Effect of micro/nanoscaled Ti phosphate/Ti oxide hybrid coating on the osseointegration of Ti implants.

OBJECTIVES: This study was performed to fabricate a bionic coating with titanium (Ti) phosphate to promote the osseointegration of Ti substrate implants. METHODS: Phosphorylated micro/nanocoating was prepared on the surface of pure titanium (i.e., TiP-Ti) by hydrothermal process under special pressure, and the untreated smooth pure titanium (cp-Ti) was selected as the control. To evaluate the characteristics of the coating surface, scanning electron microscopy, X-ray diffraction, atomic force microscopy, and contact-angle measurement were performed. In addition, the effects of TiP-Ti on the proliferation, adhesion, and differentiation of rat bone marrow mesenchymal stem cells (BMSCs) were investigated by using in vitro cytology. Finally, TiP-Ti implants were implanted into the rat tibia, and the effect of TiP-Ti on the osseointegration in the host was evaluated after 12 weeks. RESULTS: The TiP-Ti surface presented a bionic structure with coexisting nanoscale 3D spatial structure and microscale pores. In vitro experiments showed that the BMSCs had enhanced adhesion, proliferation, and osteogenic differentiation on the TiP-Ti surface. Furthermore, in vivo, TiP-Ti showed considerably stronger osseointegration compared with pure titanium, and the ultimate shear strength and maximum pushing force were significantly improved. CONCLUSIONS: A bionic structure with TiP-Ti micro/nanoscale coating was successfully fabricated, indicating a promising method for modifying the surface of implants.

Comprehensive correction of maxillofacial bone deformity-consideration and combined application of orthognathic surgery and facial contouring surgery.

The maxillofacial skeleton is the basis of the contour of the face. Orthognathic surgery and facial contouring surgery change jaw tissue and affect facial appearance in different manners. Orthognathic surgery is the main method to correct dental and maxillofacial deformities. It changes the shape of the jaw and improves the occlusal relationship by changing the three-dimensional position of the jaw. Facial contouring surgery mainly adopts the method of "bone reduction", which changes the "amount"of the jawbone by cutting a part of the bone tissue to improve the facial appearance, generally without changing oral function. The combined use of orthognathic surgery and facial contouring surgery is becoming increasingly common in clinical practice. This also requires oral and maxillofacial surgeons to have a holistic consideration of the comprehensive correction of maxillofacial bone deformity, and to perform comprehensive analysis of jaw deformities and jaw plastic surgery to achieve the most ideal results. The author's team has been engaged in the clinical work of orthognathic surgery and facial contouring surgery and accumulated rich clinical experience in the comprehensive correction of maxillofacial bone deformity. In this article, the indications, treatment goals, treatment modes, treatment methods, and key points in the surgical operations of comprehensive maxillofacial bone surgery were summarized.

[Oral treatment for obstructive sleep apnea syndrome].

Obstructive sleep apnea syndrome (OSAS) is a common clinical disease with high incidence and low treating proportion, difficult evaluation, and complicated nosogenesis. OSAS can cause systematic impairments. Various treatment methods were applied in clinical setting with the tendency of cross-disciplinary promotion. Oral treatment plays an exceedingly important role in OSAS research and therapy. This study reports the oral treatment involving OSAS therapy.

Effect of early intra-articular injection of alendronate in reducing subchondral bone loss in rat mandibular condyle after ovariectomy / 口腔疾病防治

