Seigo Ohba

In Vivo Comparison of the Bone Regeneration Capability of Human Bone Marrow Concentrates vs. Platelet-Rich Plasma

Background Bone marrow aspirate concentrate (BMAC) including high densities of stem cells and progenitor cells may possess a stronger bone regenerative capability compared with Platelet-rich plasma (PRP), which contains enriched growth factors. The objective of this study was to evaluate the effects of human BMAC and PRP in combination with β-tricalcium phosphate (β-TCP) on promoting initial bone augmentation in an immunodeficient mouse model. Methodology/Principal Findings BMAC and PRP were concentrated with an automated blood separator from the bone marrow and peripheral blood aspirates. β-TCP particles were employed as a scaffold to carry cells. After cell counting and FACS characterization, three groups of nude mice (BMAC+TCP, PRP+TCP, and a TCP control) were implanted with graft materials for onlay placement on the cranium. Samples were harvested after 4 weeks, and serial sections were prepared. We observed the new bone on light microscopy and performed histomorphometric analysis. After centrifugation, the concentrations of nucleated cells and platelets in BMAC were increased by factors of 2.8±0.8 and 5.3±2.4, respectively, whereas leucocytes and platelets in PRP were increased by factors of 4.1±1.8 and 4.4±1.9, respectively. The concentrations of CD34-, CD271-, CD90-, CD105-, and CD146-positive cells were markedly increased in both BMAC and PRP. The percentage of new bone in the BMAC group (7.6±3.9%) and the PRP group (7.2±3.8%) were significantly higher than that of TCP group (2.7±1.4%). Significantly more bone cells in the new bone occurred in sites transplanted with BMAC (552±257) and PRP (491±211) compared to TCP alone (187±94). But the difference between the treatment groups was not significant. Conclusions/Significance Both human BMACs and PRP may provide therapeutic benefits in bone tissue engineering applications. These fractions possess a similar ability to enhance early-phase bone regeneration.

Evaluation of sinus floor augmentation with simultaneous implant placement using platelet-rich fibrin as sole grafting material.

PURPOSE The objective of this study was to evaluate sinus floor augmentation with simultaneous implant placement using platelet-rich fibrin (PRF) as the only grafting material. MATERIALS AND METHODS This study included patients who underwent sinus floor augmentation with simultaneous implant placement using PRF as the sole filling material between July 2009 and January 2011 at the Department of Oral and Maxillofacial Surgery, Nagasaki University Hospital. For each patient, presurgical and postsurgical (6 months after the surgery) radiography and computed tomographic scanning were performed to assess bone formation at the implant sites. The density (in Hounsfield units [HU]) of the newly formed bone and the bone height from the sinus floor to the alveolar crest where implants were inserted were measured using implant planning software (Simplant, Materialise Dental). RESULTS Nine sinus floor augmentations were performed, and 17 implants were placed in six patients. The mean residual bone height between the sinus floor and alveolar crest was 4.28 ± 1.00 mm (range, 1.9 to 6.1 mm) prior to surgery and 11.8 ± 1.67 mm (range, 9.1 to 14.1 mm) after surgery. The alveolar bone ridge was wide enough for implant placement in all cases. The mean density of the newly gained bone around the implants was 323 ± 156.2 HU (range, 185 to 713 HU). All implants were clinically stable at the time of abutment insertion, 6 months after sinus augmentation. CONCLUSION Sinus elevation with simultaneous implant placement using PRF as the only filling material may promote natural bone regeneration.

Antisense oligonucleotide against 47-kDa heat shock protein (Hsp47) inhibits wound-induced enhancement of collagen production

It is well known that excessive collagen synthesis during the wound-healing process causes scar formation. Our recent in-vivo study indicates that antisense treatment against 47-kDa heat shock protein (Hsp47), a collagen-specific molecular chaperone, relieves scar formation following skin wounds in rats [Wang et al., Plast. Reconstr. Surg., in press]. In order to understand the mechanism of this phenomenon, we examined the effects of antisense treatment on the expression of mRNAs and proteins of Hsp47 and collagens in fibroblasts derived from wounded rat tongues. Hsp47 and procollagen alpha1(I) and alpha1(III) mRNAs were consistently increased after wounding and were maximal at day 5 post-injury. Treatment with antisense oligonucleotide against Hsp47 efficiently blocked the production of procollagen alpha2(I) and alpha1(III) proteins, but had little effect on their mRNA levels. Therefore, we conclude that antisense oligonucleotide against Hsp47 inhibits the production of procollagen type I and III proteins in fibroblasts derived from wounded tongues, overcoming the increase in their mRNAs.

