The Spatial Relationship Between Coronoid Process and Zygomatic Complex After Reduction Malarplasty

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.

The accuracy of virtual surgical planning assisted management for L-shaped reduction malarplasty: A retrospective study

This study aims to evaluate the accuracy of L-shaped reduction malarplasty with bone setback or resection on the zygoma and the mortice and tenon joint structure on the zygomatic arch under the guidance of virtual surgical planning (VSP). Adult patients with zygomatic protrusion or hypertrophy were enrolled and divided. L-shaped reduction malarplasty with or without bone resection and with the mortice and tenon joint structure on the zygomatic arch was conducted either by digital procedures comprising VSP and three-dimensional (3D) printing titanium templates (Group I) or by conventional methods (Group II). Positions of representative landmarks and superimposition models were analyzed by 3D cephalometry. Satisfaction rate and incidences of clinical complications were compared as well. Satisfactory reduction of zygomatic protrusion or hypertrophy was recognized among all 78 patients. Improved symmetry and great surgical accuracy were observed according to the cephalometry analyses. The bone segment movement of virtual plans and actual results in Group I were measured and showed no obvious difference for the inward movement (5.42 ± 0.98 mm vs. 5.33± 0.93 mm, P = 0.6906) and the sagittal overlap (4.77 ± 1.32 mm vs. 4.87± 1.21 mm, P = 0.7386) at the zygoma roots, along with the step length at the long-arm of the L-shaped osteotomy line (2.43 ± 1.11 mm vs. 2.39± 0.89 mm, P = 0.8665). The high resemblance between virtual plans and actual results was depicted via superimposition models. Meanwhile, a higher satisfaction rate (28 in 36, 78% vs. 20 in 42, 48%) and a lower incidence rate of complications (11 in 36, 31% vs. 21 in 42, 50%) were found in Group I. Within the limitations of the study it seems that the application of VSP in reduction malarplasty could significantly contribute to better surgical accuracy and reduced difficulties in the operation, which would be beneficial to patients with zygoma hypertrophy or prominence.

Volume Redistribution of the Buccal Fat Pad After Reduction Malarplasty

BACKGROUND

During reduction malarplasty, cheek bulging could be found immediately after zygomatic complex is moved inwards, backwards and upwards. As patient is in the supine position during surgery, the effect of gravity is eliminated, so the only reason for the bulge is the redistribution of the soft tissue in the deep facial spaces. The buccal fat pad, with its main body behind the zygomatic arch and buccal extension in the cheek area, is most likely to be responsible for the bulge.

METHODS

3D buccal extension models were reconstructed from preoperative and long-term follow-up CT images and the volume measured. By comparing the pre- and postoperative 3D models, the shape deviation of the buccal extension and facial soft tissue can be identified.

RESULTS

Eleven patients (22 buccal extensions) met the inclusion criteria. Compared with the preoperative buccal extension volume, the postoperative volume increased significantly. By comparing the reconstructed models, the buccal extension volume increase with anteroinferior protrusion can be visually detected, and cheek bulging was clearly identified on the lower face. The bulging area coincided with the projection of the buccal extension on the skin surface.

CONCLUSIONS

Reduction malarplasty may cause volume redistribution of the buccal fat pad. Therefore, preoperative assessment of the size of the buccal fat pad based on CT images is recommended. The buccal extension volume increase with anteroinferior protrusion is an important cause of postoperative cheek bulging and should be considered during treatment.

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 .

Anti-sagging Method in Reduction Malarplasty: Application of the Bracing System with the Preservation of the Zygomaticus Major Muscle Bony Attachment

BACKGROUND

Cheek drooping after reduction malarplasty remains a concern for patients.

OBJECTIVES

To evaluate the anti-drooping effectiveness of the bracing system technique with the preservation of the zygomaticus major muscle (ZMj) bony attachment and to determine the role of ZMj in anti-drooping.

METHODS

A retrospective analysis was conducted of patients who accepted this method in our department from February 2016 to May 2021. Patients' subjective evaluation and two plastic surgeons' objective assessment of photographs were performed. The pre- and postoperative three-dimensional (3D) ZMj models were reconstructed and compared. ZMj length and tortuosity were also measured from 3D models.