Objective @#To investigate the effects of intra-articular injection of alendronate on the mandibular condyle in ovariectomized rats.@*Methods @#Sixty female rats were randomly divided into five groups: ovariectomy with vehicle treatment alone, early alendronate treatment at ovariectomy, late alendronate treatment at 4 weeks after ovariectomy, shamoperation with vehicle treatment, and the normal control rats. The changes in subchondral bone were evaluated by micro-computed tomography (Micro-CT), tartrate-resistant acid phosphatase (TRAP) staining and real-time quantitative polymerase chain reaction (RT-PCR). @*Results @# Compared with late alendronate treatment, early alendronate treatment improved microstructural properties of the subchondral bone, with higher bone volume ratio (46.4 + 2.5 vs 37.5 + 2.1; P= 0.038), increased trabecular thickness (47.3 + 1.7 vs 34.6 + 1.4; P = 0.029), elevated trabecular number (8.5 + 0.6 vs 6.2 + 0.3; P = 0.041) and lower trabecular separation (30.2 + 1.6 vs 37.7 + 2.6; P = 0.034). Fewer TRAP-positive cells (4.2 + 0.2 vs 6.8 + 0.4; P = 0.019) and a higher OPG/RANKL ratio (0.38 + 0.01 vs 0.25 + 0.03; P = 0.043) in the subchondral bone were observed in the animals with early treatment group compared to late treatment or ovariectomy/vehicle treatment group. @*Conclusion @#Our results suggest the therapeutic potential of intra-articular alendronate injection in the treatment of osteoporosis-associated temporomandibular disorders.

Expression of Notch signaling pathway in temporomandibular osteoarthritis / 口腔疾病防治

Objective@# To investigate the expression of Notch signaling molecules in temporomandibular joint arthritis (TMJOA), and to explore the role and mechanism of Notch signaling pathway in the development and progression of TMJOA. @*Methods @#72 Kunming mice were randomly divided into experimental group, sham-surgery group and normal group. In experimental group, discs on the right TMJ were subjected to total discectomy, sham-operation group underwent the same procedure without disc removal, while normal group serve as blank control. All the left temporomandibular joint discs were not treated. 8 mice in each group were sacrificed respectively at 1 week, 2 week, 4 week after surgery. Histological examinations were performed to assess success of TMJOA model, according to the pathological standard of osteoarthritis diagnosis. Immunochemistry techniques were performed in the successful TMJOA cartilages to evaluate the expression levels of Notch1 (NICD1), Jagged1, Hes1 and Hes5. The scores were evaluated by semi-quantitative method. @*Results @#Notch1 (NICD1), Jagged1 and Hes5 were activated in the experimental group with the expression levels increased dramatically over time. While Hes1 expression was suppressed at the beginning of osteoarthritis but was up-regulated afterwards.@*Conclusion @# Notch pathway-related molecular expression changed greatly in TMJOA model, indicating that the pathway in the occurrence and development of TMJOA plays an important role.

Correction of mandibular deficiency by inverted-L osteotomy of ramus and iliac crest bone grafting.

This study was to describe the use of inverted-L osteotomy of ramus and iliac bone graft for the management of mandibular deficiency in adult patients. From 2008 to 2010, 11 patients (aged 19 to 29 years) with mandibular deficiency underwent intraoral or extraoral inverted-L osteotomy of ramus and iliac crest bone grafting. Data were collected from the patients' records, photographs and radiographs. The height and width of the ramus were successfully expanded by inverted-L osteotomy and iliac crest bone grafting with minimal complications in all patients, resulting in significant improvement in occlusion and facial appearance. Our early results showed that the inverted-L osteotomy of ramus and iliac crest bone grafting is safe and effective, and should be considered as a good alternative for the patients with mandibular deficiency.

[Narrowing and sliding genioplasty procedure combined with mandibular outer cortex ostectomy technique to correct square jaw in short face].

OBJECTIVE: To evaluate the the feasibility and effectiveness of narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy technique to reshape a square jaw in short face. METHODS: From July 2005 to October 2009, a total of 57 patients received narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure to correct square jaw in short face. All the patients had standard frontal and lateral cephalometric radiographs, panoramic radiographs, and were photographed preoperatively and postoperatively to assess their face contour. The alteration of mandibular angle, mental contour and width of lower face was observed for 6 to 24 months postoperatively. Questionnaires were used to assess the patients' satisfactory. RESULTS: It showed that the postoperative lower face had narrowed and become softer, slender and oval, with a slick mental region. The final aesthetic outcomes were quite satisfactory in all cases from both the view of surgeons and patients. CONCLUSIONS: Narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure could efficiently adjust the shape and position of chin to obtain a good proportion of the lower face, and to change square and short face to slender oval one by single operation in accordance with the fashionable aesthetics in orientals.

