± 3.5 cm3 at 1 year postoperative (P < 0.001). No major complication occurred. This pilot study showed that SMA appears to be safe and effective as part or whole of the skeletal advancement surgery for moderate-to-severe OSA.

Is it necessary to use bone grafts to prevent defects at the lower border of the mandible after mandibular advancement?-a systematic review.

INTRODUCTION: Defects in the lower border of the mandible may represent an aesthetic problem after mandibular advancement in orthognathic surgery. The use of bone grafts has been reported in the literature as a possibility to reduce these defects in the postoperative period. OBJECTIVE: The objective of this systematic review is to answer the following research question: Is it necessary to use bone grafts to prevent defects at the lower border of the mandible after mandibular advancement? METHODS: The literature search was conducted on MEDLINE via PubMed, Scopus, Central Cochrane, Embase, LILACS, and Sigle via Open Gray up until December 2020. Five studies were eligible for this systematic review, considering the previously established inclusion and exclusion criteria. RESULTS: 1340 mandibular osteotomies were evaluated, with a mean advance of 8 mm, being 510 with bone graft (42 defects), 528 without graft (329 defects), and 302 with an alternative technique (32 defects). Regarding the type of bone graft used, three articles used xenogenous or biomaterial grafts and two allogenous bone grafts. The results of the meta-analysis showed a reduction in the presence of defects in the bone graft group: OR 0.04, 95% CI = 0.01, 0.19; p = 0.0005, (I2 = 87%; p < 0.0001). CONCLUSION: The use of bone grafts seems promising in reducing defects in the lower border of the mandible after mandibular advancement. New controlled prospective studies with a larger number of participants are needed to ensure the effectiveness of this procedure.

The long-term results of modified maxillomandibular advancement in Asian OSA patients.

OBJECTIVE: Maxillomandibular advancement (MMA) surgery is considered a highly successful treatment for obstructive sleep apnea (OSA). Various modifications to the technique have been described. We aim to study the long-term results in Asian patients who underwent a modified MMA procedure intended to avoid bimaxillary protrusion and which involved four-quadrant bicuspid extractions with posterior maxillary alveolar setback. METHOD: A review of operative logs from 2000 to 2003 was conducted to identify Asian patients who underwent modified MMA during that period, for treatment of moderate and severe OSA. Sleep indices and psychometric performances were prospectively analyzed. RESULTS: Eight Asian patients were included. The mean length of follow-up was 14.4 years (range: 13.0-16.5). Mean preoperative apnea-hypopnea index (AHI) was 48.9 (range: 19.0 to 84.8). Mean post-operative AHI was 31.6 (range: 6.2 to 79.5). This reduction was statistically significant (p<0.05). Epworth Sleepiness Scale and Functional Outcomes of Sleep Questionnaire (FOSQ) revealed that majority of the patients (75%) did not have excessive daytime somnolence and all patients had high FOSQ totalled scores (mean 17.7, range 11.8 to 20), indicating good functional performance. CONCLUSION: This series is the longest follow-up of an Asian cohort who underwent modified MMA. With a mean follow-up of 14.4 years, improvement in AHI is still observed but not at a degree as large as prior studies with shorter lengths of follow-up. The purported efficacy of MMA for Caucasian patients may not be reproducible in Asian patients and long-term sustainability of this treatment's efficacy requires rigorous evaluation.

Treatment of OSA by maxillomandibular advancement: Serious Complications and Failures / Traitement du SAOS par avancement maxillomandibulaire : complications graves et échecs

