Assessing the Impact of Smoking Cessation Interventions on Periodontal Health and Gingival Inflammation in Smokers with Periodontitis.

Background: Smoking is a well-established risk factor for periodontitis, a chronic inflammatory disease of the oral cavity. While smoking cessation has been linked to improved overall health, its specific impact on periodontal health and gingival inflammation in individuals with periodontitis remains less explored. Materials and Methods: We conducted a prospective cohort study involving 200 smokers diagnosed with periodontitis. Participants were divided into two groups: Group A received comprehensive smoking cessation interventions, including counseling and pharmacotherapy, while group B continued smoking without intervention. Periodontal health was assessed through clinical parameters, including probing depth (PD) and clinical attachment level (CAL), at baseline and 6 months post intervention. Gingival inflammation was evaluated using the Gingival Index (GI). Results: After 6 months, group A exhibited a significant reduction in mean PD (from 4.5 mm to 3.2 mm) and CAL (from 5.0 mm to 3.5 mm) compared to group B. Conversely, group B showed no significant change in these parameters. The GI score significantly decreased in group A (from 2.8 to 1.2) but remained unchanged in group B. Furthermore, group A demonstrated a higher rate of smoking cessation (72%) compared to group B (14%). Conclusion: Smoking cessation interventions play a crucial role in improving periodontal health and reducing gingival inflammation in smokers with periodontitis. The observed reductions in PD, CAL, and gingival inflammation highlight the potential benefits of smoking cessation on oral health outcomes in this high-risk population.

Comparison of Different Suturing Techniques in Post-Extraction Socket Healing.

Background: The process of post-extraction socket healing is critical for ensuring proper tissue repair and minimizing complications in dental practice. Suturing techniques play a pivotal role in this process, influencing wound closure, hemostasis, and overall healing. Materials and Methods: This prospective clinical trial involved 80 participants who required single-tooth extractions. Patients were randomly assigned to four groups, each receiving a distinct suturing technique: simple interrupted sutures, horizontal mattress sutures, vertical mattress sutures, and continuous sutures. Standardized assessments, including clinical examination and cone-beam computed tomography (CBCT) scans, were performed at baseline, 1 week, and 4 weeks post-extraction. Wound dehiscence, soft tissue healing, and bone preservation were evaluated. Results: At 1-week post-extraction, the continuous suture group exhibited the lowest rate of wound dehiscence (5%) compared to other groups (simple interrupted, 15%; horizontal mattress, 10%; vertical mattress, 12%). Soft tissue healing scores at 4 weeks were significantly higher in the continuous suture group (8.7 ± 0.5) than in the other groups (simple interrupted, 7.2 ± 0.8; horizontal mattress, 7.8 ± 0.7; vertical mattress, 7.5 ± 0.6). CBCT analysis revealed superior bone preservation in the continuous suture group (98% remaining bone volume) compared to the other groups (simple interrupted, 92%; horizontal mattress, 95%; vertical mattress, 94%). Conclusion: This study demonstrates that the continuous suturing technique offers advantages in post-extraction socket healing, including reduced wound dehiscence, improved soft tissue healing, and better bone preservation.

Surgical vs. Non-Surgical Management of Temporomandibular Joint Disorders: Clinical Outcomes.

