Endothelin (ET) is a peptide comprising 21 amino acids, and its G-protein coupled ETA and ETB receptors are expressed in both cancer cells and cancer-associated cells. Cancer cells excessively express ETA and ETB receptors, and mechanical stimulation promotes the growth and migration of these cells. The autocrine and paracrine signaling of ET is involved in several cancer metabolic pathways, but how this is mediated by the ET-axis (ET and its receptors) remains to be clarified. This study investigated ET-axis-mediated autocrine/paracrine communication in rat squamous cell carcinoma (SCC) in response to direct mechanical stimulation of such cells. Intracellular free Ca²⁺ concentration ([Ca²⁺]_i) was determined using fura-2/AM from a rat SCC cell line (SCC-158). Direct mechanical stimulation of the SCC-158 cells using glass micropipettes to compress the cell membrane to 8 μm for 4 sec induced a transient increase in [Ca²⁺]_i. This increase was also observed in the neighboring cells of the stimulated SCC-158 cells. Treatment with 10 μM Gd³⁺ or 1 μM GsMTx4 almost completely inhibited the mechanical stimulation-induced increase in [Ca²⁺]_i in the SCC-158 cells. Application of 1 μM BQ-123 (an ETA receptor antagonist) inhibited the increase in [Ca²⁺]_i in the stimulated SCC-158 and neighboring cells, whereas that of BQ-788 (an ETB receptor antagonist) had no such effect. These findings suggest that rat SCC cells express the Piezo1 channel. Activation of the Piezo1 channel induced endothelin release from the mechanically stimulated SCC-158 cells. Released ET activated ETA receptors in neighboring SCC-158 cells. These findings also suggest that intercellular paracrine communication among SCC-158 cells through ET signaling plays an important role in the development and metabolism of SCC cells.

Maxillary sinus floor elevation is an option in cases where bone volume in the maxillary molar region is clearly insufficient to allow implant therapy. However, few studies have reported long-term observation of change in bone volume in the same case over a period of 10 or more years. This report describes a case of implant placement following maxillary sinus floor elevation using iliac bone with long-term monitoring of changes in peri-implant bone volume. The patient was a 58-year-old man who visited our clinic in April 2008 with the chief complaint of chewing problems due to missing teeth. The maxillary sinus floor bone had thinned on both sides, and bilateral maxillary sinus floor elevation using an iliac bone graft was therefore planned. In September 2008, trabecular bone containing bone marrow was harvested from the left side of the ilium, and bilateral maxillary sinus floor elevation was carried out with the patient under general anesthesia. After bone healing for approximately 6 months, a total of eight implants were placed in the maxilla under intravenous sedation in March and April 2009. A telescopic-retained implant-supported fixed bridge was attached as the final superstructure in April 2010. Regarding change in bone volume in the elevated maxillary sinus floor, a reduction in bone height was seen during the period between maxillary sinus floor elevation to implant placement. Following implant placement, however, there was no obvious decrease in bone volume, which has remained stable for 10 years following fitting of the superstructure. Maxillary sinus floor elevation with autologous iliac bone graft has thus shown long-term stability in bone volume over more than 10 years following the procedure. Rigorous follow-up of change in bone volume at the engraftment site is still needed, however.

This report describes a case of generalized chronic periodontitis requiring periodontal treatment including regenerative therapy. The patient was a 50-year-old woman who visited our clinic requesting periodontal therapy. An initial examination revealed 41.6% of sites with a probing depth (PD) of ≥4 mm and 63.7% of sites with bleeding on probing. The periodontal inflamed surface area (PISA) was 1539.9 mm². Radiographic examination showed furcation involvement in #26, angular bone defect in #46, and horizontal resorption in other regions. Based on a clinical diagnosis of generalized severe chronic periodontitis (Stage III Grade B), initial periodontal therapy consisting of plaque control, and scaling and root planing was performed. Following suppression of inflammation, occlusal adjustment of cuspal interference sites was performed. After re-evaluation, periodontal surgery was performed at selected sites. Periodontal regenerative therapy was performed using autogenous bone graft for #26 and enamel matrix derivative for #46. Other sites with residual periodontal pockets were treated by open flap debridement. Following further re-evaluation, the patient was placed on supportive periodontal therapy. The patient’s oral health-related quality of life showed a marked improvement after periodontal therapy. Regenerative therapy resulted in improvement in clinical parameters. Such improvement has been adequately maintained over a 7-year period. The most recent examination revealed 2.4% of sites with a PD of ≥4 mm, and the PISA was 138.2 mm². However, the furcation involvement has not been completely resolved in #26. It is necessary to continue to control inflammation and occlusion and maintain the condition of the periodontal tissue.

This report describes a case of periodontitis treated with periodontal surgery incorporating autogenous bone graft and recombinant human fibroblast growth factor (rhFGF) -2. The patient was a 49-year-old woman who visited the Tokyo Dental College Suidobashi Hospital with the chief complaint of swelling in the maxillary right gingiva. Tooth #37 had been extracted 12 years earlier. An initial examination revealed 33.9% of sites with a probing depth (PD) of ≥4 mm. The prevalence of sites with bleeding on probing was 35.2%. The plaque control record (PCR) score was 51.9%. Radiographic examination revealed angular bone resorption in tooth #16. Horizontal adsorption was also observed in other areas. A clinical diagnosis of generalized chronic periodontitis (Stage III Grade C) was made and periodontal therapy initiated. An improvement was observed in periodontal conditions at re-evaluation, with her PCR score decreasing to 15.7%. Periodontal surgery was performed for teeth with a residual PD ≥4 mm. Periodontal regenerative therapy using autogenous bone graft and rhFGF-2 were performed for an intrabony defect in #16. Open flap debridement was performed on #17, 35, and 36. Following evaluation, oral function was restored using a hard resin facing metal crown for #12 and CAD/CAM resin crowns for #14, 15, and 24. The patient was then placed on supportive periodontal therapy. The results showed that periodontal regenerative therapy with autogenous bone graft and rhFGF-2 yielded stable periodontal conditions, which facilitated a favorable level of plaque control.

Congenital muscular dystrophy (MD) is characterized by progressive muscle weakness. Such patients often present distinctive facial features characterized by excessive vertical growth due to increased muscle breakdown in the perioral muscles such as the masticatory and facial muscles, often resulting in skeletal open bite. Orthognathic treatment is one option for improving the maxillofacial morphology and malocclusion in such patients. However, it is often too risky to apply general anesthesia in such cases due to systemic myofunctional deterioration. Therefore, in many instances, the only option is to rely on orthodontic treatment alone to improve malocclusion. Furthermore, there are few reports on changes following orthodontic treatment in congenital MD patients, and many matters remain unclear regarding long-term occlusal stability. The present case was a girl aged 9 years and 3 months at the initial visit. Her chief complaint was masticatory dysfunction and articulation disorder due to open bite. The first phase of treatment delivered expansion of the upper and lower dental arches and myofunctional therapy prior to transition to the second phase. At the start of the second phase of treatment, the patient was aged 15 years and 9 months. It was determined that orthognathic treatment including surgical invasion would be too risky due general problems related to muscular function. This report describes a case of skeletal open bite due to congenital MD in which an orthodontic approach alone was adopted as camouflage treatment involving extraction of the maxillary left and right second deciduous molars and mandibular left and right first premolars. The post-treatment stability of the resulting occlusion is also described.