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Background: Hemifacial microsomia (HFM) results from the malformation of facial structures derived from the first and second pharyngeal arches. The ramus of the mandible is the most deformed part of the mandible in HFM, which subsequently affects the linear measurements of the different parts of the mandible. This study evaluated the anatomical differences between the affected and contralateral mandibular ramus and body (MRB) in a select cohort of HFM patients in South Africa. Methods: This is a serial retrospective study of 20 HFM patients. They were categorised into mild or severe groups by the Pruzansky-Kaban grading and into three age-dependent groups (1–5, 6–12 and 13–19 years old). Linear and angular measurements of the MRB components were recorded from preoperative computed tomography scans to compare severity, age groups, ramus and body index (RBI), and the affected to contralateral (A/C) sides ratio. Result: Significant differences existed in the linear and angular measurements of the mandible and RBI between affected and contralateral sides, except for the MBL. The mean differences between the mild and severe RBI deformities were insignificant. The A/C ratio was insignificantly smaller in the severe group than in the mild group. Age grouping did not significantly affect the A/C ratio in the mandible ramus and body. Conclusion: Mandibular asymmetry is more noticeable in HFM patients between 13 and 19 years old. The A/C ratio of the MRB did not worsen with different age groups and severity grading in this study. Hence, clinicians should postpone surgery until HFM patients attain skeletal maturity.

Summary: Hemifacial microsomia (HFM) is characterized by uni- or bilateral microtia and hypoplasia of the mandible, orbits, facial nerve, and adjacent soft tissues. Patients with Pruzansky–Kaban type III HFM show the most severe facial deformities and often encounter difficulty obtaining treatment. In recent years, orthognathic surgery for HFM-related deformities has often been performed after the patient has stopped growing. However, few detailed reports have described the difficulties of orthognathic surgery for patients with type III HFM. This report describes the case of a patient with type III HFM who underwent three unilateral mandibular reconstructions while still growing, including autogenous reconstructions and secondary distraction osteogenesis, followed by orthognathic surgery with iliac bone grafting for an interpositional gap between the proximal and distal segments after she had stopped growing to improve facial asymmetry and malocclusion.

This paper describes our experience with mixed reality (MR) intra-operative guides in patients with congenital craniofacial malformations. The first case was a patient with bilateral hemifacial microsomia. He underwent bilateral mandibular distraction osteogenesis. Pre-operative virtual planning determined the sites of osteotomy. Standard Tessellation Language (STL) files of mandibular 3D models with osteotomy sites were uploaded onto the HoloLens 2® MR glasses (Microsoft®, Washington, USA). The superimposed hologram denoted the osteotomy line. This was validated with a physical cutting guide. The second case was a patient with Crouzon's syndrome. A modified Lefort 2 advancement was performed to correct his midfacial deficiency. Pre-operative virtual planning was performed to determine the sites of osteotomies. Superimposed hologram using the Hololens 2® denoted the osteotomy sites. These were validated with a conventional intra-operative navigation system. The advantages of using MR include its immediate availability for use; saving time and costs. MR allows surgeons to maintain continuous line-of-sight within the operative field. A robust registration system is required to anchor the hologram onto the patient's skull without variations in hologram position from different angles of gaze. MR has the potential to function as an adjunct and possible replacement for conventional cutting guides and intra-operative navigation. LAY SUMMARY: We describe the use of mixed reality intra-operative guides in patients with congenital craniofacial malformations. Our experience shows the potential MR has as an adjunct and possible replacement for conventional cutting guides and intra-operative navigation., (Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Background: This study aimed to prospectively investigate the reference values for masseter muscle thickness and hardness using ultrasonography and shear wave elastography, respectively, in patients with hemifacial microsomia (HFM)., Methods: We enrolled 51 patients, aged 5-20 years, with HFM including 31 males and 20 females. The upper-lower, left-right, and anterior-posterior diameters of 102 masseter muscles and stiffness of 98 masseter muscles were determined by examining the unaffected and affected sides of each participant's face., Results: The upper-lower, left-right, and anterior-posterior diameters of the masseter muscle were significantly smaller at rest (4.26 ± 0.83, 2.94 ± 0.75, and- 0.80 ± 0.25 cm, respectively) and during contraction (3.95 ± 0.78, 2.71 ± 0.78, and 0.87 ± 0.29 cm, respectively) in the affected side than those in the healthy side (5.45 ± 0.66, 3.87 ± 0.49, and 0.97 ± 0.20 cm, respectively, at rest and 4.99 ± 0.45, 3.49 ± 0.53, and 1.07 ± 0.23 cm, respectively, during contraction, p < 0.05). In the resting state, the hardness of the masseter muscle on the affected side (0.77 ± 0.66 m/s) was significantly greater than that on the healthy side (0.42 ± 0.41 m/s; p < 0.05). The magnitude of changes in the upper-lower, left-right, and anterior-posterior diameters of the biting muscle in the occlusal state were significantly smaller on the affected side (-0.30 ± 0.27, -0.23 ± 0.17, and 0.08 ± 0.08 cm, respectively) than those in the healthy side (-0.47 ± 0.38, -0.37 ± 0.25, and 0.10 ± 0.12 cm, respectively, p < 0.05)., Conclusions: The knowledge of these values allows for better understanding of the disease characteristics of HFM, which may be used for its diagnosis, treatment, and prognosis. Patients experiencing different severity levels exhibited significant differences in the morphology and function of the masseter muscle on the affected-side (p < 0.05)., Evidence Level: Level III., Competing Interests: Conflicts of interest None declared., (Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

