We used cephalograms to investigate the correlation between the maxillofacial morphology of skeletal Class I malocclusion in Japanese adults and the mandibular symphysis, measuring the labiolingual width of the upper line, middle line, and lower line. Considering the morphology of the symphysis, based on the relationship between the labiolingual width and facial height, we found significant differences in the upper line width between the long-face group and the normal-face group, and between the long-face group and short-face group, in males. In females, there was a significant difference in the width of the upper line between the long-face group and the short-face group, and between the normal-face group and the short-face group. There was a significant difference in the middle-line width between the long-face group and the short-face group, and between the normal-face group and the short-face group. Considering the relationship between the labiolingual width and the ANB angle group, there was a significant difference between the large ANB angle group and the small ANB angle group on the lower line in females. These results suggest that it is necessary to pay attention to the morphology of the symphysis owing to the skeletal differences in the movement of the mandibular anterior teeth during orthodontic treatment. (J Osaka Dent Univ 2022; 56: 143-150)

Although obesity is a lifestyle-related disease and a major risk factor for type 2 diabetes mellitus, the effects of obese type 2 diabetes mellitus (ODM) on oral health have not been fully elucidated. We compared the subepithelial connective tissue and capillary network of the palatal gingiva of the maxillary first molar in ODM model rats and normal rats. The subepithelial connective tissue of the two groups differed substantially. In particular, the cross-sectional area of the subepithelial connective tissue, the cross-sectional area and height of the connective tissue papillae, and the capillary diameter were significantly lower in the ODM rats compared with the normal animals (p<0.01). In conclusion, hyperglycemia in ODM rats is associated with atrophic changes, evidenced by reduced cross-sectional area of the subepithelial connective tissue, as well as reduced cross-sectional area and height of the subepithelial connective tissue papillae. Furthermore, it causes diabetic microangiopathy in the capillary network of the palatal gingiva of the maxillary first molar in the ODM rats. (J Osaka Dent Univ 2022; 56: 151-160)

Intestinal microflora plays a significant role in systemic health and immunity. However, oral microflora is still poorly understood and research is ongoing to identify substances that improve it. Propolis, a resinous substance found in beehives, is produced by honeybees by mixing plant shoots and resin with saliva and other enzymatic secretions. The natural antimicrobial properties of propolis from several regions such as Brazil, Mexico, Taiwan, and Okinawa have been previously reported. However, the anti-microbial property of Hawaiian propolis, which is from the same botanical source in subtropical regions such as Taiwan and Okinawa remains to be characterized. In this study, we investigated the antibacterial activities of Hawaiian propolis against Actinomyces oris (A. oris), early adherents of biofilm formation on the tooth surface, and against Porphyromonas gingivalis (P. gingivalis), a periodontopathic bacterium. We measured the inhibitory effect of ethanol-extracted propolis on the growth of A. oris and P. gingivalis and determined the minimum inhibitory concentration and minimum bactericidal concentration of ethanol-extracted propolis against these oral pathogen bacteria. Our results suggest that Hawaiian propolis is an effective antimicrobial against A. oris and P. gingivalis with implications for usage in aiding dental health. (J Osaka Dent Univ 2022; 56: 161-165)

Few reports exist on the changes associated with mandibular advancement surgery and on the effects of genioplasty. We investigated the combination of genioplasty and mandibular advancement surgery in surgical orthodontic therapy for maxillary protrusion with mandibular retrognathism. A total of 17 patients (2 men and 15 women) between 17 and 32 years of age at the first visit who were diagnosed with maxillary protrusion with mandibular retrognathism, and who underwent mandibular advancement surgery at the Okashita Orthodontic Office for 6 years from 2013 to 2018 were included in the study, eight women underwent only sagittal split ramus osteotomy (the SSRO group), while 2 men and 7 women underwent combined SSRO and genioplasty (the SSRO+GP group). Cephalograms from the first visit and those taken within 3 months following the operation were evaluated.

Our study suggested that the anterior-posterior diameter of the pharyngeal airway increases when genioplasty is combined with mandibular advancement surgery in patients with maxillary protrusion. Patients with maxillary protrusion and mandible retrognathism tend to have narrow pharyngeal airways, and are reportedly more susceptible to sleep disorders with increasing age. Therefore, genioplasty should be considered not only for the improvement of the facial profile, but for functional reasons as well. (J Osaka Dent Univ 2022; 56: 167-173)

Digital technology is being applied in dentistry to facilitate treatment planning, prosthetic design and fabrication, as well as the determination of treatment efficacy. The face scanner is a tool for obtaining information on facial appearance that digitizes the patient's extraoral soft tissues. However, the details of the measurement accuracy of face scanners have not been clarified. We studied the accuracy of two dental face scanners that are currently available in Japan. A mannequin head was scanned once by a reference high-precision laser scanner (FARO) and 10 times each by two dental face scanners, the FaceHunter (FH) and the SNAP (SN). Scans from the FH and the SN were superimposed on the reference scan from the FARO using the iterative closest point (ICP) method, and the root mean square (RMS) deviation was calculated. The accuracy (trueness and precision) for the entire face was 0.117±0.004 mm for the FH and 0.378±0.023 mm for the SN, when compared with the FARO. Two-way repeated measures ANOVA showed that the RMS deviation for the SN was greater than that for the FH, with the smallest RMS deviation at the middle central of the 9 regions of the FH, while the smallest RMS deviation was at the upper central of the 9 regions of the SN. (J Osaka Dent Univ 2022; 56: 175-181)

