[Clinical analysis of 12 cases of orthognathic surgery with digital computer-assisted technique].

PURPOSE: This study was to investigate the effect of the digital computer-assisted technique in orthognathic surgery. METHODS: Twelve patients from January 2008 to December 2011 with jaw malformation were treated in our department. With the help of CT and three-dimensional reconstruction technique, 12 patients underwent surgical treatment and the results were evaluated after surgery. RESULTS: Digital computer-assisted technique could clearly show the status of the jaw deformity and assist virtual surgery. After surgery all patients were satisfied with the results. CONCLUSIONS: Digital orthognathic surgery can improve the predictability of the surgical procedure, and to facilitate patients' communication, shorten operative time, and reduce patients' pain.

[Application of computer-aided surgery in fibrous dysplasia of cranio-maxillofacial bone].

PURPOSE: To evaluate the effect of computer-aided surgical techniques in surgical treatment of cranio-maxillofacial fibrous dysplasia. METHODS: Twenty-two patients from January 1999 to December 2012 with cranio-maxillofacial fibrous dysplasia were treated in our department. According to the patients' specific conditions, surgeons designed surgical programs, and used computer-assisted surgical techniques to produce skull model and navigation template individually. The effects after surgery were evaluated. RESULTS: Twenty-two patients with resection of the bone lesions restored facial symmetry partially. The patients were followed up for 3 to 36 months, and the treatment effects were satisfactory. CONCLUSIONS: With preoperative planning, intraoperative navigation and postoperative prediction, computer-aided surgery shows its great value in improving the accuracy of cranio-maxillofacial surgery, shortening operating time and restoring facial symmetry. It is regarded as a valuable and safe surgical technique in cranio-maxillofacial surgery. Supported by Beijing Natural Science Foundation (7112124).

Clinical and radiological outcomes after treatment of sagittal fracture of mandibular condyle (SFMC) by using occlusal splint in children.

This study was designed to investigate the effects of occlusal splints in the treatment of sagittal fractures of the mandibular condyle in children. From January 1995 to December 2011, 37 sagittal fractures of the mandibular condyle in 30 patients aged 4-8 years old were included in this study. All the patients were treated with 1-2mm occlusal splints in the molar region. The mouths of the patients were kept slightly open by the occlusal splints for 3-6 months, and we reviewed the clinical and radiological remodelling of the affected condyles after treatment. Excellent (n=20) and good (n=10) clinical outcomes were achieved with full radiological remodelling seen in 19 and partial remodelling in 11. Treatment with occlusal splints is effective in delivering good results and function with minimal morbidity in children with sagittal fractures of the condyle, while permitting ongoing remodelling and growth in the short term.

[Comparative efficacies of non-surgical treatment for pediatric and adult sagittal fractures of mandibular condyle].

OBJECTIVE: To compare the efficacies of non-surgical treatment for pediatric and adult sagittal fractures of mandibular condyle. METHODS: From January 1985 to December 2010, our department treated 67 cases (82 sides) sagittal fractures of mandibular condyle with occlusal splint at a height of 1-2 mm in molar region for six months or other non-surgical treatment. Their clinical and radiological remodeling of affected condyles after treatment were reviewed at six mouths, one year and each year after treatment. They were divided into 2 groups according to age. There were 28 patients (34 sides) aged over 12 years and 39 patients (48 sides) under 12 years. During a follow-up period of 2-25 years, mandibular activity, mouth opening and parallel CT scan of condylar morphological alterations were examined. RESULTS: Under 12-year-old group:good mandibular function was observed in 39 patients. Maximal mouth opening over 35 mm was achieved at 6 months.Only 11 of 39 patients had deviation on mouth opening at 6 months.Radiological studies showed that 32 condyles were complete remodeling and 16 condyles were partial remodeling. Poor remodeling was not observed. Over 12-year-old group:Ankylosis occurred in 4 joints. And 15 of 28 patients had deviation on mouth opening at 6 months.Radiological studies showed the remodeling of condyles was complete (n = 6), partial (n = 16) and poor (n = 12) respectively. CONCLUSION: Mandibular functional recovery and condylar remodeling are better in children with more powerful healing and reconstructing capacities.

Zinc ion implantation-deposition modification of titanium for enhanced adhesion of focal plaques of osteoblast-like cells.

BACKGROUND: Surface modification by ion implantation-deposition is well established in materials science and can be an effective way to improve biocompatibility. The aim of this study is to evaluate the chemical composition of a modified titanium (Ti) surface after zinc (Zn) ion implantation and deposition and examine the effect of the modification on the formation of cellular focal adhesion plaques in vitro. METHODS: cp-Ti discs were modified with Zn ion implantation and deposition via PIIID. The chemical composition of the surface modification was characterized by X-ray photoelectron spectroscopy (XPS). The formation of focal adhesion plaques on the modified Ti was investigated with human osteoblast-like MG-63 cells that were seeded onto the Ti surfaces and quantified by morphometric analysis under a confocal microscope. RESULTS: XPS data revealed that the modified Zn-Ti surface consisted of Ti, oxygen, Zn, and carbon. In addition, Gaussian fitting of the spectra indicated that the modified surface contained titanium dioxide and zinc oxide. After 6 hours of MG-63 cell culture, there were significantly more focal adhesion plaques on the modified surfaces than observed on the nonmodified Ti (P < 0.05). CONCLUSION: Zn ion implantation and deposition greatly improved the biocompatibility of Ti for the growth of MG-63 cells.