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., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors have no commercial associations to declare., (Copyright © 2023 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Craniofacial anomalies often exhibit phenotype variability and non-mendelian inheritance due to their multifactorial origin, involving both genetic and environmental factors. A combination of epidemiologic studies, genome-wide association, and analysis of animal models have provided insight into the effects of gene-environment interactions on craniofacial and brain development and the pathogenesis of congenital disorders. In this chapter, we briefly summarize the etiology and pathogenesis of common craniofacial anomalies, focusing on orofacial clefts, hemifacial microsomia, and microcephaly. We then discuss how environmental risk factors interact with genes to modulate the incidence and phenotype severity of craniofacial anomalies. Identifying environmental risk factors and dissecting their interaction with different genes and modifiers is central to improved strategies for preventing craniofacial anomalies., (Copyright © 2023 Elsevier Inc. All rights reserved.)

This study aimed to investigate the potential progressiveness of mandibular asymmetry and to study factors that influence chin point deviation in patients with unilateral craniofacial microsomia (CFM). Paediatric patients with unilateral CFM with available radiologic imaging and medical photographs were included. Chin point deviation was measured on clinical photographs. A Jonckheere-Terpstra test and linear mixed model for repeated measurements assessed the relation of chin point deviation on natural growth, Pruzansky-Kaban score, and soft tissue score. A total of 110 patients were included. The linear mixed model showed no statistically significant changes of chin point deviation during growth (effect estimate -0.006°, 95% CI -0.04° to -0.03°, p = 0.74). A statistical significant relation between both the Pruzansky-Kaban and soft tissue score on chin point deviation was found (effect estimate -5.10°, 95% CI -6.45° to -3.75°, p ≤ 0.001 and effect estimate -3.42°, CI -5.86° to -0.98°, p ≤ 0.001, respectively). Within the limitations of the study it seems that craniofacial microsomia may be a non-progressive disorder, because chin point deviation did not change over time., Competing Interests: Declaration of competing interest There are no conflicts of interest in the materials or subject matter dealt with in the manuscript., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Owing to the complex clinical manifestations of hemifacial microsomia (HFM), multidisciplinary cooperation is required to achieve better therapeutic effects in terms of function and aesthetics. This study aimed to explore the efficacy of the expanded two-flap auricular reconstruction combined with mandibular distraction osteogenesis in the treatment of HFM., Methods: This surgical strategy was performed in three stages. In the first stage, the retroauricular skin was expanded with a tissue expander and a mandibular distraction device was installed. In the second stage, the traditional expanded two-flap method for auricular reconstruction was adapted, and the framework was fabricated with costal cartilage and wrapped with the expanded skin flap, retroauricular fascia flap, and full-thickness skin graft. In the final stage, the tragus and lobule were rebuilt, the concha cavity deepened, and the mandibular distraction device removed., Results: From January 2014 to November 2018, 166 HFM patients underwent auricular reconstruction with the expanded two-flap method and simultaneous mandibular extension in our hospital. The median follow-up period was 9.3 months. Of the 166 patients, 154 patients and their families were satisfied with the results, and only 16 patients experienced complications., Conclusions: This three-stage technique of simultaneous auricular reconstruction and mandibular distraction osteogenesis is safe and effective in achieving facial symmetry, improving occlusal contact, shortening treatment course, and relieving patient's suffering, especially for HFM patients., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Aim: This article provides a review of a decade of clinical research studies on clinical features, medical interventions, and surgical interventions for individuals with craniofacial microsomia (CFM). We also provide recommendations for future clinical research., Method: A systematic search of literature was conducted in Embase and PubMed/MEDLINE Ovid. All publications from 2010 to 2020 that included at least 10 individuals with CFM were considered relevant for this study., Results: A total of 91 articles were included. In the past decade, many new studies on CFM have been published providing more insight on the diagnosis and management of patients with CFM. This review encompasses findings on the clinical difficulties patients with CFM encounter, including the craniofacial and extracraniofacial characteristics of patients with CFM and its related clinical consequences on breathing, feeding, speech, and hearing., Conclusions: A considerable number of large multicenter studies have been published in recent years, providing new insights in the clinical consequences of CFM. The phenotypic variety between patients with CFM makes patient-specific treatment tailored to individual needs essential. The research and development of clinical care standards might be challenging because of the heterogeneity of CFM. Future research on clinical and patient-reported outcomes can help identify optimal treatment strategies. Cooperation between craniofacial centers, using uniform registration and outcome measurement tools, could enhance research and future care for these patients., Level of Evidence: Level IV., Competing Interests: Declaration of Competing Interest There are no conflicts of interest in the materials or subject matter dealt with in the manuscript., (Copyright © 2022 British Association of Plastic, Reconstructive and Aesthetic Surgeons. All rights reserved.)