Applicability of buccal fat pad grafting for oral reconstruction

This study evaluated the applicability of pedicled buccal fat pad grafting for the reconstruction of defects surgically created during oral surgery. A buccal fat pad graft was applied in 23 patients (5 males, 18 females; mean age 68.3 years) between 2003 and 2011. The graft was used to cover surgical defects of the palate, maxilla, upper gingiva, buccal mucosa, lower gingiva, oral floor, and temporomandibular joint region. Size of the surgical defects ranged from 15mm×12mm to 30mm×40mm; size of the buccal fat pad ranged from 15mm×12mm to 43mm×38mm. A pedicled buccal fat pad was prepared by incising the maxillary vestibule following primary surgery, and the surrounding connective tissue was preserved to supply nutrition to the pedicle during surgery. The buccal fat pad was placed on the raw surface of soft tissue or bone surface and sutured to the surrounding tissue of the defect. Complete epithelialization was observed within 4 weeks postoperatively. There were no complications or functional disorders during follow-up. Buccal fat pad grafting appears to be feasible for the reconstruction of surgically induced defects, and can be extended to the palate, mandible, mouth angle, and temporomandibular joint region.

Assessment of skeletal stability of intraoral vertical ramus osteotomy with one-day maxillary-mandibular fixation followed by early jaw exercise.

PURPOSE Intraoral vertical ramus osteotomy (IVRO) is an effective surgical technique for cases of mandibular setback, is simpler and has a lower incidence of mental paraesthesia when compared to sagittal split ramus osteotomy (SSRO). However, IVRO has a disadvantage in the prolonged duration of postoperative maxillary-mandibular fixation (MMF) required due to the absence of rigid bone fixation. To avoid an extended MMF period, we developed a postoperative management protocol for our IVRO patients, using jaw exercises with elastic bands starting on the second day after surgery. METHODS We evaluated the cephalometric skeletal and dental stabilities of 16 IVRO patients as they followed our protocol. RESULTS The stabilities were confirmed and were similar to those of previous reports. CONCLUSION One-day MMF and early initiation of jaw exercise after IVRO did not affect the jaw position stability. Moreover, our findings suggest that starting jaw exercise earlier after IVRO surgery is beneficial, as it allows patients to avoid a long period of rigid MMF so that they can resume their normal daily activities sooner.

Rapid Growing Myofibroma of the Gingiva: Report of a Case and Review of the Literature

PURPOSE Myofibroma is a rare benign tumor of myofibroblasts that rarely exhibits rapid enlargement and is misinterpreted as a malignant lesion. The aim of this study was to investigate its growth potential and to evaluate the usefulness of preoperative immunohistochemical study for an accurate diagnosis. MATERIALS AND METHODS A case of rapidly growing myofibroma of the lower gingiva was analyzed using 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography fused with computed tomography (PET/CT) and immunohistochemical study of Ki-67 and p53. The English-language literature from 1981 to 2012 also was reviewed. RESULTS An 18F-FDG PET/CT image displayed a high accumulation (maximum standardized uptake value, 14.1) in the lesion. A biopsy specimen showed mitotic activity of spindle-shaped cells, but atypia was not present. The MIB-1 labeling index was 10%, and the p53 test result was negative. The preoperative diagnosis of benign tumor of smooth muscle origin was made from the histopathologic and immunohistochemical features. In a review of 94 cases, tumors involved the mandible (33%), gingiva (23%), tongue (15%), cheek or buccal mucosa (12%), palate (8%), lip (4%), and other areas (5%). Nine cases (9.6%) were described as rapidly enlarging, and 8 cases (8.5%) were suspected of malignancy at initial diagnosis. The preoperative biopsy with immunohistochemical study established an accurate diagnosis in 83% of myofibromas, and no recurrences were reported in these patients. CONCLUSIONS Careful diagnosis is necessary because these lesions sometimes present clinical and radiologic features that resemble those of malignant tumors. Preoperative immunohistochemical analysis should be performed to avoid misdiagnosis or unnecessary aggressive therapy.

