Feng Niu

Reduction malarplasty with a new L-shaped osteotomy through an intraoral approach: retrospective study of 418 cases.

Background: Oriental people usually have a wide midface and a prominent zygoma. Reduction malarplasty is one of the most frequently requested procedures for improvement of the facial contour in the Orient. Some methods involve coronal or preauricular incision for osteotomy, but this increases the likelihood of skin scars and injury to facial nerves, and increases the duration of surgery. Some methods involve an intraoral approach but cannot control the degree of reduction or the precision of interosseous fixation with the designed osteotomy lines. The authors designed an L-shaped osteotomy for malar prominence reduction through an intraoral approach to overcome these shortcomings. Methods: The authors reviewed 418 patients who underwent an L-shaped osteotomy for malar reduction performed in their department between 1997 and 2007. Follow-up was from 6 to 60 months (average, 12 months). The authors analyzed the rate of complications and evaluated the therapeutic efficacy of their method. Results: Four hundred two patients (96.2 percent) were satisfied. Only 16 patients (3.8 percent) with late complications were dissatisfied. Late postoperative complications focused mainly on asymmetry and cheek drooping. Conclusion: The new L-shaped osteotomy for correction of prominent zygoma is an ideal method, with the advantages of simpler manipulation, fewer complications, better outcome, shorter operative duration, no skin scars, and integrity of the structural characteristics of the zygoma.

Restoration of facial symmetry in hemifacial microsomia with mandibular outer cortex bone grafting combined with distraction osteogenesis.

Background: Mandibular distraction is a well-established method of correcting facial asymmetry in hemifacial microsomia. However, asymmetry in lower facial width remains after distraction because of its inability to increase bone thickness. Therefore, the authors used mandibular outer cortex bone grafting to augment the lower face following distraction to restore facial symmetry. Methods: From January of 1997 to December of 2007, 21 patients with hemifacial microsomia underwent unilateral mandibular distraction followed by mandibular augmentation using mandibular outer cortex bone graft harvested from the normal side. Age at surgery ranged from 7 to 27 years. Facial symmetry was evaluated based on medical photography and radiography with a minimum 6-month follow-up. Results: Mandibular height and length were expanded successfully with distraction, resulting in improvements in chin position and oral commissure level. Lower facial width was increased on the affected side and reduced on the normal side after bone grafting. Thus, three-dimensional facial symmetry was significantly improved in all patients. Long-term follow-up showed no evidence of relapse. The majority of the patients were satisfied with the reconstructive outcome. Conclusion: Mandibular augmentation with bone grafts harvested from the contralateral outer cortex effectively addressed the asymmetry in lower facial width that was uncorrected by distraction alone, achieving three-dimensional restoration of facial symmetry in hemifacial microsomia.

The oblique mandibular chin-body osteotomy for the correction of broad chin.

Background:The position and contour of the chin are important components in facial harmony and balance. In the aesthetic facial contouring of the lower face, the mandibular angle, body, and chin should be considered as 1 aesthetic unit. Any developmental broad chin or residual square chin after mandibular angle osteotomy can often make the lower face appear unattractive. For the correction of broad chin, the technique of horizontal-T genioplasty has been introduced; however, manipulation of this technique is sometimes complicated during repositioning and fixation because there is multiple osteotomy lines and if the muscular attachment is widely detached with an unskilled hand, after the muscular attachment is stripped off when the central segment is removed, there is the risk of bone necrosis and resorption. Therefore, a more simple and effective method for narrowing genioplasty needs to be further studied. Methods:From July 2005 to September 2008, we used the technique of oblique mandibular chin-body osteotomy for the narrowing of the broad chin. Osteotomy of the everted mandibular chin-bodys inferior border and reshaping of the lateral cortex with a bur reduces the width of the chin and the mandibular body, and the lateral outline of the mandibular inferior border becomes natural and smooth. Results:Twenty-five patients underwent the operation either separately or combined with other procedures such as a mandibular angle osteotomy or advancement genioplasty. All of the patients were satisfied with the improvement of their facial appearance at both the 3 months and 2 years follow-up. Conclusion:The oblique mandibular chin-body osteotomy is a simple method that can be used for the narrowing of broad chins caused by both developmental deformity and postmandibular angle osteotomy. It can effectively reduce the width of the mandibular body and mental region and make the lower face look attractive from both the anterior and lateral perspectives. It can be used independently or as a supplementary operation to osteotomy of prominent mandibular angles and horizontal advancement genioplasty.

Staged reconstruction for adult complete Treacher Collins syndrome.

Treacher Collins syndrome is a congenital craniofacial malformation affecting the structures derived from the first and second brachial arches. For the complete form, the deformities can be severe; both the orbital-zygomatic region and mandible as well as the soft tissues should be reconstructed. To explore the surgical management of this kind of deformities, we proposed our protocol for the staged reconstruction: (1) upper-facial reconstruction with specially designed outer calvarial table, (2) mandibular lengthening by distraction osteogenesis technique and orthognathic surgery to correct the birdlike facial appearance and anterior open bite after distraction, and (3) lipofilling for the correction of residual depressive deformities. Two adult patients have undergone this protocol, and the results were satisfactory. Even though many authors advised using pedicled bone flap for the reconstruction of the orbit and zygomatic complex in young patient because free bone graft has the tendency of bone resorption and multiple onlay bone graft may need to be added in later stage, for adult patient, however, the reconstructed bone framework using outer cranial table can well maintain the bony facial contour of the orbital zygomatic region. The residual depressive deformities in the temporal and cheek regions can be treated with lipofilling. Compared with the technique of mandibular advancement osteotomy, bilateral mandibular lengthening by gradual distraction is relatively safe and can effectively elongate the mandible and the surrounding soft tissues. After the distraction, the open bite can be closed with subapical osteotomy, and the chin projection can be further added by advancement genioplasty.