In this study, the aim was to assess whether using elastic traction during the active period of distraction osteogenesis could effectively increase the vertical extension. Patients with Pruzansky-Kaban Type II mandibular deformity were recruited and randomly assigned into Elastic traction + Distraction Osteogenesis group or Distraction Osteogenesis group, respectively. During the active period, the experimental group received orthodontic elastic traction 3 days after distraction osteogenesis implantation, while the control group received no treatment. All the participants underwent computed tomography (CT) examination before surgery, at the end of the active period, 6 months and 2 years after distraction osteogenesis tractor implantation. The primary outcome was the effective vertical extension rate of the mandible from the baseline to the end of the active period after operations, and there were 7 secondary outcomes used. 70 patients were included. The effective vertical extension rates were 85.021% ± 7.432% (mean ± SD) and 68.811% ± 9.510% (mean ± SD) in the experimental and control groups, respectively (P = 0.001). The average distances between the lower middle incisor point to the sagittal plane at the end of the active period were 2.485 ± 1.411 mm and 3.938 ± 2.293 mm in the experimental and control groups, respectively (P = 0.026). At the end of the active period of distraction osteogenesis, the average values of the mandibular occlusal plane canting were -4.887 ± 3.126 mm and -0.177 ± 4.029 mm in the experimental and control groups, respectively (P = 0.026). Elastic traction-assisted distraction osteogenesis could improve traction efficiency and facial symmetry., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2021 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background and Overview: The authors successfully treat a case of hemifacial microsomia involving unilateral condylar hypoplasia using conventional orthodontic techniques followed by long-term retention., Case Description: A girl aged 10 years and 2 months received a diagnosis of hemifacial microsomia resulting from unilateral condylar hypoplasia. During a growth period, premature incisal contact was abolished. After her growth was complete, she received conventional orthodontic treatment with preadjusted edgewise appliances. After 27 months of multibracket treatment, acceptable occlusion with a class I canine and molar relationship was achieved. The occlusion remained stable throughout the 15-year retention period, although there was a slight facial change., Conclusions and Practical Implications: Early orthodontic management only can have some limitations but could be one of the treatment options for hemifacial microsomia., (Copyright © 2021 American Dental Association. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to describe the utility of 3D technology in mandibular distraction (MD) for patients with mandibular hypoplasia (MH), using 3D-printed cutting guides (CGs), and to assess the differences between virtual surgical planning (VSP) and the final result. A descriptive retrospective study of five patients diagnosed with MH, who required unilateral or bilateral MD, was carried out between January 2018 and January 2020. All patients underwent preoperative craniofacial CT scan and a 3D VSP was executed. MD was performed with the help of the 3D-printed CG. Before removal of the distractor, another CT scan was performed to compare the actual final result with the VSP. A mean difference of <4° was found for the osteotomy direction, < 7° for distractor position, and <2 mm for posterior screw placement. VSP and 3D-printed CGs have revolutionized surgical planning, facilitating surgical treatment and improving the final result. In our sample, the variations in osteotomy line, distractor position, and posterior screw placement have been minor, making the outcome more predictable., Competing Interests: Declaration of competing interest None., (Copyright © 2020 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background and Objectives: Congenital microtia may be associated with hemifacial microsomia, but little is known about their correlation and development with aging. Historically, facial asymmetry is easily assessed by observing the occlusal cant using a tongue depressor. We serially measured the occlusal cant in children with microtia to evaluate change in facial asymmetry with growth., Methods: Since 2011, frontal photographs of patients with congenital microtia biting a tongue depressor were obtained and reviewed. The occlusal angle was compared between the baseline and final photographs, and the change was compared between cant-positive (>3° at baseline) and cant-negative (<3° at baseline) groups. Multivariate analysis was conducted to determine variables associated with the change in occlusal angle., Results: Overall, 105 patients were enrolled. With a mean age of 5.4 years at baseline and a mean follow-up of 3.9 years, clinically significant aggravation was observed in 15.4% and 24.2% of cant-positive and cant-negative patients, respectively. Hemifacial microsomia (OR, 4.825; p = 0.005) and occlusal angle at baseline (OR, 0.821; p = 0.045) were associated with aggravation, but the severity of microtia showed no significant association., Conclusions: When hemifacial microsomia was present, the occlusal cant seemed to be aggravated in children with microtia at later ages. When the occlusal cant was present without noticeable hemifacial microsomia, some compensation in facial asymmetry was expected. The use of a wooden tongue depressor is a simple, non-invasive, and radiologic hazard-free aid to detect notable change in facial asymmetry in children with microtia., Competing Interests: Declaration of Competing Interest None of the listed authors have anything to disclose. No funding was received for this article., (Copyright © 2020. Published by Elsevier Ltd.)

