Soft-tissue, non-osteogenic distraction of the mandible and lower face in bilateral hemifacial microsomia-technical report.

The aim of this study is to present a sequential strategy of soft-tissue, non-osteogenic distraction with a novel device, followed by microvascular bony reconstruction for severe cases of mandibular hypoplasia. The case of a 21-year-old woman with Goldenhar syndrome is presented, whose mandible remained severely hypoplastic despite previous attempts at distraction and was not suitable for further osteogenic distraction. Soft tissue deficiency and pin track scarring prevented free fibular transfers. A personalized distractor, anchored to the cranium and the mandibular symphysis, was designed to expand the soft tissues while allowing for physiological temporomandibular joint (TMJ) movement without compression forces. Internal distractors were placed along the osteotomies to prevent condylar luxation. After completion of the soft tissue distraction, the native mandible was resected except for the condyles and reconstructed with two free fibula flaps. This report represents the proof of concept of a sequential approach to severe lower face soft-tissue and bone deficiency, which preserves TMJ function and avoids the transfer of poorly matched skin to the face.

Efficacy of navigation system-assisted distraction osteogenesis for hemifacial microsomia based on artificial intelligence for 3 to 18 years old: study protocol for a randomized controlled single-blind trial.

BACKGROUND: Mandibular distraction osteogenesis (MDO) is a major part of the treatment for hemifacial microsomia patients. Due to the narrow surgical field of the intraoral approach, osteotomy accuracy is highly dependent on the surgeons' experience. Electromagnetic (EM) tracking systems can achieve satisfying accuracy to provide helpful real-time surgical navigation. Our research team developed an EM navigation system based on artificial intelligence, which has been justified in improving the accuracy of osteotomy in the MDO in animal experiments. This study aims to clarify the effect of the EM navigation system in improving the MDO accuracy for hemifacial microsomia patients. METHODS: This study is designed as a single-centered and randomized controlled trial. Altogether, 22 hemifacial microsomia patients are randomly assigned to the experiment and control groups. All patients receive three-dimensional CT scans and preoperative surgical plans. The EM navigation system will be set up for those in the experiment group, and the control group will undergo traditional surgery. The primary outcome is the surgical precision by comparing the osteotomy position of pre- and postoperative CT scan images through the Geomagic Control software. The secondary outcomes include mandibular symmetry (occlusal plane deviation angle, mandibular ramus height, and body length), pain scale, and complications. Other indications, such as the adverse events of the system and the satisfactory score from patients and their families, will be recorded. DISCUSSION: This small sample randomized controlled trial intends to explore the application of an EM navigation system in MDO for patients, which has been adopted in other surgeries such as orthognathic procedures. Because of the delicate structures of children and the narrow surgical view, accurate osteotomy and protection of nearby tissue from injury are essential for successful treatment. The EM navigation system based on artificial intelligence adopted in this trial is hypothesized to provide precise real-time navigation for surgeons and optimally improve patient outcomes, including function and aesthetic results. The results of this trial will extend the application of new navigation technology in pediatric plastic surgery. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2200061565. Registered on 29 June 2022.

3D-CT measurements of facial symmetry in severe CFM patients: A comparative study between mandibular ascending ramus distraction osteogenesis and bone grafting.

This study aims to compare the effects of mandibular distraction osteogenesis (MDO) and bone grafting on the facial symmetry of children with Pruzansky-Kaban type IIB and III craniofacial microsomia (CFM). Medical records and three-dimensional computed tomography (3D-CT) data of CFM patients who had primarily undergone MDO and bone grafting were collected. A retrospective analysis of pre-and post-operative 3D imaging data was conducted to compare the improvement rate in facial symmetry between the two groups based on occlusal cant, affected/unaffected ramus height ratio and chin point deviation. The data were tested for normality using the Shapiro-Wilk test. When the data followed a normal distribution, a paired sample t-test was employed for the comparison between preoperative and postoperative data. When the data did not follow a normal distribution, the Wilcoxon signed-rank test for paired samples was used for preoperative and postoperative comparison. The study included 18 children with type IIB and III CFM, 11 in the MDO group and 7 in the bone grafting group. In the MDO group, postoperative Gn-FH and Gn-Cor distances increased significantly, whereas the postoperative Gn-Mid distance decreased significantly. Occlusal cant decreased significantly and ramus height affected/unaffected ratio increased significantly after MDO. In the bone graft group, there was no statistically significant difference in the postoperative ratios of chin deviation, occlusal cant, and ramus height affected/unaffected compared to the preoperative values. Compared to bone grafting, MDO can significantly enhance ramus height ratio, level occlusal plane, and centralize the chin point among patients with CFM. Furthermore, MDO achieves superior enhancements in facial symmetry.