Aim: The focus of this report was to analyze patients who presented for second opinion due to complications and failure following maxillomandibular advancement (MMA)performed elsewhere. Methods: During a five-year period, 16 patients presented with complications and/or failure of MMA. The indication for treatment was obstructive sleep apnea (OSA). Analysis of treatment records including plane radiography and/or cone beam computed tomography (CBCT), progress photographs and clinical examination were performed. Results: Complete clinical and imaging records were available in all patients for analysis. Thirteen patients were surgical failures with advancement ranging from -4 to 5 mm. Five of the 13 patients had limited advancement at the initial surgery, and eight patients had hardware failure that required removal with resultant retrodisplacement of the mandible. Due to complications occurring in 11 patients, additional surgery ranging from two to six additional procedures after the initial operation was required. The complications included hardware failure (ten patients) that led to bone segment displacement (eight patients), non-union of the maxilla (two patients), non-union of the mandible (eight patients), chronic facial and/or joint pain (five patients), facial nerve injury (two patient), complete anesthesia of the lip/chin (five patients) and severe malocclusion (four patients). Conclusions: Although MMA is typically a predictable operation with excellent outcomes, failure of improvement and severe long-term sequelae from surgical complications are possible. Surgical precision with sufficient skeletal advancement for airway improvement and stable skeletal fixation is necessary to achieve a successful outcome.

Objectif: L'objectif de ce rapport était d'analyser les patients qui se sont présentés pour un deuxième avis, en raison de complications et d'un échec survenus après un avancement maxillo-mandibulaire (AMM) réalisé ailleurs. Méthodes: Au cours d'une période de cinq années, seize patients se sont présentés avec des complications et/ou un échec de leur AMM. L'indication du traitement était l'apnée obstructive du sommeil (AOS). Une analyse des dossiers de traitement, comprenant une radiographie 2D et/ou une tomographie à faisceau conique (CBCT), des photographies de l'évolution et un examen clinique, a été effectuée. Résultats: Des dossiers cliniques et d'imagerie complets étaient disponibles pour tous les patients aux fins d'analyse. Treize patients étaient des échecs chirurgicaux avec un avancement allant de -4 à 5 mm. Cinq des 13 patients avaient un avancement limité lors de la chirurgie initiale, et huit patients ont été confrontés à une défaillance du matériel qui en a nécessité la dépose avec pour conséquence un rétro-déplacement de la mandibule. En raison de complications survenues chez 11 patients, une chirurgie supplémentaire, allant de deux à six interventions additionnelles après l'opération initiale, a été nécessaire. Les complications comprenaient une défaillance du matériel (dix patients) qui a entraîné un déplacement du segment osseux (huit patients), une pseudarthrose du maxillaire (deux patients), une pseudarthrose de la mandibule (huit patients), une douleur faciale et/ou articulaire chronique (cinq patients), une lésion du nerf facial (deux patients), une anesthésie complète de la lèvre/menton (cinq patients) et une malocclusion grave (quatre patients). Conclusions: Bien que l'AMM soit généralement une opération prévisible avec d'excellents résultats, une absence d'amélioration et de graves séquelles à long terme dues à des complications chirurgicales sont possibles. La précision du geste chirurgical, associée à un avancement du squelette suffisant pour améliorer les voies respiratoires et une bonne stabilité de l'ostéosynthèse du squelette, sont nécessaires pour obtenir un résultat satisfaisant.

Central and mixed sleep apnea related to patients treated with maxillomandibular advancement for obstructive sleep apnea: A retrospective cohort study.

The aim of this study was to evaluate the clinical efficacy of maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) patients with a percentage of central and mixed apnea index in the total apnea-hypopnea index (CMAI%) ≧25%. Patients treated with MMA for OSA were retrospectively evaluated for baseline and postoperative patient data and polysomnographic results. The pre- and postoperative obstructive, central and mixed apnea parameters were compared. Of the included 78 patients, 21 patients (27%) presented with CMAI% ≧25% (median CMAI%, 49.1%; 35.9-63.8) prior to MMA. In 67% of these cases, MMA resulted in CMAI% <25 (median CMAI%, 6.1%; 2.1-8.9) and significantly improved the apnea-hypopnea index (AHI) (p < 0.001), the lowest oxyhemoglobin saturation (p < 0.001), central and mixed apnea index (p < 0.001), percentage of central and mixed apneas of total AHI (p = 0.004), central apnea index (p < 0.001), and mixed apnea index (p < 0.001). CMAI% ≧25% emerged in 25% of patients after MMA (median CMAI%, 49.1%; 35.9-63.8). Within the undeniable limitations of the study, it seems that the presence of CMAI% ≧25% should not be regarded as a contraindication for MMA in OSA patients.

