Background Reduction malarplasty presents challenges in terms of postoperative complications, particularly limited mouth opening. Excessive inward displacement of the zygomatic complex can impinge on the coronoid process resulting in restricted mouth opening. This study aimed to assess the spatial relationship between the coronoid process and the zygomatic complex after reduction malarplasty. Methods A retrospective study was conducted, including consecutive patients underwent reduction malarplasty. Radiological measurements were performed before surgery and during the final follow-up, including the coronoid-condylar index, distance between the coronoid process and zygomatic complex, and thickness and density of the temporal and masseter muscles. Clinical and radiographic data were recorded and analyzed. Results A total of 159 female patients were included with an average age of 28.1 years and a mean follow-up of 6.7 months. The mean coronoid-condylar index was 1:1.4, ranging from 1:0.6 to 1:2.6. Following surgery, the distances between the coronoid process and the anterior zygoma decreased by approximately 1 mm. Additionally, the postoperative distance between the highest point of the coronoid process and the zygomatic arch decreased by around 4 mm horizontally and changed approximately 1 mm vertically. No significant changes were observed in the thickness and density of the temporal and masseter muscles after surgery. Conclusions Reduction malarplasty led to a slight decrease in the distance between the coronoid process and the zygoma. The operation generally resulted in proximity between the highest point of the coronoid process and the zygomatic arch. However, we believe that common reduction malarplasty rarely leads to osseous impingement. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266

Objective: A flat superciliary arch is relatively common in East Asian women. Superciliary arch augmentation aims to increase the facial three-dimensionality of the upper face. However, there are few reports in the literature specifically introducing the surgery. In this study, the authors present the clinical outcomes after a series of superciliary arch augmentation with silicone implants. Methods: From May 2020 to December 2022, 54 patients underwent superciliary arch augmentation with silicone implants. Silicone implants generally have a length of 50 to 60 mm, a width of 13 to 14 mm, and an arc of 170 degrees. The thickness was 2 to 7 mm. The implant was placed subperiosteal at the lower edges of the eyebrows through a 7 mm incision below the brow tail. All patients evaluated the outcome according to the Global Esthetic Improvement Scale. Four plastic surgeons evaluated postsurgery results with a 5-point Likert Scale (5 = excellent, 4 = good, 3 = fair, 2 = no change, and 1 = worse). Results: Fifty-four patients were successfully enrolled. The mean follow-up period was 12.02 ± 3.38 months. The mean thickness was 4.55 ± 0.67 mm for the thickest part of the implant. The minor complication rate was 44.44%. They all subsided within 1 month without treatment. Patients’ outcome ratings were 4.45 ± 0.55 (3 mo), 4.51 ± 0.48 (6 mo), and 4.51 ± 0.45 (1 y). The surgeons’ outcome scoring was 4.49 ± 0.31. Conclusions: Superciliary arch augmentation with silicone implants is a quite simple, effective, inexpensive, and safe strategy to improve the three-dimensionality and contour of the upper face in East Asians.

Objective:To investigate the influence on osteogenesis during mandibular augmentation with a new sandwichosteotomy with interpositional natural coral and coralline hydroxyapatite (CHA).Methods:Nine goats were randomly divided into three groups and observed at 6 months, 12months and 18 months after surgery. All goats received splitting of bilateralmandibular outer cortex and interpositional grafting with natural coral and corallinehydroxyapatite respectively (sandwich osteotomy). Partial mandible in each group had been harvested to do histology examination(HE staining and Toluidine blue staining) and ultrastructure analyses (Scanning electron microscope, SEM).Results:All subjects were evaluated atdifferent time points. Both natural coral and coralline hydroxyapatite side healed at three groups. Natural coral were degraded at about 6 months postoperation, coralline hydroxyapatite at about 12 months. The results of HE staining, Toluidine blue staining and SEM revealed that natural coral side had better osteogenesis than coralline hydroxyapatite side at 6 months after operation.However, Natural coral and coralline hydroxyapatite side had no significant differences at 12 and 18months.Conclusions:This study suggests an alternative method for mandibular augmentation witha sandwich osteotomy and interpositional grafting with natural coral and CHA.Bothcoral hydroxyapatite and natural coral have good osteogenesic effect for mandibular augmentation.

