A preliminary investigation into the impact of soft tissue augmentation-based periodontal phenotype modification therapy for patients exhibiting class III decompensation.

BACKGROUND: Patients with skeletal angle Class III malocclusion usually have inadequate hard and soft tissue volume at the mandibular anterior teeth. The labial proclination at the teeth may lead to gingival recession. The purpose of this study was to explore whether periodontal phenotype modification therapy with soft tissue augmentation (PhMT-s) can prevent gingival recession in these patients. METHODS: Four patients with skeletal Class III malocclusion and a thin periodontal phenotype underwent surgical-orthodontic treatment. Prior to tooth movement, they underwent a minimally invasive vestibular incision with subperiosteal tunnel access combined with autogenous connective tissue grafts for periodontal phenotype modification with soft tissue augmentation (PhMT-s). The labial gingival thickness of the anterior mandibular teeth was measured at three distinct levels: at the cementoenamel junction (GT0), 3 mm apical to the CEJ (GT3), and 6 mm apical to the CEJ (GT6). These measurements were taken at baseline, three months following PhMT-s, and after tooth decompensation. Additionally, a biopsy sample was obtained from the PhMT-s site of one patient. All sections were subsequently stained using hematoxylin and eosin, Masson trichrome, Sirius Red, and immunohistochemistry. RESULTS: The thickness of the labial gingiva was increased about 0.42 to 2.00 mm after PhMT-s. At the end of pre-orthognathic surgical orthodontic treatment, the thickness of the labial gingiva was increased about - 0.14 to 1.32 mm compared to the baseline and no gingival recession occurred after the pre-orthognathic surgical orthodontic treatment. The histologic results demonstrated that the grafts obtained from the PhMT-s site exhibited increased deposition of collagen fibers. Moreover, the proportion of type III collagen increased and the grafts displayed significantly reduced positive expression of CD31 and OCN. CONCLUSIONS: PhMT-s increased the thickness of the soft tissue, stabilizing the gingival margin for teeth exhibiting a thin periodontal phenotype and undergoing labial movement. This is attributed to the increased deposition of collagen fibers.

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

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

Abnormal tooth maturation associated with port wine stains.

OBJECTIVE: This study aims to evaluate the potential impact of port wine stains on the development of permanent teeth in mixed dentition and provide insights for managing tooth abnormalities in patients with port wine stains. MATERIALS AND METHODS: A retrospective analysis was conducted on 21 patients with mixed dentition and unilateral maxillary port wine stains. Two researchers concurrently utilized Nolla Analysis to assess the developmental stage of bilateral maxillary and permanent mandibular teeth based on panoramic radiographs. The cumulative developmental values of upper and lower permanent teeth on both sides were calculated, and a comparison was made between the developmental stages of the upper and lower jaws. RESULTS: Port wine stains can influence the maturity of permanent upper teeth, within the unilateral maxillary port wine stains range, with an early developmental completion observed on the affected side compared to the unaffected side. While the developmental stages of the lower teeth on both sides showed similarities. CONCLUSIONS: Port wine stains can accelerate the maturity of teeth on the affected side, leading to alterations in the order of tooth eruption and subsequent abnormal occlusion in children with mixed dentition. These findings provide a basis for developing appropriate management strategies for addressing tooth abnormalities in patients with port wine stains.

Camouflage orthodontic treatment combined with genioplasty distraction osteogenesis for skeletal class II relationship secondary to osteosarcoma excision surgery.

OBJECTIVE: The treatment of orthodontic patients who survive head and neck tumors is challenging because of dentoskeletal deformities and other unexpected dental and facial complications. This case report describes the case of a 26-year-old woman who presented with mandibular retrognathia after survival from osteosarcoma. CLINICAL CONSIDERATIONS: Camouflage orthodontic treatment was chosen instead of combined orthodontic-orthognathic surgery after primary reconstructive surgery with an iliac bone graft. Genioplasty distraction osteogenesis (DO) was performed to achieve an optimal facial profile. Although unexpected condyle dislocation and epithelial hyperplasia occurred during treatment, a favorable facial profile and optimal skeletal and dental relationships were accomplished after 32 months of treatment. CONCLUSIONS: The patient underwent genioplasty DO and experienced unexpected left condyle dislocation. However, the treatment achieved esthetic goals after intermaxillary elastics were applied.

