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This study compared clinical and magnetic resonance imaging (MRI) findings in patients with anterior disk displacement without reduction (ADDWOR) who improved to anterior disk displacement with reduction (ADDWR) vs. patients who did not improve after mandibular manipulation (MM) and conservative self-administered physical therapy (CSAPT).Of 15 patients diagnosed with ADDWOR by MRI, 7 improved to ADDWR (WOR-WR) and 8 did not improve (WOR-WOR). The clinical and MRI findings before and after therapy were compared in each group.Significant differences between the groups included age, period of awareness of trismus, and maximum mouth opening (MMO). The MRI findings revealed significant differences in the degree of ADD and morphology of the disk and condyle. MMO significantly improved in the WOR-WR group between initial and follow-up visits.Patients who were successfully treated with MM and CSAPT tended to be30 years old, with a longer period of awareness of trismus, MMO40 mm, a slight or moderate degree of ADD, no deformity of the disk, and no morphologic change in the condyle. Patients with ADDWOR who are treated with MM and CSAPT require an accurate clinical examination and MRI before treatment.

Calcifying odontogenic cysts (COC) and adenomatoid odontogenic tumors (AOT) have similar radiographic findings. We examined the radiographic and computed tomography (CT) images of patients histologically diagnosed with COC or AOT and identified their characteristic findings. The subjects included 12 patients histologically diagnosed with COC or AOT (one female and five males per group), who underwent CT at our hospital between Nov 1998 and Jun 2019. The location of the lesion, impacted tooth, bone expansion, root resorption, tooth migration, calcified body, and presence or absence of a high-intensity zone in the marginal area of the lesion were examined. In patients with COC, five patients with COC exhibited bone expansion toward the buccal side. The lesion encompassing the crown was attached to the cement-enamel junction and contained a radiopaque lesion with a calcified body. In 6 patients with COC, irregularly shaped calcified bodies were observed with small tooth-like structures. In patients with AOT, all six patients with AOT exhibited bone expansion toward the buccal and lingual sides. The lesion encompasses a part of the tooth root or the entire tooth. Punctate calcification was observed within the lesion and the marginal area in three patients, and a high-intensity zone was observed in the marginal area of the lesion in two patients. We report imaging findings that may be characteristic of COC and AOT, suggesting that CT findings may be useful for differentiating between COC and AOT.

Impacted mandibular third molar extraction is one of the most frequent procedures performed in the field of oral surgery. Oral surgeons sometimes face cases that cannot be extracted using the conventional procedure because of atypical tooth structure or irregular tooth position in the mandible. Here, we report an unusual impacted third mandibular molar with atypical root form, which was extracted by buccal cortex osteotomy of the mandibular ramus. A 42-year-old Japanese female presented with a complaint of discomfort in the left molar region. Radiographical examination showed an impacted third molar with a mushroom-like root overlapping the mandibular canal. This lesion was radiographically diagnosed as cemental hyperplasia. The tooth could not be extracted using the conventional procedure, and buccal cortex osteotomy was applied. Briefly, bones necessary for extraction were removed once from the mandibular ramus. After extraction, the bony fragment was repositioned in the original position. The patient experienced no postoperative complications such as nerve paralysis, mandibular angle fracture, and infections. Buccal cortex osteotomy is a simple and easy technique to extract impacted mandibular third molars that cannot be extracted by conventional methods.

A concise spherical granulation method is required to prepare extemporaneously granules remanufactured from oral dosage forms for administration to individuals who cannot swallow tablets or capsules. In this study, we determined the feasibility of spherical granulation using a planetary centrifugal mixer. A model formulation, 20% ibuprofen (IBP) granules, was prepared using a lactose/cornstarch (7 : 3, w/w) mixture or D-mannitol as diluents, and changes in granule characteristics (mean diameter (d50), distribution range of granule size (span), and yield) were evaluated according to the amount of water added and the granulation time. The amount of water was assessed using the plastic limit value as measured using a digital force gauge. We successfully produced granules, and larger amounts of water and longer granulation times resulted in larger d50 values and smaller span values. The optimal granulation time was 45 s and the optimal water contents were 70 and 67.5% of the plastic limit value for the lactose/cornstarch mixture and D-mannitol, respectively. When compared to commercial 20% IBP granules, powder X-ray diffraction and differential scanning calorimetry analyses showed that the granulation process did not alter the crystallinity of the drug. Thus, this novel granulation method using a planetary centrifugal mixer may be a promising technique for compounding in pharmacies and in pharmaceutical manufacturing.