Objective: Facial asymmetry is one of common complaints in plastic and craniofacial surgery in Orient. Hemimandibular dysplasia has considered to be the key role in facial asymmetry. Despite of the undergrow of mandibular length and height, the lackness of mandibular thickness contributes to the asymmetry. The aim of this study was to describe the therapeutic efficiency of mandibular augmentation with a new sandwich osteotomy with interpositional natural coral and coralline hydroxyapatite (CHA). Methods: Nine goats were randomly divided into 3 groups and observed at 6, 12, and 18 months after surgery. All goats received splitting of bilateral mandibular outer cortex and interpositional grafting with natural coral and CHA, respectively (sandwich osteotomy). Data were evaluated and statistically analyzed by t-test. Results: All goats were observed at 3 different time points. The computed tomography images show that the area of operation was healed and the thickness of the mandible was increased in 3 time points. In the 3 groups, mandibular thickness and volume were significantly different compared with those before operation (P<0.05). The volume of CHA group improved better than coral group (P<0.05). Conclusion: This study provides a promising alternative method for mandibular augmentation with a sandwich osteotomy and interpositional grafting with natural coral and CHA. The thickness and volume of mandible had been effectively increased in follow-ups.

Objective To establish three-dimensional finite element model of the repair for orbital defect with Medpor implant, and to explore biomechanical characteristics including displacement and stress analysis of Medpor implant with the state of implantation in orbital floor, in order to provide the reference basis for surgeons. Methods The three dimensional model was established by Mimics software via reading the CT data of DICOM format of a patient with left orbital floor fracture. Followed the 3D model remeshing by Magics finite element software, material properties assignment with gray value conversion, the three-dimensional finite element model for the repair of orbital defect with Medpor implant was modeled. Then displacement and stress analysis of Medpor implant was done by finite element method under the load of different simulated gravity: no fixation, one and two screws fixation. Results The finite element was established in this study successfully.No fixation between Medpor implant and orbital wall allowed large displacement with no stress. Fixation by one screw or two screws has the same stress value. Conclusion Three-dimensional finite element model of the repair for orbital defect with Medpor implant was established firstly. According to finite element method, the screw implant can play a good role in the fixation of Medpor,and fixation by one screw or two screws has the same effect.

Background: Interpositional arthroplasty (IPA) with temporalis fascia flap has been one of the most frequently performed procedures to treat temporomandibular joint (TMJ) ankylosis. However, recurrence often occurs when the flap lacks bulk or atrophies. Whether to perform IPA or distraction osteogenesis (DO) first has long been a controversial issue when patients presented mandibular dysplasia (MD). This study provided IPA a new graft material sufficient to prevent recurrence, combined the modified protocol of performing DO 6 months after IPA, and evaluated its efficacy in treating TMJ ankylosis patients with MD. Methods: Six patients with unilateral TMJ ankylosis and MD were treated in the authors’ study. The temporalis fascia flap and part of adjacent galea aponeurotica were filled the space after surgical release. Mouth-opening exercises started immediately post-IPA. Distraction osteogenesis was performed 6 months after IPA and had a 4-month consolidation. The maximum interincisal distance at preoperative, immediately post-IPA and the latest follow-up were recorded, as was the distraction length. The body mass index was measured at each patient's postoperative visit. Result: All patients had significant improvements in facial aesthetic, mouth-opening, and occlusion. No major complication or recurrence was observed at 3 to 4 years’ follow-up. The mean maximum interincisal distance was 4.83 ± 2.79 mm preoperative and 35.67 ± 3.39 mm at the latest follow-up. The mean distraction distance was 16.17 ± 5.98 mm. The body mass index improved from 17.33 ± 0.64 kg/m2 preoperative to 18.75 ± 0.60 kg/m2 before DO. Conclusions: Temporalis fascia flap and adjacent galea aponeurotica as new graft materials are recommended for IPA. The modified staged treatment proved to be reliable and effective to prevent recurrence, improve mandibular length and final occlusion.

Objective To establish a cranial bone defect model of goat and to study application in craniomaxillo-facial surgery.Methods Electron beam computed tomography (EBCT) scanner was used to scan goat'heads and faces in series and thin layers.Data of EBCT were input in workstation from digital inlet,and then to three-dimensional reconstruction with method of surface shadow.After final data were transformed to the files,the rapid prototyping machine was able to identify and establish the 3D model.Results The EBCT continuous thin-layer (1 mm) scanning data were passed to wave filter,falling coarse,distinguishing and collecting the outline,3D-reconstruction,curved surface reconstruction with CAD and the substance reconstruction.The final data were input into the laser rapid prototyping machine.Three-dimensional bionic cranium models were fabricated by machine in layer by layer manufacturing principle.Conclusions Establishment of the cranial bone defect model in the goat is very useful to the three-dimensional measurement,individualized reconstruction and basic and clinical research for the cranial bone defect.

