Surgical correction of mandibular hypoplasia in hemifacial microsomia: A retrospective study in 39 patients

Clinical presentation of hemifacial microsomia in a South African population

BACKGROUND

Hemifacial microsomia (HFM) presentation includes gross distorted ramus, malposition temporomandibular joint, small glenoid fossa, distorted condyle and notch, malformed orbit, cupping ear or absent external ear, and facial nerve palsy. HFM is the second most prevalent congenital deformity of the face, with little literature from the South African population. This retrospective study elucidated the demographic characteristics and clinical presentations of HFM patients in a select South African population and compared it to the literature.  Methods: A retrospective study of HFM patients diagnosed through clinical presentation and confirmed by plain radiograph or computed tomography was conducted. The patient's charts were reviewed for age, sex, laterality, side, the severity of the deformity, and associated craniofacial and extra-craniofacial anomalies. The clinical presentation of malformations was categorised according to the OMENS classification, using five major craniofacial manifestations of HFM.

RESULTS

Twenty-five patients were included, with a male-to-female ratio of 1:1.78. The population distribution is 60% Black, 32% Indian, 4% White and 4% Coloured. A right-to-left laterality ratio of 1.4:1 and 4% bilateral affectation. This study showed 100% mandibular hypoplasia, 84% ear deformity, 40% orbital deformity, 60% facial nerve defect and 100% soft tissue defect affectation with noticeable facial asymmetry. Other craniofacial anomalies were recorded in 84%, while extracraniofacial anomalies were recorded in 40% of this HFM population.

CONCLUSION

There is a high degree of variability in the deformities in HFM in the South African population, distinguishing it from the international population. A multidisciplinary approach is required for its treatment and management.

Long-Term Outcomes and Growth Analysis of Costochondral Grafts for Hemifacial Microsomia: 24-Year Experience of a Single Surgeon

BACKGROUND

Costochondral grafts (CCGs) can be used in mandibular reconstruction of Kaban-Pruzansky IIB/III hemifacial microsomia (HFM). Their growth is variable, occasionally necessitating secondary surgery. This study examined one surgeon's 24-year experience to better quantify long-term outcomes and surgical care required in CCG reconstruction of HFM mandibles.

METHODS

Serial 3-dimensional computed tomography scans, from preoperative to most recent, were analyzed in patients with a minimum of 4 years of clinical follow-up after CCG reconstruction. Graft/ramus height, length, volume, bilateral mandibular body length, and chin deviation were measured. Changes in measurements were analyzed preoperatively, immediately postoperatively, at the most recent imaging before secondary surgery, and at the most recent imaging overall. Growth rates per measure were calculated using scans after CCG but before secondary surgery.

RESULTS

Thirteen patients were analyzed. Median (SD) clinical follow-up was 10.0 (5.1) years. One patient developed temporomandibular joint ankylosis secondary to stacked-graft malposition, which was repaired without further complications. CCG reconstruction led to immediate improvement in graft/ramus height ( P = 0.03), length ( P = 0.002), and volumetric symmetry ( P = 0.02). No difference was found between graft and native ramus height ( P = 0.4) or length measures ( P = 0.5), whereas graft volume and the affected mandibular body grew significantly more slowly. According to the latest imaging, 63% of patients required secondary surgery, including distraction osteogenesis or orthognathic surgery, due to differential graft or hemimandible growth behavior. Based on the most recent clinical follow-up, this proportion increased to 93%.

CONCLUSIONS

CCGs provide significant short-term mandibular and facial symmetry improvement in HFM IIB/III. Long-term analysis reveals frequent undergrowth requiring secondary intervention to promote and maintain symmetry.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Dental anomalies in craniofacial microsomia and condylo-mandibular dysplasia: A retrospective study of 103 patients

INTRODUCTION

Craniofacial microsomia (CFM) and camel-hump condylo-mandibular dysplasia (CMD) are developmental disorders affecting the mandible that share common clinical features. This study aimed to investigate and compare the dental anomalies (DA) between the two entities for differential diagnosis and to propose appropriate treatment.