Objective Plasma rich in growth factors (PRGF) and platelet-rich plasma (PRP) can be rapidly obtained from patient blood. They are a new and potentially useful adjunct in oral and maxillofacial bone repair or regenerative surgery. The aim of this study was to compare the possibility of new bone formation using PRGF and PRP. Methods The osteogenic potential with transplantation of PRGF or PRP onto rat calvaria was evaluated by histologic examination and microCT. PRGF or PRP was prepared by centrifugation of rat whole blood (WB). First, the cells in the blood product were counted; there were no leukocytes in PRGF, and PRP included leukocytes. PRGF contained higher levels of TGF-β1 and PDGF-BB than PRP. Furthermore, PRGF or PRP was transplanted onto calvarial bone of rats. Results MicroCT showed that PRGF promoted an increase in bone volume when compared to PRP. Histological observation demonstrated that the PRGF group showed newly formed bone in a wide range. In addition, the PRP group showed numerous inflammatory cells compared to the PRGF group in HE-stained specimens. This suggests that PRP might delay bone regeneration due to the inflammatory response. Conclusions PRGF has more availability for bone regeneration than PRP, and PRGF may be useful in bone regeneration treatment.

Osteomas are uncommon, benign, slow-growing osteogenic tumors, arising from the bones, can be classified as central, peripheral, or extra-skeletal. Peripheral osteomas develop as masses attached to the cortical bone, and are mushroom-shaped masses protruding from the periphery of the jaw bones. Here we report an unusual solitary compact osteoma arising from the inferior border of the mandible but predominantly in the anterior belly of the digastric muscle. A 58-year-old Japanese woman had a hard mass in the submental region. Computed tomography showed a hyperdense, well circumscribed mushroom-like lesion measuring 2.1 × 1.2 cm in size, and the lesion was located from the inferior border of the mandible in the left anterior belly of the digastric muscle. The clinical and radiological diagnosis was peripheral osteoma. The patient underwent resection of the osteoma through the submental skin incision under general anesthesia. Intraoperatively, the mass was present in the anterior belly of digastric muscle, and the tendinous origin of the muscle adhered to not to the mass but to the mandible. Histopathological examination showed a compact osteoma. The postoperative course was uneventful and there was no recurrence 5 years after surgery.

The dental follicle is an ectomesenchymal tissue surrounding developing tooth germ that contains osteoblastic-lineage-committed stem/progenitor cells. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression during stem cell growth, proliferation, and differentiation. The aim of this study was to investigate the key regulators of miRNA during osteogenic differentiation in human dental follicle cells (hDFC). We analyzed miRNA expression profiles in hDFC during osteoblastic differentiation. Expression of miR-204 was decreased in hDFC during osteogenic induction on microarray analysis. Real-time and RT-PCR analysis also showed that the expression of miR-204 was decreased in all three hDFC during osteogenic differentiation. To investigate whether miR-204 has an effect on osteogenic differentiation, miR-204 was predicted to target alkaline phosphatase (ALP), secreted protein acidic and rich in cysteine (SPARC), and Runx2 in the in the 3'-UTRs by in silico analysis. When miR-204 was transfected into hDFC, the activity of ALP and protein levels of SPARC and Runx2 were decreased. mRNA levels of ALP, SPARC and Runx2 were also decreased by miR-204 transfection. Our data suggest that miR-204 negatively regulates the osteogenic differentiation of hDFC by targeting the bone-specific transcription factor Runx2, the mineralization maker ALP and the bone extracellular matrix protein SPARC.