Evaluation of Mandibular Symmetry in Patients With Condylar Osteochondroma Who Underwent Intro-Oral Condylar Resection and Simultaneous Bimaxillary Orthognathic Surgery.

Mandibular condylar osteochondroma (OC) can result in facial asymmetry, malocclusion, and temporomandibular joint dysfunction. The authors have previously demonstrated a novel method for conservative condylectomy and simultaneous orthognathic surgery for treatment of mandibular condylar OC. The purpose of this study was to evaluate the immediate improvement and long-term stability of mandibular symmetry in the treatment of condylar OC. Fifty-six patients with unilateral mandibular condylar OC combined with secondary facial asymmetry and malocclusion were enrolled in this retrospective study. The computerized tomography (CT) scans were acquired with the mandible in centric relation (CR) before surgery, 1 week and 12 to 18 months after surgery. The images were reconstructed and processed for the analysis with ProPlan CMF 2.1 software. After defining the skeletal landmarks and the reference planes, the chin deviation, chin rotation and mandibular asymmetry index were calculated. The operations and healing were uneventful and the patients showed no signs of recurrence or temporomandibular joint ankylosis during the follow-up. Facial symmetry was greatly improved right after the surgery in the chin deviation (from 9.2 to 1.7 mm, P < 0.01), chin rotation (from 11.2 to 2.3, P < 0.01) and the asymmetry index of three mandibular landmarks (Go, MF and Sg, all P < 0.01). It also showed a stable result after 12 to 18 months follow-up. We also established a novel measurement method, which showed that the combination of conservative condylectomy via the intraoral approach based on intraoperative navigation and simultaneous orthognathic surgery is effective for improving the facial symmetry when treat the mandibular condylar OC.

A Modified Method of Proximal Segment Alignment After Sagittal Split Ramus Osteotomy for Patients With Mandibular Asymmetry.

PURPOSE: The purpose of this study was to evaluate a modified method of aligning the proximal segment after bilateral sagittal split ramus osteotomy (BSSO) in the treatment of patients with facial asymmetry. PATIENTS AND METHODS: Eleven patients with mandibular excess and facial asymmetries were enrolled in this prospective study. The surgery was planned according to a computer-aided surgical simulation protocol. In addition, the proximal segment on the hypoplastic side was intentionally flared out after the distal segment was rotationally set back. If the gap between the proximal and distal segments was too wide, then bone grafts were used. The surgery was completed according to the computerized plan. The proximal segment on the hypoplastic side was fixed with bicortical lag screws, and the proximal segment on the hyperplastic side was fixed with a 4-hole titanium miniplate. Postoperative evaluation was performed 6 months after surgery. Statistical analyses were performed. RESULTS: All surgeries were completed uneventfully. Of the 11 patients, 4 also underwent genioplasty and 3 underwent bone grafting to fill in the gap and smooth the anterior step. The physicians and patients were satisfied with the surgical outcomes. Only 1 patient underwent a secondary revision using an onlay hydroxyapatite implant. Results of statistical analyses showed that the computerized surgical plan could be accurately transferred to the patients at the time of surgery and the surgical outcomes achieved with this modified method were better than with the routine method of aligning the proximal and distal segments in maximal contact. CONCLUSION: The present modified method of aligning the proximal segment for BSSO can effectively correct mandibular asymmetry and obviate a secondary revision surgery.

Endoscopic-assisted navigation-guided removal of long-standing metallic foreign body near to the sphenoid.