[Correction of low angel-square jaw with mandibular "V-Line" ostectomy combined with mandibular outer cortex ostectomy].

OBJECTIVE: To evaluate the feasibility of mandibular "V-Line" osteotomy combined with mandibular outer cortex osteotomy for correction of low angle-square jaw. METHODS: From Jul. 2005 to Nov. 2007, 31 patients with low angle-square jaw were corrected with mandibular "V-Line" osteotomy combined with mandibular outer cortex osteotomy. The patients were followed up for 6-24 months. Pre- and Post-operative standard images and X-ray cephalometric examination were used to assess the therapeutic effect. RESULTS: The wounds were healed primarily in all the 31 cases with no severe complication. The lower labial numbness was happened in 13 cases, which was recovered within 4 months. All the patients achieved esthetic improvement at the frontal and lateral view. The mandibular angle and the mandibular plane angle reached 110 degrees - 120 degrees and 25 degrees - 30 degrees after operation. The distance between the angles was decreased. CONCLUSIONS: The low angle-square jaw can be corrected satisfactorily with mandibular "V-Line" osteotomy combined with mandibular outer cortex osteotomy.

Free grafting of autogenous coronoid process for condylar reconstruction in patients with temporomandibular joint ankylosis.

OBJECTIVE: This article describes the clinical effects of condylar reconstruction by free grafting of autogenous coronoid process in patients with temporomandibular joint (TMJ) ankylosis. STUDY DESIGN: Fifteen cases of uni- or bilateral TMJ ankylosis during a 3-year period from March 2004 to March 2007 were surgically treated, and the average observation period was 22 months. All patients were treated by condylar reconstruction of immediate autogenous coronoid process grafts. Temporal muscle myofascial flaps or native articular disc was used as an interpositional tissue. Clinical examination, radiographs, and photographs were used postoperatively to evaluate the grafts and TMJ function. RESULTS: Satisfactory mouth opening was achieved in 14 cases, and 1 patient showed signs of reankylosis of the joint (20 mm mouth opening). Radiographic examination showed that bone union occurred between the grafts and the ramus in all cases. Some bony resorption of the grafted coronoid process was observed in all patients, but no occlusal changes were noted. CONCLUSION: Satisfactory clinical outcomes are obtained after the condylar reconstruction by free grafting of autogenous coronoid process. Therefore, autogenous coronoid process may be a suitable bone resource for condylar reconstruction in patients with TMJ ankylosis.

Growth of the mandible after condylar reconstruction using transport distraction osteogenesis: an experimental investigation in goats.

BACKGROUND: Mandibular condyle damage during childhood disturbs mandibular growth and facial skeletal development. Transport distraction osteogenesis provides a new treatment for condyle reconstruction, but there are no data available on mandibular growth in growing individuals following surgery. The authors investigated the effect of condylar reconstruction by transport distraction osteogenesis on mandibular growth in goats. METHODS: A condylar defect was created unilaterally in 44 growing goats. The animals were divided randomly into group A (n = 22) and group B (n = 22). Transport distraction was used to reconstruct the condyles in group A, whereas group B served as sham controls. Three-dimensional computed tomographic imaging was performed at different intervals. Ten animals from each group were used for mandibular growth measurements at 48 weeks after the end of distraction. Four animals from each group were euthanized at 12, 24, and 48 weeks after surgery. Their transport disks were harvested and processed for histologic evaluation. RESULTS: In group A, the hemimandible of the distracted side exhibited similarities to the contralateral side except for the larger neocondyles. In group B, ramus height and width were significantly shorter on the undistracted side than on the contralateral side; concomitantly, there was mandibular deviation to the operated side. Well-organized fibrocartilage was seen at the neocondylar surface over time in group A but not in group B. CONCLUSIONS: This study suggests that a neocondyle reconstructed by means of transport distraction has the potential to grow under functional stimuli of the temporomandibular joint. Therefore, this technique may serve as an alternative method for condylar reconstruction in growing individuals.