Background: Temporomandibular joint disorders (TMDs) encompass a range of clinical conditions affecting the temporomandibular joint (TMJ) and associated structures. Management approaches for TMDs vary and include both surgical and non-surgical interventions. Materials and Methods: In this retrospective cohort study, medical records of 150 patients diagnosed with TMDs were reviewed. Patients were categorized into two groups: surgical intervention and non-surgical intervention. The surgical group underwent various surgical procedures, including arthroscopy, arthroplasty, and joint replacement, while the non-surgical group received conservative treatments such as physical therapy, pharmacotherapy, and occlusal splints. Pain levels, TMJ function, quality of life (QoL), and patient satisfaction were assessed at baseline and post-treatment (6 months and 1 year). Results: At the 6-month follow-up, both groups experienced a significant reduction in pain scores (surgical group: 6.3 ± 1.2 to 2.4 ± 0.9, non-surgical group: 6.1 ± 1.1 to 3.2 ± 1.0). TMJ function improved in both groups (surgical group: 2.5 ± 0.8 to 4.8 ± 0.6, non-surgical group: 2.6 ± 0.7 to 4.2 ± 0.9). QoL scores increased (surgical group: 35.2 ± 4.6 to 50.3 ± 5.1, non-surgical group: 35.5 ± 4.2 to 45.7 ± 4.8), and patient satisfaction rates were high (surgical group: 92%, non-surgical group: 87%) at the 1-year follow-up. Conclusion: Both surgical and non-surgical management approaches demonstrated significant improvements in pain relief, TMJ function, QoL, and patient satisfaction for individuals with TMDs.

A Case of Broken Local Anesthetic Needle in the Pterygomandibular Space; Diagnostic Approaches and Surgical Management.

Needle fracture during dental local anesthetic injections is a rare but significant, potentially serious complication. Various approaches for the location and removal of broken needles have been described; however, there are several difficulties and concerns related to the potential complications and critical anatomic challenges peculiar to the head and neck region. In this case, we describe the diagnostic approaches utilized in locating a broken needle that migrated in the pterygomandibular space following gag reflex, and sudden head movement of a middle-aged male patient. A meticulous diagnostic approach was employed to locate the needle utilizing CBCT scan, CT scan with contrast, and C-arm X-ray machine. The needle was successfully retrieved using an angled hemostat inserted through an oral incision, guided by a C-arm X-ray machine and ENT endoscopic instruments. While careful planning could prevent many complications that may arise during oral surgical procedures, inadvertent events leading to serious complications should be addressed using the appropriate and timely diagnostic techniques pre-and intra-operatively.

Solitary Angiokeratoma of the Labial Mucosa: Report of a Rare Case and Literature Review.

Oral angiokeratoma is a rare vascular lesion that has various clinical presentations. It usually occurs as part of generalized angiokeratoma and rarely appears as a solitary lesion with no underlying systemic diseases. Only 33 cases were reported so far worldwide. In this case report, we present a rare case of isolated solitary oral angiokeratoma in a 22-year-old female patient, which is the first case to be reported in the labial mucosa that has been treated successfully by surgical excision.

Jaw-related complications in COVID-19 patients; a systematic review.

OBJECTIVE: The aim of this review was to highlight jaw-related complications in COVID-19 manifestations, their etiology, and prevention methods. METHODS: A systematic review of literature was conducted. MEDLINE/PubMed, and Google Scholar were searched for the following keywords: "COVID-19" "Oral manifestations", "Musculoskeletal patients", "Mandible", "Jaw", "Osteonecrosis", "MRONJ", and "dry socket". RESULTS: Only nine articles were included in this review. Jaw-related disorders associated with COVID-19 were dry socket, osteonecrosis, and orofacial pain related to temporomandibular joint disorders (TMD) and giant cell arteritis (GCA). CONCLUSION: COVID-19 potentially predisposes to osteonecrosis due to thrombotic inflammatory phenomena caused by the disease itself or its therapeutic modalities. All jaw osteonecrosis cases reported so far in relation to COVID-19 affected the upper jaw. Orofacial pain in COVID-19 patients was related to TMD and GCA. Clinical evidence-based studies are required to investigate the actual prevalence and possible correlation between COVID-19 and jaw-related disorders.

COVID-19 Infection in Academic Dental Hospital Personnel; A Cross-Sectional Survey in Saudi Arabia.

