Histopathological and Immunohistochemical Study of Peri-Implant Epithelium

Background: Human beta-defensins (HBDs), epithelial-derived antimicrobial peptides, contribute to gingival health and periodontal disease. Particularly, the upregulation of HBD-3 expression in periodontal tissues is described to contribute to periodontal tissue regeneration. Specifically, the upregulation of HBD-3 expression in periodontal tissues is described to contribute to periodontal tissue regeneration. But there has been insufficient investigation of the inner epithelium in peri-implantitis, especially the HBD expression patterns as protection against oral infection. Objectives: The purpose of this study was to investigate the histopathological characteristics of the inner implant epithelium in peri-implantitis using histopathological and immunohistochemical methods and to compare it with the inner marginal epithelium in periodontitis. Materials and Methods: The biopsied cases consisted of 10 peri-implantitis, 11 periodontitis, and 10 controls. HE observation, measurement of the thickness of the inner epithelium, and immunohistochemical analysis for Ki-67 and HBD-3 were conducted. Results: Concerning the thickness of the inner epithelium, it was significantly higher in periodontitis (156.2 [138.0, 186.4] μm) than in peri-implantitis and control, 70.7 [67.5, 97.5] μm and 80.7 [76.6, 89.4] μm, respectively (p Conclusion: Decreased production of HBD-3 in keratinocytes composing the inner implant epithelium may be one of the factors affecting tissue repair in peri-implantitis.

Comparative Cytological and Histopathological Study of Peri-Implantitis and Periodontitis

Peri-implant diseases, such as peri-implant mucositis and peri-implantitis, pose significant challenges to the long-term prognosis of dental implants. This study aimed to comprehensively compare peri-implantitis with periodontitis from cytological and histopathological perspectives, shedding light on the morphological characteristics associated with peri-implantitis. Thirteen patients, including six with peri-implantitis and seven with periodontitis, were included in the study. Cytological examination of affected gingival mucosa revealed distinct differences between the two conditions. Peri-implantitis exhibited an inflammatory background predominantly composed of neutrophils with lobulated nuclei, accompanied by stratified squamous epithelial cells showing signs of keratinization. In contrast, periodontitis showed a similar neutrophilic inflammatory background but with non-keratinized epithelial cells. Histopathological examination further confirmed these differences, with peri-implantitis showing keratinized epithelium in the inner epithelial layer. This histological finding aligns with the notion that peri-implantitis has a distinct mucosal profile compared to periodontitis. Additionally, cytological analysis revealed that peri-implantitis had a lower occurrence rate of Light green-positive cells, indicating a tendency toward keratinization. This finding suggests that the presence of keratinized mucosa might be associated with peri-implant health, although further research is needed to clarify this relationship. Overall, this study demonstrates the potential of cytological examination and Papanicolaou staining for assessing mucosal inflammatory conditions and distinguishing between keratinized and non-keratinized cells. These findings underscore the utility of oral mucosal smears as a valuable tool for diagnosing peri-implantitis and enhancing our understanding of its pathogenesis.

Comparative Study of Cell Findings by Conventional Smear and Liquid-Based Cytology for Oral Exfoliative Cytology

Background: Liquid-based cytology (LBC) is a method of manufacturing cyto-diagnostic specimens. Improved accuracy is expected from standardizing specimen production and use of this method is rapidly spreading in oral cytology. On the other hand, LBC reportedly requires training to show peculiar cell findings compared to those of conventional smear cytology (CVC). Few studies have compared detailed cell findings for oral CVC and LBC. Objectives: The aim of this study was to compare cytological findings between CVC and LBC using cytomorphological image analysis. Materials and Methods: Cytological specimens were collected from 20 patients (negative for squamous neoplasia in 10, dysplasia in 5, squamous cell carcinoma in 5) and 5 controls of the tongue between January 2017 and December 2018. Two different preparation techniques were investigated cytomorphologically for CVC and LBC (BD CytorichTM). Results: LBC showed significantly higher cell numbers than CVC for all lesions. LBC-to-CVC ratio ranged from 9.52 (hyperkeratosis) to 1.87 (deep cells in oral squamous cell carcinoma (OSCC)). Nuclear area of normal, hyperkeratosis, and inflammation were significantly higher in LBC than those of CVC. Hyperchromasia was significantly more frequent with CVC than with LBC for hyperkeratosis, inflammation, dysplasia and OSCC. There was no significant difference in circularity between CVC and LBC among all lesions. Conclusion: Only one cytomorphological disadvantage was seen with LBC, in the form of decreased hyperchromasia. Further clarification of the advantages and disadvantages of LBC is needed, including management of precision and screening practices.

