Long-standing temporomandibular joint dislocation treated by intraoral condylectomy: a case report and review of the literature.

BACKGROUND: Noninvasive management by closed reduction is a desirable treatment for temporomandibular joint dislocation. However, reduction of long-standing temporomandibular joint dislocation is often difficult. Various conservative treatments have been attempted, but these often render poor outcomes. This article reports the case of long-standing temporomandibular joint dislocation that was successfully closed using intraoral condylectomy. CASE PRESENTATION: A 69-year-old Japanese man who sustained an injury in a car collision was unable to close his mouth. Owing to the diagnosis of long-standing temporomandibular joint dislocation, intraoral condylectomy was performed. In the case of temporomandibular joint dislocation, it is convenient to reach the condyle from the oral cavity because sufficient opening is maintained. The condyle can be clearly visualized using an approach similar to sagittal split ramus osteotomy, and the operation using surgical instruments can be facilitated by resecting the coronoid process. By separating the surrounding soft tissue and pulling the cut condyle with sufficient visual field, the condyle can be resected while addressing the hemostasis. During the 12-month postoperative follow-up period, no temporomandibular joint dislocation recurred and the occlusion remained stable. CONCLUSIONS: The limited intraoral incision of this surgical technique provides sufficient access for condylectomy. The results of this case report suggest that condylectomy by intraoral approach could become the treatment of choice for long-standing temporomandibular joint dislocation.

Melatonin­induced miR­181c­5p enhances osteogenic differentiation and mineralization of human jawbone­derived osteoblastic cells.

Our previous study revealed that treatment with a combination of fibroblast growth factor­2 and melatonin (MEL) synergistically augmented osteogenic activity and mineralization of MC3T3­E1 mouse preosteoblast cells. Thus, the objective of the present study was to assess the effect of MEL on osteogenetic characteristics in human osteoblastic cells. Human jawbone­derived osteoblastic (hOB) cells were isolated from mandibular bone fragments. RUNX family transcription factor 2 (Runx2) expression, alkaline phosphatase (ALP) enzyme activity and the mineralization ability of hOB cells in the presence of MEL were evaluated. Microarray analysis was also performed to assess the expression of MEL­induced microRNAs (miRNAs/miRs) in hOB cells. Treatment with MEL significantly enhanced Runx2 expression, ALP activity and mineralization staining. However, this effect was significantly reduced following transforming growth factor­ß1 treatment. In total, 124 miRNAs were differentially expressed in MEL­treated hOB cells, compared with untreated cells. Of the upregulated miRNAs, miR­181c­5p exhibited the largest fold change. Runx2 mRNA expression and mineralization staining in the presence of MEL were significantly reduced following transfection with a miR­181c­5p inhibitor. In addition, transfection with miR-181c-5p mimics significantly increased Runx2 expression and mineralization staining. These results suggested that MEL­induced miR­181c­5p was involved in osteogenic differentiation and mineralization of hOB cells. Using TargetScan, a putative miR­181c­5p binding site was identified in the Notch2 gene. Moreover, Notch2 mRNA and protein expression levels in hOB cells were significantly reduced following transfection with miR­181c­5p mimics, confirming Notch2 as a target gene for miR­181c­5p. Notch2 siRNA knockdown significantly increased Runx2 expression and mineralization staining, which suggested that Notch2 may negatively regulate osteogenic differentiation of hOB cells by downregulating Runx2. In conclusion, MEL­induced expression of miR­181c­5p enhanced osteogenic differentiation and calcification of hOB cells.

Morphological Evaluation of Bone by CT to Determine Primary Stability-Clinical Study.

BACKGROUND: Primary stability is an important prognostic factor for dental implant therapy. In the present study, we evaluate the relationship between implant stability evaluation findings by the use of an implant stability quotient (ISQ), an index for primary stability, and a morphological evaluation of bone by preoperative computed tomography (CT). SUBJECTS AND METHODS: We analyzed 98 patients who underwent implant placement surgery in this retrospective study. For all 247 implants, the correlations of the ISQ value with cortical bone thickness, cortical bone CT value, cancellous bone CT value, insertion torque value, implant diameter, and implant length were examined. RESULTS: 1. Factors affecting ISQ values in all cases: It was revealed that there were significant associations between the cortical bone thickness and cancellous bone CT values with ISQ by multiple regression analysis. 2. It was revealed that there was a significant correlation between cortical bone thickness and cancellous bone CT values with ISQ by multiple regression analysis in the upper jaw. 3. It was indicated that there was a significant association between cortical bone thickness and implant diameter with ISQ by multiple regression analysis in the lower jaw. CONCLUSION: We concluded that analysis of the correlation of the ISQ value with cortical bone thickness and values obtained in preoperative CT imaging were useful preoperative evaluations for obtaining implant stability.

Application of interconnected porous hydroxyapatite ceramic block for onlay block bone grafting in implant treatment: A case report.

Autogenous block bone grafting as treatment for alveolar ridge atrophy has various disadvantages, including a limited availability of sufficiently sized and shaped grafts, donor site morbidity and resorption of the grafted bone. As a result, interconnected porous hydroxyapatite ceramic (IP-CHA) materials with high porosity have been developed and used successfully in orthopedic cases. To the best of the author's knowledge, this is the first report of clinical application of an IP-CHA block for onlay grafting for implant treatment in a patient with horizontal alveolar atrophy. The present study performed onlay block grafting using an IP-CHA block to restore bone volume for implant placement in the alveolar ridge area without collecting autogenous bone. Dental X-ray findings revealed that the border of the IP-CHA block became increasingly vague over the 3-year period, whereas CT scanning revealed that the gap between the block and bone had a smooth transition, indicating that IP-CHA improved the process of integration with host bone. In follow-up examinations over a period of 5 years, the implants and superstructures had no problems. An IP-CHA block may be useful as a substitute for onlay block bone grafting in implant treatment.