Objective To design a method of mandibular division for plastic surgery.Methods From January 2009 to June 2017,118 patients who underwent mandibular plastic surgery were observed,measured and analyzed.Combined with clinical experience,a new method of mandibular division was designed.The mandible was divided into right and left sides and each side was subdivided into five subunits (A,B,C,D,E).Area A is mandibular ramus upper 1/2 and mandibular coracoid area;Area B is mandibular lower 1/2 area;Area C is mandibular body area;Area D is chin area;Area E is mandibular angle.Results The mandibles of 118 patients were divided according to the new method to obtain the characteristics of mandibular deformities and guide the design of the surgical plan.Conclusions The new method of mandibular division is concise and scientific,which is in favor of the diagnosis and surgical design of plastic surgery.

Objective To discuss the establishment of three-dimensional mirror image plane ofhemifacial microsomia.Methods 32 cases of hemifacial microsomia from Jan .2006 to Jan.2017 were collected in our hospital .CT scanning was performed for all patients .Then, the deformity characteristics were summarized through three steps : 3D reconstruction, mirror and discrepancy analysis .Results After statistical analysis, the stability of these three points was good .Clinical result showed that the patient's appearance was greatly improved .Conclusions Using these three points to determine the mirror image plane is helpful to analyze the patient＇s facial features and facilitate the surgical design .

Objective To explore the effect of the application of three-dimensional digitalization in the malformation of the chin. Methods Preoperative three-dimensional measurements were performed by using Mimics software in order to determine the degree of de-formity accurately, in three dimensions. Using the chin horizontal osteotomy method, the preoperative design and operation guide were unified and the osteotomy block was moved to improve chin deformities. All patients underwent genioplasty after accurate design. Results Twenty patients’wounds healed primarily without severe complications. Lower lip numbness was resolved after 3 to 6 months. Conclusion The right operation method and precise operation design can effectively improve all kinds of chin deformities.

Objective To aesthetically evaluate the mandible,to position the gonion landmark of the aesthetic female with digital techniques and to establish three-dimensional mandibular measurements database of the aesthetic female.Methods 14 aesthetic volunteers were chosen by plastic surgeons and ordinary people based on the identical view of esthetic mandible.The heads were scanned by a spiral CT scanner,and the data were imported into Mimics 18.0 to generate the 3D skull images.Distance,angle and ratio measurements,which could represented the aesthetic characters of the mandible,were made on the images.All the data were transferred into the SPSS 22.0 software to perform statistical analysis.A two-tailed t test was used to compare the symmetry of bilateral mandibles.Dynamic database of aesthetic mandibles was established.The mean,standard deviation,standard error and 95％ confidence interval of data were calculated by statistical software automatically.Results The results suggested that the mean of aesthetic mandibular angle was 123.91°,and the mean of mandibular plane angle was 27.03°.The ratio between the mandibular body and ramus approximated to 2 ∶ 1,and the ratio of the distance between gonion and mental foramen to ramus was close to 1.4.Conclusions The study of mandibular esthetics contributes to positioning the new gonion accurately for patients with prominent mandibular angle and gonion reconstruction,and it can assist surgeons in surgical designing,simulating and performing.

目的 评价标准化二维数码照片测量数据,量化分析颧骨突出面部特征的可行性.方法 回顾自2013年10月至2015年10月行颧骨L形截骨降低术的非对称性颧骨突出患者35例,对术前、术后的标准化斜侧位照片进行颧骨突度P值、高度H值测量,所得数据配对分析(包括术前颧骨较大侧与较小侧、术前与术后及术后双侧).结果 标准化斜侧位照片测量数据显示,术前颧骨较大侧与较小侧颧骨突度P值及高度H值差异均有显著的统计学意义(P＜0.05);术后颧骨突度P值减小明显,具有统计学意义,而颧骨高度变化不显著;术后双侧颧骨突度及高度对比,差异无统计学意义(P＞0.05).结论 采用标准化二维数码照片行颧骨面部测量,能真实、可靠地反映颧骨突度和高度,可操作性强.