BACKGROUND: Close patient contact is an essential component of clinical dental education, which can expose students and faculty to risk of COVID-19 and its sequelae. METHODS: The study was a cross-sectional survey conducted among faculty and clinical students at an academic dental hospital in Al Madinah western Saudi Arabia. An online questionnaire was distributed to collect data on prevalence, risk factors, clinical manifestations, and long-term health and socioeconomic complications of COVID-19 infection. RESULTS: Prevalence of COVID-19 was 19.6% among a total of 316 students and faculty. Participants cited family and friends as the primary source of infection (40.3%). Among cross-infection control practices, they cited failure to practice distancing as the primary reason for infection transmission (61.3%). The disease was symptomatic in 85.5% of infected personnel. Most frequently reported clinical manifestations were: fever, cough, malaise, and diarrhoea (74.1%, 56.5%, 40.3%, 32.3%, respectively). A proportion of 37.1% of infected personnel stated that they had long COVID-19, and 58.3% of infected students reported deteriorated academic achievement. CONCLUSIONS: One in five of clinical dental students and their faculty had COVID-19. Most cases were symptomatic, and a large proportion developed long COVID or adverse socioeconomic consequences. Regardless of the severity of symptoms encountered during the acute stage of COVID-19 infection, all infected dental healthcare personnel should be followed, especially those who report long COVID. Continuous follow-up and assistance for infected students may be warranted to mitigate the potential academic and mental drawbacks caused by the pandemic. Dental schools should adopt clear policies regarding COVID-19 transmission and prevention and should implement them in their infection-control education and training.

Side Effects Reported by Jordanian Healthcare Workers Who Received COVID-19 Vaccines.

Background Distribution of COVID-19 vaccines has been surrounded by suspicions and rumors making it necessary to provide the public with accurate reports from trustworthy experts such as healthcare professionals. Methods We distributed a questionnaire in Jordan among physicians, dentists and nurses who received a COVID-19 vaccine to explore the side effects (SE) they encountered after the first or the second dose of one of three vaccines namely: AstraZeneca Vaxzevria (AZ), Pfizer-BioNTeck (PB), and SinoPharm (SP) vaccines. Results A total of 409 professionals participated. Approximately 18% and 31% of participants reported no SE after the first dose and second dose, respectively. The remainder had mostly local side effects related to injection site (74%). Systemic side effects in the form of fatigue (52%), myalgia (44%), headache (42%), and fever (35%) prevailed mainly after the first dose. These were significantly associated with AZ vaccine, and age ≤ 45 years (p = 0.000 and 0.01, respectively). No serious SE were reported. Conclusions We can conclude that SE of COVID-19 vaccines distributed in Jordan are within the common range known so far for these vaccines. Further studies are needed to include larger sample size and longer follow-up period to monitor possible serious and long-term SE of the vaccines.

Measuring the impact of systemic sclerosis on oral health-related quality of life in a UK population.

BACKGROUND: The objective of the present study was to identify the impact of systemic sclerosis (SSc) upon oral health-related quality of life (OHRQoL) of affected individuals resident in the UK. METHODS: A total of 100 patients and their partners or carers were invited to complete questionnaires regarding the impact of SSc on quality of life and psychological well-being using valid and reliable patient-reported outcome measures (OHIP-14, MHISS, OIDP, MDAS and HADS). A total of 50 patients with SSc and 18 partners or carers who acted as controls returned the completed questionnaires. Statistical analyses were performed for comparisons of different variables. RESULTS: All the mean scores of OHIP-14 (SSc [16.5 ± 12.4] Vs controls [6.06 ± 7.6, p = 0.001]) and MHISS components were significantly higher in patients than those of control group (SSc [21.26 ± 12] Vs controls [4.8 ± 7.3, p < 0.0001]). Majority of OIDP mean scores were significantly worse in patients compared with controls [SSc (10 ± 8.7) Vs controls (1.72 ± 3.4, p < 0.0001)]. The mean of total MDAS [SSc (11.7 ± 5.3) Vs controls (9.5 ± 4.4)] and HADS scores were higher in patients compared to controls (SSc depression [4.8 ± 3.3] and anxiety [6 ± 4.6] Vs controls [3.7 ± 3.1] [4.7 ± 3.9]). CONCLUSIONS: Although the present study is limited by the low response rate and its cross-sectional design, present results highlighted that systemic sclerosis has a negative impact on OHRQoL of the affected individuals; hence, the evaluation of associated psychological impact including anxiety and depression symptoms is needed to better understand, monitor and evaluate the disease comorbidity in patients with SSc.