Three-dimensional Analysis of the Temporal Bone Morphology in Patients with Craniofacial Microsomia.

OBJECTIVE: To characterise the morphology of temporal bone in patients with craniofacial microsomia (CFM). DESIGN: A retrospective study. SETTING: A craniofacial centre. PATIENTS: Ninety-four patients with unilateral craniofacial microsomia. INTERVENTIONS: Mimics 21.0 (Materialise Inc., Belgium) was used to locate temporal bone landmarks on preoperative computed tomography data. The spatial Cartesian coordinate system was established in 3-matic 13.0 (Materialise Inc., Belgium). The coordinates of each landmark and the distances and angles between the landmarks were calculated. A classification system was used to quantify the severity of the zygomatic arch deformity. MAIN OUTCOME MEASURE(S): The bilateral differences in coordinates, linear and angular measurements, and the severity of temporal bone deformity (TTL δ, Psag δ, Paxiδ, and Tsag δ) among the groups were compared using the paired t-test and Kruskal-Wallis test, respectively. RESULTS: Compared to those of the unaffected side, the landmarks of the inner ear and petrous part on the affected side showed a decrease in the Z-coordinate or an increase in the X-coordinate. A superolateral rotation tendency of the temporal bone on the affected side was found. There were no significant differences in the linear and angular measurements between the groups. The degree of zygomatic arch deformation was lower in the mild group; however, no significant difference was found between the moderate and severe groups. CONCLUSIONS: In patients with CFM, asymmetry of the temporal bone and its inner organs (vestibulocochlear organ, facial nerve, and vessels) exists in multiple dimensions; its severity is not completely consistent with the degree of mandibular involvement.

Vascular variation of temporoparietal fascia in microtia associated with hemifacial microsomia.

The study analyzed vascular variations in microtia associated with hemifacial microsomia (HFM). A retrospective analysis was conducted on 47 patients with microtia and HFM, who underwent computed tomography angiography between November 2011 and May 2022. The vascular course and branching supplying the TPF were analyzed. Craniometric measurements were conducted to determine the horizontal distance from the porion and fronto-zygomatic suture (F-Z suture) to the vessels. On the affected side, the TPF was primarily supplied by either the superficial temporal artery (STA) or the postauricular artery-originated STA (Po-STA). The Po-STA (n = 29) was more prevalent than the STA (n = 18), and mostly exhibited a single frontal branch (n = 20). Craniometric analysis revealed that the Po-STA was closer to the porion, ear vestige, and F-Z suture than the STA on the non-affected side. Furthermore, a significant correlation was observed between the severity of mandibular hypoplasia and presence of Po-STA variation (Cramer's V = 0.498, p = 0.005). Microtia associated with HFM exhibits vascular variations in the TPF - in particular, a unique Po-STA variation. The Po-STA is prone to injury during ear reconstruction because of its proximity to the external auditory canal and ear vestige. Surgeons should be cautious of these anatomical variations for safer ear reconstruction procedures, and utilize preoperative imaging for meticulous planning.

Condylar resorption post mandibular distraction osteogenesis in craniofacial microsomia: A retrospective study.