PURPOSE: It is unusual to see a metallic foreign body having stayed at the temporal surface of the sphenoid greater wing for 2 decades. Because of the change of proximity anatomy and the difficult access to delicate structure, removal of this foreign body seemed challenging. The application of surgical navigation system combined with endoscopy from other directions could reduce damage to the surrounding tissues during the removal and lower the risk. RESULTS: Computed tomographic scan on the head indicated that finalposition was the temporal surface of the sphenoid greater wing posterior to the lateral orbital wall. To relieve the patient from sustaining pain caused by the metallic foreign body, surgical navigation system combined with endoscopy was adopted to remove the foreign body. Two different incisions were made to place the probe of the navigation and the endoscope respectively, in which way we could get a better view of the anatomic structures when reaching the metallic foreign body. The patient's problem was solved safely and efficiently. No sequela was observed. CONCLUSIONS: In case of complicated anatomic structure, surgical navigation system combined with endoscopy from another direction proved to be a practical and safe method to remove foreign bodies.

Comprehensive treatment approach for hemifacial microsomia: Integrating orthognathic surgery with sequential customized implantation.

OBJECTIVE: This study aimed to evaluate the clinical outcomes of combining orthognathic surgery with staged patient-specific implants (PSIs) for comprehensive craniofacial asymmetry reconstruction in adult patients with hemifacial microsomia (HFM). METHODS: Six adults with HFM (1 Type I and 5 Type IIa) underwent orthognathic surgery to correct skeletal malocclusion and chin deviation. Sequential PSIs were implanted to address craniofacial asymmetry. Digital lateral cephalograms and cranial computed tomography scans were obtained at four time points: pre-orthognathic surgery (T0), within three months after orthognathic surgery (T1), one year after orthognathic surgery and just before personalized implantation (T2), and after personalized implantation (T3). Evaluation parameters included skeletal and dentoalveolar measures, occlusal cant, chin deviation, skeletal stability, and facial contour symmetry. RESULTS: At T1, no significant differences were observed in skeletal movements compared with planned surgical movements (p > 0.05). Similarly, at T2, skeletal movements did not significantly differ from those observed at T1 (p > 0.05), indicating surgical precision and stability. Analysis of skeletal and dentoalveolar parameters, occlusal cant, and chin deviation revealed significant increases in SNB, FH-NPo, and ST N vert-Pog at T1 compared to T0 (p < 0.05), along with notable improvements in chin deviation and occlusal cant (p < 0.05). Comparison of T2 to T1 showed no significant changes in SNB, FH-NPo, ST N vert-Pog, chin deviation, or occlusal cant (p > 0.05), indicating substantial postoperative stability. After personalized implantation (T3), further significant improvements were observed in skeletal symmetry. CONCLUSION: Combining orthognathic surgery with staged PSIs effectively reconstructs craniofacial asymmetry in adult patients with HFM, achieving significant improvements in skeletal alignment, occlusal cant, and chin deviation, with stable outcomes over time.

[Accuracy of tooth segmentation algorithm based on deep learning].

PURPOSE: The established automatic AI tooth segmentation algorithm was used to achieve rapid and automatic tooth segmentation from CBCT images. The three-dimensional data obtained by oral scanning of real isolated teeth were used as the gold standard to verify the accuracy of the algorithm. METHODS: Thirty sets of CBCT data and corresponding 59 isolated teeth were collected from Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. The three-dimensional tooth data in CBCT images were segmented by the algorithm. The digital information obtained by scanning the extracted teeth after processing was used as the gold standard. In order to compare the difference between the segmentation results and the scanning results of the algorithm. The Dice coefficient(Dice), sensitivity (Sen) and average symmetric surface distance (ASSD) were selected to evaluate the segmentation accuracy of the algorithm. The intra-class correlation coefficient(ICC) was used to evaluate the differences in length, area, and volume between the single tooth obtained by the AI system and the digital isolated tooth. Due to the existence of CBCT with different resolution, ANOVA was used to analyze the differences between groups with different resolution, and SNK method was used to compare them between two groups. SPSS 25.0 software package was used to analyze the data. RESULTS: After comparing the segmentation results with the in vitro dental scanning results, the average Dice value was (94.7±1.88)%, the average Sen was (95.8±2.02)%, and the average ASSD was (0.49±0.12) mm. By comparing the length, area and volume of a single tooth obtained by the digital isolated tooth and the AI system, the ICC values of the intra-group correlation coefficients were 0.734, 0.719 and 0.885, respectively. The single tooth divided by the AI system has a good consistency with the digital model in evaluating the length, area and volume, but the segmentation results were still different from the real situation in terms of specific values. The smaller the voxel of CBCT, the higher the resolution, the better the segmentation results. CONCLUSIONS: The CBCT tooth segmentation algorithm established in this study can accurately achieve the tooth segmentation of the whole dentition in CBCT at all resolutions. The improvement of CBCT resolution ratio can make the algorithm more accurate. Compared with the current segmentation algorithms, our algorithm has better performance. Compared with the real situation, there are still some differences, and the algorithm needs to be further improved and verified.

