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.

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.

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.

Total temporomandibular joint reconstruction prosthesis in hemifacial microsomia: A systematic review.

Hypoplastic asymmetry due to hemifacial microsomia (HFM) often represents the most difficult reconstruction in the craniomaxillofacial clinic. Although autogenous grafts are generally used for temporomandibular joint reconstruction (TMJR), the use of TMJR prostheses is not well established. The aim of this review was to identify, collect and analyse the use of extended TMJR (eTMJR) prostheses in patients with HFM, describing clinical features, surgical procedures and postoperative complications. Online searches of all major databases were performed according to PRISMA guidelines. All studies with HFM patients treated with the eTMJR prostheses were included. Descriptive statistics were used for data analysis. A total of 19 studies, including 08 case studies, 06 case series and 05 retrospective cohort studies, met the inclusion criteria, where a total of 42 HFM patients were reported from 18 countries, mostly from the United States (05; 26%). Fifteen of the 42 cases (~36%) were male. The mean ± SD (range) age of patients in all studies was 19.79 ± 5.81 (9-36) years. The mean ± SD (range) of patient follow-up was 41.30 ± 35.50 (6-136) months. A total of 5 (10.6%) patients were implanted with bilateral eTMJR prostheses. The Pruzansky classification was used in 18 (~89.5%) studies, OMENS classification in 01 (~5%) study, whereas no classification was reported in one study. Only 01 (7.1%) study had documented the eTMJR classification for the prosthesis used. In growing patients with or without a history of failed autogenous tissues, TMJR prostheses may provide a viable alternative. Randomized studies with large cohorts are warranted to validate these preliminary results.

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.

[Model test study on treatment of Pruzansky type â ¡B and â ¢ hemifacial microsomia with artificial condyle-mandibular distractor complex].

Objective: To preliminarily verify the effectiveness of self-designed artificial condyle-mandibular distraction (AC-MD) complex in the treatment of Pruzansky type ⅡB and Ⅲ hemifacial microsomia (HFM) through model test. Methods: Five children with Pruzansky type ⅡB and Ⅲ HFM who were treated with mandibular distraction osteogenesis (MDO) between December 2016 and December 2021 were selected as the subjects. There were 3 boys and 2 girls wih an average age of 8.4 years (range, 6-10 years). Virtual surgery and model test of AC-MD complex were performed according to preoperative skull CT of children. The model was obtained by three-dimensional (3D) printing according to the children's CT data at a ratio of 1∶1. The occlusal guide plate was designed and 3D printed according to the children's toothpaste model. The results of the model test and the virtual surgery were matched in three dimensions to calculate the error of the residual condyle on the affected side, and the model test was matched with the actual skull CT after MDO to measure and compare the inclination rotation of the mandible, the distance between the condylar of the healthy side and the residual condyle of the affected side, and the lengthening length of the mandible. Results: The error of residual condyle was (1.07±0.78) mm. The inclination rotation of the mandible, the distance between the condylar of the healthy side and the residual condyle of the affected side, and the lengthening length of the mandible after 3D printing model test were significantly larger than those after MDO ( P<0.05). Conclusion: In the model test, the implantation of AC-MD complex can immediately rotate the mandible to the horizontal position and improve facial symmetry, and the residual condyle segment can be guided close to the articular fossa or the preset pseudoarticular position of the skull base after operation.

Modified horizontal muscle transposition without tenotomy and splitting for a case of inferior rectus and inferior oblique muscles aplasia with hemifacial microsomia.

Aplasia of the inferior rectus and inferior oblique muscles is extremely rare. Failure of the normal embryologic development of the inferior mesodermal complex can lead to agenesis of inferior rectus, inferior oblique, and lower sections of the lateral rectus muscles. This rare condition is usually seen in association with craniofacial syndromes or in conjunction with microcornea, microphthalmos, Axenfeld-Rieger syndrome, and coloboma. The usual treatment for this condition is a reverse Knapp procedure to improve the vertical alignment; however, this procedure can lead to complications, such as anterior segment ischemia, undercorrection, and torsional problems. To our knowledge, unilateral inferior rectus and inferior oblique muscle aplasia has not been described previously in a patient with congenital facial nerve palsy and optic nerve hypoplasia. In the present case, the patient was successfully treated with a modified minimally invasive horizontal rectus muscle transposition procedure.

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.

Goldenhar syndrome complicated with subglottic airway stenosis: a case report.