What the dental practitioner needs to know about pharmaco-therapeutic modalities of COVID-19 treatment: A review.

BACKGROUND/PURPOSE: Several pharmacotherapeutic methods have been used for the treatment of COVID-19 with varying degrees of success. No definitive treatment or vaccine has been officially approved to-date. This review aimed to highlight COVID-19 pharmacotherapeutic agents that are relevant to dental practice in terms of their clinical indications in COVID-19 and dental practice, as well as their adverse effects as they impact the dental patient. MATERIAL AND METHODS: Systematic search was performed using the following keywords combinations: Pharmacotherapy AND COVID-19 OR Pharmacotherapy AND SARS-CoV-2 OR Treatment AND COVID-19. Studies were categorized according to the type of pharmacotherapy used. Pharmacotherapeutic agents were extracted and only those relevant to dental practice were included for review. RESULTS: For analysis, a total of 79 clinical trials research articles were included that included COVID-19 pharmacotherapeutic agents relevant to dental practice. Those were analgesics (paracetamol; non-steroidal anti-inflammatory agents); antibiotics (azithromycin, doxycycline, metronidazole); antivirals (penciclovir); and immunomodulatory agents (hydroxychloroquine, corticosteroids). While some COVID-19 drugs are less relevant to dental practice, as antivirals and hydroxychloroquine, their association with long-term adverse effects requires adequate knowledge among dental practitioners. CONCLUSION: Many of COVID-19 pharmacotherapeutic agents are used to treat oral diseases particularly orofacial pain and inflammatory conditions. Furthermore, some of these drugs may induce adverse effects that complicate dental treatment. Thorough knowledge of COVID-19 therapy and its dental implications is essential for dental practitioners, and is expected to contribute to a better understanding and effective utilization of these therapeutic agents.

Utilization of Teledentistry in Antimicrobial Prescribing and Diagnosis of Infectious Diseases during COVID-19 Lockdown.

OBJECTIVES: This study aimed to analyze Jordanian dentists' inquiries on oral infections and antimicrobial prescribing using dental professional WhatsApp groups during coronavirus disease lockdown period. MATERIALS AND METHODS: Three professional WhatsApp groups of Jordanian dentists were reviewed and analyzed for inquiries posted during the period from January to May 2020. Inquiries were sent from patients to their dentists who posted these inquiries to the professional WhatsApp dental groups for consultation and professional advice. All queries regarding oral infections and antimicrobial prescribing were extracted and analyzed. RESULTS: Three WhatsApp professional groups with a total numbers of members of 750 dentists who posted queries about their patients were included in this study. Dentist members posted queries about their patients to these professional WhatsApp groups. There was a total of 32 inquiries regarding oral lesions and 11 consultations regarding prescribing and dental management of medically compromised patients giving a total of 43 consultations. Among which there were 19 inquiries on oral infections and 9 inquiries on antimicrobial prescribing giving a total of 28 consultations. Most common inquiries were on bacterial infections (localized dentoalveolar abscess, pericoronitis, cellulitis, and lymphoid hyperplasia of the tongue), viral herpetic infections, and Candida infections (erythematous and pseudomembranous candidiasis). CONCLUSIONS: Many dental practitioners cannot distinguish the correct diagnostic features of oral infections particularly viral and fungal infections. Continuing education should be considered to focus on clinical manifestations of various oral infections. Further, educational activities that focus on variations in treatment protocols for various infections should be introduced particularly those that concern indications for antimicrobial prescribing.

COVID-19: Present and Future Challenges for Dental Practice.