Mandibular distraction osteogenesis at an early age is the standard hemifacial microsomia treatment. Nevertheless, the recurrence rate remains high and the definition of early age is controversial. We explored the optimal timing for mandibular distraction, when the surrounding skeleton, such as maxilla, can grow compensatory, to reduce recurrence. Hemifacial microsomia patients were prospectively divided into Groups A (1-3 years old) and B (4-6 years old), according to maxillary and mandibular growth curves. Computed tomography scans were obtained before distractor implantation and after removal surgery. Maxillary volume increase percentage was the main outcome indicator; other indicators (maxillary symmetry and complications) were secondary outcomes. Fifty-eight patients were enrolled and all but one patient in Group A (failed distraction) completed the study. Two patients had facial nerve injury and another two had mouth-opening limitation, which was relieved after coracoid resection. The difference in percentage increase in maxillary volume between the affected and unaffected sides was 5.06 ± 2.73% and 3.18 ± 1.99% in Groups A and B, respectively, suggesting better compensatory growth in younger patients (P = 0.004). Maxillary symmetry was apparently elevated after mandibular distraction. Mandibular distraction osteogenesis was confirmed to be feasible and safe at age <4 years., (Copyright © 2020 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: Unilateral posterior vertical insufficiency (PVI) is a growth defect of the mandibular condyle that results in a facial asymmetry. Various surgical procedures can be used to elongate the hypoplastic ramus. The aim of this study was to evaluate long-term aesthetic and architectural outcomes of vertical ramus osteotomy (VRO) in patients with unilateral PVI., Materials and Methods: Patients operated on with unilateral VRO were included in this retrospective study. Aesthetic and architectural parameters were evaluated on frontal photographs as well as on frontal and lateral cephalograms preoperatively, postoperatively, at 1-year and at the end of the follow-up., Results: A total of 48 patients were analyzed. The aesthetic assessment revealed significant correction of the chin deviation (CD) and of the lip commissural line tilt after VRO (p1 = 0.0038 and p2 = 0.0067, respectively) with stable results. The architectural analysis revealed significant improvement in the maxillary and mandibular occlusal planes, as well as the chin deviation (p < 0.0001). A tendency to relapse was noted for the mandibular canting and the CD during the follow-up. VRO allowed for a mean mandibular lengthening of 8.39 mm (ranging from 2.5 to 14 mm)., Conclusion: VRO allows for immediate restoration of the symmetry of the lower third of the face in patients with unilateral PVI. A revisional procedure may be needed due to a tendency for the chin deviation to relapse., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Postoperative infection is a complication of mandibular distraction osteogenesis (DO) in patients with hemifacial microsomia (HFM). The risk of surgical wound infection in DO is reported to be high due to the long duration of the distraction process. Treatment during the perioperative period is critical in combating infection., Aim: This study aimed to evaluate the effectiveness of red-blue irradiation in the prevention of surgical wound infection after mandibular distraction., Methods: In our single-centered, randomized clinical study, 118 patients diagnosed with HFM who had undergone DO between April 2016 and April 2018 were included. The patients were randomly divided into two groups: the experimental group received red-blue irradiation treatment and the control group received white-light irradiation., Results: None of the infections occurring in this study resulted in serious complications. The postoperative infection rate during the 4 weeks after DO in the experimental group was 1.7%, whereas that in the control group was 13.6% (p = 0.016) (based on a modified NHSN wound infection criterion). The total social cost during the active period for the experimental group was 3386840 RMB, 5.12% higher than for the control group (3221882 RMB)., Conclusions: Red-blue irradiation is recommended as adjunctive therapy after mandibular distraction osteogeneis in HFM., (Copyright © 2019 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Distraction osteogenesis can be used to treat hemifacial microsomia in patients of any age group. Application of three-dimensional (3D) technology in the surgical planning of distraction osteogenesis allows the placement of an intraoral distractor to define the cutting line and help predict the outcome of surgery., Aim: This study compared the results of distraction osteogenesis performed, using computer-assisted surgery, on OMENS-plus-classified M2A, M2B, and M3 type patients. Comparisons were in terms of either accuracy or predictability., Methods: 40 patients were selected to participate in the 8-month study. Preoperative image data from 3D-CT scans of the 40 patients were translated into DICOM format 3D cephalometrics, run using the computer software MIMICS version 18, and based on eight reference anatomical landmark points, five lines of measurement, and the midline of the mandibular plane. The distraction vector for the affected side of mandible was selected and the elongation process simulated repeatedly until satisfactory results were obtained. The surgical guide was created using CAD/CAM-RP technology. The distraction osteogenesis procedure was then performed using the surgical guides. Follow-up for all patients continued until 8 months postoperatively. Accuracy with and without computer-assisted surgery was assessed linearly and volumetrically. Simple mean comparisons and paired t-tests were conducted using IBM SPSS V21., Results: In those patients who received computer-assisted surgery, distraction in the M2A type mandible showed accuracy of around 97.77% ± 7.92% (p > 0.05) for height and 97.91% ± 10.23% (p > 0.05) for length of the mandible. Meanwhile, the M2B type mandible presented accuracy of around 93.85% ± 8.07% (p > 0.05) for height and 95.85% ± 10.16% (p > 0.05) for length. For the M3 type mandible accuracy was around 98.42% ± 6.58% (p > 0.05) for height and 97.14% ± 11.45% (p > 0.05) for length. These measurements showed no significant differences between preoperative design and real outcome., Conclusions: Individualized guides improve the accuracy of distraction osteogenesis. They help the surgeon to identify the mandibular defect and ensure the desired outcome after the operation., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: To quantify the surface facial asymmetry in a group of young patients with hemifacial microsomia (HFM) and to investigate differences with a homogeneous sample of healthy subjects, using a novel stereophotogrammetric method., Materials and Methods: Twelve patients (mean age 13.1 ± 3.1 years) with different degrees of HFM and 15 healthy controls (mean age 12.2 ± 3.5 years) were imaged with a stereophotogrammetric facial scanner. The root mean square error (RMSE) of the distances between the corresponding points of each original photograph and its mirror copy was calculated for the whole face and for each trigeminal third, as defined by the innervation of trigeminal branches. A statistical analysis was performed to compare the RMSE value of all facial areas within each group and between patients and controls., Results: RMSE values progressively increased from the upper to the lower third of face, both in patients and controls. The level of asymmetry was significantly higher in HFM subjects for middle third (p < 0.01), lower third (p < 0.001) and whole face (p < 0.001); no statistically significant differences were found between the groups for the upper third., Conclusions: The reported technique provides an accurate topographic analysis of the facial asymmetry, and is recommended for conditions such as HFM affecting only part of the face., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: Craniofacial microsomia (CFM) is the result of a disturbance in embryologic development and is characterised by an asymmetric, mostly unilateral facial underdevelopment. The aim of this study is to understand the midfacial involvement in CFM using principal component analysis (PCA)., Materials and Methods: Pre-operative data from 19 CFM and 23 control patients were collected. A set of 71 landmarks was placed on three-dimensional (3D) reconstructions of all skulls to compare both populations. PCA visualised variation within both groups and calculated the vector of change. Linear measurements were taken to compare ratios between the populations and between the affected and unaffected sides in CFM patients., Results: PCA defined a vector that described shape changes between both populations. Videos showed the variation within the control and CFM group and the transformation from a mean CFM skull into a normal phenotype. Linear measurements showed a significant difference between the affected and unaffected sides in CFM patients., Conclusion: PCA has not been applied on asymmetrical data before, but it has proved to be a useful method to describe CFM. The virtual normalisation of a mean CFM skull enables visualisation of the bony shape changes, which is promising to delineate and to plan surgical correction and could be used as an outcome measure., (Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.)