RESULTS

Twenty-two patients (44 ZMjs) met the inclusion criteria. Most patients (21/22, 95.45%) were satisfied with the postoperative appearance without ageing after reduction malarplasty, except for one feeling slightly older after the operation. The objective scoring results showed no deepening of the nasolabial fold in the majority (20/22, 90.91%) of patients. Two patients were one-grade worse, from score 1 to 2. Upward movement of the postoperative ZMj bony attachment was clearly observed compared with the preoperative 3D model. The significantly reduced ZMj tortuosity (p < 0.001) and the slightly increased ZMj length (not significant) after surgery supported the straightening of the ZMj which was also seen in the 3D comparison.

CONCLUSIONS

The bracing system technique with preservation of the bony attachment of the ZMj is an effective and cost-effective anti-sagging method for reduction malarplasty. The ZMj was lifted and straightened after reduction malarplasty, which helped to prevent sagging.

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 .

Three-dimensional radiographic assessment of different fixation methods stability after l-shaped osteotomy reduction malarplasty: A comparative retrospective study

BACKGROUND

Reduction malarplasty (RM) is a common facial contouring procedure among Orientals. Currently, fixation methods selection and placement vectors are controversial. Therefore, this study aimed to evaluate the effect of different zygomatic complex fixation methods on surgical outcomes stability after RM.

MATERIALS AND METHODS

In this retrospective study, 60 consented patients (120 operated zygoma) who met inclusion criteria were included. ITK-SNAP and 3D Slicer software were used to measure the displacement of the zygomatic complex using postoperative CTs (T1: one week and T2: six months). The region of interest included zygomatic body fixation methods (ZBFm), namely: two bicortical screws (2LS); an l-shaped plate with one bicortical screw (LPLS); an l-shaped plate with short-wing on the zygoma (LPwZ) and on the maxilla (LPwM), combined with zygomatic arch fixation methods (ZAFm), including Mortice-Tenon (MT); 3-hole plate (3HP); and short screw (SS). ANOVA test was used to compare the displacement values among ZBFm/ZAFm combinations.

RESULTS

The 2LS and LPLS groups showed lower displacement than the single l-shaped plate (P< 0.001, P = 0.001), which performed better when the short-wing was fixated on the maxilla (0.9 ± 0.4 mm and 1.2 ± 0.6 mm respectively).

CONCLUSION

After RM, the two-bridge fixation methods (2LS and LPLS) provide better stability than the single l-shaped plate. All ZAF methods showed similar stability when combined with 2LS or LPLS as zygomatic body fixation methods.

Hoarseness and arytenoid dislocation: A rare complication after facial bony contouring surgery

BACKGROUND

Arytenoid dislocation is a rare complication after endotracheal intubation and may result in permanent hoarseness, which cannot be tolerated during cosmetic surgeries, such as facial bony contouring surgery. This study aimed to identify the clinical characteristics of this patient subgroup and share the process of diagnosis and treatment.

METHODS

We retrospectively collected the medical records of patients who underwent facial bony contouring surgery under general anesthesia with endotracheal intubation from September 2017 to July 2022. We divided the patients into a nondislocation group and a dislocation group. Demographic, anesthetic, and surgical characteristics were collected and compared.

RESULTS

441 patients were enrolled, and 5 (1.1%) were diagnosed with arytenoid dislocation. The patients in the dislocation group were more likely to be intubated with the video laryngoscope (P = 0.049), and head-neck movement during surgery may predispose patients to arytenoid dislocation (P = 0.019). The patients in the dislocation group were diagnosed around 5-37 days after surgery. Three of them regained their normal voice after close reduction, and two recovered with speech therapy.

CONCLUSION

Arytenoid dislocation may result from multiple factors instead of one high-risk factor. Head-neck movement, the skills and experience of anesthetists, the time of intubation, and the use of intubation tools may all predispose patients to arytenoid dislocation. To acquire timely diagnosis and treatment, patients should be fully informed of this complication before surgery and observed closely afterward. Any postoperative voice or laryngeal symptoms lasting more than 7 days need a specialist evaluation.