COVID-19 was declared a pandemic by the World Health Organization, with a high fatality rate that may reach 8%. The disease is caused by SARS-CoV-2 which is one of the coronaviruses. Realizing the severity of outcomes associated with this disease and its high rate of transmission, dentists were instructed by regulatory authorities, such as the American Dental Association, to stop providing treatment to dental patients except those who have emergency complaints. This was mainly for protection of dental healthcare personnel, their families, contacts, and their patients from the transmission of virus, and also to preserve the much-needed supplies of personal protective equipment (PPE). Dentists at all times should competently follow cross-infection control protocols, but particularly during this critical time, they should do their best to decide on the emergency cases that are indicated for dental treatment. Dentists should also be updated on how this pandemic is related to their profession in order to be well oriented and prepared. This overview will address several issues concerned with the COVID-19 pandemic that directly relate to dental practice in terms of prevention, treatment, and orofacial clinical manifestations.

Association of Dental Caries, Retained Roots, and Missing Teeth with Physical Status, Diabetes Mellitus and Hypertension in Women of the Reproductive Age.

OBJECTIVES: To investigate in women of reproductive age a possible association between particular dental diseases-dental caries, retained roots, and missing teeth-with some systemic conditions-physical status score- ASA (American Society for Anesthesiologists), diabetes mellitus, and hypertension. METHODS: Dental and medical history were retrieved from the electronic files of dental patients. Statistical analysis was performed using cross tabulation with the Chi-square test to explore the significance of an association between variables pertaining to dental diseases and the investigated systemic conditions. Logistic regression was further used to explore the significance of the above dental diseases as predictors for systemic conditions. RESULTS: A total of 1768 female patients in the age range 18-55 were included, with a mean age of 31.2 ± 10.13 years. A total of 228 (12.9%) patients had a chronic systemic disease within the ASA II category, 66 (3.7%) were diabetic, and 76 (4.3%) were hypertensive. Missing teeth were significantly associated with the ASA II category, diabetes mellitus, and hypertension (p < 0.001, p = 0.009, p = 0.005 respectively), while retained roots were significantly associated with the ASA II category only (p = 0.023). Logistic regression showed a low predictive capacity of models describing the three systemic conditions. CONCLUSIONS: Diabetes mellitus and hypertension were the most common systemic diseases among the study sample. While carious teeth had no significant association with the investigated systemic conditions, retained roots were significantly associated with the ASA II category only, and missing teeth were significantly associated with all investigated systemic conditions. However, oral diseases expressed a low predictive power of these systemic conditions.

Proteomic and histopathological characterization of the interface between oral squamous cell carcinoma invasion fronts and non-cancerous epithelia.

Oral squamous cell carcinomas (SCCs) are frequently associated with pre-invasive lesions including carcinoma in-situ (CIS), and CISs further form lateral interfaces against surrounding normal or dysplastic epithelia (ND). At the interface where keratin (K) 17 positive (+) SCC/CIS cells are in contact with K13+ ND cells, "cell competition" must be evoked between two such different cell types. Thus, the aim of this study was to characterize the histopathology of the SCC/CIS-ND interface and to determine protein profiles around the interface by proteomics. A total of 112 lateral interfaces were collected from 55 CIS and 57 SCC foci, and they were investigated by immunohistochemistry and liquid chromatography-tandem mass spectrometry. The interfaces were morphologically classified into three types: vertical, oblique, and convex. There were several cellular changes characteristic to the interface, including apoptosis and hyaline bodies, which were more emphasized in SCC/CIS sides. The results suggested that ND cells were winners of cell competition against SCC/CIS cells. Then, the interfaces were divided into four vertical segments, and each segment was separately laser-microdissected from tissue sections with immunostaining for K13 or K17; the four segments included SCC/CIS away from (#1) or adjacent to (#2) the interface, and ND adjacent to (#3) or away from (#4) the interface. Proteome analyses revealed approximately 4000 proteins from SCC/CIS sides [#1 and #2] and 2800 proteins from ND sides [#3 and #4]. We quantitatively selected the top 25 proteins including ladinin-1 or interleukin-1 receptor antagonist protein, which were most contrastively increased or decreased in SCC/CIS or ND sides, respectively, and their specific immunohistochemical expression modes were confirmed in tissue sections as well as in cultured SCC cells. These molecules should be involved in the cellular crosstalk toward cell competition at the lateral interface of oral SCC/CIS and would be new candidates for histopathological distinction of oral malignancies.