Purpose: The goal of this study was to understand the three-dimensional (3D) structural characteristics of hemifacial microsomia (HFM) mandible in terms of skeletal units, especially to locate the underdeveloped skeletal regions for treatment. Another goal was to compare the HFM structure of different age groups to understand growth potential relevant to treatment scheduling., Materials and Methods: We reconstructed 3D mandibles from computed tomographic images of French and Korean patients with HFM (N = 28; group II) and normal subjects (N = 27; group I). Each mandible was classified by Pruzansky's HFM types I, II and III, and by age group (child, adolescent, and adult). The mandible was divided into skeletal units, and geometrical representation by skeletal unit line was performed, including the condylar, body, coronoid, and angular units. Their length and angulations were measured and statistically analyzed., Results: The results showed that the affected condylar unit in type II HFM and the condylar/coronoid unit in type III were smaller in young age groups than were other units. The angulation between the skeletal units in type II, though not type III, tended toward normalcy with age, but not to the normal degree of angulations in group I., Conclusion: Our study shows the major involvement of condylar unit and minor involvement of body unit for HFM, improving with age in type II. The mandibular skeletal unit analysis seems to be a useful tool for individualized diagnosis, allowing identification of the major etiopathogenic area and treatment planning, including a simulation to set up a regimen for successful reconstruction of HFM., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

A retrospective cohort study was initiated to analyse the prevalence, risk factors and treatment modalities of feeding difficulties in patients with craniofacial microsomia. This study included 755 subjects with craniofacial microsomia from three craniofacial centres. Medical charts were reviewed for severity of the deformity, documented feeding difficulties, age at which feeding difficulties first presented and treatment, presence of cleft lip/palate, extracraniofacial anomalies, and obstructive sleep apnoea. In total, 199 patients (26.4%) had documented feeding difficulties. Patients with bilateral involvement, Pruzansky-Kaban III classification, cleft lip/palate, or obstructive sleep apnoea were significantly more at risk for developing feeding difficulties and significantly more often needed additional feeding via a nasogastric tube than patients without these risk factors., (Copyright © 2018. Published by Elsevier Ltd.)

Introduction: Mandibular reconstruction in craniofacial microsomia (CFM) has been described and reviewed at length although final results are not always (aesthetically) satisfactory due to maxillo-mandibular asymmetry, for which optimal correction techniques remain unclear. The aim of this systematic review is to provide an overview of the surgical options for maxillary correction in patients with unilateral CFM., Material and Methods: MEDLINE/Pubmed, Embase, Cochrane and Web of Science databases were searched up to April 15, 2017. Inclusion criteria were: studies reporting patients with unilateral CFM (n > 4) who had maxillary correction (with/without simultaneous mandibular correction) with a minimal follow-up of 6 months. The outcome measures included type of treatment (including preceding facial procedures), type and severity of mandibular deformity (by Pruzansky-Kaban system: Types I/IIa/IIb/III), asymmetry analysis method, outcome (i.e. occlusion, canting, stability, esthetic result, facial symmetry), complications and additional treatment needed., Results: Nine studies met the inclusion criteria. Analysis showed that Le Fort I + mandibular distraction osteogenesis (LeFort + MDO) and BiMaxillary osteotomy (BiMax) were used for treatment, as single or multiple-stage procedures. All studies reported aesthetic and functional improvement., Conclusion: Types I/IIa benefited from LeFort + MDO; Type IIb from LeFort + MDO or BiMax; and Type III from BiMax (with 50% of cases having preceding mandibular procedures, including patient-fitted prosthesis) at a mean age of 20.2 years. Four studies recommended additional (esthetic) procedures., (Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.)