The aim of this study was to develop and evaluate novel polyglycerol fatty acid ester (PGFE)-based nanoparticles (NPs) for the dermal delivery of tocopherol acetate (TA). TA-loaded PGFE-based NPs (PGFE-NPs) were prepared by mixing PGFE, soya phosphatidylcholine, dimyristoylphosphatidylglycerol, and TA with film using the film rehydration and extrusion method. The prepared formulations were analyzed by dynamic light scattering, small-angle X-ray diffraction and polarization microscopy. An in vitro skin accumulation test was performed with TA under occlusive and non-occlusive applications, using Yucatan micropig skin. The size range of the TA-loaded liposome and PGFE-NPs was 107–128 nm, and they were encapsulated in 1.6–2.3 mg/mL TA. All PGFE-NP formulations were negatively charged and stable for 2 weeks. Under occlusive applications, all formulations induced small amounts of TA accumulation in the epidermis but not in the dermis. However, under non-occlusive applications, some of PGFE-NP formulations enhanced TA accumulation in the epidermis. Furthermore, only the polyglycerol 4-laurate (PG4L)-based formulation induced dermal TA accumulation with the change in the formulation from a vesicular to bilayer stacked structure following water evaporation under non-occlusive applications. These results indicated that the novel TA-loaded PG4L formulation enabled the dermal delivery of TA in non-occlusive applications.

Peri-implant squamous cell carcinoma is an uncommon pathological manifestation, whereas peri-implantitis is commonly found in association with dental implants. Both present similarly with loss of supporting soft and hard tissue around dental implants; therefore, a careful differential diagnosis is required. The present case concerns a 62-year-old Japanese man who had a dental implant which had been in the left maxillary incisor region for 4 years who apparently developed peri-implantitis. This did not respond to localized therapy and antibiotics so was referred for specialist surgical management. A biopsy confirmed it to be a squamous cell carcinoma rather than an inflammatory lesion. A literature review shows that this is an unusual presentation without a previous history of malignancy, mucosal disease or risk factors for cancers. Although rare, the possibility of peri-implant squamous cell carcinoma should be borne in mind by all practitioners who monitor implant patients.

The aim of this study was to investigate the capacity of human dental follicle cells (hDFCs) for bone formation in vivo. hDFCs were obtained from wisdom teeth extracted from patients aged 14 and 22 years. hDFCs from the 5th to 8th passages were grown in three-dimensional (3D) culture using gelatin sponges. Cells were transplanted onto the calvaria of F344/NJcl-rnu/rnu male rats (immunodeficient rats). Haematoxylin and eosin (HE) staining and immunohistochemistry were performed, and newly formed bone was evaluated by micro-computed tomography (micro-CT). HE staining showed newly formed bone in 3D culture. Immunohistochemistry showed bone morphogenetic protein 2 (BMP-2), runt-related transcription factor 2 (RUNX2), and osterix staining in areas with newly formed bone. Furthermore, micro-CT showed that, in comparison to controls, transplanted hDFCs promoted better bone quality and bone mineral density (BMD 582 ± 131.1 vs. 300.5 ± 77.7 mg/cm(3); P=0.039), bone mineral content (BMC 5.6 ± 1.1 vs. 2.1 ± 0.4 mg; P = 0.006), bone volume (BV 9.7 ± 0.5 × 10(-3) vs. 7.0 ± 0.4 × 10(-3) cm(3); P = 0.002), BMC/total volume (TV) (399.9 ± 76.3 vs. 147.7 ± 30.8 mg/cm(3); P = 0.006), and BV/TV (69.1 ± 3.6% vs. 49.6 ± 3.1%; P=0.002). This suggests that human dental follicles are potentially useful for regenerative therapy.

In a product market with network externality, outperforming products are not always disseminated. Product markets are often modeled and examined by simulation to clarify product diffusion processes. In earlier work, where multiagent systems and complex networks were used to model the product market, consumer heterogeneity was not considered despite its influence on the product diffusion process. This paper introduces threshold models into multiagent-systembased simulation in complex networks to realize consumer heterogeneity. The feasibility of the proposed method is discussed using computer simulation results, and consumer heterogeneity and network structure affect product diffusion processes.