BACKGROUND: Goldenhar syndrome is a congenital disease that involves an absence or underdevelopment of structures that arise from the first and second pharyngeal arches and more or less severe extracranial anomalies. A variety of supraglottic malformations may be observed, including mandibular hypoplasia, mandibular asymmetry and micrognathia. Subglottic airway stenosis (SGS), which can cause difficulties in airway management during the perioperative period, is seldom emphasized in literature descriptions of Goldenhar syndrome, but can be clinically significant. CASE PRESENTATION: An 18-year-old female with a history of Goldenhar syndrome presented for placement of a right mandibular distractor, right retroauricular dilator, and stage I transfer of a prefabricated expanded flap under general anesthesia. During tracheal intubation, the endotracheal tube (ETT) met resistance unexpectantly when attempting to pass through the glottis. Subsequently, we attempted the procedure with a smaller size ETT but again met resistance. With fiberoptic bronchoscope, we found that the whole segment of the trachea and bilateral bronchi were obvious narrow. Given the finding of unexpected severe airway stenosis and the associated risks with proceeding with the surgery, the operation was cancelled. We removed the ETT once the patient was fully awake. CONCLUSIONS: Anesthesiologists should be aware of this clinical finding when evaluating the airway of a patient with Goldenhar syndrome. Coronal and sagittal measurements on computerized tomography (CT) and three-dimensional image reconstruction can be used to evaluate the degree of subglottic airway stenosis and measure the diameter of the trachea.

Respiratory outcome of mandibular distraction osteogenesis on obstructive sleep apnea in craniofacial microsomia: A retrospective study.

This study aimed to evaluate the effect of mandibular distraction osteogenesis (MDO) on respiratory function in CFM patients with obstructive sleep apnea (OSA) according to polysomnography (PSG). This study retrospectively analyzed patients with CFM who underwent PSG before surgery and after completion of mandible distraction. Patients who met the inclusion criteria were selected. The Pediatric Sleep Questionnaire (PSQ) was used to assess patients' signs and symptoms related to OSA. The obstructive apnea-hypopnea index (OAHI) and lowest oxygen saturation (LSaO2) were imported into SPSS version 26.0. The Wilcoxon signed-rank test was used to assess the differences in PSG before and after MDO. Other data were described using descriptive statistics. A P-value less than 0.05 was considered statistically significant. A total of 25 unilateral CFM patients were included in this study. Most patients (72%) had mild OSA; moderate and severe OSA were 12% and 16%, respectively. Snoring (52%) was the most common symptom among these patients. After completion of mandibular distraction, snoring and other OSA-related symptoms were significantly improved. Twelve patients had normalized PSG and the severity of OSA improved significantly in 3 patients. The total effective rate of MDO for OSA was 60%. The statistical results showed that OAHI (P = 0.045) decreased and LSaO2 (P = 0.009) increased significantly compared to preoperative values. MDO can improve OSA-related symptoms in CFM patients. In addition, respiratory function was improved in most patients after MDO, based on PSG. CFM patients, especially those with OSA, can benefit from MDO.

Modified Nishida's procedure for esotropia in Duane syndrome associated with Goldenhar syndrome.

Modified Nishida's procedure (no split, no tenotomy transposition) has been recently described as an effective surgery for monocular elevation deficiency and for traumatic rupture of the inferior rectus muscle. We report the modified Nishida's procedure combined with medial rectus muscle recession for the treatment of esotropia in unilateral Duane syndrome associated with Goldenhar syndrome. Following the surgery and over a 1-year follow-up period, the patient was orthophoric at distance and near, abduction improved, and the abnormal head position resolved.

Quantitative Analysis on Cartilage Growth Between Ipsilateral and Contralateral Donor Sites in Microtia Patients.

BACKGROUND: Costal cartilage harvest is required in patients with unilateral microtia when autologous reconstruction is being considered. However, whether an ipsilateral or contralateral donor site should be used remains controversial. This is the first study to compare cartilaginous growth between ipsilateral and contralateral donor sites in patients with unilateral microtia. METHODS: In this retrospective study of 58 patients, the lengths of the sixth to ninth costal cartilages and 3 position-defining measurements with respect to the sixth to ninth costochondral junctions were calculated using 3-dimensional costal cartilage imaging. Patients were divided into subgroups, and the lateral differences between isolated microtia and hemifacial microsomia and between the growing and adult age groups, were compared. RESULTS: In the isolated group, the sixth and seventh costal cartilages were longer on the contralateral side. The transverse dimension on the contralateral side, with respect to the sixth and seventh costochondral junctions, was also larger than that on the ipsilateral side in growing patients. However, no significant difference was observed between the 2 sides in the hemifacial microsomia group; there was also no difference between the age-related groups in this regard (P > 0.05). CONCLUSIONS: These findings suggest that age- and side-related differences in donor sites should be considered in patients with isolated microtia.