Three-dimensional analysis of zygomatic change after L-shaped reduction malarplasty with bone setback or resection

PURPOSE

Reduction malarplasty is one of the most popular procedures for esthetic facial contouring in East Asians. The retrospective observational study aimed to analyze the association between the zygomatic change and bone setback or resection to propose quantitative guidance for L-shaped reduction malarplasty based on computed tomographic (CT) images.

METHODS

A retrospective observational study was conducted on patients who underwent L-shaped reduction malarplasty with bone resection (Group I) or without bone resection (Group II). The amount of bone setback and resection was calculated. The unilateral width changes of the anterior, middle, and posterior zygomatic regions as well as zygomatic protrusion change were also evaluated. Pearson correlation analysis and linear regression analysis were used to analyze the relationship between the bone setback or resection and the zygomatic changes.

RESULTS

Eighty patients who underwent L-shaped reduction malarplasty were included in this study. Significant correlation was observed between the bone setback or resection and the change of anterior, and middle zygomatic width as well as protrusion in both the two groups (P < .001). The correlation between bone setback or resection and the posterior zygomatic width change was not significant (P ＞.05).

CONCLUSION

The bone setback or resection of L-shaped reduction malarplasty lead to the anterior and middle zygomatic width and zygomatic protrusion changes. Furthermore, the linear regression equation can be referenced as a guidance for a preoperative surgical plan.

Stability of different fixation methods after reduction malarplasty under average and maximum masticatory forces: a finite element analysis

BACKGROUND

Although titanium plates/screws are effective fixation methods (FM) after L-shaped osteotomy reduction malarplasty (LORM), the ideal FM remains controversial. This first finite element analysis (FEA) aimed to study the effect of various zygomatic body/zygomatic arch FM combinations and their placement vectors on the zygoma complex stability after virtual LORM under the effect of both average (150 N/mm2) and maximum (750 N/mm2) forces and three-dimensional (3D) mapping of stress and strain parameters distribution over the zygomatic bone, fixation methods, and total model.

RESULTS

The fixation methods about the short-arm of the L-shaped osteotomy showed lower stress, strain, and displacement values than those across the long-arm osteotomy site. Combined with any zygomatic arch fixation methods (ZAFm), the two bicortical screws group (2LS) on the zygomatic body osteotomy site resulted in smaller displacements and the lowest zygoma bone stress and displacement when combined with Mortice-Tenon structure (MT) as zygomatic arch fixation method. Applied forces caused statistically significant differences in zygomatic bone stress (P < 0.001 and P = 0.001) and displacement (P = 0.001 and P = 0.002).

CONCLUSION

All FMs both on the zygomatic body and zygomatic arch provide adequate zygomatic complex stability after LORM. The 2LS group showed better resistance than rectangular plate (RP) and square plate (SP) with lower stress concentrations. The L-shaped plate with short-wing on the maxilla (LPwM) is more stable than having the short-wing on the zygoma bone (LPwZ). Future prospective clinical studies are required to validate the current findings.

A Systematic Review and Meta-Analysis of Complications among Various Reduction Malarplasty

BACKGROUND

Reduction malarplasty is one of the most common aesthetic procedures to improve a wide bizygomatic width and a prominent zygomatic body. Although there are various kinds of modifications, any method is imperfect, while some complications may occur. The purpose of this review was to compare kinds of complications of reduction malarplasty to provide certain suggestions for clinical application.

METHODS

A comprehensive computerized search of scientific literature was performed via the PubMed, Web of Science, and Library of Congress databases, involved in articles from January 1st, 1983 to February 28th, 2022. The outcomes were extracted and analyzed by 3 independent authors, including patient demographics, diagnoses, surgical techniques, postoperative outcomes, and complications.

