Guofang Shen

Navigation-Guided Reduction and Orbital Floor Reconstruction in the Treatment of Zygomatic-Orbital-Maxillary Complex Fractures

PURPOSEnTo evaluate the effectiveness of image-guided navigation on open reduction and orbital floor reconstruction as treatment for zygomatic-orbital-maxillary complex fractures.nnnPATIENTS AND METHODSnSix patients with zygomatic-orbital-maxillary complex fractures were enrolled in the present study. With preoperative planning and 3-dimensional simulation, the normal anatomic structures of the deformed area were recreated by superimposing and comparing the unaffected side with the affected side. The position of dislocated bone for reduction was defined, and surgical simulation was performed. All patients underwent open reduction and orbital floor reconstruction under the guidance of the navigation system.nnnRESULTSnA fairly accurate match between the intraoperative anatomy and the computed tomography images was achieved through registration, with a systematic error of 1-mm difference. With guidance of the navigation system, open reduction of zygomatic-orbital-maxillary complex fractures and orbital floor reconstruction were performed in all cases. The reduction was checked by postoperative computed tomography scans, with a good match with preoperative planning noted. The maximal deviation between the reduction and preoperative planning was less than 2 mm. The symptoms associated with the orbital floor defects were eliminated, and the postoperative facial appearance of the patients was clearly improved.nnnCONCLUSIONnNavigation-guided open reduction of zygomatic-orbital-maxillary complex fractures with orbital floor reconstruction can be regarded as a valuable treatment option for this potentially complicated procedure.

Yes-associated protein promotes cell proliferation by activating Fos Related Activator-1 in oral squamous cell carcinoma

In our previous study, we established an in vitro cellular carcinogenesis model of oral squamous cell carcinoma (OSCC), including a human immortalized oral epithelial cell (HIOEC) and a cancerous cell line (HB96). Microarray analysis showed that the gene encoding Yes-associated protein (YAP) was significantly increased in HB96 cells compared with HIOEC cells. But the underlying mechanism of YAP on oncogenesis, especially its downstream targets, are still not clear. YAP expression in OSCC cell lines and tissue specimens were investigated by using real-time PCR, western blotting and immunohistochemistry staining. YAP put-back plasmid with four mutation sites after YAP-siRNA interference was constructed by site-directed mutagenesis. Cell growth and colony formation were observed after YAP-siRNA interference or YAP put-back again in CAL27 cells. YAP expression was increased in the cellular carcinogenesis models and the clinical samples from primary OSCC patients. Inhibition of YAP by siRNA interference in CAL27 cells significantly inhibited cell proliferation and colony formation in soft agar, but these abilities were rescued when YAP was put-back again. At the same time, Fos Related Activator-1 (Fra-1) was down-regulated when YAP was inhibited by siRNA interference while Fra-1 was rescued when YAP was put-back again. Immunohistochemistry results also indicated that higher levels of YAP were significantly associated with Fra-1 overexpression in OSCC clinical samples. YAP could promote cell proliferation by activating transcription factor Fra-1 in oral squamous cell carcinoma.

Evaluation of alveolar bone grafting using limited cone beam computed tomography

OBJECTIVEnThe objective of this study was to evaluate the bone resorption of alveolar bone grafting using LCBCT scan.nnnSTUDY DESIGNnThis was a prospective study. Nineteen patients with alveolar cleft were divided into 2 groups depending on the spontaneous eruption of the permanent tooth. All patients underwent alveolar bone grafting with iliac crest cancellous bone. LCBCT scans were taken 1 month and 6 months postoperatively.nnnRESULTSnLCBCT scans obtained the length, width, and height of the bone grafts. Three-dimensional (3D) reconstruction of the bone grafts enabled a valuable objective assessment of the graft volume. The resorption ratio was 10.4% when the permanent tooth erupted spontaneously into the graft. In the group with absence of the permanent tooth, the resorption ratio was 36.6%.nnnCONCLUSIONnLCBCT scan and 3D reconstruction is a promising method for evaluation of the outcome of alveolar bone grafts. Bone grafts showed a high grade of resorption in patients lacking permanent tooth eruption.