[Character of zinc-modified titanium surface and its antibacterial property to S.mutans].

PURPOSE: To evaluate the chemical composition of the zinc modified surface of implanted titanium and to assess its effect on the antibacterial activity in vitro. METHODS: Pure commercial titanium discs were modified with zinc by plasma immersion ion implantation and deposition (PIIID) technique. The surfaces were characterized by X-ray photoelectron spectrometer. To measure the bacterial responses, S. mutans were seeded onto the surfaces of discs in 24-well culture plates at a density of 1×10(9) CFU/mL and observed by a scanning electron microscope. The statistical significance of difference was assessed by ANOVA using SPSS 13.0 software package, followed by a Bonferroni test. RESULTS: The full range XPS indicated that the main difference of zinc PIIID on the disc was the appearance of the signals of zinc and oxygen. At the same time, the relative atomic concentration of zinc increased gradually with the implanting time, the concentration of zinc in Zn-Ti-80 min group being the highest among the groups. The zinc implanted titanium could affect adherence and the form of S.mutans. The adherence amount of bacteria in Zn-Ti-60 min and -80 min group was significantly less than those in cp-Ti group, Zn-Ti-20 min and -40 min group. CONCLUSIONS: PIIID can successfully introduce zinc into pure titanium surface, which can change adherence and the form of S.mutans slightly.

The adjuvant use of stromal vascular fraction and platelet-rich fibrin for autologous adipose tissue transplantation.

Autologous adipose transplantation is rapidly gaining popularity for the restoration of soft tissue defects and lipoatrophy as well as for aesthetic improvements (e.g., facial reconstruction and rejuvenation). However, the current technique is crude that suffers from serious demerits, particularly the long-term unpredictability of volume maintenance due to resorption of the grafted adipose tissue and limited adipogenesis. We hypothesized that the adjuvant use of patient-derived adipose stromal vascular fraction (SVF) and platelet-rich fibrin (PRF) may enhance the overall outcome of autologous fat grafting in plastic and reconstructive surgery. Autologous SVF, with a mean cell number of (4.8±3.79)×107 cells/mL and a mean cell viability of 71.8%, and autologous PRF, with sustained release of multiple angiogenic growth factors, were created before surgical use. The following adipose tissue implants were injected subcutaneously into a rabbit ear's auricula according to the following study design: 2 mL adipose granules and 0.2 mL normal saline solution (AG+NS group), 2 mL adipose granules and 0.2 mL SVF (AG+SVF group), 2 mL adipose granules and 0.2 mL PRF (AG+PRF group), or 2 mL adipose granules combined with 0.1 mL SVF and 0.1 mL PRF (AG+SVF+PRF group). Histological examinations showed that the implanted adipose granules were well engrafted in the AG+SVF+PRF group, with a higher microvessel density 4 weeks postimplantation compared with the other three groups (p<0.01). Twenty-four weeks postimplantation, the resorption rates of implanted tissue in each group were 49.39%±9.47%, 27.25%±4.37%, 36.41%±8.47%, and 17.37%±6.22%, respectively, and were significantly different (p<0.01). The results demonstrated that the efficacy of adipose tissue implantation can be enhanced by using autologous PRF and SVF as therapeutic adjuvants, offering a clinically translatable strategy for soft tissue augmentation and reconstruction.

[Analysis of human mandible and temporomandibular joint using three-dimensional finite element method under different mechanical models].

OBJECTIVE: Analysis the result of human mandible and temporomandibular joint using two different three-dimensional finite element method under different mechanical models. METHODS: The 3-dimensional model including cortical and cancellous bone for human mandible was obtained through computed tomography (CT) scan. Then the model was meshed in the software ICEM CFD. The passive and active muscle-force loadings were separately applied on the FE model to simulate the anterior clenching. Stress distributions in two models were compared. RESULTS: The stress distributions of two models were apparently different. In the passive muscle-force model, high stress was mainly distributed in mandibular angle, retromolar trigone, notch and bite point on crown. In the active muscle-force model, high stress was mainly distributed in condylar vertex and neck, mandibular angle, retromolar trigone and bite point on crown. There were some similarities between passive and active muscle loadings. However, large difference existed in condylar region due to the vertices reaction force disparity. CONCLUSION: Closer to actual stressing state of human mandible and temporomandibular joint, the active muscle-force model is a proper biomechanical model for human mandible under anterior clenching.

[Evaluation of the clinical results of non-surgical treatment for pediatric sagittal fracture of mandibular condyle].

OBJECTIVE: To investigate the clinical results of occlusal splint in the treatment of sagittal fracture of mandibular condyle (SFMC) in children. METHODS: Thirty-nine patients (48 condyles)aged 3-8 years with sagittal fracture of mandibular condyle were included in this study. All the patients were treated by occlusal splint.Slight open occlusion was maintained by occlusal splint for 3-6 months. Clinical and radiological examination was performed six mouths and every year after treatment. RESULTS: Good mandibular function was observed in 39 patients. Maximal mouth opening over 35 mm was achieved at 6 months. But 11 of the 39 patients presented with deviation on mouth opening at 6 months. The radiology showed an complete remodeling in 32 condyles (28 patients) and partial remodeling in 16 condyles (11 patients). Poor remodelling was not observed in any patients. CONCLUSIONS: Good clinical results can be obtained by using occlusal splint in the treatment of pediatric sagittal fracture of mandibular condyle.