[Study of reconstruction of mandibular condyle by transport distraction osteogenesis in monkeys].

OBJECTIVE: To evaluate the applicability and effectiveness of reconstruction of mandibular condyle by transport distraction osteogenesis in an animal model of rhesus monkeys. METHODS: Six adult rhesus monkeys were used in this study. Bilateral condyles and articular discs were extirpated, and the technique of transport distraction osteogenesis was performed to reconstruct the condyle. X-ray and CT scanning films were taken at various intervals. Two monkeys selected at random were sacrificed respectively at 4, 12 and 24 weeks after completion of distraction, and the newly formed condyles resulted from bony transport disc were harvested and processed for histologic examination. The removed condyles at surgery were used as normal control and prepared in the same manner. RESULTS: Open bite was seen in all animals postoperatively, and disappeared at the end of distraction. The shape and appearance of the bony transport disc was similar to original condyles at sacrifice. The articular cavity was filled with fibrous connective tissue and considerable cartilage cells were observed in the surface of the condyle stump. Bone regeneration was perfect in the distraction gap. CONCLUSION: A neocondyle with functional shape can be created by transport distraction osteogenesis, which suggested that this technique might be an alternative method in reconstruction of the condyle.

Autogenous coronoid process as a new donor source for reconstruction of mandibular condyle: an experimental study on goats.

OBJECTIVE: To evaluate the feasibility and effectiveness of autogenous coronoid process grafts for reconstruction of the mandibular condyle. STUDY DESIGN: Two groups of 9 goats each were used. Each animal underwent unilateral total condyle and disk removal and was treated by grafting an autogeneous coronoid process. The animals in group A were sacrificed at 4, 12, and 24 weeks after surgical procedure, and their grafted coronoid processes were harvested for histological observation. All animals in group B received 3-dimensional CT scanning examination at different times and were sacrificed at 24 weeks after surgical procedure. The items of ramus height (RH), transverse dimension of the condyle (CT), and posteroanterior dimension of the condyle (CP) were measured for comparison with the operated and nonoperated sides. RESULTS: Despite the differences in the measurements of RH, CT, and CP between the operated and nonoperated sides, the grafted coronoid process had a similar shape and histological structures to the normal condyle at 24 weeks after surgical procedure. The head of the neocondyle was covered by a cap of fibrous tissue, which might play the role of the articular disc. CONCLUSIONS: Under the mechanical stimuli of the temporomandibular joint site, the grafted coronoid process could gradually remodel to a neocondyle with functional shape and structure in goats. This animal study suggests that autogenous coronoid process could be considered as a new donor source for reconstruction of the mandibular condyle.

[Quantitative histomorphometric observation of distraction osteogenesis during mandibular lengthening].

PURPOSE: To evaluate the regenerating bone during mandibular distraction osteogenesis by bone histomorphometry combining tetracycline bone labeling fluorescence microscopy. METHODS: Osteotomy was performed on bilateral mandibles in ten goats. A custom-made distractor was applied to lengthen the mandible at a rate of 1 mm/d (0.5 mm/12 hrs) for ten days. Every two animals were sacrificed at 10 d, 15 d, 25 d, 35 d and 45 d postoperatively. Two additional goats were used as normal control. The bony specimens were collected and prepared for bone histomorphometry and tetracycline bone labeling fluorescence microscopy with analysis of variance. RESULTS: From 10 days subgroup to 45 days subgroup, bone volume fraction,trabecular thickness,trabecular number and volume density were gradually increased (P<0.05), while trabecular separation distance and surface density were gradually decreased (P<0.05). Between 15 days subgroup and 45 days subgroup,the index of osteoblast was significantly higher than normal control (P<0.05) and index of osteoclast was increased gradually (P<0.05). Compared with normal control, bone formation rate was accelerated by thousand times between 15 days subgroup and 45 days subgroup (P<0.05). CONCLUSIONS: During the process of mandibular distraction osteogenesis, the bone formation is active, the newly formed bone trabecula gradually become mature, and the remodeling activities of regenerated bone are enhanced gradually. The rate of bone formation within distraction period is faster than consolidation period.