Takamitsu Mano

Usefulness as guided bone regeneration membrane of the alginate membrane

Alginate membrane is a new bioabsorbable, guided bone regeneration (GBR) membrane, which is placed directly on the surface of the bone defect. It is designed to drop a calcium chloride aqueous solution into the bone defect, which is filled with sodium alginate aqueous solution. Alginate membrane is an excellent agent for this procedure due to its close assimilation to the surface of the bone. In this study, we evaluated the short-term biocompatibility of alginate membrane in the bone defects of rat tibiae. GBR membrane availability was also examined. Consequently, we found that the healing process in bone defects covered with an alginate membrane was delayed in comparison with that of controls, however, the defect was restored to nearly original condition. In contrast, in the controls, bone defect repairs exhibited partitioning as a result of connective tissue involvement. Furthermore, we observed a relation between the sodium alginate concentration and the rate of absorption of the sodium alginate membrane. Absorption of a 1.5% sodium alginate membrane was slow. As a result, the compound was not absorbed completely and bone repairs resembled an hourglass. Moreover, the inflammatory response was absent surrounding the alginate membrane. The present findings suggested that the alginate membrane functions effectively as a GBR membrane. In addition, the alginate membrane derived from 3% calcium chloride and 1% sodium alginate was most suitable as a GBR membrane.

Self-setting barrier membrane for guided tissue regeneration method: Initial evaluation of alginate membrane made with sodium alginate and calcium chloride aqueous solutions

Alginate membrane was proposed as a self-setting barrier membrane that can be used for guided tissue regeneration (GTR). The alginate membrane can be prepared and placed at the bone defect during the surgical procedure. The procedure consists of two simple steps. First, the bone defect is filled with sodium alginate (Na-Alg) aqueous solution. Then calcium chloride aqueous solution is dropped on the surface of the Na-Alg aqueous solution. An alginate membrane is formed on the bone defect, keeping the inside of the bone defect filled with unreacted Na-Alg aqueous solution. In this investigation, a preliminary animal study was conducted for an initial evaluation as to whether or not the alginate membrane can be used as a barrier membrane for the GTR method. Bone defects were made in the tibiae of 15-week-old rats. The alginate membrane was made on the surface of existing bone by filling the defect with Na-Alg aqueous solution and then dropping calcium chloride aqueous solution onto the surface of the Na-Alg solution. Four weeks after surgery, the bone defect was found to be reconstructed with new bone when the defect had been covered with alginate membrane whereas the bone defect was filled only with connective tissue when it had been kept open. We concluded, therefore, that this alginate membrane may be a useful barrier membrane when the GTR method is employed.

Initial tissue response to a titanium implant coated with apatite at room temperature using a blast coating method.

We previously reported a blast coating method (BC method) as a new coating method of titanium (Ti) with apatite (AP) at room temperature. The BC method gives much stronger AP coating on the Ti surface compared with those obtained by other room temperature coating methods. However, no in vivo study has been made, so far, to evaluate the stability or the tissue response to the implant. As an initial step to evaluate the feasibility of the BC method, we evaluated the tissue response and stability of AP coated Ti implant prepared with the BC method (AP-BC implant) using rats as experimental animals. The AP coating adhered tightly to the Ti surface even after the implant procedure and throughout the experimental period up to six weeks post operation. AP-BC implant caused no inflammatory response, showed strong bone response and much better osteoconductivity compared with the pure Ti implant. The new bone formed on the surface of AP-BC implants was thinner compared with that formed on the surface of Ti implant. Therefore, the AP-BC implant has a good potential as an osteoconductive implant material.