Gap arthroplasty combined with distraction osteogenesis in the treatment of unilateral ankylosis of the temporomandibular joint and micrognathia

Our aim was to evaluate the efficacy of simultaneous gap arthroplasty and distraction osteogenesis (DO) in the treatment of unilateral ankylosis of the temporomandibular joint (TMJ) in patients with micrognathia. During the period January 2000-December 2006, 11 patients with unilateral ankylosis of the TMJ and micrognathia were treated with simultaneous gap arthroplasty, mandibular osteotomy, and implantation of a distractor. Mouth opening exercises were started on the first postoperative day and distraction on the fifth postoperative day. All patients had satisfactory mouth opening at follow-up, the mean (range) being 32.4 (28-37) mm in 13 to 58 months follow-up. Mean length (range) of the mandibular body increased by DO was 12.4 (7-15) mm. Facial asymmetry was corrected and satisfactory occlusions achieved with the help of postoperative orthodontic treatment. We conclude that DO and gap arthroplasty can be used simultaneously in the treatment of patients with ankylosis of the TMJ and micrognathia.

The effect of co-culturing costal chondrocytes and dental pulp stem cells combined with exogenous FGF9 protein on chondrogenesis and ossification in engineered cartilage

Dental pulp stem cells (DPSCs), which arise from cranial neural crest cells, are multipotent, making them a candidate for use in tissue engineering that may be especially useful for craniofacial tissues. Costal chondrocytes (CCs) can be easily obtained and demonstrate higher initial cell yields and expansion than articular chondrocytes. CCs have been found to retain chondrogenic capacity that can effectively repair articular defects. In this study, human CCs were co-cultured with human DPSCs, and the results showed that the CCs were able to supply a chondro-inductive niche that promoted the DPSCs to undergo chondrogenic differentiation and to enhance the formation of cartilage. Although CCs alone could not prevent the mineralization of chondro-differentiated DPSCs, CCs combined with exogenous FGF9 were able to simultaneously promote the chondrogenesis of DPSCs and partially inhibit their mineralization. Furthermore, FGF9 may activate this inhibition by binding to FGFR3 and enhancing the phosphorylation of ERK1/2 in DPSCs. Our results strongly suggest that the co-culture of CCs and DPSCs combined with exogenous FGF9 can simultaneously enhance chondrogenesis and partially inhibit ossification in engineered cartilage.

Minimally invasive endoscopic resection of benign tumours of the accessory parotid gland: an updated approach ☆

The most common conventional approaches for the resection of benign tumours in the accessory parotid gland are a standard parotidectomy incision, a modified standard parotidectomy incision, or a face-lift incision. The resulting scars may severely affect the patients postoperative appearance. The previously reported endoscopically assisted approach offers a less aesthetically invasive technique, but it may still leave a visible preauricular scar 4-5 cm long. We have used a modified endoscopic approach with minimal, and concealed, incisions for the resection of benign tumours in the accessory parotid gland. Five patients were diagnosed by physical examination, imaging, and preoperative fine-needle aspiration biopsy. They had endoscopically assisted resections using our modified approach, and we evaluated its feasibility. All the resections were successful. The mean operating time was 108 min (range 90-130). The postoperative scars were concealed and aesthetically satisfactory. There were no facial paralyses, salivary fistulas, or recurrences in the short term. Using endoscopically assisted resection we completely removed benign tumours from the accessory parotid gland and obtained good aesthetic results. Our updated endoscopic approach for these resections is successful with shorter, concealed incisions. It is a viable alternative to conventional approaches.