Preoperative oral health care reduces postoperative inflammation and complications in oral cancer patients.

The records of 70 patients with oral cancer who were treated at a single institution between 2008 and 2014 were reviewed. The body temperature, white blood cell count, and C-reactive protein (CRP) levels were compared between those who had received preoperative oral care (oral care group) and those who had not received any (non-oral care group). When the patients were divided into those who underwent minimally invasive surgery and those who underwent severely invasive surgery, the mean CRP level in the early postoperative period was lower in the oral care group as compared with the non-oral care group in those who underwent minimally invasive surgery as well as those who underwent severely invasive surgery. However, the mean CRP level was most evidently reduced in the severely invasive group on days 1 and 3-5. However, no significant differences were observed with regard to the percentage of postoperative infectious complications (for example, surgical site infection, anastomotic leak and pneumonia) between the oral care (13.6%) and non-oral care (20.8%) groups, though a reduced prevalence of postoperative complications following preoperative oral care was noted. The results of the present study suggest that preoperative oral care can decrease inflammation during the early postoperative stage in patients with oral cancer who undergo severely invasive surgery.

Effects of Apatite Cement Containing Atelocollagen on Attachment to and Proliferation and Differentiation of MC3T3-E1 Osteoblastic Cells.

To improve the osteoconductivity of apatite cement (AC) for reconstruction of bone defects after oral maxillofacial surgery, we previously fabricated AC containing atelocollagen (AC(ate)). In the present study, we examined the initial attachment, proliferation and differentiation of mouse osteoblastic cells (MC3T3-E1 cells) on the surface of conventional AC (c-AC), AC(ate) and a plastic cell dish. The number of osteoblastic cells showing initial attachment to AC(ate) was greater than those attached to c-AC and similar to the number attached to the plastic cell wells. We also found that osteoblastic cells were well spread and increased their number on AC(ate) in comparison with c-AC and the wells without specimens, while the amount of procollagen type I carboxy-terminal peptide (PIPC) produced in osteoblastic cells after three days on AC(ate) was greater as compared to the others. There was no significant difference in regard to alkaline phosphatase (ALP) activity and osteocalcin production by osteoblastic cells among the three surface types after three and six days. However, after 12 days, ALP activity and the produced osteocalcin were greater with AC(ate). In conclusion, AC(ate) may be a useful material with high osteoconductivity for reconstruction of bone defects after oral maxillofacial surgery.

Bone formation and osseointegration with titanium implant using granular- and block-type porous hydroxyapatite ceramics (IP-CHA).

The aim of the present study was to examine whether interconnected porous hydroxyapatite ceramics (IP-CHA) could be used as bone substitute for implant treatment in reconstructive surgery. We firstly assessed if surround of the titanium surface placed into granular or block-type IP-CHA can observe new bone formation in a rabbit bone defect model. Subsequently, osseointegration and stability of titanium implant inserted into block-type IP-CHA was investigated in a rabbit onlay graft model. Direct contact between new bone and the surface of the titanium in granular- or block-type IP-CHA was found in a rabbit bone defect. Further, new bone formation was found in direct contact with the implant surface in the block-type IP-CHA in an onlay graft model, and the implant stability quotient (ISQ) values were significantly increased after surgery. Therefore, IP-CHA may be a useful material for implant treatment in reconstructive surgery strategies.

Risk of bacterial contamination of bone harvesting devices used for autogenous bone graft in implant surgery.

BACKGROUND: Various instruments have been developed for collecting bone debris during intraoral autogenous bone graft procedures in implant surgery. The aim of this study was to quantitatively determine the degree of contamination in bone debris collected by different devices. METHODS: Twelve patients underwent autogenous bone collection using a bone chisel, bone scraper, trephine drill, and bone filter during bone augmentation surgery as a part of implant therapy, and the total bacterial count in bone debris collected by each was determined. RESULTS: Following anaerobic incubation, bacterial colony formation was found in all of the samples. The mean colony forming units (CFU)/g in samples collected by the trephine drill was found to be significantly lower than that of samples obtained with the other devices, while those values for samples collected by the bone scraper and bone filter was significantly higher as compared to the bone chisel and trephine drill. CONCLUSION: The bacterial levels may still carry the infection risk. Thus prophylactic antibiotic therapy maybe indicated when using bone particles for intraoral augmentation procedures.

3-dimensional composite scaffolds consisting of apatite-PLGA-atelocollagen for bone tissue engineering.

We fabricated 3-dimensional scaffolds consisting of biodegradable poly(D, L-lactide-co-glycolic acid)(PLGA)(75/25) with hydroxyapatite particles containing atelocollagen (aAC). The aim of this study was to evaluate this new type of scaffold in regard to its basic properties and biocompatibility. Characterization of the obtained scaffolds was performed to know the porosity, shrinkage, diametral tensile strength, and biocompatibility. Composite scaffolds made of PLGA with hydroxyapatite particles containing atelocollagen (PL-aAC) showed a greater strength and stability than PLGA scaffolds. PL-aAC also exhibited superior performance in terms of cell attachment and proliferation as compared to PLGA, while histological findings showed that PL-aAC had an excellent response toward soft tissues. Our results strongly suggest that PL-aAC is more useful for cell transplantation as compared to PLGA for bone tissue engineering.