Ectomesenchymal Six1 controls mandibular skeleton formation.

Craniofacial development requires intricate cooperation between multiple transcription factors and signaling pathways. Six1 is a critical transcription factor regulating craniofacial development. However, the exact function of Six1 during craniofacial development remains elusive. In this study, we investigated the role of Six1 in mandible development using a Six1 knockout mouse model (Six1 -/- ) and a cranial neural crest-specific, Six1 conditional knockout mouse model (Six1 f/f ; Wnt1-Cre). The Six1 -/- mice exhibited multiple craniofacial deformities, including severe microsomia, high-arched palate, and uvula deformity. Notably, the Six1 f/f ; Wnt1-Cre mice recapitulate the microsomia phenotype of Six1 -/- mice, thus demonstrating that the expression of Six1 in ectomesenchyme is critical for mandible development. We further showed that the knockout of Six1 led to abnormal expression of osteogenic genes within the mandible. Moreover, the knockdown of Six1 in C3H10 T1/2 cells reduced their osteogenic capacity in vitro. Using RNA-seq, we showed that both the loss of Six1 in the E18.5 mandible and Six1 knockdown in C3H10 T1/2 led to the dysregulation of genes involved in embryonic skeletal development. In particular, we showed that Six1 binds to the promoter of Bmp4, Fat4, Fgf18, and Fgfr2, and promotes their transcription. Collectively, our results suggest that Six1 plays a critical role in regulating mandibular skeleton formation during mouse embryogenesis.

A Proposal for the Classification of Temporomandibular Joint Disc Deformity in Hemifacial Microsomia.

Hemifacial microsomia (HFM) is the second most common congenital craniofacial disease and has a wide spectrum of symptoms. The classic diagnostic criterion for hemifacial microsomia is the OMENS system, which was later refined to the OMENS+ system to include more anomalies. We analyzed the data of 103 HFM patients with magnetic resonance imaging (MRI) for temporomandibular joint (TMJ) discs. The TMJ disc classification was defined into four types: D0 for normal disc size and shape; D1 for disc malformation with adequate length to cover the (reconstructed) condyle; D2 for disc malformation with inadequate length to cover the (reconstructed) condyle; and D3 for no obvious presence of a disc. Additionally, this disc classification was positively correlated with the mandible classification (correlation coefficient: 0.614, p < 0.01), ear classification (correlation coefficient: 0.242, p < 0.05), soft tissue classification (correlation coefficient: 0.291, p < 0.01), and facial cleft classification (correlation coefficient: 0.320, p < 0.01). In this study, an OMENS+D diagnostic criterion is proposed, confirming the conjecture that the development of the mandibular ramus, ear, soft tissue, and TMJ disc, as homologous and adjacent tissues, is affected to a similar degree in HFM patients.

Reconstruction of Dentomaxillofacial Deformity Secondary to Mandibular Defect Using Concomitant Orthognathic Surgery and Fibula Free Flap.