An epidemiological and clinical analysis of craniomaxillofacial fibrous dysplasia in a Chinese population

BackgroundCraniomaxillofacial fibrous dysplasia (FD) is a benign bone lesion characterized by facial disfigurement and functional impairment. The aim of this study was to characterize the epidemiological and clinical features of craniomaxillofacial FD by presenting data from a representative Chinese population during a 15-year period (1994–2009).MethodThe craniomaxillofacial disease registries of two Chinese tertiary referral hospitals (Shanghai Ninth People’s Hospital and Stomatological hospital of Jiangsu Province) were searched and reviewed to collect relevant information for patients with craniomaxillofacial FD between Jan.1994 and Dec.2009. All included cases were further analyzed with regard to associated epidemiological and clinicopathological variables.ResultsA total number of 266 cases with definitive diagnosis were identified with 219 primary cases and 47 recurrent cases. There were 111 males and 155 females with a male to female ratio of 0.716:1. They were clinically categorized into three groups: monostotic (71.1%), polysotic (27.4%) and Albright syndrome (1.5%). Maxilla alone or with adjacent bones was the most common affected site. The serum alkaline phosphatase (ALP) in patients was much higher than that in healthy control, whereas comparable between primary patients and recurrent ones. Three patients (3/266, 1.1%) with polysotic lesions underwent spontaneous malignant transformation into osteosarcoma. The majority of patients underwent conservative surgery, while the others received radical resection with or without reconstruction.ConclusionsCraniomaxillofacial FD is a rare bony disorder with defined epidemiological and clinicopathological features in Chinese population. Further investigations are warranted to establish the optimized timing, treatment strategy and prognostic prediction for this clinical entity.

Facial reconstruction with vascularised serratus anterior muscle flap in patients with Parry–Romberg syndrome

OBJECTIVEnParry-Romberg syndrome, popularly known as progressive hemifacial atrophy, is a rare and complicated craniofacial deformity characterized by idiopathic and progressive atrophy of patients face with compromised facial aesthetics and functions. In the present study, we performed a retrospective review on the vascularised serratus anterior muscle flap transfer for the treatment of the hemifacial atrophy in 4 consecutive Chinese patients with Parry-Romberg syndrome.nnnMETHODSnThe serratus anterior muscle flaps were harvested and transferred to correct the facial defects together with simultaneous nerve anastomosis between the long thoracic nerve and the ipsilateral cervical branch of facial nerve in the patients with Parry-Romberg syndrome. The postoperative results from patients own perception of improvement of facial profile and symmetry were also evaluated.nnnRESULTSnIn this patient series, both of the vessels and nerves of all flaps were anastomosed successfully in the recipient facial regions without any microvascular failures. Satisfactory facial contour and favorable symmetry were achieved with minimal donor-site morbidity, complications, recurrence and little resorption in surgical reconstruction of hemifacial atrophy during our follow-up period.nnnCONCLUSIONSnOur results suggested that vascularised serratus anterior muscle flap transfer combined with simultaneous nerve anastomosis is a reliable and effective treatment of choice that offers satisfactory results in the surgical correction of facial atrophy associated with Parry-Romberg syndrome.

Distraction osteogenesis after irradiation in rabbit mandibles.

The aim of this study was to investigate the influence of irradiation on the formation of bone after distraction osteogenesis in rabbit mandibles. Sixteen rabbits were randomly divided into 3 groups: one was given 50Gy (n=6), one was given 60Gy (n=6), and one acted as a control group (n=4). One month after irradiation, the distractors were inserted. The control group was not irradiated. After a latency period of 8 days, distraction was activated at a rate of 0.4mm twice a day. The mandibles were harvested 6 weeks after consolidation. The specimens and histological examination showed good formation of bone. Histological slides stained with haematoxylin and eosin confirmed that the regeneration was bone. The bony trabeculae of the control group were much better than those of the irradiated groups. However, the nuclei of osteocytes were round and the osteoblasts around the trabeculae were columnar or cubic in shape in the irradiated groups. Osteoid was present in the dense fibrous connective tissue. There were significant differences in the surface:volume ratio of areas of bony trabeculae between the control and both experimental groups (p=0.010 and p=0.001), but there was no significant difference between the 50Gy and 60Gy groups. The results suggested that preoperative radiation prevented optimal regeneration of bone. However, the microscopic appearance of osteocytes and osteoblasts and the osteoid in the dense fibrous connective tissue in both irradiated groups showed that osteogenesis was still active and in progress. These findings may indicate that bone formation had only been delayed. The evidence was similar for both 50Gy and 60Gy.