Patient-reported outcome measures following maxillomandibular advancement surgery in patients with obstructive sleep apnoea syndrome.

Maxillomandibular advancement (MMA) is an effective treatment for obstructive sleep apnoea syndrome (OSAS) that is refractory to conventional treatment. However, it is a highly invasive procedure with several recognised side effects, and we know of few data on its effect on important patient-reported outcome measures (PROMS). Here we describe a case series of patients selected for MMA through our joint respiratory/maxillofacial surgery clinic, detailing the effect of MMA on objective physiological measurements and important PROMS. Patients with confirmed moderate/severe symptomatic OSAS who could not tolerate continuous positive airway pressure (CPAP) or mandibular advancement devices (MAD) were assessed in the clinic for consideration of MMA. Preoperative and postoperative airway measurements, apnoea/hypopnoea index (AHI), Epworth sleepiness scale (ESS) score, and quality of life (10-point Likert scale), were recorded. A customised questionnaire was administered postoperatively to assess selected psychosocial and functional domains (sleep quality, energy levels, appearance, ability to perform daily activities, and mood) and patient satisfaction using five-point Likert scales. Over an 18 month period, 39 patients were referred for consideration of MMA. Ten patients (7 men and 3 women, mean age 49.9, mean BMI 27.5) underwent surgery, which resulted in significant improvements in ESS, quality of life, AHI, and airway diameters. All patients reported improvements in all psychosocial/functional domains except appearance, in which five reported no change or worsened appearance. All subjects felt that MMA provided better symptom control than CPAP. The most commonly reported side effects were facial/lip numbness (9/10) and affected bite (6/10). MMA resulted in significant improvements in ESS, quality of life, and a range of PROMS, with a high level of patient satisfaction.

Does suprahyoid muscle complex pull cause relapse following genial advancement by distraction osteogenesis? An electromyographic study.

Active pull of the suprahyoid muscle complex (SMC) was thought to be the main contributor of relapse in mandibular or chin advancement, but literature evidence lacks human studies that assess the role of the SMC following genial advancement (GeA). This study therefore aimed to analyse the influence of SMC pull on relapse following GeA by distraction osteogenesis based on electromyographic (EMG) changes. EMG was recorded and analysed preoperatively (T0), at four months (T1), and at one-year follow up (T2) at three submental regions during two different activities. The outcome variables were EMG changes of the SMC, and hard and soft tissue relapse. Assessment was carried out by comparison of EMG and lateral cephalograms taken at T0, T1, and T2. Ten patients (7 male and 3 female; median (SD) age 21.2 (3.99) years, range 18-28) were included. The EMG values revealed a statistically significant reduction between T0 and T1. T2 values were not higher than T0 during any activity. The results of Pearson's correlation demonstrated no significant relation between the amount of relapse and change in EMG values. This study concluded that active pull of the SMC is not the actual reason for skeletal relapse in chin or mandibular advancement. Passive biomechanics such as adnexial or muscular connective tissue, and paramandibular periosteum pull with native bone remodelling might be the prime reasons for relapse. However, further large sample studies are warranted to find the actual causes of relapse.

How effective is a thick plate on stabilisation in 10 mm mandibular advancement?

We compared the stability and stress analysis of four different fixation methods after sagittal split ramus osteotomy (SSRO) in mandibular models. In the first model (1P1B) we adapted a four-hole, 2.0 mm standard miniplate on the osteotomy line with one bicortical screw at the top. In the second (2P) we placed two four-hole 2.0 mm standard miniplates above and below the osteotomy line. In the third (3B), we applied three inverted L-shaped bicortical screws, and in the last (1RP1B) we used a four-hole miniplate with increased thickness on the osteotomy line with one bicortical screw at the top. A static vertical load of 200 Newtons (N) was then applied to each model from the occlusal of the first molar. The maximum and minimum principal stresses on the bone were observed more in the proximal segment close to the osteotomy line in all groups. Maximum von Mises stresses were 2705.21 Megapascals (MPa), 1633.56 MPa, 1121.4 MPa, and 1734.44 MPa for the 1P1B, 2P, 3B, and 1RP1B groups, respectively. Displacement values were 1.92 mm, 1.15 mm, 0.79 mm, and 1.42 mm for the 1P1B, 2P, 3B, and 1RP1B groups, respectively. The reinforced plate contributed to the stabilisation, but it was not as effective as three bicortical screws and a double plate.

