Synergistic effect of zoledronate and compressive force suppresses proliferation and differentiation of human gingival fibroblasts.

We investigated the effects of zoledronate (ZA) and compressive force, separately and in combination, on the proliferation and differentiation of human gingival fibroblasts (HGFs) to verify the mechanism underlying medication-related osteonecrosis of the jaw (MRONJ). The addition of 100 µM ZA markedly inhibited cell proliferation. Expression of type I collagen, fibroblast growth factor 2, and connective tissue growth factor genes, was decreased by ZA and compressive force. Similar results were observed for collagen expression by using Sirius red staining. These results, together with clinical findings that MRONJ is more common in cases with excessive mechanical stress on the oral mucosa, suggest that bisphosphonates such as ZA and mechanical stress may act in conjunction as risk factors for the development of MRONJ by affecting homeostasis of the oral mucosal tissues, including HGFs.

Ultrasound-guided arthrocentesis for condylar head fracture: a technical report.

OBJECTIVES: Double puncture arthrocentesis (DPA) of the temporomandibular joint (TMD) is considered an effective preservative option for managing mandibular condylar head fractures. However, the procedure is commonly performed by a traditional "blind" method using anatomical characteristics. In the present study, an ultrasonography (US) device was applied for the treatment of a case with a fractured mandibular condyle. METHODS: A 79-year-old female was diagnosed right side condylar head fracture complaining pain of right TMD and reduced mouth opening range: inter-incisor distance of 20 mm. Since the fracture position was high and inoperable, the decision was made to perform DPA of the TMD. The US probe was positioned parallel and slightly oblique to the major axis of the mandibular ramus. Both the posterior and anterior insertions into the joint space were performed according to the axis mentioned above, which enabled the operator to visualize the entirety of the needle. RESULTS: The device offered safety and ensured accuracy by providing real-time visual aid to the surgeon. The procedure provided an early increase in the inter-incisor distance (31 mm) and pain relief. CONCLUSIONS: Hence, for the preservative treatment of mandibular condylar head fractures, based on the present study, we recommend US-guided arthrocentesis as a safe, feasible, and effective therapeutic option instead of the conventional "blind" method.

Clinical evaluation of bone quality of particulate cancellous bone and marrow, and implant prosthetic rehabilitation.

This study aimed to subjectively evaluate bone quality in the particulate cancellous bone and marrow (PCBM) graft area and to assess the survival rates of implants. A retrospective review was conducted based on patient age, sex, diagnosis, reconstructed site, number of implants, prosthetic type, and duration of follow-up. Images from computed tomography (CT) before implant insertion were obtained and used in this study. We selected a 4.0-mm diameter × 8.0-mm length region of interest in the implant placement area, and measured the CT attenuation value. No significant correlations were seen between CT attenuation values and implant survival rates in the maxilla and mandible. On the other hand, CT attenuation values and implant survival rates were significantly lower in patients with malignancy than in non-malignant cases. Placing implants in PCBM grafted bone requires a full understanding of bone quality before surgery and drilling to ensure primary stability, along with consideration of soft tissue management and maintenance programs.

Factors influencing delayed referral of oral cancer patients from family dentists to the core hospital.

Background/purpose: Most oral cancer (OC) cases are identified by family dentists in Japan. However, a significant number of patients with OC in Japan are referred to core hospitals at advanced stages. Therefore, identifying the factors that contribute to delayed referrals from family dentists to core hospitals is crucial for detecting OC in its earlier stages. The aim of this retrospective study was to identify the risk factors for referral delays from family dentists to core hospitals. Materials and methods: The study included 63 patients with OC who were referred by family dentists to the Yamagata University Hospital between 2010 and 2022. The clinical parameters related to referral delays were retrospectively investigated using letters of reference provided by the family dentists and patient charts. Backward multiple regression analysis was performed to identify the relationships between the length of referral delay and potential risk factors. Additionally, backward multivariate logistic regression analysis was performed to examine the independent association between referral delays of >4 weeks and several clinical parameters. Results: Multiple regression analysis revealed that misdiagnosis of malignant lesions by family dentists (P = 0.047) was significantly associated with longer referral delays. Additionally, misdiagnosis of malignant lesions by family dentists was also an independent risk factor for referral delays of >4 weeks (odds ratio, 10.387; P = 0.006). Conclusion: Misdiagnosis of malignant lesions by family dentists was a significant risk factor for referral delays from family dentists to core hospitals. Our results will motivate family dentists to improve their ability to diagnose OC.