Treatment outcome of Photofrin-based photodynamic therapy for T1 and T2 oral squamous cell carcinoma and dysplasia

BACKGROUND Photodynamic therapy (PDT) is a minimally invasive treatment modality for early and superficial malignancy or premalignancy in the head and neck regions. However, few studies have examined the use of Photofrin-mediated PDT to manage early carcinoma and dysplasia in the oral cavity. METHODS Between January 2004 and November 2008, 25 T1 to T2 patients with N0 oral squamous cell carcinoma and mucosal dysplasia in the oral cavity were treated by Porfimer sodium (Photofrin(®))-mediated PDT at Nagasaki University Hospital. Clinical responses were evaluated according to the guidelines of the Response Evaluation Criteria in Solid Tumors (RECIST). After the PDT and a 2-year follow-up period, disease specific survival rates were then calculated. RESULTS A total of 30 regions in 25 patients (18 with squamous cell carcinoma and 7 with epithelial dysplasia with hyperkeratosis in the oral cavity) were treated by PDT. Complete response was achieved in 24 of the 25 patients (96%), with a partial response found in the remaining patient. For the three patients who exhibited recurrence at 4, 5, and 15 months after PDT, salvage surgery or a second PDT was performed. Of these three patients, one died due to another disease, while one died due to local lymphatic metastasis that occurred during the follow-up period. Overall, the disease specific survival rate was 95.8%. Treatment-related edema and pain emerged within 24h after irradiation. Pain control using non-steroid anti-inflammatory drugs and opiates was required for 3-4 weeks in all patients. Complete healing was attained at 4-6 weeks after the treatment. No persistent problems related to functional or esthetic outcomes were noted.

Short lingual osteotomy without fixation: a new strategy for mandibular osteotomy known as “physiological positioning”

We describe the strategy of physiological positioning, which we regard as a new alternative treatment to conventional orthognathic operations, and treated 18 patients with skeletal mandibular prognathism using it. The positions of SNB, FMA, and Me were measured postoperatively to assess skeletal stability, changes in the angle and perpendicular length of the upper and lower central incisors were measured to assess dental stability, and we confirmed that both skeletal and dental stability were excellent. The width to which the jaw could be opened recovered early, and we saw only one case of disorder of the temporomandibular joint. Short lingual osteotomy with physiological positioning is an effective new approach to the treatment of deformities of the mandible.

Diminished Progression of Periapical Lesions with Zoledronic Acid in Ovariectomized Rats

INTRODUCTION The aim of this study was to investigate the effects of systemically administered zoledronic acid (ZOL) on the progression of periapical lesions in estrogen-deficient rats. METHODS Female Wistar rats were divided into the following groups: SHAM-veh, sham surgery treated with vehicle (physiological saline); OVX-veh, ovariectomy treated with vehicle; SHAM-ZOL, sham surgery treated with ZOL; and OVX-ZOL, ovariectomy treated with ZOL. Vehicle or ZOL was administered intravenously once a week for 4 weeks. The pulp of the mandibular first molar of all rats was exposed to the oral environment to induce a periapical lesion, and the lesions were analyzed after 7 and 30 days. The mandibles were examined by micro-computed tomographic imaging and histopathologic, histometric, and immunohistochemical analyses. RESULTS Histopathologically, the OVX-veh group had more severe inflammation and bone loss and a larger number of cells that were positive for tartrate-resistant acid phosphatase compared with the SHAM-veh and OVX-ZOL groups; the SHAM-veh and OVX-ZOL groups were similar to each other. The SHAM-ZOL group had the lowest magnitude of these conditions. Tomographically, the OVX-veh group had greater bone loss than the other groups at both time points. The SHAM-veh, SHAM-ZOL, and OVX-ZOL groups had similar bone loss at both time points. In the sagittal section on day 30, the SHAM-ZOL group had lower bone loss compared with the SHAM-veh and OVX-ZOL groups. CONCLUSIONS The hypoestrogenic condition aggravates the progression of periapical lesions. ZOL therapy may help contain bone destruction of periapical lesions.

The skeletal stability after maxillo-mandibular osteotomy with a “physiological positioning strategy”

The aim of this study was to estimate skeletal and dental stability after maxillomandibular osteotomy with physiological positioning. Ten patients (7 men and 3 women) with skeletal mandibular prognathism were treated by conventional Le Fort I osteotomy for the maxilla and unfixed short lingual osteotomy for the mandible together with physiological positioning. We used cephalometric analysis to evaluate the skeletal and dental stability preoperatively, immediately after maxillomandibular osteotomy, and more than 1 year later. The immediately postoperative measurements for the SNA and the SN-palatal planes were 0.15° (p=0.67) and 1.0° (p=0.17), respectively. The positions of the anterior nasal spine, posterior nasal spine, and A point showed minimal changes 1 year postoperatively. The postoperative difference for SNB was 0.76° (p=0.04). Dental stability was apparent postoperatively. We conclude that reliable stability of both the maxilla and the mandible was achieved after maxillomandibular osteotomy with physiological positioning in patients with mandibular prognathism.