RESULTS

A total of 29 studies covering 6611 patients were included according to the inclusion and exclusion criteria. The L-shaped osteotomy may obtain a better effect when someone has both zygomatic body and arch protrusion. In the view of complications, our conclusion suggested that L-shaped osteotomy without bony resection reduced the zygomatic complex effectively with the lowest incidence of postoperative complications (0.02%). But the amount of bone resection is limited. If increasing bone resection is necessary, L-shaped osteotomy with long arm bony resection and L-shaped osteotomy with short arm bony resection are both preferable choices with lowest incidence of structural and functional complications, respectively.

CONCLUSION

L-shaped osteotomy may obtain a better effect when a patient has both zygomatic body and arch protrusion. L-shaped osteotomy without bony resection reduced the zygomatic complex effectively with the lowest incidence of postoperative complications.

LEVEL OF EVIDENCE III

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 .

Digital localization of osteotomy position in prominent zygomatic arch

The study aimed at introducing a digital method of locating the osteotomy position of the zygomatic arch during surgery and analyze the accuracy of this method. Patients with a prominent zygomatic bone who underwent zygomatic arch osteotomy and reduction in the orthognathic surgery department of our hospital were selected. Preoperative and postoperative computed tomography (CT) data of the patients were imported into modeling and analysis software Mimics 23.0 in DICOM format to construct 3D models of the zygomatic bone and zygomatic arch region. The data were obtained by locating the simulated osteotomy position of the zygomatic arch before the surgery, applying the digitally modeled osteotomy position of the zygomatic arch during the surgery, and locating the actual osteotomy position of the zygomatic arch after the surgery. The accuracy of the experimental method was verified by matching the preoperative simulation data with the postoperative osteotomy data. A Wilcoxon rank sum test was performed to compare the 20 cases' osteotomy positions obtained by preoperative simulation with the actual postoperative position. There was no significant difference in zygomatic arch osteotomy position between the preoperative simulation and the real postoperative position (Z=-1.867, P=0.062). The digital method to locate the zygomatic arch osteotomy seems to show an acceptable accuracy to achieve the proper osteotomy position and, therefore, should adopted whenever appropriate.

The Relationship Between the Facial Proportion Changes in Hard Tissue and the Satisfaction of Patients After Reduction Malarplasty: a Research Based on Three-Dimensional Cephalometry

OBJECTIVE

We aim to measure the zygomatic width and protrusion changes in hard tissue after reduction malarplasty and then calculate facial proportion changes and analyze the relationship between facial proportion changes and patients' satisfaction.

METHODS

We retrospectively reviewed our database and selected 36 eligible patients who underwent isolated reduction malarplasty in our department from March 2015 to July 2018. The preoperative and postoperative facial width and protrusion, as well as head height, in hard tissue were measured using ProPlan software. Patients' satisfaction was evaluated by questionnaire. The correlations between the facial proportion changes and patients' satisfaction were analyzed using Spearman correlation analysis.

RESULTS

The preoperative and postoperative midface widths were 135.87 ± 4.09 mm and 129.06 ± 4.95 mm. The relative zygomatic protrusion was reduced by 3.29 ± 1.54 mm in the left and 2.88 ± 1.73 mm in the right after surgery. The ratio of the midface width to lower face width changed from 1.43 ± 0.05 to 1.36 ± 0.06 after surgery. And the ratio of the head height to midface width changed from 1.53 ± 0.05 to 1.61 ± 0.05 after surgery. The ratios were indeed close to the ideal ratios we presumed (4:3 and 1.618). Moreover, patients' total and morphology satisfaction were both significantly higher with the postoperative ratio of the midface width to lower face width closer to 4:3 (R = - 0.732, P < 0.001; R = - 0.906, P < 0.001, respectively). But only morphology satisfaction was higher with the ratio of the head height to midface width closer to 1.618 (R = - 0.404, P = 0.014) and the ratio of the postoperative midface to lower face width decreased (R = - 0.434, P = 0.008).

CONCLUSIONS

We found patients' morphology satisfaction was higher with the proportion of the postoperative midface to lower face width decreased. What's more, the proximity degree between the postoperative facial proportion and the ideal facial proportions we presumed was significantly correlated with patients' high satisfaction. Therefore, 4:3 and 1.618 may be the ideal postoperative facial ratios for the patients who underwent reduction malarplasty.

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 https://www.springer.com/00266.