Three-dimensional preoperative design of distraction osteogenesis for hemifacial microsomia.

AbstractThe 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.

Applying computer techniques in repairing mild mandibular asymmetry with high-density porous polyethylene.

Objective The purpose of this study was to explore a new method to repair mild mandibular asymmetry using computer-aided design technique. Methods Medical three-dimensional image reconstruction and mirror technique were applied to design individual Medpor implant before operation. A surgical procedure was performed in 9 patients with mild mandibular asymmetry according to the preoperative planning. The Medpor implants in the body were displayed using surface rendering technique after operation, and the postoperative evaluation was performed using matching technique. Results All the patients had an ideal clinical outcome, with no complications. Virtual images from preoperative design and postoperative three-dimensional images were registered and superimposed onto each other. The percentage of matching was 87.6% to 96.8% with an average of 93.8% ± 2.4%. Conclusions The computer techniques play an important role in repairing mandibular asymmetry and will be used widely in craniofacial surgery.

Biomechanical analysis of reduction malarplasty with L-shaped osteotomy.

Background Reduction malarplasty with L-shaped osteotomy is widely used for surgical correction of prominent zygoma and bilateral zygomatic asymmetry. One of the keys to this surgery is the formation of the greenstick fracture on the root of the zygomatic arch. However, the greenstick fracture cannot be seen directly both in the postoperative x-ray films and three-dimensional computed tomography images, and it is unknown how the greenstick fracture forms biomechanically. So it is of great concern to both the doctors and patients whether the greenstick fracture can really take place on the root of the zygomatic arch. This study focused on the biomechanism and deformation effects of the surgery by using the method of finite element (FE) analysis. Methods Computed tomography data of 2 patients with prominent malar complex were obtained for three-dimensional reconstruction. The FE models of the zygomatic complex with L-shaped osteotomy were established by using Mimics via thresholding, segmentation techniques, and material properties assignment with gray value conversion. Then simulations including the boundary conditions and the forces of the surgery were performed in ABAQUS. Results The FE models have fine quality; the first one contains 63,053 units and 100,995 nodes, and the other one contains 70,238 units and 136,219 nodes. Under the loading of pressures, the zygoma and the zygomatic arch inward have deformation displacement. Maximum stress concentration was found just at the root of the zygomatic arch. Conclusions A appropriate zygomatic pressure will generate a stress concentration to form the greenstick on the root of the zygomatic arch. This study can help surgeons understand and conduct the reduction malarplasty with L-shaped osteotomy from a biomechanical insight.

Feasibility of absorbable plates and screws for fixation in reduction malarplasty with L-shaped osteotomy.

Reduction malarplasty with L-shaped osteotomy has been widely applied to correct malar prominence because of its simple manipulation, satisfactory outcome, and few complications in east Asians. Secondary surgery for the removal of titanium miniplates or microplates and screws is often needed because of the drawbacks of implants. To overcome the disadvantage, the authors applied absorbable plates and screws instead of titanium fixation system and evaluated the feasibility of them. A total of 47 women (mean age, 26.8 y) diagnosed with malar prominence were randomly selected and received L-shaped osteotomy for malar reduction from January 2008 to December 2009. Of these, 22 patients (group A) received absorbable plates and screws (Fixsorb-MX, Takiron, Japan) for fixation and 25 patients received titanium fixation system as control (group B). The outcomes were evaluated by photographs and x-ray films. The distance of the anterior protrusive point of the bilateral zygoma (Zv-Zv), the distance from the paries anterior of acoustic duct (P) to the anterior protrusive point of zygoma (P-Zv), and the angle formed by the nasion-Zv line and the P-Zv line (∠NZP) were analyzed through posteroanterior and lateral cephalograms preoperatively, 10 days postoperatively, and at 6 to 12 months of follow-up, respectively. In group A, 20 patients (90.9%) were satisfied with the outcomes compared with 92.0% in group B. No zygomatic nonunion and other complications occurred after surgery in both groups. In group A, the values of Zv-Zv and P-Zv were 88.4 ± 1.6 and 68.6 ± 6.8 mm at 10 days after surgery, which increased to 90.6 ± 1.5 and 70.7 ± 3.0 mm at 6 to 12 months of follow-up. The value of ∠NZP was 105.0 ± 4.3 degrees at 10 days after surgery and 103.2 ± 3.6 degrees at 6 to 12 months after surgery. In group B, the values of distance and degree maintained almost the same at different time points after surgery. The results had no significant difference between groups A and B (P > 0.05). The findings of the study suggested that the application of absorbable plate system in reduction malarplasty with L-shaped osteotomy is feasible. The absorbable fixation system would have a wider application in craniofacial surgery.

Application of Computer Techniques in Correcting Mild Zygomatic Assymetry With Unilateral Reduction Malarplasty.

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.Abstract 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.

Computer-assisted design of sequential surgical procedure for oblique facial clefts with mandibular outer cortex autografts.

BackgroundOblique 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. MethodsFrom 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. ResultsAll 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. ConclusionsThis 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.