The aim of this study was to investigate the characteristics of condylar resorption in craniofacial microsomia (CFM) patients following mandibular distraction osteogenesis (MDO). Patients with unilateral type-IIa and type-IIb CFM, who had completed MDO and mandibular distractor extraction (MDE), were recruited. The height and volume of the condyle were measured on three-dimension models created by the analysis of computed tomography (CT) data. Normality analysis was performed using the Shapiro-Wilk test. Data for the affected and unaffected sides were compared using the paired t-test or Wilcoxon signed-rank test. Data for both type-IIa and type-IIb CFM were compared using the independent-samples t-test or Mann-Whitney U test. The Pearson or Spearman correlation was used to determine the correlations of condylar resorption rate with related measurements. In total, 48 type-IIa and 48 type-IIb CFM patients were included. The condylar resorption rate in type-IIa CFM (0.35 ± 0.32) was significantly associated with the height of the condyle (r = 0.776, p < 0.001) and distraction distance (r = 0.447, p = 0.001), while the condylar resorption rate in type-IIb CFM (0.49 ± 0.46) was significantly associated with the height of the condyle (r = 0.924, p < 0.001). However, there was no significant difference in condylar resorption rate between type-IIa and type-IIb CFM (p = 0.075). In addition to occlusal changes, no other negative symptoms of the TMJ were observed with condylar resorption. Condylar resorption was evident in CFM patients following mandibular distraction osteogenesis, and the condylar resorption rate showed a relationship with distraction distance and condylar height.

Single-stage Repair of Bilateral Cleft Lip and Bilateral Transverse Facial Cleft in Goldenhar Syndrome: A Case Report.

Goldenhar syndrome (GS) is a rare congenital disorder characterized by multiple facial anomalies. This case report describes a GS presenting with bilateral cleft lip and palate and bilateral transverse facial cleft. We performed a single-stage surgery to repair the bilateral cleft lip and bilateral transverse facial cleft when the patient was 4-months-old. Bilateral cleft lip repair using the Mulliken method was performed first, and then the bilateral transverse facial cleft was corrected. Orbicularis oris muscle repair was done at each clefts. Anatomical approximation technique was used and the final oral commissure was determined considering symmetry. Satisfactory outcomes were achieved without complications.

Craniocervical Instability in Oculoauriculovertebral Spectrum.

INTRODUCTION: The oculoauriculovertebral spectrum (OAVS) are anomalies of the first and second pharyngeal arches, causing craniofacial changes, principally facial asymmetry, as well as anomalies in the spine, that can be a cause of instability of the craniocervical junction - manipulation of an unstable spine can result in morbimortality. However, few studies have related OAVS to craniocervical instability. OBJECTIVES: Correlate patients with OAVS through radiography with craniocervical instability and prediction of its occurrence. MATERIAL AND METHODS: Through a radiographic study of the cervical spine, the assessment of vertebral malformations and the presence of craniocervical instability was performed and clinical assessment using the OMENS score as a phenotypic criteria for patients with OAVS, by a specialized multidisciplinary team. Student's t test, Kolmogorov-Smirnova, and χ 2 were performed. RESULTS: Twenty-six patients with OAVS were evaluated, 7 (26.9%) had craniocervical instability, the OMENS score was 3 times higher, but without statistical significance. All patients with instability also had spinal malformations, and of those without craniocervical instability (19 patients), 57.8% had spinal malformations. Vertebral malformations had a similar incidence in those with and without instability, the most common being scoliosis. There was no statistical significance in the presence or absence of spinal malformations with the presence or absence of craniocervical instability. Extracraniofacial findings were found in all patients with instability; 71.4% of them were radial. CONCLUSIONS: Patients with higher OMENS scores had more craniocervical instability but without statistical significance. It also did not show statistical relevance between the presence of malformations and craniocervical instability.

Orthognathic Surgery in Goldenhar Syndrome With a Rare Course of the IAN.

Although there are multiple variations of accessory foramina described in the literature, to our knowledge there is only 1 report of an isolated mandibular foramen and inferior alveolar neurovascular bundle that courses through the lateral ramus, particularly in those with branchial arch syndromes. Goldenhar syndrome, of the oculo-auriculo-vertebral spectrum, is a rare congenital condition, which most characteristically presents with hemifacial microsomia. Depending on the severity of hemifacial microsomia, there are predictable treatment modalities to correct the consequent facial asymmetry. We report on a patient with Goldenhar syndrome who was found to have a unique course of the inferior alveolar nerve during orthognathic surgery work-up and treatment.

