Clinical Study of 14 Cases of Bone Augmentation with Selective Laser Melting Titanium Mesh Plates.

Additive manufacturing techniques are being used in the medical field. Orthopedic hip prostheses and denture bases are designed and fabricated based on the patient's computer-aided design (CAD) data. We attempted to incorporate this technique into dental implant bone augmentation. Surgical simulation was performed using patient data. Fourteen patients underwent bone augmentation using a selective laser melting (SLM) titanium mesh plate. The results showed no evidence of infection in any of the 14 patients. In 12 patients, only one fixation screw was used, and good results were obtained. The SLM titanium mesh plate was good adaptation in all cases, with bone occupancy greater than 90%. The average bone resorption of the marginal alveolar bone from the time of dental implant placement to the time of the superstructure placement was 0.69 ± 0.25 mm. Implant superstructures were placed in all cases, and bone augmentation with SLM titanium mesh plates was considered a useful technique.

Histological comparison of three apatitic bone substitutes with different carbonate contents in alveolar bone defects in a beagle mandible with simultaneous implant installation.

Since bone apatite is a carbonate apatite containing carbonate in an apatitic structure, carbonate content may be one of the factors governing the osteoconductivity of apatitic bone substitutes. The aim of this study was to evaluate the effects of carbonate content on the osteoconductivity of apatitic bone substitutes using three commercially available bone substitutes for the reconstruction of alveolar bone defects of a beagle mandible with simultaneous dental implant installation. NEOBONE, Bio-Oss, and Cytrans that contain 0.1, 5.5, and 12.0 mass% of carbonate, respectively, were used in this study. The amount of newly formed bone in the upper portion of the alveolar bone defect of the beagle's mandible was 0.7, 6.6, and 39.4% at 4 weeks after surgery and 4.7, 39.5, and 75.2% at 12 weeks after surgery for NEOBONE, Bio-Oss, and Cytrans, respectively. The results indicate that bone-to-implant contact ratio was the largest for Cytrans. Additionally, the continuity of the alveolar ridge was restored in the case of Cytrans, whereas the continuity of the alveolar ridge was not sufficient when using NEOBONE and Bio-Oss. Both Cytrans and Bio-Oss that have a relatively larger carbonate content in their apatitic structure was resorbed with time. We concluded that carbonate content is one of important factors governing the osteoconductivity of apatitic bone substitutes.

Compositional and histological comparison of carbonate apatite fabricated by dissolution-precipitation reaction and Bio-Oss®.

Carbonate apatite (CO3Ap) is an inorganic component of bone. This study aimed to compare the composition and tissue response to of CO3Ap (CO3Ap-DP) fabricated by the dissolution-precipitation reaction using calcite as a precursor and Bio-Oss®, which is widely used in orthopedic and dental fields as a synthetic bone substitute. X-ray diffraction and Fourier transform infrared results showed that CO3Ap-DP and Bio-Oss® were both B-type carbonate apatite with low crystallinity. The average sizes of CO3Ap-DP and Bio-Oss® granules were 450 ± 58 and 667 ± 168µ m, respectively, and their carbonate contents were 12.1 ± 0.6 and 5.6 ± 0.1 wt%, respectively. CO3Ap-DP had a larger amount of CO3 than Bio-Oss® but higher crystallinity than Bio-Oss®. When a bone defect made at the femur of rabbits was reconstructed with CO3Ap-DP and Bio-Oss®, CO3Ap-DP granules were partially replaced with bone, whereas Bio-Oss® remained at 8 weeks after implantation. CO3Ap-DP granules elicited a significantly larger amount of new bone formation at the cortical bone portion than Bio-Oss® at 4 weeks after the implantation. The results obtained in the present study demonstrated that CO3Ap-DP and Bio-Oss® showed different behavior even though they were both classified as CO3Ap. The CO3 content in CO3Ap played a more important role than the crystallinity of CO3Ap for replacement to bone and high osteoconductivity.

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.

Efficacy of elemental diet on prevention for chemoradiotherapy-induced oral mucositis in patients with oral squamous cell carcinoma.