Application of the Bracing System in Reduction Malarplasty in Asian Population

BACKGROUND

In the East, a broad and prominent malar is considered to express an aggressive and unpleasing impression; therefore, patients seek to improve their appearance through malar reduction. Although most of the techniques have been greatly improved, still there are some pitfalls in the form of cheek sagging or bone nonunion. In this study, we performed a reduction malarplasty using a firm bracing system to minimize major postoperative complications.

METHOD

This was a retrospective study evaluating the results of a total of 157 patients (139 women and 18 men) who underwent reduction malarplasty using a bracing system via intraoral and periauricular. The age of the patients ranged from 17 to 44 with a mean age of 25.3 years. The mean follow-up period was 9.4 months. All patients underwent routine physical and laboratory examinations. Facial photographs in the frontal, oblique, and submentovertical views were taken. Patients with severe facial asymmetry and facial deformities were excluded from the study. Preoperative states and patients' desires were considered. In some patients, combined malarplasty with mandibular angle reduction or genioplasty was performed.

RESULTS

A total of 157 patients who underwent this modified reduction malarplasty between January 2015 and January 2019 were retrospectively reviewed. Decent postoperative facial stability and satisfactory aesthetic results were realized among all patients. Major complications such as severe asymmetry or bone nonunion were not observed in our patients.

CONCLUSION

Based on a thorough anatomic understanding of zygoma and masseter action, we modified previous L-shaped reduction malarplasty through constructing a firm bracing system on the malar complex. Satisfactory surgical outcomes were obtained. Our method is an ideal surgical method to effectively reduce the height and width of the zygomatic arch and prevent complications such as bone nonunion and cheek drooping.

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.

Lowering Lateral Canthoplasty and Orbital Rim Shaving: An Ignored but Necessary Procedure for Maximizing the Effect of Reduction Malarplasty in Asians

BACKGROUND

Although reduction malarplasty is a well-accepted procedure for Asians with prominent cheek bones, some patients are not fully satisfied with the outcomes and request further surgery. This is because much attention on the contouring procedure has focused on the position of the zygomatic body and arch. As a result, periorbital appearance including the axis of the lateral canthal angle and the protrusion of the inferolateral orbital rim are often overlooked or ignored. The authors introduce a new surgical technique for maximizing the effect of reduction malarplasty that allows for both the lowering of the lateral canthal angle and reduction of the orbital rim in selected Asian patients.

METHODS

In this retrospective study, the medical records of 41 patients who underwent lowering lateral canthoplasty in conjunction with reduction malarplasty were reviewed. Of those, orbital rim reduction was combined in 21 patients. In addition to the intraoral and preauricular approach for standard reduction malarplasty using an L-shaped osteotomy, lower eyelid and continuous canthotomy incisions were made. And then the protruding inferolateral orbital rim was shaved off, followed by inferolateral repositioning of the lateral canthus. Outcome measurements included a square millimeter of the cheek area surface using a software program (image J: IJ 1.46r) in 17 patients.

RESULTS

A statistically significant difference can be observed between preoperative and postoperative measurements of the area. Average decreases of measurements were 4761.59 mm² (18.5%) from 23,639 mm² preoperatively to 18,878 mm² postoperatively (P < 0.05, paired t test). The up-slanting lower eyelid margin was lowered, and the protruding zygomatic body with inferolateral part of the orbital rim was reduced by the procedure in all cases. Cosmetic outcomes were encouraging and satisfying to most patients. Four complications occurred: asymmetry in two patients (4.9%) and lid malposition in two patients (4.9%). Conjunctival edema was noted in half of the patients but resolved within 1 month.

CONCLUSIONS

The simultaneous lowering lateral canthoplasty and reduction malarplasty offer Asian patients desiring a slim and soft image a novel surgical option. The procedures proved to be a reliable and consistent technique that provided satisfactory results in carefully selected patients.

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 .