Minor Salivary Gland Tumors: A Retrospective Study of 37 Cases

Salivary gland tumors represent 2% - 6.5% of all head and neck tumors. Since salivary gland tumors have various clinical features and histological types, it is often difficult to diagnose and treat them. The aim of this study was to conduct a retrospective clinical-statistical analysis of 37 minor salivary gland tumors (MSGTs) treated in the Department of Oral Surgery at Nihon University School of Dentistry at Matsudo over a 16-year period. The frequencies and distributions of sex, age, occurrence site, preoperative examination (fine needle cytology and/or biopsy), treatment, and prognosis of the tumors were analyzed and compared with previous reports. The average age at diagnosis was 58.1 years (range 22 - 91 years). The peak occurrence of tumors was in the sixties (10 cases, 27.0%), followed by the forties (8 cases, 21.6%) and the seventies (7 cases, 18.9%). The average age of patients with benign tumors was 56.8 years (range 22 - 91 years). For malignant tumors, the average age was 61.7 years (range 42 - 81 years). The male-female ratio was 1:2.1 for all minor salivary gland tumors, 1:2.4 for benign tumors, and 1.5:1 for malignant tumors. There were 27 (73.0%) benign and 10 (27.0%) malignant tumors. Pleomorphic adenoma (PA) was the most common tumor (24 (64.9%) cases). Most salivary gland tumors originated from the palate (21 cases, 56.8%);the second most common site was the buccal mucosa (14 cases, 37.8%). For most patients, an intraoral mass was the primary presentation, and the second most common symptom was swelling. Surgical treatment was performed for all cases, both benign and malignant tumors. There was one case of local recurrence of PA, as well as one of multiple lung metastases after surgery for adenoid cystic carcinoma. Diagnosis and treatment of MSGTs are often delayed because the patients have few symptoms, and it is difficult to distinguish benign from malignant tumors. More cases need to be examined in the future, and the diagnostic accuracy of imaging and histopathological diagnosis needs to be improved.

Histopathological and Immunohistochemical Study of the Distinction between Oral Lichen Planus and Oral Lichenoid Lesions

Background: Oral potentially malignant disorders, which include oral lichen planus (OLP), are clinical presentations that carry a risk of development to cancer in the oral cavity. Oral lichenoid lesions (OLLs) are also termed interface/lichenoid mucositis. Malignant transformation of them remains controversial, but distinct clinical and histological criteria for how to differentiate OLP from OLLs have not been developed. Objectives: The purpose of this study was to elucidate findings that can allow histopathological differentiation of OLP and OLLs using histomorphological and immunohistochemical analyses. Materials and Methods: Analyses were performed in 10 cases diagnosed with OLP and 9 cases diagnosed with OLLs. Cytokeratin 19 (CK19), Ki-67 and CD3 were used as primary antibodies to detect basal cells, proliferative activity and T-cell distribution, respectively, and Perlecan and COX-2 to evaluate epithelial intracellular arrangements and interstitial distributions of proteoglycans and enzymes. Results: For CK19, positive cells were significantly found in OLLs at both the prominent area and site adjacent to the lesion comparison with those of OLP’s. The number of COX-2 positive cells was significantly higher in spinous and basal layers in OLLs of the prominent area. Additionally, OLLs showed mild to moderate expression for perlecan in the basal to spinous layers and in subepithelial tissue. Conclusion: Almost no basal cells were noted in the prominent area in OLP. COX-2 and perlecan were found in the basal to spinous layers in OLLs. Although there are restrictions, these suggested the possibility of helping to distinguish between OLP and OLLs.