PURPOSE: Oral mucositis induced by radiation or chemoradiation can compromise the quality of life of oral squamous cell carcinoma (OSCC) patients. The present study was designed to evaluate the preventive effects of elemental diet (ED), Elental®, on radiotherapy- or chemoradiotherapy-induced mucositis in OSCC patients. PATIENTS AND METHODS: Seventy-four patients who underwent radiation (60-70 Gy) with/without chemotherapy [S-1, cisplatin (CDDP), CDDP plus S-1] were enrolled in this retrospective study; 37 had received Elental® during treatment (Elental® group) and 37 had not (control group). Factors related to alleviation of oral mucositis were identified by multivariate logistic regression analysis. Rates of completion of chemoradiation treatments were compared between Elental® and control groups according to the treatment regimen. The comparison of the nutritional status between groups was also performed. RESULTS: Multivariate analysis indicated that the administration of Elental® and no combined chemotherapy (radiation alone) were significant factors associated with the degree of oral mucositis, i.e., most of the patients who consumed Elental® suffered from a lower degree of mucositis compared to the control group. Elental® was associated with a significantly improved rate of completion of chemoradiation (no interruption). There was no significant difference between Elental® group and control group in terms of mean change of body weight or total protein and albumin levels in blood serum before and after (chemo)radiation. CONCLUSIONS: The present study indicates that Elental® is effective for ameliorating oral mucositis induced by (chemo)radiation in OSCC patients. Elental® was also associated with improved completion rates of (chemo)radiotherapy.

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.

Efficacy of the Silensor for treating obstructive sleep apnea syndrome.

INTRODUCTION: Although mandibular repositioning devices were found to be very effective for treating obstructive sleep apnea (OSAS), they can cause side effects such as temporomandibular joint disorder and occlusal deviation. A semi-rigid device with a low frequency of side effects, the Silensor, (Erkodent Gmbh, Tuttlingen, Germany) was reported previously. The purpose of this study is to determine whether the Silensor is effective for treating OSAS. MATERIALS AND METHODS: Thirty-five OSAS patients (27 males and 8 females) who were treated with the Silensor were enrolled in this study. The mean age and body mass index of the patients were 52.2 years (23-72 years) and 24.5 kg/m(2) (19.3-31.6 kg/m(2)), respectively. The patients were classified into two groups based on the length of the apparatus connector: 0-2 or 3-4 mm. A polysomnography test was performed twice, at the first visit and after the improvement of subjective symptoms. These data were statistically analyzed using the Wilcoxon signed-rank test. RESULTS: The apnea-hypopnea index significantly improved in all OSAS patients, the mild to moderate OSAS patients, severe OSAS patients, 0- to 2-mm group, and the 3- to 4-mm group (91.4 %; p < 0.01, 88.9 %; p < 0.01, 100 %; p < 0.05, 86.4 %; p < 0.01, 100 %; p < 0.01, respectively). The only side effects of the Silensor were broken apparatus and damage to the buccal mucosa. DISCUSSION: The Silensor is useful for the treatment of OSAS. In particular, the Silensor is suitable for the first phase of OSAS treatment with oral appliances because the efficacy of the Silensor was equal to that of other oral appliances and had few side effects.

Comparison of apatite-coated titanium prepared by blast coating and flame spray methods--evaluation using simulated body fluid and initial histological study.

It has previously been demonstrated that apatite may be coated on the surface of titanium (Ti) at room temperature when the titanium is blasted with apatite powder. This method is known as the blast coating (BC) method. In this study, the osteoconductivity and tissue response to Ti implants blast-coated with apatite (BC implants) were evaluated using apatite-coated Ti implants produced using the flame spraying (FS) method (FS implants) and pure Ti implants as a control. Initial evaluation using simulated body fluid demonstrated higher osteoconductivity in BC implants than in FS implants. Therefore, specimens were implanted in rat tibias for 1, 3 and 6 weeks. At one week after implantation, BC implants showed much higher bone contact ratio when compared with FS implants; the bone contact ratio of BC implants was 75.7%, while the FS and pure Ti implants had ratios of 30.8% and 5.5%, respectively. The difference in bone contact ratio between BC and FS implants decreased with implantation time and the ratios were equal after 6 weeks. In conclusion, BC implants show higher osteoconductivity than FS implants, and thus BC implants are beneficial for early fixation of implants to bone tissue.

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.

Development of a simulation system in mandibular orthognathic surgery based on integrated three-dimensional data.

PURPOSE: Surgical simulation should reflect the 3D movement of dentition and the resultant movement of the osteotomized segments, which can influence surgical outcome. The present study was aimed at developing a new simulation system that enables virtual osteotomy of a given surgical situation and evaluation of the bony interference between the osteotomized segments of the mandible. SUBJECTS AND METHODS: The data of 3D computer tomography (CT) for maxillomandibular dental casts were integrated into the standard coordinates of a 3D cephalogram. To evaluate the accuracy of the system, measurement errors of the 3D CT virtual model from a dry skull were compared with the computer simulation system and a contact-type 3D digitizer. To examine the clinical accessibility, 15 mandibular prognathism patients with mild to severe asymmetry were evaluated with the simulation program. RESULTS: The average error of measurement in all directions was 1.31 mm. It was possible to simulate various osteotomy procedures by conversion of the 3D coordinates of the dental cast and CT data into the standard coordinate system of a 3D cephalogram. Using this simulation system, it was possible to prevent condylar torque or segment malpositioning by removing the bony interference visualized by a 3D virtual model. CONCLUSION: A new system, which enables the precise visualization of osteotomized segments and calculation of bony interference, was proposed in the present study. This new system provides an acceptable precision of treatment planning of orthognathic surgery, especially for facial asymmetry.

