Mechanical Properties of Human Concentrated Growth Factor (CGF) Membrane and the CGF Graft with Bone Morphogenetic Protein-2 (BMP-2) onto Periosteum of the Skull of Nude Mice.

Concentrated growth factor (CGF) is 100% blood-derived, cross-linked fibrin glue with platelets and growth factors. Human CGF clot is transformed into membrane by a compression device, which has been widely used clinically. However, the mechanical properties of the CGF membranes have not been well characterized. The aims of this study were to measure the tensile strength of human CGF membrane and observe its behavior as a scaffold of BMP-2 in ectopic site over the skull. The tensile test of the full length was performed at the speed of 2mm/min. The CGF membrane (5 × 5 × 2 mm3) or the CGF/BMP-2 (1.0 µg) membrane was grafted onto the skull periosteum of nude mice (5-week-old, male), and harvested at 14 days after the graft. The appearance and size of the CGF membranes were almost same for 7 days by soaking at 4 °C in saline. The average values of the tensile strength at 0 day and 7 days were 0.24 MPa and 0.26 MPa, respectively. No significant differences of both the tensile strength and the elastic modulus were found among 0, 1, 3, and 7 days. Supra-periosteal bone induction was found at 14 days in the CGF/BMP-2, while the CGF alone did not induce bone. These results demonstrated that human CGF membrane could become a short-term, sticky fibrin scaffold for BMP-2, and might be preserved as auto-membranes for wound protection after the surgery.

Adenomatous ductal proliferation/hyperplasia in the parotid gland associated without any other pathological lesions; a report and survey of the literatures.

Adenomatous ductal proliferation/hyperplasia (ADP/H) is a rare hyperplastic condition of the salivary gland. It is mostly associated with other salivary gland pathologies such as tumors and inflammations, and is incidentally found in tissue sections during histopathological examinations of those diseases. Herein, we report a case of ADP/H in the parotid gland not associated with any other pathological lesions, and present a review of the literature on this condition. A 60-year-old Japanese female complained of swelling on the left side of parotid region. Clinical examination revealed a swelling on the lower lobe of the left parotid gland. The lesion was firm but non-tender and was not attached to adjacent structures. A clinical diagnosis of benign salivary gland tumor was reached, and surgical excision was performed under general anesthesia. Histopathological examination revealed an intact parotid gland capsule with isomorphic and basaloid cells within scanty cytoplasm. In addition, an admixture of hyperplasia and proliferation of the intercalated ducts, the presence of zymogen granules, the absence of solid nests, and a peripheral palisaded arrangement of the cells were observed. Based on these findings, a diagnosis of ADP/H was confirmed. ADP/H is a non-tumorous lesion; therefore, tumor involvement should be ruled out before the diagnosis is reached.

Immunohistochemical evaluation of Klotho and DNA methyltransferase 3a in oral squamous cell carcinomas.

Carcinoma follows a course of multiple changes that are affected by several important factors, with epigenetic silencing of the promoter gene being one of them. A series of studies have suggested that epigenetic changes in the anti-aging gene Klotho may be one of the emerging areas of concern in the study of carcinogenesis. We hypothesized that epigenetic silencing of Klotho due to hypermethylation of DNMT3a may be one of the causes of carcinoma in the oral and maxillofacial region. In this study, we analyzed the immunohistochemical expressions of Klotho and DNMT3a in tissues obtained from oral dysplasia and oral squamous cell carcinoma. Our results showed increased immune expression of DNMT3a, and decreased expression of Klotho in cells of the cancer tissues when compared with those in the dysplasia and healthy control samples. Chi-square tests complemented by adjusted residual analysis revealed significantly higher number of Klotho-positive and DNMT3a-negative cases in healthy controls, Klotho-negative and DNMT3a-negative cases in ODL, and Klotho-negative and DNMT3a-positive cases in OSCC when compared with the other types among the three groups (X 2 = 46.66, p < 0.001). Thus, downregulation of Klotho may be associated with the overexpression of DNMT3a in cancer tissues.

Total temporomandibular joint replacement in recurrent temporomandibular joint ankylosis: a case report.

Total temporomandibular joint replacement (TMJR) is a surgical procedure in which end-stage temporomandibular joint disorders are replaced with an alloplastic prosthesis between the mandible and the base of the skull when autogenous grafts are inadvisable. These alloplastic prostheses may be available as stock or custom-made prostheses consisting of the mandibular condyle and glenoid fossa components. Although the first total temporomandibular joint prosthesis was used in the 1960s, we present the case of a 20-year-old female patient, probably the first case of total temporomandibular joint arthroplasty in Nepal, performed at Dhulikhel Hospital in Kavrepalanchok. The patient underwent bilateral TMJR with a custom joint prosthesis for recurrent TMJ ankylosis. Postoperatively, the patient noticed significant improvements in mouth opening, chewing ability, facial esthetics and, most importantly, her self-esteem and confidence.

Dental Caries on Deciduous Molars among Children Visiting Dental Outpatient Department of a Tertiary Care Centre.