Purpose: Hemifacial microsomia (HFM) is a frequently encountered congenital malformation syndrome involving both hard and soft tissue. Various surgical methods have been described to correct the deformities of HFM in the literature. This study aims to evaluate the therapeutic efficacy for HFM with the assistance of virtual surgical planning (VSP) and 3-dimensionally printed surgical templates., Materials and Methods: From January 2010 to January 2016, a total of 46 patients were referred to the study. Different surgical procedures under the guidance of VSP and 3-dimensionally printed surgical templates combined with orthodontic treatment were used to correct the deformities. Clinical outcomes were evaluated by comparing the differences of affected-side ramus height, occlusal cant degrees and chin point deviation between the preoperative VSP and postoperative surgical results., Results: Satisfactory facial contour and occlusion were achieved with the combination of orthognathic and orthodontic treatment. Postoperative examination results showed that VSP was accurately transferred into actual surgery. The difference between the preoperative design and the postoperative outcome was not statistically significant., Conclusion: VSP and 3-dimensionally printed surgical templates serve as a reliable method and show great value in improving the accuracy and efficacy of surgical treatment of HFM., (Copyright © 2018. Published by Elsevier Ltd.)

Hemifacial microsomia (HFM) is the second most common congenital craniofacial malformation. Although many sporadic and familial cases have been studied to explore the etiology and pathogenesis of HFM, no common understanding has been reached. We aimed to further probe into the etiology of HFM through studying monozygotic twins. Here, we report two cases of pairs of monozygotic twins discordant for HFM, and performed whole-exome sequencing (WES) and bioinformatics analysis to help determine the underlying molecular mechanisms. We identified 93 and 83, and 101 and 104 genes containing rare germline mutations in the twins of the two pairs, respectively. No positive gene candidates were found among the samples, and none of the analyses results revealed a clear intersection with previously reported gene candidates. The pathogenesis of HFM twin pairs does not appear to be related to single nucleotide variants or small insertions/deletions. Thus, HFM may be caused by structure variations, epigenetic alterations, and/or instability of short repeat sequences, which requires further investigation in a larger cohort with sequencing technology for verification., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Many researchers have studied the relationship between facial asymmetry and cranial base morphology, but they have failed to reach a consensus. In this study, we aimed to verify whether the cranial base is involved in hemifacial microsomia (HFM)., Methods: We included 66 patients with HFM who were treated at the Plastic and Reconstructive Surgery Department of Shanghai Ninth People's Hospital from January 2013 to October 2016. The patients were divided into three groups according to Pruzansky and OMENS classifications, separately. The controls were 20 patients diagnosed with mandibular angle hypertrophy but with no facial asymmetry. Angular and linear measurements of the cranial base were obtained for all patients., Results: The two classification methods yielded similar results. The intersection angle between two planes showed differences in the severe group. In the moderate and severe groups, the middle and posterior cranial angles were significantly different and the CIP and SP lengths were shorter in the affected side. Landmarks such as the carotid canal and internal acoustic canal could be considered as references., Conclusions: The cranial base is involved in hemifacial microsomia. This relationship supports the hypothesis of HFM pathogenesis and opens new avenues to classification methods., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: To assess the two- and three-dimensional airway changes following unilateral vertical mandibular distraction osteogenesis (vMDO) in patients with hemifacial microsomia (HFM)., Methods: A retrospective evaluation was performed for consecutive patients over an 18-month period with HFM and with Kaban-Pruzansky Type-II mandibular deformities who underwent unilateral vMDO for correction of vertical mandibular asymmetry. Patients with complete records and a minimum of 12 months of clinical follow-up post-consolidation were included. Pre-operative airway dimensions (diameters, cross-sectional areas, and volumes) were measured for the oropharynx and nasopharynx. Pre-operative airway dimensions were compared to post-distraction measurements taken from 3D-CT data obtained at a minimum of 3 months post-consolidation., Results: Five patients met inclusion criteria. Median age was 12.6 years, 3 were female, and median distraction length was 21.3 mm. Median final follow-up CT was performed 5 months after completion of distraction. There were no major or minor complications. Median total airway volume change was +33.7%, corresponding to median volume changes of 80.5% and 10.5% for the oropharyngeal and nasopharyngeal airways, respectively., Conclusion: Unilateral vMDO expands the minimum diameter and volume of the oropharyngeal to a greater extent than the nasopharyngeal airway in HFM patients with Kaban-Pruzansky Type-II mandibular deformities., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: Craniofacial microsomia (CFM) is a congenital malformation of structures derived from the first and second pharyngeal arches leading to underdevelopment of the face. However, besides the craniofacial underdevelopment, extracraniofacial anomalies including cardiac, renal and skeletal malformation have been described. The aim of this study is to analyse a large population of patients with regard to demographics, typical phenotypes including craniofacial and extracraniofacial anomalies, and the correlations between the different variables of this condition., Material and Methods: A retrospective study was conducted in patients diagnosed with CFM with available clinical and/or radiographic images. All charts were reviewed for information on demographic, radiographic and diagnostic criteria. The presence of cleft lip/palate and extracraniofacial anomalies were noted. Pearson correlation tests and principal component analysis was performed on the phenotypic variables., Results: A total of 755 patients were included. The male-to-female ratio and right-to-left ratio were both 1.2:1. A correlation was found among Pruzansky-Kaban, orbit and soft tissue. Similar correlations were found between ear and nerve. There was no strong correlation between phenotype and extracraniofacial anomalies. Nevertheless, extracraniofacial anomalies were more frequently seen than in the 'normal' population. Patients with bilateral involvement had a more severe phenotype and a higher incidence of extracraniofacial and cleft lip/palate., Conclusion: Outcomes were similar to those of other smaller cohorts. Structures derived from the first pharyngeal arch and the second pharyngeal arch were correlated with degree of severity. Extracraniofacial anomalies were positively correlated with CFM. The findings show that bilaterally affected patients are more severely affected and should be approached more comprehensively., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. All rights reserved.)