Objective To explore the surgical treatment of chin asymmetry in hemifacial microsomia. Methods From August 2010 to September 2015, 14 patients with hemifacial microsomia were enrolled. Preoperative measurement were done by using Uniweb Server, and all patients were performed genioplasty following accurate design to correct chin asymmetry. Results All incisions healed by first intension without severe complication. Good appearance was achieved. Lower lip numbness was observed and all back to normal after 1 month to half a year. Conclusion The right choice of operative method and accurate design can effectively improve the chin asymmetry deformity in hemifacial microsomia.

Purpose: To achieve optimal outcomes in reduction malarplasty, the amount of removed zygomatic bone must be planned accurately. This study aimed to analyze the associations between the width of bony resection and changes in zygomatic bony parameters, to propose a geometric model to guide surgical planning, and to objectively evaluate the surgical outcomes of reduction malarplasty based on computed tomographic (CT) images.Patients and Methods: This was a retrospective observational study of patients who underwent reduction malarplasty. Digitized CT images were used to evaluate the bony parameters of the zygomatic complex. A geometric model was proposed to guide surgical planning for malar reduction. The primary predictor variable was the width of the bony segment to be resected. The primary outcome variables were changes in malar prominence and attractiveness. Other variables included gender, age, and other bony parameters of the zygoma. Bivariate correlation analysis and multiple linear regression analyses were performed between predictor and outcome variables. Presurgical and postsurgical data were analyzed with paired-samples t test to evaluate surgical outcomes. Differences were considered statistically significant at a P value less than .05.Results: Fifty-one patients who underwent reduction malarplasty with an L-shaped osteotomy from 2012 through 2014 were included in the study. Statistical analysis showed a significant decrease in malar prominence and increased attractiveness between presurgical and postsurgical images (P < .001). The width of bony resection was statistically associated with all outcome variables after adjusting for potential confounders.Conclusions: Reduction malarplasty with a modified L-shaped osteotomy resulted in a notable decrease in malar prominence and a statistical decrease in the zygomatic arch width. The amount of bone that must be removed from the zygoma to achieve a desired reduction can be calculated with geometric equations. The proposed methodology could assist surgical design and improve surgical accuracy. (C) 2015 American Association of Oral and Maxillofacial Surgeons

BACKGROUND:Oblique facial clefts are congenital craniofacial malformations affecting the paramedian line of facial structures. Correction of these defects involves bone and soft tissue reconstruction. The authors have developed a computer-aided sequential surgical procedure for oblique facial clefts, including mandibular outer cortex autografting, medial canthal ligament reduction and fixation, and fat autografting. METHODS:From 2004 to 2013, 12 patients (9 women, 3 men) with oblique facial clefts were treated with the 3-step procedure in our clinic. Mean patient age at the first surgery was 18 years (range, 13-25 years). Preoperative three-dimensional surgical simulations assisted the surgeries. A retrospective review of patients' clinical, photographic, and radiographic records was performed. RESULTS:All patients achieved significant treatment effects and high satisfaction. The patients' self-assessed scores on a 10-point scale of deformity severity were lower after surgery (P < 0.001) and remained stable after 6 to 12 months (P = 0.069). Good repositioning of the inner canthus was achieved (P < 0.001) with no significant relapse (P = 0.096). The mean (SD) recovery of mandibular donor sites was 48.44% (16.89%) (range, 11.03%-71.33%). Grafted bone absorption was not significantly different at different recipient sites. Only minor complications occurred in 6 patients. CONCLUSIONS:This procedure was an effective treatment for oblique facial clefts, resulting in high satisfaction, remarkable improvements in facial symmetry, little skin scarring, acceptable bone graft resorption, and dramatic recovery of mandibular donor sites. Computer-assisted surgical simulation effectively describes characteristic skeletal deformities and provides a useful guide to surgical reconstruction.

Zygomatic assymetry is common in the population, which often requires surgical correction for aesthetic concerns. Previously, surgeons performed the surgery often based on their personal experience and visual evaluation. The purpose of this study was to apply computer techniques in patients with mild zygomatic asymmetry treated with unilateral reduction malarplasty to improve surgical accuracy and reduce preoperative risks. The authors used computer techniques to plan osteotomies, to produce surgical template, and to evaluate the surgical outcome. Postoperative follow-up demonstrated that zygomatic asymmetry was corrected in all the patients without complications. The proposed methodology was considered to be helpful in improving the surgical accuracy and efficiency for treatment of zygomatic asymmetry, while greatly minimizing operative risk.