Initial tissue response to anti-washout apatite cement in the rat palatal region: Comparison with conventional apatite cement

Initial tissue response to anti-washout apatite cement (aw-AC) in the palatal region was studied. Conventional apatite cement (c-AC) was employed as a control material. Bone defects generated in the rat palatal region, where complete hemostasis is difficult to effect, were filled with both cement types and examined histologically for up to 8 weeks. At 1-week postfilling, a portion of the c-AC had washed out, resulting in slight inflammation and severe foreign-body response. The degree of foreign-body response to c-AC was reduced over time; however, foreign-body response continued to be in evidence 8 weeks after surgery. As a result, poor bone formation was observed in the case of c-AC at 8 weeks post-surgery. In contrast, aw-AC set well, maintained its shape at implantation, and caused little foreign-body response. Osteoblasts were observed at 2 weeks following surgery. Moreover, the bone defect was completely covered with new bone at 8 weeks post-surgery. This observation suggests that aw-AC may be used without complication in cases where complete hemostasis is difficult to achieve, that is, where the use of c-AC is contraindicated.

Loss of 3p26.3 is an independent prognostic factor in patients with oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignancy worldwide and the prognosis for patients with advanced-stage OSCC is particularly poor. To identify DNA copy number aberrations and candidate genes associated with a poor or favorable outcome, we analyzed the genome profiles of OSCC tumors by array-based comparative genomic hybrid-ization (A-CGH). This technique uses DNA microarray technology to detect genomic copy number variations at a higher resolution level than chromosome-based CGH. Fifty patients with primary OSCCs were included in the study. Of these 50 patients, 37 were treated surgically and 13 were treated without surgery and had received irradiation and/or chemotherapy. All samples were analyzed by A-CGH. Gains were detected frequently (>50%) at chromosomal regions 5p15.33, 7p22.3, 8q21.1-24.3, 9q34.3, 11q13, 16p13.3 and 20q13.3. Losses were frequently detected at 3p22, 3p14 and 4q35.2. High-level gains were recurrently (>10%) detected at each of 5p15, 7p22, 7p11, 8q24, 11q13, 11q22 and 22q11. Gains of 2p25.1, 11p15, 16p13.3, 16q24.3 and 20q13.3 were inversely correlated with nodal metastasis. In 37 of the 50 OSCC patients treated with surgery, gains of 8q12.1-24.22 and losses of 3p26.2-3 were associated with disease-specific survival (p<0.01). Loss of a 0.2 Mb chromosomal region in 3p26.3 was associated with a poor prognostic outcome in the Kaplan-Meier analysis (p<0.01 by the log-rank test). Multivariate analysis revealed that loss of 3p26.3 is an independent prognostic factor (p<0.01) of OSCC. Loss of a 0.2 Mb chromosomal region in 3p26.3 including the CHL1 (cell adhesion molecule with homology to L1CAM1) gene was identified as a novel potential marker for predicting the prognosis of patients with OSCC.

Screening for DNA copy number aberrations in mucinous adenocarcinoma arising from the minor salivary gland: two case reports.

Mucinous adenocarcinoma (MAC) is a rare malignancy in the minor salivary gland. To our knowledge, genomic alterations in this tumor have not been reported previously. To identify DNA copy number aberrations, we applied comparative genomic hybridization (CGH) to four samples of MAC in minor salivary gland derived from two patients: a primary tumor and two cervical metastatic lymph nodes from one patient, and a primary tumor from the other patient. Copy number increases were commonly detected in 1q21∼q31 and 20q13, and these may play an important role in MAC carcinogenesis. Copy number increases in 1q, 12p, 12q, and 20q were commonly detected in all three samples derived from patient 1, and gain of 7p and loss of chromosome 4 were additionally detected in the two samples derived from metastatic lymph nodes. Amplifications were also detected in the chromosomal regions 8q22∼qter, 12p11∼p12, 12q11∼q21, and 20q13. Amplification of MDM2 (12q15) and of AURKA (20q13) was detected with fluorescence in situ hybridization. The DNA copy number aberrations detected in MAC in minor salivary glands were different from those reported for colorectal MAC. The present findings are novel in identifying genomic alterations of MAC arising from the minor salivary gland.

Central Adenoid Cystic Carcinoma of the Mandible With Multiple Bone Metastases: Case Report

ndodontic or restorative procedure. In addition, postperative tooth hypersensitivity induced by the odonectomy should be taken into consideration as a potenial complication. This case report describes a novel pproach to the extraction of horizontally impacted andibular third molars that have a high risk of IAN aresthesia. This staged approach may be promising, nd further investigations may be warranted to evaluate ts efficacy in a large sample of patients.