Introduction: Dental caries is one of the most common, yet preventable childhood diseases. The aetiology of dental caries lies in the interplay between host, microorganism, substrate, and time. Risk factors for dental caries include physical, biological, environmental, behavioural, and lifestyle-related factors such as high numbers of cariogenic bacteria, inadequate salivary flow, insufficient fluoride exposure, poor oral hygiene, inappropriate methods of feeding infants, and poverty. The aim of the study was to find out the prevalence of dental caries on deciduous molars among children visiting dental Outpatient Department of a tertiary care centre. Methods: This descriptive cross-sectional study was conducted on children who visited the dental outpatient department of Kathmandu University School of Medical Sciences, Dhulikhel Hospital from 15 June 2023 to 30 July 2023. Ethical approval was taken from the Institutional Review Committee of the same institute. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Results: The prevalence of dental caries on deciduous molars in children was 252 (93.33%)(90.35-96.30, 95% Confidence Interval). One-third of the children had visited dental clinics for the first time. Lack of topical fluoride application was seen in the majority of the children. Conclusions: The prevalence of dental caries on deciduous molars among pediatric patients was found to be higher than in other studies done in similar settings. Keywords: children; dental caries; molars; prevalence.

Bio-Absorption of Human Dentin-Derived Biomaterial in Sheep Critical-Size Iliac Defects.

The aim of this study was to evaluate the bio-absorption and bone regeneration of human tooth-derived dentin scaffold, entitled as perforated root-demineralized dentin matrix (PR-DDM), after in vivo implantation into the critical-size iliac defects. The dentin scaffolds were prepared from human vital, non-functional teeth. Thirty artificial macro-pores (Ø 1 mm) were added after removing the enamel portion. The modified teeth were supersonically demineralized in 0.34 N HNO3 for 30 min. The microstructure was observed by scanning electron microscope (SEM). The 3D micro-CT and histological analysis were carried out to evaluate the bio-absorption of PR-DDM at 2 and 4 months. A smooth dentin collagen surface with symmetrical macro-pores and tube-type dentinal tubules (Ø 1-2 µm) with micro-cracks were observed on the perforated region. A significant number of custom-made macro-pores disappeared, and the size of the macro-pores became significantly wider at 4 months compared with the 2 months (p < 0.05) evaluated by 3D micro-CT. Histological images revealed the presence of multinucleated giant cells attached to the scalloped border of the PR-DDM. The morphological changes due to bio-absorption by the cellular phagocytes were comparable to the 3D micro-CT and histological images at 2 and 4 months. Altogether, the results demonstrated that the PR-DDM block was gradually absorbed by multinucleated giant cells and regenerated bone. Human PR-DDM might serve as a unique scaffold for extraoral bone regeneration.

Accelerated Bone Induction of Adult Rat Compact Bone Plate Scratched by Ultrasonic Scaler Using Acidic Electrolyzed Water.

Fresh compact bone, the candidate graft material for bone regeneration, is usually grafted for horizontal bone augmentation. However, the dense calcified structure inhibits the release of growth factors and limits cellular and vascular perfusion. We aimed to create mechano-chemically altered dense skull bone by ultrasonic treatment, along with partial demineralization using commercially available acidic electrolyzed water (AEW). The parietal skull bone of an 11-month-old Wistar rat was exposed and continuously treated with a piezoelectric ultrasonic scaler tip for 1 min, using AEW (pH 2.3) or distilled water (DW, pH 5.6) as irrigants. Treated parietal bone was removed, cut into plates (5 × 5 × 1 mm3), grafted into the back subcutaneous tissues of syngeneic rats, and explanted at 1, 2, and 3 weeks. AEW bone showed an irregular surface, deep nano-microcracks, and decalcified areas. SEM-EDS revealed small amounts of residual calcium content in the AEW bone (0.03%) compared to the DW bone (0.86%). In the animal assay, the AEW bone induced bone at 2 weeks. Histomorphometric analysis showed that the area of new bone in the AEW bone at 2 and 3 weeks was significantly larger. This new combination technique of AEW-demineralization with ultrasonic treatment will improve the surface area and three-dimensional (3D) architecture of dense bone and accelerate new bone synthesis.

Osseous choristoma of the tongue: two case reports.

BACKGROUND: Osseous choristoma is a very rare, benign lesion in the maxillofacial region. It appears as a benign mass of normally matured bony tissue covered by the normal epithelium of the tongue. It is usually seen in front of the foramen cecum of the tongue. Surgical excision is the treatment of choice with an excellent prognosis and there have been very few cases of recurrence. CASE PRESENTATION: Here we present two cases of osseous choristoma on the dorsum of the tongue. Case 1 was a 15-year-old Japanese girl who presented with a painless but gradually growing swelling on the dorsum of her tongue approximately 1 year before her admission. Case 2 was a 21-year-old Japanese woman with a complaint of pain in the lower left, posterior side of her mouth. Histological findings showed that both lesions were composed of well-organized, mature, compact bone beneath the oral mucosal membrane. Subsequent to simple surgical excision, no recurrence of the lesions was observed after the follow-up period. Previous literatures have proposed both malformation and trauma hypotheses as the etiopathologies of osseous choristoma. However, the histopathological findings of the two cases in the present study do not support the trauma hypothesis. CONCLUSIONS: Although osseous choristoma is clinically a benign condition, the underlying histopathological processes are important. The outcome of aberrant formation of calcified tissue in the vicinity of vital structures such as nerves and blood vessels may be of clinical significance.