The purpose of this research was to simulate mandibular movement calculated from three-dimensional computed tomography (CT) data to determine the linear distractor position to correct mandibular deformities in a series of patients with hemifacial microsomia (HFM). Preoperative CT scans from 6 HFM patients were obtained and imported into a CT-based software program (Mimics) to produce three-dimensional images and data. After measurement of the mandibular deficiency in 3 dimensions (horizontal and vertical), the angle between the distraction device and the ramus was determined by a geometric calculation, and then the surgery was performed on the three-dimensional model constructed using the rapid prototyping technique. This planning method was finally used in the treatment of 6 HFM patients. The HFM was corrected, and a symmetrical facial contour obtained without any complications in these 6 patients. The results matched the expectation before surgery that the distractor elongation would range from 18 to 22 mm. The distraction tracing model fitted the actual postdistraction tracing to within 2 mm. The preoperative design and three-dimensional modeling technique are considered to be helpful in enhancing the predictability and improving the outcome of the treatment of distraction osteogenesis.

Objective To investigate the surgical therapy of midline skull defect accompanied with frontal sinus injury.Methods 11 cases with midline skull defect accompanied with frontal sinus injury were treated.Free temporal fascia was transplanted to close the top of frontal sinus after curettage of the frontal sinus wall.Then titanium prostheses were used to repair the skull defects at the same stage in 10 patients.1 patient received skull defect repair at the second stage operation.Results Good results were achieved in 10 cases.The titanium prosthesis had to be taken out in one case due to frontal sinusitis and the anastomosis of frontal sinus and nasal cavity was performed.Conclusions In patients with midline skull defect accompanied with frontal sinus injury,free temporal fascia could be used to close the top of frontal sinus after curettage of frontal sinus wall.If there is no infection or mild infection in frontal sinus,the skull defect repair could be performed in the same stage.If there is severe frontal sinusitis,the defect repair should be done at the second stage.

Objective To establish three dimensional finite element model of the Reduction Malarplasty with L-shaped Osteotemy,and to explore biomechanical characteristics of the surgery.Methods By using medical image processing software,three dimensional reconstruction and L-shaped osteotemy simulation were performed based on the CT data of a patient with prominent malar complex.Followed the 3D model remeshing,material properties assignment with gray value conversion,and setting the boundary conditions,the finite element model of the Reduction Malarplasty with L-shaped Osteotemy was established.The FEA model was carried out biomechanical analysis under the load of simulated zygomatic pressure.Results The finite element model established in this study has high geometric and mechanical similarity.The zymomatic pressures performed in operation caused a single stress concentration on the root of the zygomatic arch,and an inward displacement of the malar complex.Conclusion Pressing the zygoma in the Reduction Malarplasty with L-shaped Osteotemy can lead to an expected greenstick fracture just on the root of the zygomatic arch,which result in an inward and lower deformation.

Distraction osteogenesis (DO) has been popular to improve hypoplastic mandible in patients with hemifacial microsomia in craniofacial surgery. However, changes in width of the lower face after DO still lack in literatures. The aim of this pilot study was to evaluate cephalometric changes in width of the lower face at different time points after DO and to give an insight into the influence on facial contour. A total of 10 patients (8 males and 2 females) with hemifacial microsomia received DO of the mandibular body measured by posteroanterior cephalograms. Five landmarks (crista galli, latero-orbitale, gonion of the unaffected side, incisor point superior of the unaffected maxilla, incisor point inferior of the unaffected side of the mandible) were chosen for cephalometric analysis. Six distances from the soft tissue contour perpendicularly to the vertical reference line (through crista galli) were calculated through the incisor point superior of the unaffected maxilla, gonion of the unaffected side, incisor point inferior of the unaffected side of the mandible. Measurements were taken preoperatively and postoperatively on the day distraction started (time 1), at the end of distraction (time 2), and at the end of the consolidation period (time 3). Calculations for statistical significance were done for all patients. Mean differences between 3 periods were measured by repeated-measures analysis with significance determined at the 0.05 level of confidence. The results suggested that the values of 6 distances at times 2 and 3 had no significant differences when compared with the values at time 1 (P > 0.05). In conclusion, DO of the unilateral mandibular body in patients with hemifacial microsomia should not be beneficial to improve the width of the lower face at a short-term follow-up.