METHODS

This retrospective cross-sectional study was based on panoramic radiographs of patients diagnosed with CFM or CMD. DA were evaluated using the classification reported by Bilge. Delayed tooth eruption on the affected side was noted based on a comparison with the contralateral side. Nolla's stages of tooth calcification were used to assess dental development.

RESULTS

A total of 103 patients were included, 80 subjects (77.7 %) in CFM group and 23 patients (22.3 %) in CMD group. The prevalence of DA among CFM and CMD-affected patients were 80.0 % and 95.7 %, respectively. Tooth ectopia, tooth impaction, dental development delay, and delayed tooth eruption on the affected side exhibited a significant association with the two craniofacial malformations. The overall affected teeth (molars, premolars, canines) differed between the two craniofacial malformations. Dental abnormalities such as oligodontia, hyperdontia, dentin dysplasia, and anomalies of shape were seen only in subjects affected by CFM.

CONCLUSION

DA were widely observed in patients with CFM and CMD. The global distribution of affected teeth differed between the two conditions and some DA were detected only in CFM patients. When clinical diagnosis remains uncertain, some specific radiological characteristics of DA can be used to differentiate CFM from CMD.

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.

3D analysis of condylar and mandibular remodeling one year after intra-oral ramus vertical lengthening osteotomy

OBJECTIVES

Among the existing techniques for the correction of mandibular posterior vertical insufficiency (PVI), the intra-oral ramus vertical lengthening osteotomy (IORVLO) can be proposed as it allows simultaneous correction of mandibular height and retrusion. This study assessed the 3D morpho-anatomical changes of the ramus-condyle unit and occlusal stability after IORVLO.

MATERIALS AND METHODS

This retrospective analysis compared immediate and 1-year post-operative 3D CBCT reconstructions. The analysis focused on the condylar height (primary endpoint) and on the changes in condylar (condylar diameter, condylar axis angle) and mandibular (ramus height, Frankfort-mandibular plane angle, gonion position, intergonial distance, angular remodeling) parameters. Additionally, this analysis investigated the maxillary markers and occlusal stability.

RESULTS

On the 38 condyles studied in 21 included patients (mean age 23.7 ± 3.9 years), a condylar height (CH) loss of 0.66 mm (p < 0,03) was observed, with no correlation with the degree of ramus lengthening (mean 13.3 ± 0.76 mm). Only one patient presented an occlusal relapse of Class II, but a 3.4 mm (28%) condylar diameter loss and a 33% condylar volume reduction with loss of 1 mm and 3.4 mm in CH and condyle diameter, respectively. A mean 3.56 mm (p < 0.001) decrease in ramus height was noted, mainly due to bone resorption in the mandibular angles.

CONCLUSION

This study confirms the overall stability obtained with IORVLO for the correction of PVI.

CLINICAL RELEVANCE

This study aims to precise indication of IORVLO, and to validate the clinical and anatomical stability of 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.

Treatment of Facial Asymmetry Using Distraction Osteogenesis in a Mandible First Approach

Background

Facial asymmetry includes several etiologies, among them trauma to the condylar area during early childhood and congenital malformations such as hemifacial microsomia. This article describes the management of facial asymmetry in adolescents and young adults using a mandible first approach by distraction osteogenesis, followed by maxillary Le-Fort I as a second stage.

Methods

Eighteen patients 14-25 years of age presented with unilateral hypoplasia of the jaws which manifested clinically by deviation of the chin and canting of the occlusal plane. Etiology included hemifacial microsomia and trauma injuries at early childhood.All patients underwent orthodontic treatment and two phases of surgical treatment. Surgical treatment included unilateral mandibular distraction followed by Le-Fort I osteotomy for alignment of the maxilla. Additional bone graft in the affected side and sliding genioplasty were done as required.