[Treatment of mild hemifacial microsomia in children by autologous nano-fat mixed granule fat transplantation].

Objective: To investigate the effectiveness of autologous nano-fat mixed granule fat transplantation in the treatment of facial soft tissue dysplasia in children with mild hemifacial microsomia (HFM). Methods: A total of 24 children with Pruzansky-Kaban type Ⅰ HFM were admitted between July 2016 and December 2020. Among them, 12 children were treated with autologous nano-fat mixed granule fat (1∶1) transplantation as study group and 12 with autologous granule fat transplantation as control group. There was no significant difference in gender, age, and affected side between groups ( P>0.05). The child's face was divided into region Ⅰ(mental point-mandibular angle-oral angle), region Ⅱ (mandibular angle-earlobe-lateral border of the nasal alar-oral angle), region Ⅲ (earlobe-lateral border of the nasal alar-inner canthus-foot of ear wheel). Based on the preoperative maxillofacial CT scan+three-dimensional reconstruction data, the differences of soft tissue volume between the healthy and affected sides in the 3 regions were calculated by Mimics software to determine the amount of autologous fat extraction or grafting. The distances between mandibular angle and oral angle (mandibular angle-oral angle), between mandibular angle and outer canthus (mandibular angle-outer canthus), and between earlobe and lateral border of the nasal alar (earlobe-lateral border of the nasal alar), and the soft tissue volumes in regions Ⅰ, Ⅱ, and Ⅲ of healthy and affected sides were measured at 1 day before operation and 1 year after operation. The differences between healthy and affected sides of the above indicators were calculated as the evaluation indexes for statistical analysis. At 1 year after operation, the parents, the surgeons, and the nurses in the operation group made a self-assessment of satisfaction according to the frontal photos of the children before and after operation. Results: The study group and the control group were injected with (28.61±8.59) and (29.33±8.08) mL of fat respectively, with no significant difference ( t=0.204, P=0.840). After injection, 1 child in the control group had a little subcutaneous induration, and no related complications occurred in the others. All children in both groups were followed up 1 year to 1 year and 6 months, with an average of 1 year and 4 months in the study group and 1 year and 3 months in the control group. At 1 year after operation, the asymmetry of the healthy and affected sides improved in both groups; the satisfactions of parents, surgeons, and nurses in the study group were all 100% (12/12), while those of the control group were 100% (12/12), 83% (10/12), and 92% (11/12), respectively. The differences between healthy and affected sides in mandibular angle-oral angle, mandibular angle-outer canthus, earlobe-lateral border of the nasal alar, and the soft tissue volume in 3 regions of the two groups after operation were significantly smaller than those before operation ( P<0.05). There was no significant difference in the above indexes between the two groups before operation ( P>0.05). After operation, all indexes were significantly lower in study group than in control group ( P<0.05). Conclusion: Autologous nano-fat mixed granule fat transplantation and autologous granule fat transplantation can both improve the facial soft tissue dysplasia in children with mild HFM, and the former is better than the latter.

The etiology, clinical features, and treatment options of hemifacial microsomia.

The second most frequent craniomaxillofacial congenital deformity is hemifacial microsomia (HFM). Patients often accompany short mandible, ear dysplasia, facial nerve, and soft tissue dysplasia. The etiology of HFM is not fully understood. To organize the possible up-to-date information on the etiology, craniofacial phenotypes, and therapeutic alternatives in order to fully comprehend the HFM. Reviewing the potential causes, exploring the clinical features of HFM and summarizing the available treatment options. Vascular malformation, Meckel's cartilage abnormalities, and cranial neural crest cells (CNCCs) abnormalities are three potential etiology hypotheses. The commonly used clinical classification for HFM is OMENS, OMENS-plus, and SAT. Other craniofacial anomalies, like dental defects, and zygomatic deformities, are still not precisely documented in the classification. Patients with moderate phenotypes may not need any treatment from infancy through adulthood. However, patients with severe HFM require to undergo multiple surgeries to address facial asymmetries, such as mandibular distraction osteogenesis (MDO), autologous costochondral rib graft (CCG), orthodontic and orthognathic treatment, and facial soft tissue reconstruction. It is anticipated that etiology research will examine the pathogenic mechanism of HFM. A precise treatment for HFM may be possible with thoroughly documented phenotypes and a pathogenic diagnosis.

Craniofacial microsomia - more than a structural malformation.