Introduction: The goal in treating Hemifacial microsomia (HFM) is to improve facial symmetry, allow functional jaw movement, obtain stable occlusion, and achieve patient satisfaction. This study was planned with an aim to assess the outcome of simultaneous maxillomandibular distraction osteogenesis in hemifacial microsomia., Material & Methods: Seven patients with hemifacial microsomia were included in this study and demographic data was obtained. Simultaneous maxillo-mandibular distraction was planned for correction of maxillary cant, vertical ramal lengthening and midline, by performing unilateral mandibular osteotomy in ramus and distractor fixation, a Le Fort I osteotomy, with fixation at contralateral zygomatic buttress and intermaxillary elastics. Derriford Appearance Scale was used to measure individual responses to address problems of appearance., Results: 6 males and 1 female, with age range 18-26 years, mean 22.14 were included in the study. Maxillary occlusal cant varied from 4-16°, mean 9.85° and distraction achieved ranged from 12-19 mm, mean 15.57. Preoperatively DAS score ranged from 42-61, mean 51.7 and improved to 10-27, mean 18.4. 100% success was achieved in 5 cases, while other two showed 96% and 99% success., Conclusion: Simultaneous maxillomandibular distraction osteogenesis improves facial esthetics and obviates the need for postoperative orthodontics, minimizing the treatment period.

Purpose: Distraction osteogenesis is a technique of bone lengthening which uses the bone's natural healing process. Current devices for craniofacial distraction require a transmucosal or transcutaneous activator and are associated with numerous complications. The aim of this study was to evaluate the feasibility of a rodless magnetic activation device that could be used in craniofacial distraction., Methods: The method is based on the torque applied between two unaligned permanent magnets. This torque depends on magnet size, shape, composition, magnetization and distance between the two magnets. Using a configuration close to that which would be applied in actual distraction osteogenesis (in terms of the distance between the two magnets), we performed an analytical study and evaluated the results., Results: We observed good agreement between the model and the experimental results, finding that the transmitted force value is comparable to the force required in mandibular distraction. Thus, we proposed a design of a new distracting device consisting of a cylindrical permanent magnet diametrically magnetized and fixed to an endless screw along its main axis. Activation of the distraction motion is achieved through interaction of the first magnet with a second cylindrical magnet whose magnetization is orthogonal to its main axis and to the device's endless screw., Conclusion: This preliminary study demonstrates that magnetic activation for mandibular osteogenic distraction is feasible and that device size is not a constraint. We propose a prototypic device., (Copyright © 2016. Published by Elsevier Ltd.)

Introduction: Oculo-auriculo-vertebral spectrum (OAVS OMIM 164210) is a craniofacial developmental disorder affecting the development of the structures derived from the 1st and the 2nd branchial arches during embryogenesis, with consequential maxillary, mandibular, and ear abnormalities. The phenotype in OAVS is variable and associated clinical features can involve the cardiac, renal, skeletal, and central nervous systems. Its aetiology is still poorly understood., Methods: We have evaluated the clinical phenotypes of 51 previously unpublished patients with OAVS and their parents, and performed comparative genomic hybridization microarray studies to identify potential causative loci., Results: Of all 51 patients, 16 (31%) had a family history of OAVS. Most had no relevant pre-natal history and only 5 (10%) cases had a history of environmental exposures that have previously been described as risk factors for OAVS. In 28 (55%) cases, the malformations were unilateral. When the involvement was bilateral, it was asymmetric. Ear abnormalities were present in 47 (92%) patients (unilateral in 24; and bilateral in 23). Hearing loss was common (85%), mostly conductive, but also sensorineural, or a combination of both. Hemifacial microsomia was present in 46 (90%) patients (17 also presented facial nerve palsy). Ocular anomalies were present in 15 (29%) patients. Vertebral anomalies were confirmed in 10 (20%) cases; 50% of those had additional heart, brain and/or other organ abnormalities. Brain abnormalities were present in 5 (10%) patients; developmental delay was more common among these patients. Limb abnormalities were found in 6 (12%) patients, and urogenital anomalies in 5 (10%). Array-CGH analysis identified 22q11 dosage anomalies in 10 out of 22 index cases screened., Discussion: In this study we carried out in-depth phenotyping of OAVS in a large, multicentre cohort. Clinical characteristics are in line with those reported previously, however, we observed a higher incidence of hemifacial microsomia and lower incidence of ocular anomalies. Furthermore our data suggests that OAVS patients with vertebral anomalies or congenital heart defects have a higher frequency of additional brain, limb or other malformations. We had a higher rate of familial cases in our cohort in comparison with previous reports, possibly because these cases were referred preferentially to our genetic clinic where family members underwent examination. We propose that familial OAVS cases show phenotypic variability, hence, affected relatives might have been misclassified in previous reports. Moreover, in view of its phenotypic variability, OAVS is potentially a spectrum of conditions, which overlap with other conditions, such as mandibulofacial dysostosis. Array CGH in our cohort identified recurrent dosage anomalies on 22q11, which may contribute to, or increase the risk of OAVS. We hypothesize that although the 22q11 locus may harbour gene(s) or regulatory elements that play a role in the regulation of craniofacial symmetry and 1st and 2nd branchial arch development, OAVS is a heterogeneous condition and many cases have a multifactorial aetiology or are caused by mutations in as yet unidentified gene(s)., (Copyright © 2015. Published by Elsevier Masson SAS.)