One-year stability of the mandibular advancement and counterclockwise rotation for correction of the skeletal class II malocclusion and high mandibular plane angle: Dental and skeletal aspect.

BACKGROUND: The purpose of this study was to evaluate the stability on dental and skeletal aspect after surgical advancement and counterclockwise rotation for the correction of the mandibular deficiency in patients with high mandibular plane angle (MPA). METHODS: We analyzed the records of patients who had undergone surgical treatment for dentofacial deformities with mandibular deficiency and high MPA. Clinical and radiological data were taken 1 month before surgery (T0), 6 weeks after surgery (T1) and 1 year after surgery (T2). Cephalometric values of the MPA were recorded and compared. The cephalometric changes in the different time periods were defined as follows: A: postsurgical changes (T0-T1), B: one-year changes (T1-T2), and C: short term changes (T0-T2). RESULTS: Twenty-seven patients had prominent mandibular deficiency with an MPA of over 35° (high angle). The mean age of patients at surgery was 29.7 years. Seven patients had a single jaw procedure, 20 patients had bilateral sagittal split osteotomy (BSSO) combined with a Le Fort I osteotomy, and 14 patients had additional genioplasty. MPA values differed significantly between the time periods (p < 0.05) with an observed relapse of the angle. However, satisfactory clinical improvement was achieved in the dental and skeletal presentation. The overjet improvement was evident from 8.815 ± 2.085 mm (T0) to 3.426 ± 1.253 mm (T2). CONCLUSION: Counterclockwise surgical advancement of the mandible to correct mandibular deficiency in patients with a high mandibular plane angle showed an overall acceptable stability during one-year follow-up.

Is Intensive Care Unit Monitoring Necessary After Maxillomandibular Advancement for Management of Obstructive Sleep Apnea?

PURPOSE: Maxillomandibular advancement (MMA) is an accepted treatment modality for obstructive sleep apnea. The purpose of this study was to evaluate the incidence of complications requiring an intensive care unit (ICU) level of care and the necessity of routine overnight ICU airway monitoring after MMA. PATIENTS AND METHODS: This was a retrospective cohort study of patients undergoing MMA at Massachusetts General Hospital from 2003 to 2020. The primary predictor variable was postoperative admission to the ICU versus post anesthesia care unit (PACU) or ward. The primary outcome variable was grade IV or V complications as scored using the Clavien-Dindo classification system. The secondary outcome variables included postoperative SpO2 nadir and length of hospital stay. Descriptive and bivariate statistics were computed to measure the association between complications and predictor variables. RESULTS: The study sample consisted of 104 patients (74.0% male, mean age 37.6 ± 12.1 years), 61 of whom were admitted to the ICU (58.7%). During the initial 24 hours of airway monitoring, the mean SpO2 nadir was 93.7 ± 2.59% for patients admitted to the ICU compared with 94.0 ± 6.56% for patients admitted to the PACU or ward (P = .862). Patients experienced 2 grade IV complications (1.92%) and no grade V complications, with no statistical association between complications and postoperative admission location (P = 1.000). Age (P = .002) and operative time (P = .046) were the only variables statistically associated with grade IV or V complications. There was no difference in length of hospital stay between patients admitted to the ICU (2.64 ± 1.37 days) versus PACU or ward (2.58 ± 1.62 days). CONCLUSIONS: The incidence of complications requiring ICU-level care after MMA for obstructive sleep apnea is low. Additional studies are warranted to guide development of feasible, cost-effective perioperative protocols for patients undergoing MMA.