SUMMARY: The reconstruction of mandibular defects may be delayed or compromised for many reasons, especially in pediatric patients. With the growth of the remaining mandible and the maxilla in the malocclusion status, secondary dentomaxillofacial deformity is plausible. To treat the concomitant mandibular defect and secondary dentomaxillofacial deformity, a hierarchical algorithm using orthodontics, orthognathic surgery, and fibula free flap was developed. This retrospective case series included six patients with long-term mandibular defects caused by tumor resection without repair or with compromised costochondral reconstruction. All patients were treated using the same staged protocol, but with minor changes: (1) presurgical orthodontics, (2) virtual surgical planning, (3) fabrication of the guides and splints, (4) sequenced operations, and (5) postoperative care. The sequence of surgery included the Le Fort I osteotomy, mandibular sagittal split ramus osteotomy of the remaining ramus, final occlusion registration, repositioning of the distal segment of the mandible, segmented fibula reconstruction, and finally, the fixation of mandibular sagittal split ramus osteotomy. The operations and wound healing were uneventful in all patients, and no flap failure or severe complications were detected. Also, the patients exhibited no signs of temporomandibular joint ankylosis during the follow-up. The subspinale-nasion-supramental angle was significantly reduced after surgery. A significant improvement was detected in the facial contour symmetry measurements postoperatively. This proposed workflow of concomitant orthognathic surgery and the fibula free flap is effective and reliable for the reconstruction of dentomaxillofacial deformity secondary to the long-term mandibular defect.

A Neural Crest-specific Overexpression Mouse Model Reveals the Transcriptional Regulatory Effects of Dlx2 During Maxillary Process Development.

Craniofacial morphogenesis is a complex process that requires precise regulation of cell proliferation, migration, and differentiation. Perturbations of this process cause a series of craniofacial deformities. Dlx2 is a critical transcription factor that regulates the development of the first branchial arch. However, the transcriptional regulatory functions of Dlx2 during craniofacial development have been poorly understood due to the lack of animal models in which the Dlx2 level can be precisely modulated. In this study, we constructed a Rosa26 site-directed Dlx2 gene knock-in mouse model Rosa26 CAG-LSL-Dlx2-3xFlag for conditionally overexpressing Dlx2. By breeding with wnt1 cre mice, we obtained wnt1 cre ; Rosa26 Dlx2/- mice, in which Dlx2 is overexpressed in neural crest lineage at approximately three times the endogenous level. The wnt1 cre ; Rosa26 Dlx2/- mice exhibited consistent phenotypes that include cleft palate across generations and individual animals. Using this model, we demonstrated that Dlx2 caused cleft palate by affecting maxillary growth and uplift in the early-stage development of maxillary prominences. By performing bulk RNA-sequencing, we demonstrated that Dlx2 overexpression induced significant changes in many genes associated with critical developmental pathways. In summary, our novel mouse model provides a reliable and consistent system for investigating Dlx2 functions during development and for elucidating the gene regulatory networks underlying craniofacial development.

ITPR1 Mutation Contributes to Hemifacial Microsomia Spectrum.

Hemifacial microsomia (HM) is a craniofacial congenital defect involving the first and second branchial arch, mainly characterized by ocular, ear, maxilla-zygoma complex, mandible, and facial nerve malformation. HM follows autosomal dominant inheritance. Whole-exome sequencing of a family revealed a missense mutation in a highly conserved domain of ITPR1. ITPR1 is a calcium ion channel. By studying ITPR1's expression pattern, we found that ITPR1 participated in craniofacial development, especially the organs that corresponded to the phenotype of HM. In zebrafish, itpr1b, which is homologous to human ITPR1, is closely related to craniofacial bone formation. The knocking down of itpr1b in zebrafish could lead to a remarkable decrease in craniofacial skeleton formation. qRT-PCR suggested that knockdown of itpr1b could increase the expression of plcb4 while decreasing the mRNA level of Dlx5/6. Our findings highlighted ITPR1's role in craniofacial formation for the first time and suggested that ITPR1 mutation contributes to human HM.

Modified Usage of Negative Pressure Wound Therapy for the Management of Severe Deep Fascial Space Infections in the Head and Neck.