Intrauterine diagnosis and follow-up of a child with Goldenhar Syndrome: case report / Diagnóstico intrauterino e seguimento de uma criança com Síndrome de Goldenhar: relato de caso

Abstract Introduction: goldenhar syndrome is a rare congenital syndrome that affects the craniofacial morphogenesis. It is a complex syndrome, with heterogeneous presentation which the diagnosis can still be performed in the intrauterine through morphological ultrasound. Description: a case report of a 4-year-old male patient diagnosed with Goldenhar syndrome, along with its clinical presentation, diagnostic investigation and follow-up. Discussion: the follow-up on these patients remains a challenge, since it can affect different systems and with different presentations. The earlier the diagnosis is performed, the greater the patient's chances of having a favorable prognosis with multidisciplinary stimulation. The objective of this article is to contribute to the medical literature, in order to assist in the diagnosis and management of future cases.

Resumo Introdução: a síndrome de Goldenhar é uma síndrome congênita rara que afeta a morfogênese craniofacial. Trata-se de uma síndrome complexa, de apresentação heterogênea, cujo diagnóstico pode ser realizado ainda intra-útero através do ultrassom morfológico. Descrição: relato de caso de um paciente do sexo masculino de quatro anos, com diagnóstico de síndrome de Goldenhar, sua apresentação clínica, a investigação diagnóstica e seguimento. Discussão: o acompanhamento desses pacientes continua sendo um desafio, já que pode acometer diversos sistemas e com apresentação diversa. O diagnóstico e a estimulação multiprofissional precoce, podem levar a maiores chances de um prognóstico favorável. O objetivo deste trabalho é contribuir para a literatura médica, de forma a auxiliar no diagnóstico e conduta perante futuros casos.

Three-dimensional measurements on the mandible of patients with hemifacial microsomia.

BACKGROUND: Hemifacial microsomia (HFM), which involves multiple sites with different levels of severity, is the second most common congenital craniofacial deformity after cleft lip and palate. However, three-dimensional (3D) measurements of mandibular deformities have not yet been studied in detail. The objective of this study is to investigate the method of 3D measurements of mandibular deformities in HFM patients. METHODS: A total of 48 HFM patients were included in this study. All clinical treatment for patients was performed in the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences at Peking Union Medical College from June 2006 to June 2020. The patients' 3D computerized tomography scan data were processed using medical imaging software, following four iterative steps: 3D reconstruction, mirroring, differential analysis, and partition. RESULTS: The characteristics of the mandibular bone in HFM patients are mainly presented as follows: (1) compared to the normal side, the part of the bone body that extends from the ascending ramus to the pogonion (Po-NB) is analyzed using a dynamic process: less fullness-fullness-more fullness; (2) absences were frequently observed among the angular zones, that is, the height of the ascending ramus is deficient. CONCLUSIONS: HFM is a complicated condition with numerous variations in clinical presentation. We employed both 3D image reconstruction and computerization image processing techniques to investigate asymmetrical mandibular deformity in HFM patients in detail and with great accuracy. This will be of great use to clinicians for disease management.

Effects of mandibular distraction osteogenesis on anesthetic implications in children with hemifacial microsomia.