Results

Marked ramal elongation of 18.94 mm concomitant with mandibular forward traction of 12.5 mm was noted while achieving symmetry. In all cases, the maxilla was centered to the midline in proper occlusion. Post distraction, posteroanterior cephalometric radiographs demonstrated elongation of the affected ramus, improvement in facial symmetry, and correction of the occlusal canting. Relapse was minimal based on long-term follow-ups of 47.4 months.

Conclusions

The two-stage surgical approach that includes elongation of the mandible as a first stage followed by adaptation of the maxilla is useful in correcting facial asymmetry. Using this protocol at the correct age (14-18) is very stable, as demonstrated by our results, yet one should always remember the transverse deficiency in the gonial angle requires additional bone grafting or patient specific implants.

Reconstruction of the temporomandibular joint using a vascularized medial femoral condyle osteocartilaginous flap: an experimental investigation in miniature pigs

BACKGROUND

Reconstruction of the temporomandibular joint (TMJ) is a significant challenge in maxillofacial surgery. A vascularized medial femoral condyle (MFC) osteocartilaginous flap is a good choice for TMJ reconstruction. In this study, we evaluated the radiographic and histological changes of MFC after TMJ reconstruction.

METHODS

A ramus-condyle unit (RCU) defect was created unilaterally in five adult male Bama miniature pigs. The ipsilateral vascularized MFC osteocartilaginous flap was used to reconstruct the TMJ, and the non-operative sides served as controls. Multislice spiral computed tomography (CT) was performed preoperatively, immediately postoperatively, and at two weeks, three months, and six months postoperatively. Three animals were euthanized at 6 months postoperatively. Their reconstructed condyles, natural condyles and the MFCs on the opposite side were collected and subjected to µCT and histological evaluation.

RESULTS

In the miniature pigs, the vascularized MFC osteocartilaginous flap was fused to the mandible, thus restoring the structure and function of the RCU. The postoperative radiographic changes and histological results showed that the reconstructed condyle was remodeled toward the natural condyle, forming a similar structure, which was significantly different from the MFC.

CONCLUSIONS

In miniature pigs, the RCU can be successfully reconstructed by vascularized osteocartilaginous MFC flap. The reconstructed condyle had almost the same appearance and histological characteristics as the natural condyle.

A new treatment strategy for hemifacial microsomia: Auricular reconstruction with an expanded two-flap method and simultaneous mandibular distraction osteogenesis

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.

A decade of clinical research on clinical characteristics, medical treatments, and surgical treatments for individuals with craniofacial microsomia: What have we learned?

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.

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.

Facial visual attention to menton deviation: An objective evaluation by laypeople

PURPOSE

This study aimed to quantitatively evaluate whether the severity of menton deviation (MD) influenced facial perceptions of laypeople. We also aimed to determine the effectiveness of surgery in normalizing the distribution of the facial visual attention of laypeople.

METHODS

The scanning paths of 177 laypeople were recorded using an eye tracking device while observing images of individuals without MD and pre- and post-treatment subjects with different degrees of MD. The fixation durations on the areas of interest (AOIs) in each group were compared and analysed.

RESULTS

When observing the images of non-MD subjects, the eyes were the focus of the most significant fixation (higher than the fixations on the nose and lower face). When the MD increased to 3°, attention on the lower face increased (p = 0.001) with decreased attention to the eyes (p = 0.0126). At an MD of 9°, attention to the lower face sharply increased, even more so than that to the eyes, with decreased attention to the nose (p = 0.0104). Compared with the findings for the post-treatment images, the laypeople who observed the pretreatment images focused longer on the lower face and less on the eyes and nose (p = 0.001, p = 0.0322 and p = 0.0023, respectively). The distribution of the fixation duration when observing the post-treatment images was similar to that when observing the images of the non-MD subjects.