Purpose of the Study: To assess the growth potential of costochondral graft in temporomandibular joint reconstruction in patients with temporomandibular ankylosis and hemifacial microsomia., Method: Systematic review after inclusion of articles fulfilling the following criteria: (1) only human studies; (2) patients of temporomandibular joint ankylosis and hemifacial microsomia; and (3) studies with minimum of five cases and with a minimum follow-up for a period of 5 years. The primary outcome measure was the percentage of patients with optimum growth of costochondral graft. Secondary outcomes were any abnormal growth and restoration of function. Delphi's criteria were used for assessing the quality of the included studies., Result: Only three studies satisfied all the inclusion criteria. A total of 96 costochondral grafts were placed in the included studies. Optimum growth was reported in 54 grafts, undergrowth in 1 graft, overgrowth in 7 grafts, lateral overgrowth in 1 graft and no growth in 1 graft. Graft resorption, reankylosis and sequestration were seen in 21, 8 and 3 cases, respectively. When the Delphi's criteria were applied to the case series for the assessment of quality, majority of the studies could be considered as satisfying at least 50% of the criteria., Conclusion: There are no randomised clinical trials and the only evidence is in the form of case series that is considered as the lowest level of evidence for any study. No inference can be interpreted regarding growth potential of costochondral graft. Thus, on the basis of available evidence, it can be concluded that use of costochondral graft for temporomandibular joint reconstruction lacks scientific evidence.

Background: Through three-dimensional real time imaging, augmented reality (AR) can provide an overlay of the anatomical structure, or visual cues for specific landmarks. In this study, an AR Toolkit was used for distraction osteogenesis with hemifacial microsomia to define the mandibular osteotomy line and assist with intraoral distractor placement., Methods: 20 patients with hemifacial microsomia were studied and were randomly assigned to experimental and control groups. Pre-operative computed tomography was used in both groups, whereas AR was used in the experimental group. Afterwards, pre- and post-operative computed tomographic scans of both groups were superimposed, and several measurements were made and analysed., Results: Both the conventional method and AR technique achieved proper positioning of the osteotomy planes, although the AR was more accurate. The difference in average vertical distance from the coronoid and condyle process to the pre- and post-operative cutting planes was significant (p < 0.01) between the two groups, whereas no significant difference (p > 0.05) was observed in the average angle between the two planes. The difference in deviations between the intersection points of the overlaid mandible across two cutting planes was also significant (p < 0.01)., Conclusion: This study reports on an efficient approach for guiding intraoperative distraction osteogenesis. Augmented reality tools such as the AR Toolkit may be helpful for precise positioning of intraoral distractors in patients with hemifacial microsomia in craniofacial surgery., (Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Hemifacial microsomia (HFM) is a congenital disorder characterized by craniofacial malformation of one or both sides of the lower face. Since these anomalies are associated with soft-tissue deficiencies, corrective surgery is often difficult. Bone grafts have typically been used for augmentation, but distraction osteogenesis now offers an alternative for many craniofacial deficiencies, but there are few if any appropriate distraction devices and surgical procedures for the augmentation of craniofacial transversal dimensions., Methods: The aim of this study was to evaluate a technique for guided augmentation of craniofacial transversal dimensions through distraction osteogenesis. We tested the efficacy of a prototype distractor, developed in collaboration with Medartis, using cadavers and demonstrated its application for the correction of the transverse dimension of the temporozygomatic region in a patient with Goldenhar syndrome., Results: CT scans showed a 4-mm transverse augmentation of the bony surface after 9 days and a 10-mm increase after 30 days. Upon removal of the distractor (60 days after the first surgery) CT indicated good bony fusion and a stable result in the transverse plane. Six months after removal of the distractor, 3D computed tomography confirmed the success of the transverse augmentation, as it appeared to be stable and reliable., Conclusions: Distraction osteogenesis, using our device, can be used to correct the transverse dimension of the temporozygomatic region in HFM patients. It should also be considered for the correction of residual postsurgical skeletal deficiency due to surgical relapse or deficient growth, and unsatisfactory skeletal contour., (Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)