BACKGROUND: Hemifacial microsomia (HFM) is a congenital craniofacial malformation, and its features include hypoplasia and asymmetry in skeletal tissue and soft tissue. These features are usually associated with a difficult airway. Mandibular distraction osteogenesis can achieve mandibular advancement, but its effect on the subsequent laryngoscopic views has not been adequately documented. AIM: The aim of this study was to determine the change in laryngoscopic views after mandibular distraction osteogenesis (MDO) in children with HFM and to examine the radiological changes after MDO by using computed tomography (CT)-based three-dimensional (3-D) airway reconstruction. METHODS: An observational prospective study was carried out in children with HFM undergoing MDO. All children underwent 3-D airway reconstruction preoperatively before the placement and removal of the distractor. The temporomandibular joint lesions in children were classified by the Pruzansky-Kaban classification. The Cormack-Lehane grade was assessed after induction under direct laryngoscopy. The relationship between difficult laryngoscopy and the Pruzansky-Kaban classification was assessed. Changes in the upper pharyngeal airway parameters and laryngoscopic views were analyzed. RESULTS: Forty children (ages ranging from 5 to 16 years, males = 26, females = 14) with HFM underwent 80 anesthesia for MDO. The incidence of difficult laryngoscopy before mandibular distraction was 5/12 (41.7%) in type IIa, 19/24 (79.2%) in type IIb and 1/4 (25%) in type III HFM. The mean difference in the incidence of difficult laryngoscopy before and after MDO was 33.3% (95% CI: -6.7% to 73.3%), 50.0% (95% CI: 8.4% to 91.6%), and 0% for type IIa, type IIb, and type III, respectively. In type IIb, 12/19 cases of difficult laryngoscopy became easy after mandibular distraction: this was associated with an increase in the palatopharyngeal and glossopharyngeal CT parameters (p < .05). In type IIa, 5/5 cases of difficult laryngoscopy became easy after mandibular distraction, and 1/7 cases of easy laryngoscopy became difficult laryngoscopy. However, there were no significant changes in the palatopharyngeal, glossopharyngeal, and hypopharyngeal CT parameters in type IIa and type III HFM (p > .05). CONCLUSIONS: MDO can improve the laryngoscopic views in children with HFM. According to the Pruzansky-Kaban classification, children with type IIb showed the highest incidence of difficult laryngoscopy before MDO. After MDO, the improvement in laryngoscopic views under direct laryngoscopy in type IIb was related to the increase in the palatopharyngeal and glossopharyngeal volume.

Is the pattern of mandibular asymmetry in mild craniofacial microsomia comparable to non-syndromic class II asymmetry?

OBJECTIVES: To compare the characteristics of mandibular asymmetry in patients with unilateral craniofacial microsomia (CFM) and class II asymmetry. MATERIALS AND METHODS: Pretreatment cone-beam computed tomography of consecutive adults with Pruzansky-Kaban type I and IIA CFM (CFM group) was analyzed by 3D cephalometry. Fourteen mandibular landmarks and two dental landmarks were identified. The mandibular size and positional asymmetry were calculated by using landmark-based linear and volumetric measurements, in terms of asymmetry ratios (affected/non-affected side) and absolute differences (affected - non-affected side). Results were compared with non-syndromic class II with matched severity of chin deviation (Class II group). Statistical analyses included independent t test, paired t test, chi-square test, and ANOVA. RESULTS: CFM group (n, 21; mean age, 20.4 ± 2.5 years) showed significantly larger size asymmetry in regions of mandibular body, ramus, and condyle compared to Class II group (n, 21; mean age, 27.8 ± 5.9 years) (p < 0.05). The curvature of mandibular body was asymmetric in CFM. Regarding the positional asymmetry of mandibular body, while a comparable transverse shift and a negligible yaw rotation were found among the two groups, the roll rotation in CFM was significantly greater as well as the occlusal (6.06° vs. 4.17°) and mandibular (7.84° vs. 2.80°) plane cants (p < 0.05). CONCLUSIONS: Mild CFM showed significantly more severe size asymmetry and roll rotation in mandible than non-CFM class II asymmetry. CLINICAL RELEVANCE: To improve the mandibular size and positional asymmetry in CFM, adjunct hard tissue augmentation or reduction in addition to OGS orthodontics with a meticulous roll and yaw planning is compulsory, which is expected to be distinct from treating non-CFM class II asymmetry.

Proposed clinical approach and imaging studies in families with oculo-auriculo-vertebral spectrum to assess variable expressivity.