Aberrant expression of the tight junction molecules claudin-1 and zonula occludens-1 mediates cell growth and invasion in oral squamous cell carcinoma.

We reported that altered cell contact mediated by E-cadherin is an initial event in the pathogenesis of oral epithelial malignancies. To assess other effects of cell adhesion, we examined the expression levels of tight junction (TJ) molecules in oral carcinoma in situ (CIS) and squamous cell carcinoma (SCC). To identify changes in the expression of TJ molecules, we conducted an analysis of the immunohistochemical profiles of claudin-1 (CLDN-1) and zonula occludens-1 (ZO-1) in surgical specimens acquired from patients with oral SCC containing foci of epithelial dysplasia or from patients with CIS. We used immunofluorescence, Western blotting, reverse-transcription polymerase chain reaction, and RNA interference to evaluate the functions of CLDN-1 and ZO-1 in cultured oral SCC cells. TJ molecules were not detected in normal oral epithelial tissues but were expressed in SCC/CIS cells. ZO-1 was localized within the nucleus of proliferating cells. When CLDN-1 expression was inhibited by transfecting cells with specific small interference RNAs, SCC cells dissociated, and their ability to proliferate and invade Matrigel was inhibited. In contrast, although RNA interference-mediated inhibition of ZO-1 expression did not affect cell morphology, it inhibited cell proliferation and invasiveness. Our findings indicated that the detection of TJ molecules in the oral epithelia may serve as a marker for the malignant phenotype of cells in which CLDN-1 regulates proliferation and invasion.

Tumour-associated macrophages are recruited and differentiated in the neoplastic stroma of oral squamous cell carcinoma.

To confirm our hypothesis that macrophages recruited to fight against oral squamous cell carcinoma (SCC) invasion are functionally differentiated within neoplastic stromata, we analysed arrangements of macrophage subtypes and cancer-associated fibroblasts (CAFs) in their association with blood vasculatures in the neoplastic stroma. Surgical specimens of oral SCC were immunohistochemically examined for macrophage phenotypes (CD68, CD163, and CD204) and stromal environments (perlecan, connexin 43, and CD31). Human monocytes were co-cultured with ZK-1 cells of oral SCC origin in different culture conditions. SCC stromata were divided into two types: fascicular (fibroblast-rich) and reticular (perlecan-rich). Regardless of stromal types, CD68 positive (+)/CD163+/CD204+ macrophages were recruited when blood vessels were abundant. Connexin 43+ fibroblasts were enriched in the fascicular stroma, where blood vessels were depleted. In co-culture experiments, monocytes, in the presence of ZK-1 cells, showed TNF-α(low)/IL-12(low) and IL-10(high)/VEGF(high)/MMP-9(high) with increased expression levels for fibronectin and perlecan. With direct contact with monocytes, SCC cells also expressed CD68 and CD163. SCC stromata were characterised by CD163+/CD204+ tumour-associated macrophages (TAMs) and connexin 43+ CAFs. TAMs are differentiated from monocytes by the physical contact with oral SCC cells in the perlecan-rich neoplastic stroma, which is also induced by the cross-talk between SCC cells and stromal cells including TAMs.

Differential immunohistochemical expression profiles of perlecan-binding growth factors in epithelial dysplasia, carcinoma in situ, and squamous cell carcinoma of the oral mucosa.