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.

Diagnosis and treatment of an infant case with temporomandibular joint osteoarthritis caused by tumor.

INTRODUCTION: We reported an infant with temporomandibular joint (TMJ) osteoarthritis who required long-term tracheostomy. CASE FINDINGS: At 1 year of age, he received urgent tracheostomy because of apnea due to pneumonia. The tracheal cannula could not be removed thereafter due to trismus. Computed tomography (CT) images demonstrate irregular bone formation. However, we could not diagnose osteoarthritis of temporomandibular joint because TMJ adhesion was not clear on CT images. INTERVENTIONS: Arthroplasty was performed under general anesthesia, but there was no significant improvement. A 3-D plastic model based on intraoperative findings showed that atrophic change of the muscles also disturbed movement of the mandible. Therefore, an additional procedure called "pan-muscle-release surgery" was performed, resulting in further improvement of mandible movement. After confirming that mouth opening was stable, the tracheal cannula was removed.

[Clinical phase I trial of S-1 in the combination with DOC using super-selective intra-arterial infusion with oral cancer].

The super-selective intra-arterial infusion, which has high anti-tumor effect to infuse high concentration of drugs into arterial in the control of tumor, has been expected to have local control. S-1, developed by the scientific theory of both potentiating antitumor activity of 5-fluorouracil(5-FU)and reducing gastrointestinal toxicity induced by 5-FU, is an active agent for squamous cell carcinoma of the head and neck(HNSCC). Docetaxel(DOC)is the drug Taxanes which has anti-tumor effect by mechanism different from conventional anti-tumor mechanism of action. In Yamaguchi University, DOC+CDDP+5-FU in the three-drug combination therapy shows high anti-tumor effect for advanced oral cancer. In the present study, we conducted a phase I study to examine local control of S-1 in the combination with DOC using super-selective intra-arterial infusion with oral cancer. The study performed super-selective intra-arterial infusion of DOC on the first day, and was considered as the schedule which prescribes three-week S-1 for patients every day from same day. Since blood toxicity nature grade 4 discovered the result in S-1: 65 mg/m(2)day and DOC: 50 mg/ m(2), we decided that recommended dose(RD)was S-1: 65 mg/m(2) and DOC: 40 mg/m(2).

Comparison of ready-made and self-setting alginate membranes used as a barrier membrane for guided bone regeneration.

In order to understand the requirements of guided bone regeneration (GBR) involving alginate base self-setting barrier membranes, GBR was performed in the case of bicortical bone defects formed at the tibiae of experimental animals employing self-setting and ready-made alginate membranes. Connective tissue ingress into the bone defects at the skin side of the tibia was observed when GBR was generated utilizing ready-made alginate membrane. In contrast, bone defects were reconstructed with bone tissue when GBR was generated with self-setting alginate membrane formed from aqueous 3% sodium alginate and 3% CaCl(2) solutions. The unreacted aqueous sodium alginate solution inherent to self-setting alginate membrane did not inhibit bone tissue regeneration. Rather, callus bone was formed using sodium alginate as the nucleus. However, when GBR was effected with self-setting alginate membrane formed from aqueous 10% CaCl(2) solution, membrane was too thick and thus regeneration of bone tissue in the bone cavity was prevented. Therefore, we concluded that self-setting alginate membrane is very useful as a barrier membrane for GBR upon appropriate adjustment of conditions with respect to preparation of alginate membrane.

Skeletal Class III oligodontia patient treated with titanium screw anchorage and orthognathic surgery.

This article reports the successful treatment of a patient, aged 15 years 8 months, with a Class III malocclusion and oligodontia; a titanium screw was used for absolute anchorage during treatment. The patient had a concave profile because of mandibular excess and asymmetric spaces in both arches. Titanium screws were implanted in the retromolar area during intraoral vertical ramus osteotomy combined with LeFort I osteotomy. Absolute anchorage was provided with anchorage wires extending from the screws to the left canine and the right lateral incisor. After orthodontic space closure, the mandibular molars were moved mesially without lingual tipping of the mandibular incisors. A good interincisal relationship was achieved. Our results suggest that titanium screws and anchorage wires in the retromolar area are useful for the mesial movement of mandibular molars.

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.

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.