CONCLUSIONS

Laypeople can perceive an MD of 3°, which causes changes in the distribution of visual attention, with attention focusing on the MD. When the deviation reaches 9°, it is very noticeable. Surgery can normalize the distribution of the facial visual attention of laypeople, as shown by the responses to the post-treatment images.

Temporomandibular Joint Dysplasia in Cranio-Maxillofacial Dysplasia: A Retrospective Study. Guideline Treatment Proposal

INTRODUCTION

Cranio-Maxillofacial Dysplasias (CMD), including Craniofacial Microsomias, syndromes (such as Treacher Collins or Williams) and isolated Condylo-Mandibulo-Dysplasia, is a controversial subject with treatments as diverse as diagnostic classifications. The authors present here a retrospective study of 85 patients, with congenital condyle dysplasia arising from these 3 main types of CMD, treated with different techniques that aimed to normalize the facial skeleton and occlusion.

METHODS

The authors studied retrospectively 85 patients, aged from 3 to 53 years old, affected by different types of CMD. Treatment options included: costochondral grafts, orthognathic surgeries, distraction osteogenesis procedures, orthodontic and dentofacial orthopedic treatments, and soft tissues surgeries. Outcomes were evaluated by the surgical team.

RESULTS

Seventeen patients were treated with costochondral grafting, 14 with distraction osteogenesis, 17 with orthodontic and dentofacial orthopedic, and 45 with orthognathic surgery. The authors did not perform any nerve grafting or temporomandibular joints prosthesis placement. Fifty-one patients presented an excellent result, 10 a good result, 9 a poor result, 2 a bad result, and 14 an unknown result.

DISCUSSION

Several different treatments of CMD can be proposed. The authors think that major defect in children should undergo costochondral grafting because of its growth potential while in case of minor defect, orthopedic treatment should be tried in the first place. Distraction osteogenesis should be reserved for cases with poor response after orthopedic treatment or growth insufficiency with costochondral grafting. Orthognathic surgery is often necessary at the end of the growth period to obtain an excellent result. Temporomandibular joints prosthesis should be reserved for extreme cases.

Outcomes following Microvascular Mandibular Reconstruction in Pediatric Patients and Young Adults

Background:

The etiology and treatment of complex mandibular defects in children differ markedly from those of adults, although treatment with free bone flaps is historical in both groups. While adult outcomes and complication rates are well known, few pediatric data exist, especially for patients with congenital deficiencies. This study reports early and late outcomes from a cohort of young, primarily syndromic patients undergoing microvascular mandibular reconstruction.

Methods:

This is a retrospective case series of patients who underwent microvascular mandibular reconstruction between 1995 and 2016.

Results:

Thirteen patients received a total of 13 fibula transfers and 1 medial femoral condyle transfer. Most patients carried a congenital diagnosis (77%), and the average age during surgery was 11.7 ± 5.7 years. The median (interquartile range) [IQR] length of follow-up was 6.3 (5.7) years. There was a 100% flap survival rate, although 86% of all patients experienced at least one complication. Half of all procedures resulted in an early complication. Nine patients (69%) developed late complications, of which temporal mandibular joint ankylosis was the most common (n = 5; 38%).

Conclusions:

This study is one of few detailing outcomes following mandibular reconstruction by free flap transfer in pediatric patients. These patients were primarily syndromic with appreciable complication rates higher than in other adult and pediatric studies. Some complications are manageable or self-resolving, but others lead to functional problems that may require late operative interventions to correct. Microsurgical treatment should be reserved for children with large, complex mandibular defects when other options are unavailable or have been exhausted.