PURPOSE: Although negative pressure wound therapy (NPWT) has been widely used in complicated wound care, there are still some obstacles regarding its use in the treatment of severe deep fascial space infections in the head and neck. The purpose of this study is to describe a new modified usage of NPWT and investigate the clinical efficacy of this system in a consecutive case series of severe deep fascial space infections. METHODS: The investigators implemented a new modification of NPWT for the management of severe deep fascial space infections. In this new system, the half-plugged bar-shaped foam material was arranged along with the through-and-through side-holed latex drainage tube, which could maintain negative pressure in the distal part of the spaces, and the tube was easy to remove 5-7 days after surgery. Twelve patients had severe deep fascial space infections in the head and neck with a direct threat to the airway. The median time of removal of the NPWT device, the median amount of drainage fluid and the median healing time were investigated. RESULTS: A total of 7 male and 5 female patients with an average age of 63.2 years old were included in this study. The median time of removal of the NPWT device was 6 days (ranging from 4 to 7 days). The median amount of drainage fluid within 3 days after surgery was 420 mL (ranging from 280-760 mL), and the median time for complete wound healing was 12 days (ranging from 10 to 21 days). CONCLUSION: The results of this study suggest that the modification of NPWT provides various advantages and leads to excellent clinical outcomes in the treatment of severe deep fascial space infections. Future studies will focus on the safety verification of portable usage and the cost effectiveness analysis of NPWT.

Course of the mandibular canal in hemifacial microsomia: a retrospective computed tomography study.

OBJECTIVE: The aim of this study was to evaluate the anatomic course of the mandibular canal in patients with hemifacial microsomia (HM). STUDY DESIGN: In this retrospective study, 77 patients were included and stratified according to the Pruzansky-Kaban classification. The mandibular canal and the mandible were reconstructed on the basis of computed tomography data. The entrance, route, and exit of the mandibular canal (representing the entrance, route, and exit of the inferior alveolar nerve [IAN], respectively), and the antilingula were analyzed in different types of mandibular deformities in patients with HM. RESULTS: No significant difference in the course of the mandibular canal was detected between the affected and unaffected sides in patients with type I and type IIa HM. Abnormalities were observed in some patients with type IIb and type III HM. Significant differences were found between patients with type IIb and type III HM in the entrance (P = .015) and route (P = .001) of the canals. The antilingula was identified only in patients with type IIb and type III HM and was more common in patients with type III HM than in those with type IIb HM. CONCLUSIONS: Variation of the anatomic course of mandibular canal exists in patients with Pruzansky-Kaban type IIb and type III HM. Evaluation of the course of the canal in patients with HM is recommended before surgical intervention to avoid IAN damage.

Surgery-first/early-orthognathic approach may yield poorer postoperative stability than conventional orthodontics-first approach: a systematic review and meta-analysis.

OBJECTIVE: There are conflicting views on the postoperative stability of surgery-first and surgery-early approaches in orthognathic surgery. We systematically reviewed the literature to compare the difference in postoperative stability between a surgery-first/early orthognathic approach (SFEA) and a conventional orthodontics-first approach (COA). STUDY DESIGN: PubMed, Embase, and Cochrane Library were searched for studies related to the postoperative stability of SFEA. The primary outcome was the horizontal relapse at the pogonion. Weighted mean differences with 95% confidence intervals were pooled using a random-effects model. RESULTS: We analyzed 12 studies (total of 498 participants). The pooled estimate suggested that the SFEA group manifested less postoperative stability than COA group (weighted mean difference, 1.50; P < .00001), with moderate heterogeneity (I2 = 53%). The result of subgroup analysis yielded no subgroup difference. Sensitivity analysis conducted by omitting one study at a time further validated the robustness of the result. CONCLUSIONS: Based on the meta-analysis, the mandible tends to rotate counterclockwise more in the SFEA group, which indicate a poorer postoperative stability than in the COA group. Patient screening and treatment plans should be reviewed carefully to compensate for possible postoperative relapse when adopting SFEA.