A diagnosis of oculo-auriculo-vertebral spectrum (OAVS) is established when microtia is present in association with hemifacial hypoplasia (HH) and/or ocular, vertebral, and/or renal malformations. There is no consensus on which imaging studies should be used to rule out variable expressivity and distinguish "sporadic" from "familial" patients. This observational and descriptive study was performed in a Mexican population of 51 patients (32 males, 19 females, 0-18 years old) with microtia/OAVS, and their available parents. A clinical history, genealogy, and physical examination were obtained from all included patients, as were a computed tomography (CT) scan of the ear, audiological evaluation, orthopantomography, complete spine radiography, and renal ultrasound. The same approach was completed in their available parents (51 mothers and 40 fathers), excluding the CT scan and audiological evaluation. By genealogy, 53% of patients were classified as "sporadic"; of the "familial" patients, at least 79.1% had suggestion of a multifactorial inheritance. In the available parents, orthopantomography, complete spine X-ray, and renal ultrasound identified the following OAVS-related manifestations: HH (16.2%, n = 14/86), vertebral alterations (10.9%, n = 10/91), and renal anomalies (2.2%, n = 2/90). Our evaluation of the parents allowed three patients to be reclassified from "sporadic" to "familial" (5.8%, n = 3/51). Our proposed clinical and imaging approach allowed the identification of variable expressivity that more clearly distinguished between "sporadic" and "familial" OAVS patients, which is of utmost importance in providing proper genetic counseling to these families.

Three-Dimensional Morphology and Configuration Analyses of the Craniovertebral Junction in Children with Hemifacial Microsomia.

STUDY DESIGN: Observational and morphological study with three-dimensional (3D) computed tomography (CT) analysis. OBJECTIVE: To discover the morphology and configuration deformities of craniovertebral junction (CVJ) and upper cervical spine in children with unilateral hemifacial microsomia (HFM). To determine whether there are specific HFM patients who are at higher risk of certain cervical vertebral anomaly. SUMMARY OF BACKGROUND DATA: The evaluation for cervical vertebrae anomaly in HFM children, especially in CVJ region, is underreported. METHODS: Eighty-eight unilateral HFM children (64 males, 24 females) with four Pruzansky-Kaban types (I, Ila, Ilb, and III) underwent cranial and cervical CT scanning from skull to C5 in neutral position. The 3D morphology and configuration of the occipital condyle, atlas, and axis, etc. were evaluated on the presence of deformed detailed structures of CVJ region. RESULTS: No C1 deformation was found in type I group. Six (14.3%) type Ila cases, seven (33.3%) type IIb cases, and six (37.5%) type Ill cases had lateral masses asymmetry of C1 (P  < 0.05). Five (55.6%) type I cases, 17 (40.5%) type Ila cases, 12 (57.1%) type Ilb cases, and 10 (62.5%) type Ill cases had C2 anomaly (P > 0.05). The incidence rate of C1-C2 instability for four groups were 33.3% (type I), 33.3% (type IIa), 33.3% (type IIb), and 31.3% (type Ill), respectively (P > 0.05). CONCLUSION: For HFM children, the incidence of C1 deformation increased from type I to type Ill. The probability of C2 anomaly and C1-C2 instability in children with different types of HFM is nearly the same. The craniovertebral junction of every HFM child must be monitored carefully for C1-C2 instability before any surgical procedure to avoid atlantoaxial dislocation and spinal cord injury.Level of Evidence: N/A.

A new association of Oculoauriculovertebral spectrum and persistent fifth aortic arch -double lumen aorta: a case report.

BACKGROUND: Oculo-auriculo-vertebral spectrum is a heterogeneous group of genetic disorder, also known as Goldenhar Syndrome, which has several phenotypic features including craniofacial anomalies, cardiac, vertebral and central nervous system defects. Cardiovascular anomalies include ventricular septal defects, atrial septal defects, patent ductus arteriosus, Tetralogy of Fallot, double outlet right ventricle, aberrant right subclavian artery, coarctation of aorta, transposition of the great arteries, double inlet left ventricle, cor triatriatum, pulmonary artery stenosis, aortic stenosis, persistent left superior vena cava, partially or totally abnormal pulmonary venous return and bicuspid aortic valve. Persistent fifth aortic arch, also named as double lumen aortic arch, is a very rare cardivascular anomaly and usually associate other cardiac defects. CASE PRESENTATION: We present a 7 month old patient with oculo-auriculo-vertebral spectrum signs as facial asymmetry, short neck, choanal atresia, cleft palate, bilateral preauricular skin tags, bilateral hypoplastic ear lobes, epibulbar dermoid cyst, rib, vertebrae and cardiovascular anomalies. Cardiovascular anomalies detected with echocardiography and computed tomography were malalignment ventricular septal defect and double lumen aorta, known as persistent fifth aortic arch. CONCLUSION: Various cardiovascular anomalies may accompany Goldenhar Syndrome. We present a case with persistent fifth aortic arch and Oculo-auriculo-vertebral spectrum and this is a new association that was not reported before in the literature.