The intercellular deposit of perlecan, a basement-membrane type heparan sulfate proteoglycan, is considered to function as a growth factor reservoir and is enhanced in oral epithelial dysplasia and carcinoma in situ (CIS). However, it remains unknown which types of growth factors function in these perlecan-enriched epithelial conditions. The aim of this study was to determine immunohistochemically which growth factors were associated with perlecan in normal oral epithelia and in different epithelial lesions from dysplasia and CIS to squamous cell carcinoma (SCC). Eighty-one surgical tissue specimens of oral SCC containing different precancerous stages, along with ten of normal mucosa, were examined by immunohistochemistry for growth factors. In normal epithelia, perlecan and growth factors were not definitely expressed. In epithelial dysplasia, VEGF, SHH, KGF, Flt-1, and Flk-1were localized in the lower half of rete ridges (in concordance with perlecan, 33-100%), in which Ki-67 positive cells were densely packed. In CIS, perlecan and those growth factors/receptors were more strongly expressed in the cell proliferating zone (63-100%). In SCC, perlecan and KGF disappeared from carcinoma cells but emerged in the stromal space (65-100%), while VEGF, SHH, and VEGF receptors remained positive in SCC cells (0%). Immunofluorescence showed that the four growth factors were shown to be produced by three oral SCC cell lines and that their signals were partially overlapped with perlecan signals. The results indicate that perlecan and its binding growth factors are differentially expressed and function in specific manners before (dysplasia/CIS) and after (SCC) invasion of dysplasia/carcinoma cells.

Paradental cyst is an inclusion cyst of the junctional/sulcular epithelium of the gingiva: histopathologic and immunohistochemical confirmation for its pathogenesis.

OBJECTIVE: The aim of this study was to characterize the histologic and immunohistochemical profiles of paradental cyst-lining epithelia to clarify its histopathogenesis. STUDY DESIGN: Ten surgical specimens of paradental cysts were examined for clinical profiles and to determine the histopathologic characteristics of the lining epithelia. Immunohistochemical profiles for keratin (K) subtypes, as well as for perlecan, UEA-I lectin binding, and proliferating cell nuclear antigen (PCNA), were determined and compared. RESULTS: The paradental cyst was clinically characterized by its occurrence in young adults (mean age, 36.8 years; male, 42.8, female 27.8). Eight of the 10 cases arose in the retromolar area. The cyst wall was basically granulation tissue that was attached to the periodontal ligament space. Thin irregular anastomosing epithelial cords lined the cyst walls of immature granulation tissue with vascular dilation and hemorrhage. The intercellular space of the lining epithelia was widened with inflammatory cell infiltrates. Immunohistochemically, the lining was positive for K13, K14, K17, K19, UEA-I binding, and perlecan, suggesting its junctional/sulcular epithelial character. CONCLUSION: The results showed that the paradental cyst was lined by epithelial cells with characteristics of the junctional/sulcular epithelium. The cyst can thus be considered as a kind of inclusion cyst arising in the periodontal pocket, most frequently of the mandibular third molars of young adults.

Protease-activated receptor 2 modulates proliferation and invasion of oral squamous cell carcinoma cells.

Based on our previous finding that protease-activated receptor 2 (PAR-2) regulates hemophagocytosis of oral squamous cell carcinoma (SCC) cells, which induces their heme oxygenase 1-dependent keratinization, we have formulated a hypothesis that PAR-2 functions in wider activities of SCC cells. To confirm this hypothesis, we investigated immunohistochemical profiles of PAR-2 in oral SCC tissues and its functional roles in cell proliferation and invasion in SCC cells in culture. The PAR-2 expression modes were determined in 48 surgical tissue specimens of oral SCC. Using oral SCC-derived cell systems, we determined both gene and protein expression levels of PAR-2. SCC cell proliferation and invasive properties were also examined in conditions in which PAR-2 was activated by the synthetic peptide SLIGRL. PAR-2 was immunolocalized in oral SCC and carcinoma in situ cells, especially in those on the periphery of carcinoma cell foci (100% of cases), but not in normal oral epithelia. Its expression at both gene and protein levels was confirmed in 3 oral SCC cell lines including ZK-1. Activation of PAR-2 induced ZK-1 cell proliferation in a dose-dependent manner. PAR-2-activated ZK-1 cells invaded faster than nonactivated ones. The expression of PAR-2 is specific to oral malignancies, and PAR-2 regulates the growth and invasion of oral SCC cells.