Reduction Malarplasty that Uses Malar Setback Without Resection of Malar Body Strip

BACKGROUND

Various surgical methods have been developed and used to reduce prominent malar bones. The most common reduction malarplasty methods are resection of the bone strip of the malar bone with L-osteotomy or I-osteotomy, followed by setback and fixation. However, these methods could be associated with complications due to the bone strip resection. The present article introduces an effective and safe method that reduces the zygoma without resection of a malar bone strip.

METHODS

Through preauricular and intraoral incisions, we performed the current L-osteotomy without resection of the malar bone strip using a reciprocating saw. We created back space for zygoma setback by removing the posterior wall of the maxillary sinus, which acted as a bony interference. We were able to set the lateral segment of the zygoma back about 3-5 mm. We fixed the zygomatic arch with wire and the zygomatic body with a prebent plate and screw. Thereafter, we performed rasping of the anterior part of the zygoma to achieve sufficient reduction. After performing our reduction malarplasty for 139 patients, clinical outcomes were evaluated.

RESULTS

Most patients responded to the satisfaction survey as excellent and good. There were no major complications 6 months postoperatively.

CONCLUSIONS

The key of our method of reduction malarplasty is to create posterior space without resecting the malar body strip, which results in an effective setback. This method enables surgeons to effectively maintain the zygoma body, which leads to high satisfaction rates and fewer complications. Therefore, this study proved the safety and effectiveness of our method of reduction malarplasty.

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 .

Bone Resection Versus Setback in Reduction Malarplasty: A Quantitative Analysis of the Migration of the Summit of the Zygoma

BACKGROUND

We hypothesized that the amount of bone resection and setback together controls the effect of reducing the zygomatic body during reduction malarplasty; however, quantitative analyses of this movement are lacking.

METHODS

A retrospective study of patients who underwent reduction malarplasty between Aug. 2013 and Jan. 2015 was performed. We used 3-dimensional computed tomography (3D CT) scanning to measure movements of the summit of the zygoma (SOZ). We analyzed 394 zygomas in 197 patients.

RESULTS

The bone resection amount was not significantly correlated with the anteroposterior movement of the SOZ (p = 0.270); in contrast, the setback amount, was significantly correlated with anteroposterior SOZ movement (p < 0.001). The bone resection amount was not correlated with cephalocaudal movement (p = 0.158); however, cephalocaudal movement was significantly correlated with the setback amount (p < 0.001). Both the bone resection amount and the setback amount were correlated with mediolateral movement (p < 0.001). The amount of bone resection determined the mediolateral movement. Both the bone resection amount and the setback amount were correlated with the mean movement distance of the SOZ (p < 0.001). Both the R (2) (0.704 > 0.084) and β (0.839 > 0.290) values indicated that the setback amount made a larger contribution to the SOZ movement distance than did the bone resection amount.

CONCLUSIONS

Whereas bone resection was the major factor in the medial movement of the SOZ, bone setback was the major factor in the anterior and superior movement of the SOZ and a minor factor in the medial movement. The results indicate that both bone reposition and bone resection are important factors in maximizing surgical results of the reduction malarplasty.

LEVEL OF EVIDENCE III

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 .

External radiopaque marking of Gillies posterior zygomatic arch osteotomy in reduction malarplasty

Although the Gillies (temporal) approach to reduction malarplasty helps preserve supportive soft tissue and avoid facial scars, the osteotomy site is difficult to gauge when using this blind technique. Our experience with external radiopaque marking of the zygomatic arch to guide this process is presented herein. This retrospective review included all patients who underwent reduction malarplasty (as above) at our clinic between August 2013 and September 2015. Procedures entailed L-shaped osteotomy only (no segmental excision) of the zygomatic body by the intraoral route, and posterior zygomatic arch osteotomy by the Gillies approach, guided by external radiopaque markings. Patient characteristics, surgical outcomes, and complications were analyzed to assess the merits of this strategy. Postoperative results were evaluated by both the patients and the surgeon. Most patients expressed satisfaction during the follow-up period (range, 3-27 months). Posterior osteotomies were properly performed as planned, with no major complications (i.e., malunion or nonunion, cheek drooping, or facial nerve injury), although minor complications were recorded in three instances. Use of external radiopaque markings provides guidance during malarplasty by the Gillies approach and may help avoid procedural complications.