Three-dimensional surgical management of a patient with Pruzansky I hemifacial microsomia and severe facial asymmetry: A 4-year follow-up.

Treatment of hemifacial microsomia is challenging and often requires multiple interventions to restore function and facial esthetics. In this article, the combined orthodontic-surgical treatment of a young patient exhibiting Pruzansky I hemifacial microsomia is reported. The patient was aged 15 years, but his bone age was determined to be 18 years. His facial asymmetry was severe, with the nose and a retrusive chin deviated to the left side and a canted smile. The presurgical phase was aimed at centering the mandibular midline to the center of the chin through the distal movement of the mandibular left buccal dentition. The surgery was planned with 3-dimensional computer-aided surgical simulation and included a LeFort I and unilateral sagittal split osteotomies combined with a genioplasty. This report illustrates the therapeutic stages and a 4-year follow-up of a unique and complex orthognathic surgical approach, chosen among other alternatives and leading to improved function and appearance and stable results.

Postoperative Changes in the Upper Airway Following Mandibular Distraction Osteogenesis in Pediatric Hemifacial Microsomia.

BACKGROUND: Patients with hemifacial microsomia (HFM) may undergo unilateral mandibular distraction osteogenesis (MDO) before skeletal maturity in an effort to improve facial symmetry. Mandibular distraction osteogenesis's effect on airway volumes have been studied in the past, though to our knowledge, none have accounted for the effect of head and neck posture on airway morphology. This study aimed to tackle this shortcoming, using imaging to analyze the upper airway of patients with HFM before and after surgical intervention with MDO. METHODS/DESCRIPTION: The authors retrospectively reviewed patients with a diagnosis of unilateral HFM whom underwent unilateral MDO with an oblique vector at age 4 to 14 years at a single institution from 2004 to 2019. Patients with pre- and post-MDO three-dimensional computed tomography scans of the upper airway within 12 months of distractor placement and removal, respectively, were included. Head and neck postures were determined by craniocervical, pitch, roll, and yaw angles. Pre- and post-operative pharyngeal airway volumes, pharyngeal surface area, minimum retropalatal cross-sectional areas (RP CSA) and retroglossal (RG) CSA and associated anteroposterior distances were measured using Mimics 22.0 (Materialise; Leuven, Belgium). Comparison was done using Kruskal-Wallis tests and linear mixed-effects models controlling for head and neck postures. RESULTS: Ten patients met inclusion criteria. Mean age at pre-distractor placement computed tomography scan was 99 ±â€Š35 months, and mean duration between pre- and post-surgery scans was 220 ±â€Š90 days. Head and neck posture were found to be significant predictors of all airway dimensions. After controlling for significant factors with fixed effects linear modeling, surface area was found to be significantly smaller in patients after MDO by 189.48 mm2 (F[10.8] = -3.47, P = 0.0053), compared to their preoperative measurements. Surgery was not a significant predictor of changes in airway volume (F[11.6] = 0.52, P = 0.61), minimum RP CSA (F[12.2] =  -0.64, P = 0.53), minimum RG CSA (F[12.6] =  -1.64, P = 0.13), RP anteroposterior distance (F[14.0] = 0.30, P = 0.77), or RG anteroposterior distance (F[20.0] =  -0.04, P = 0.97). CONCLUSIONS: Oblique vector MDO in patients with HFM is associated only with statistically significant changes in the surface area of the upper airway, and is not associated with statistically significant changes in dimensions like volume, CSA, or anteroposterior dimension. This is an important finding, as it may guide discussions surrounding risk/benefit ratio for MDO in childhood.