Association of Mandibular Dysplasia With Maxillary Volumetric and Linear Measurements in Children With Hemifacial Microsomia

In hemifacial microsomia (HFM), the correlations between mandibular dysplasia and maxillary deformities in HFM patients have not yet been assessed. The objective of the present study was to examine the association of maxillary volumetric and linear measurements with mandibular ramus height or corpus length on the affected side in children with unilateral HFM.In this retrospective research, a total of 70 children with unilateral HFM were enrolled at our department from 2010 to 2019. Demographic information was recorded, and computed tomographic scan were reconstructed and analyzed by segmentation, volumetric, and cephalometric measurements. Analyses involved independent sample t-test, univariable, and multivariable linear regression.In the overall population, mandibular ramus height (MRH) was positively associated with the maxillary bone volume (MBV) (r = 0.484, P < 0.001) and maxillary total volume (MTV) (r = 0.520, P < 0.001). Similarly, mandibular corpus length (MCL) was significantly associated with the MBV (r = 0.467, P < 0.001) and MTV (r = 0.520, P < 0.001). Multivariate regression analysis revealed that the MRH or MCL were significantly and independently associated with MBV or MTV (MRH/MBV β = 0.420, P < 0.001; MRH/MTV β = 0.391, P < 0.001; MCL/MBV β = 0.403, P < 0.001; MCL/MTV β = 0.307, P < 0.01).These results demonstrated that the MBV and MTV are independently associated with MRH or MCL on the affected side in children with unilateral HFM, suggesting a potential interaction between mandibular dysplasia and maxillary deformities.

Costochondral graft in growing patients with hemifacial microsomia case series: Long-term results compared with non-treated patients

OBJECTIVE(S)

The aim of this study was to evaluate the long-term effectiveness of costochondral graft in hemifacial microsomia (HFM) type III patients.

SETTINGS AND SAMPLE POPULATION

A sample of 10 patients affected by HFM type III treated during growth in the same Centre with costochondral graft (CCG patients group) is compared with a control group (CG) sample of 10 non-treated patients affected by the same malformation in order to understand whether surgery during growth provides advantages in terms of bony and facial symmetry after an 8-year follow-up.

MATERIALS AND METHODS

The growth of the CCG was assessed on panoramic X-rays. To assess facial symmetry, a photometric evaluation on the frontal view was carried out.

RESULTS

In CCG patients group the graft grown in mean less than the healthy ramus, a good facial symmetry was achieved after surgery, but was lost in the majority of the cases at the most recent control. In CG, occlusal canting slightly increased and facial asymmetry was relatively stable during the years.

CONCLUSION

In patients with a congenital deformity, restoring the height of the ramus leads to an immediate restitution of facial symmetry, but in the long term, there is a return to the asymmetrical pattern. In CG, the asymmetry is stable during years with no increase of the facial deformity.

Evaluation of vertical ramus osteotomy for the surgical correction of unilateral mandibular posterior vertical insufficiency: Long-term follow-up results

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.

The accuracy of virtual-surgical-planning-assisted treatment of hemifacial microsomia in adult patients: distraction osteogenesis vs. orthognathic surgery

Hemifacial microsomia (HFM) is a common congenital craniofacial deformity with a high prevalence. Orthognathic surgery and distraction osteogenesis are two conventionally used treatments of HFM. The main objective of this retrospective study was to evaluate the accuracy of two treatments with the help of virtual surgical planning in adult HFM patients. Sixty-eight adult patients with unilateral HFM were enrolled in this study. Preoperative surgical planning and simulation were performed on three-dimensional computed tomography models. Orthognathic surgery or distraction osteogenesis was performed under the guidance of three-dimensional surgical templates. Postoperative evaluation of the intervention was performed by comparison of the affected ramus height, chin deviation and the occlusal cant in surgical planning and actual result. Outcome and feedback information (an average of 14 months) showed that virtual surgical planning was accurately transferred to actual surgery in both surgical approaches. There were no statistical differences between the accuracy of affected ramus height and the occlusal cant in two surgical approaches. The orthognathic group showed significantly higher accuracy in chin deviation. In conclusion, virtual surgical planning and three-dimensional surgical templates were proved to facilitate treatment planning and offer an accurate surgical result in the treatment of adult HFM patients.