Evaluation of computer-assisted mandibular reconstruction with vascularized fibular flap compared to conventional surgery.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of computer-assisted mandibular reconstruction with a vascularized fibular flap and compare it with conventional surgery. STUDY DESIGN: In this retrospective study conducted between February 2009 and December 2012, 8 patients underwent computer-assisted mandibular reconstruction, and 14 patients underwent conventional surgery. The accuracy of virtual surgical planning was determined, and the outcomes in the two groups were compared. RESULTS: In the computer-assisted group, the deviation in fibula segment length was 1.34 ± 1.09 mm, the angular deviation was 2.29 ± 1.19°, and the mean 3-D deviation was 0.53 ± 0.06 mm. Mean differences in intercondylar distance, intergonial angle distance, anteroposterior distance, gonial angle, and duration of ischemia were all improved in the computer-assisted group compared with the conventional surgery group. CONCLUSIONS: Computer-assisted surgery, including preoperative virtual surgical planning, intraoperative cutting and reconstructive guides, and postoperative analysis is highly accurate in fibular flap mandibular reconstruction.

Effects of DLX2 overexpression on the osteogenic differentiation of MC3T3-E1 cells.

Distal-less genes (DLX) play important roles in regulating organism development. DLX2 is crucial for the differentiation and development of the primordium, which determines the subsequent development and phenotype of the maxillofacial skeletal patterns, and is the primary candidate gene that regulates the development of the first branchial arch. The aim of the present study was to investigate the effects of DLX2 overexpression on the osteogenic differentiation of MC3T3-E1 cells in vitro. A DLX2-expression retrovirus vector was constructed by subcloning with a murine stem cell virus (MSCV) and verified by sequencing. MC3T3-E1 cells were transfected with pMSCV-DLX2 and stable clones were selected with puromycin. The mRNA and protein expression levels of DLX2 were determined using quantitative polymerase chain reaction (PCR) and western blot analysis, respectively. In addition, the expression levels of the osteogenic biomarkers, alkaline phosphatase (ALP), osteocalcin (OCN), runt-related transcription factor (RUNX)2 and Msh homeobox (MSX)2, were assessed by quantitative PCR. ALP detection and Alizarin red staining were conducted to evaluate the effect of DLX2 overexpression on osteogenic differentiation. The data were analyzed by analysis of variance using the Student-Newman-Keuls method. Successful pMSCV-DLX2 construction, as verified by direct sequencing, enabled DLX2 overexpression in vitro. Enhanced ALP activity and Alizarin red staining were observed in the MC3T3-E1-DLX2 cells when compared with the control group. During osteogenic induction, DLX2 overexpression was demonstrated to upregulate ALP and MSX2 expression at the early stage and OCN expression at the late stage, while no statistically significant difference was observed in RUNX2 expression when compared with the control group. Therefore, DLX2 overexpression in vitro induced the osteogenic differentiation of MC3T3-E1 cells via upregulating bone formation-associated genes, such as ALP and MSX2.

[Piezosurgery for surgically assisted rapid maxillary expansion under local anesthesia].

OBJECTIVE: This study evaluates piezosurgery for surgically assisted rapid maxillary expansion (SARME) under local anesthesia. METHODS: SARME was performed on adults with maxillary transverse deficiency under local anesthesia with a piezosurgical device. Fourteen patients (six males and eight females) underwent lateral maxillary osteotomies, midpalatal osteotomies, and bilateral pterygomaxillary disjunction. The feelings of patients during the operation were determined through questionnaires. RESULTS: All patients underwent SARME in the out-patient operating room. The surgical procedures were completed under local anesthesia. All patients exhibited satisfactory tolerance. Ultrasonic bone-cutting surgery was recently introduced as a feasible alternative to the conventional tools of cranio-maxillofacial surgery for its technical characteristics of precision and safety. The device used was unique in that cutting action occurred when the tool was employed on mineralized tissues, but stoped on soft tissues. The results of the questionnaires showed that eight (57.14%) patients felt a mild sensation of ultrasonic vibration, tweleve (85.7 1%) felt mild tolerable pain and tooth soreness during surgery, and eleven (78.57%) felt little fear and hardly heard the ultrasonic sound. Preoperative and postoperative six months later measurements showed an evident effect of expansion. CONCLUSION: Piezosurgery enabled patients to undergo all the steps of SARME under local anesthesia, but more cases and longer follow-up are needed to verif ' the results.