OBJECTIVES: To analyse the prevalence and distribution of craniofacial microsomia (CFM) cases in Finland and their most frequent comorbidities. The second aim was to analyse the patients' need for specialized healthcare services. MATERIALS AND METHODS: Data were gathered from two complementary registers: The Register of Congenital Malformations and the Care Register for Social Welfare and Health Care (Hilmo) of the Finnish Institute for Health and Welfare (THL). RESULTS: The prevalence of CFM patients in Finland was 1:10 057. They were evenly distributed across the five university hospital districts. Their most frequently used ICD-10 diagnosis codes were F40-48 (Neurotic, stress-related and somatoform disorders), 60% of patients in adolescent and adult psychiatry; Q67.0 (Facial asymmetry), 43% in plastic surgery; Z00.4 (General psychiatric examination, not elsewhere classified), 31% in child psychiatry; Z31.5 (Genetic counselling), 28% in clinical genetics and Q67.40 (Other congenital deformities of the skull, face and jaw, Hemifacial atrophy), 18% in dental, oral and maxillofacial diseases. Of the patients, 70% had had visits in clinical genetics, 60% in plastic surgery, 41% in dental, oral and maxillofacial diseases, 28% in adolescent/adult psychiatry and 21% in child psychiatry. The majority of the patients' plastic surgery visits were concentrated in one university hospital. Other services were mainly provided by patients' own hospital districts. CONCLUSIONS: Even though the majority of CFM patients' visits in specialized healthcare services are related to correction of facial asymmetry and ear malformations, the obvious need for psychiatric care was apparent in all age groups.

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.

Feasibility of a Robot-Assisted Surgical Navigation System for Mandibular Distraction Osteogenesis in Hemifacial Microsomia: A Model Experiment.

This study aimed to investigate the feasibility and accuracy of osteotomy and distractor placement using a robotic navigation system in a model surgical experiment of mandibular distraction osteogenesis for hemifacial microsomia. Imaging data from 5 patients with Pruzansky-Kaban type II (IIa: 4; IIb: 1) mandibular deformities were used to print 3D models for simulated mandibular distraction osteogenesis. In the experimental group, a robot-assisted surgical navigation system was used to perform the surgery under robotic guidance following registration, according to the preoperative design. Conventional surgery was performed in the control group, in which the operation was based on intraoperative estimations of the preoperative design by experienced surgeons. The accuracies of the osteotomy and distractor placement were assessed based on distance and angular error. Osteotomy accuracy was higher in the experimental group than in the control group, and the distance error ( t =9.311, P <0.001) and angular error ( t =5.385, P =0.001) were significantly reduced. The accuracy of distractor placement was also significantly higher in the experimental group, while the distance error ( t =3.048, P =0.016) and angular error ( t =3.524, P =0.024) were significantly reduced. The present results highlight the feasibility of robot-assisted distraction osteogenesis combined with electromagnetic navigation for improved surgical precision in clinical settings.

Model test study on treatment of Pruzansky type ⅡB and Ⅲ hemifacial microsomia with artificial condyle-mandibular distractor complex / 中国修复重建外科杂志

OBJECTIVE@#To preliminarily verify the effectiveness of self-designed artificial condyle-mandibular distraction (AC-MD) complex in the treatment of Pruzansky type ⅡB and Ⅲ hemifacial microsomia (HFM) through model test.@*METHODS@#Five children with Pruzansky type ⅡB and Ⅲ HFM who were treated with mandibular distraction osteogenesis (MDO) between December 2016 and December 2021 were selected as the subjects. There were 3 boys and 2 girls wih an average age of 8.4 years (range, 6-10 years). Virtual surgery and model test of AC-MD complex were performed according to preoperative skull CT of children. The model was obtained by three-dimensional (3D) printing according to the children's CT data at a ratio of 1∶1. The occlusal guide plate was designed and 3D printed according to the children's toothpaste model. The results of the model test and the virtual surgery were matched in three dimensions to calculate the error of the residual condyle on the affected side, and the model test was matched with the actual skull CT after MDO to measure and compare the inclination rotation of the mandible, the distance between the condylar of the healthy side and the residual condyle of the affected side, and the lengthening length of the mandible.@*RESULTS@#The error of residual condyle was (1.07±0.78) mm. The inclination rotation of the mandible, the distance between the condylar of the healthy side and the residual condyle of the affected side, and the lengthening length of the mandible after 3D printing model test were significantly larger than those after MDO ( P<0.05).@*CONCLUSION@#In the model test, the implantation of AC-MD complex can immediately rotate the mandible to the horizontal position and improve facial symmetry, and the residual condyle segment can be guided close to the articular fossa or the preset pseudoarticular position of the skull base after operation.