Relationships between Airway Morphology and Sleep Breathing Indices in Jaw Deformity Patients

Purpose: The purpose of this study was to clarify how sleep breathing indices and airway morphology vary according to skeletal classification and the relationships between airway morphology and sleep breathing indices. Method: Forty-four non-syndromic female Japanese patients, who were diagnosed with jaw deformities and underwent surgical orthodontic treatment were enrolled in this study. Using the Alice 5 diagnostic sleep system (Philips Respironics; Murrysville, PA), the apnea hypopnea index (AHI), apnea index (AI), and 4% oxygen desaturation index (4%ODI) were evaluated in each patient before they underwent orthognathic surgery. The following dimensions were measured on 2D CT images: the cross-sectional area at the level of the hard palate (HP), the cross-sectional area at the top of the uvula (TU), the cross-sectional area at the base of the tongue (BE). The following volumes were measured on 3D CT images: the volume of the upper airway (total volume), the volume of the region between the level of the hard palate and the top of the uvula (HP- TU volume), the volume of the region between the top of the uvula and the base of the epiglottis (TP-BE volume). Result: There were no significant differences in airway morphology or sleep breathing indices among the three groups. Negative correlations were detected between HP-TU volume and 4%ODI, and between the HP area and AHI (p<0.05). Conclusion: Our results establish that upper airway morphology also has important effects on the nocturnal breathing of jaw deformity patients.

Appearance of cell-adhesion factor in osteoblast proliferation and differentiation of apatite coating titanium by blast coating method

We have already reported that the apatite coating of titanium by the blast coating (BC) method could show a higher rate of bone contact from the early stages in vivo, when compared to the pure titanium (Ti) and the apatite coating of titanium by the flame spraying (FS) method. However, the detailed mechanism by which BC resulted in satisfactory bone contact is still unknown. In the present study, we investigated the importance of various factors including cell adhesion factor in osteoblast proliferation and differentiation that could affect the osteoconductivity of the BC disks. Cell proliferation assay revealed that Saos-2 could grow fastest on BC disks, and that a spectrophotometric method using a LabAssayTM ALP kit showed that ALP activity was increased in cells on BC disks compared to Ti disks and FS disks. In addition, higher expression of E-cadherin and Fibronectin was observed in cells on BC disks than Ti disks and FS disks by relative qPCR as well as Western blotting. These results suggested that the expression of cell-adhesion factors, proliferation and differentiation of osteoblast might be enhanced on BC disks, which might result higher osteoconductivity.

Different therapeutic mechanisms of rigid and semi-rigid mandibular repositioning devices in obstructive sleep apnea syndrome

To clarify the mechanisms of rigid and semi-rigid mandibular repositioning devices (MRDs) in obstructive sleep apnea syndrome (OSAS), seven and 13 patients received rigid and semi-rigid MRDs, respectively. Each patient underwent polysomnographic and computed tomographic examinations at the initial consultation and after symptom improvement. Three-dimensional models of the upper airway (hard palate level to epiglottic base) were reconstructed by image processing software (Mimics version 14.2) to measure airway morphology. The mean age and body mass index were 58.1 years and 24.8 kg/m(2), respectively, in the rigid MRD group and 57.9 years and 23.2 kg/m(2), respectively, in the semi-rigid MRD group. The apnea-hypopnea index significantly improved (P < 0.05, Wilcoxon signed-rank test) from 22.0 to 8.9 and 20.5 to 11.5 events per hour of sleep in the respective groups. The cross-sectional areas measured at the epiglottic tip (from 2.0 to 2.6 cm(2)) and hard palate (from 2.6 to 3.3 cm(2)) levels also increased in the respective groups (P < 0.05). However, airway volume, cross-sectional area measured at the uvular tip level, and anteroposterior and transverse diameters of the airway were not significantly different. In conclusion, both types of MRDs improve respiratory status, but they affect different parts of the airway.