We report a clinical study involving 3956 patients who underwent malignant tumor surgery at Osaka Red Cross Hospital in the 5 years from April 2014 to March 2019. 1576 patients received perioperative oral management and 2380 did not. No significant differences were found between the two groups in the length of the hospital stay, the length of the postoperative hospital stay, or the incidence of postoperative complications. Although thoracoscopic and laparoscopic surgeries tended to have lower postoperative complication rates than open chest and abdominal surgeries, the difference was not significant. Patients who visited their family dentist and received oral care regularly were significantly less likely to require dental treatment during perioperative oral management. These results suggest that continuous oral management may help keep the treatment progress on schedule. (J Osaka Dent Univ 2022; 56: 183-191)

Heated tobacco products (HTPs) are increasingly attracting attention, and many people are using them in addition to regular cigarettes. However, more research is needed because there are still unanswered questions about the health effects of the long-term use of HTPs. Therefore, it is important to study the effects of tobacco smoke components (TSCs) of HTPs on oral health in vivo. We used the I-Quit-Ordinary-Smoking (iQOS) HTP to develop a collection method for low volatile TSCs obtained from HTPs. Our method afforded better collection of the low volatile TSCs. We also determined the amount of nicotine and glycerol present in low volatile TSCs by NMR analysis. (J Osaka Dent Univ 2022; 56: 193-196)

Dental pulp stem cells (DPSCs) play an important role in the homeostasis of the pulp tissue and have a high potential for osteogenic differentiation. Enamel matrix derivative (EMD) has been used in periodontal regeneration therapy. Previously, we designed a synthetic amelogenin peptide (AP) derived from EMD. In this study, we investigated the effects of AP on DPSCs and evaluated its usefulness as a dental pulp capping material. DPSCs were cultured in medium supplemented with AP (0 and 100 ng/mL) to examine the effect of DPSCs on cell morphology and the cell migration ability. In addition, DPSCs were cultured with osteogenic medium supplemented with AP at 0 and 100 ng/mL, and their osteogenic differentiation was examined by Alizarin Red staining. AP promoted cell extension by altering cell morphology, and also significantly promoted DPSCs chemotaxis and cell migration. Moreover, the number of calcified nodule formations stained by Alizarin Red increased in the AP group. In summary, AP may be useful as a dental pulp capping material. (J Osaka Dent Univ 2022; 56: 197-201)

Antibacterial photodynamic therapy using light emitting diodes (LEDs) has been shown effective against periodontitis and peri-implantitis. In recent years, there has been research on the application of photodynamic therapy using LEDs in regenerative medicine. It uses "light" as a method of host activation, which is one of the three elements of regeneration. We reported that irradiation of human periodontal ligament stem cells with high-power red LEDs under appropriate irradiation conditions promotes hard tissue differentiation. It has also been confirmed that LEDs can be applied to bone marrow mesenchymal cells and osteoblasts to promote hard tissue differentiation. We investigated cell proliferation and hard tissue differentiation of human dental pulp stem cells, as one of the cell sources of undifferentiated mesenchymal stem cells, in order to clarify the effect of high-power red LEDs on hard tissue regeneration. (J Osaka Dent Univ 2022; 56: 203-208)

We compared the clinical characteristics and incidence of dysphagia after mechanical ventilation in patients with acute respiratory distress syndrome (ARDS) occurring with or without coronavirus disease 2019 (COVID-19). Sixty-seven patients who were diagnosed with ARDS due to COVID-19 and were managed with mechanical ventilation between January 2020 to March 2021 were included in the COVID-19 group. This group was compared with 32 patients who were diagnosed with ARDS due to diseases other than COVID-19 between January 2017 and March 2021 (the non-COVID-19 group). Clinical characteristics and dysphagia during the time after being in the intensive care unit and hospital discharge were compared for the two patient groups. The Functional Oral Intake Scale (FOIS) was used to evaluate dysphagia. FOIS levels 1 to 5 are defined as dysphagia. There were no statistically significant differences in patient characteristics between the two groups other than their Acute Physiology and Chronic Health Evaluation II scores (18.82±5.949 vs 25.97±6.977, p<0.001). Multivariate analysis showed that the incidence of dysphagia at hospital discharge in patients with COVID-19-associated ARDS was statistically significantly lower than in patients with ARDS due to other causes (OR 0.238, 95% CI 0.071-0.798; p=0.02). (J Osaka Dent Univ 2022; 56: 209-214)

We sought to determine the actual incidence of wrong-site treatment or attempted treatment at our hospital and to determine what needs to be done to prevent these treatments. We analyzed the incident reports of the cases of wrong-site treatment or tried therapy in our hospital between January 1, 2013, and December 31, 2021 that were registered in the incident reporting system including those cases that did not cause health problems to patients (incident levels 0 to 3a). Although the average number of wrong-site or attempted treatment cases was 14.1 per year, based on the total number of patients per year, one case occurred for every 20,000 patients, which is infrequent.

The overwhelming majority of wrong-site treatment or attempted treatment cases occurred in outpatient clinics (72.6%). Although the number of reports by the department was slightly greater in oral surgery, they occurred in almost all the departments or divisions. Input errors in the medical-related records accounted for one-third of the total wrong-site or attempted treatments. Left-right errors were the leading cause, and accounted for 69.0% of all cases of wrong-site treatment or attempted treatment. When statistics focusing on dentists with less than one year of clinical experience (residents) were examined, it was found that although residents accounted for 14.4% of dentists in the hospital, they accounted for 30.3% of cases involving treatment or attempted treatment of the wrong site. This indicates that addressing residents is an urgent issue. It is essential to conduct patient safety because mistakes are often left-right errors, and residents often make this mistake. (J Osaka Dent Univ 2022; 56: 215-221)

Acrylic resin-based vascular corrosion casting is an excellent method of observing three-dimensional vascular morphology. Although an improved casting method using rats has been established, this technique has yet to be confirmed in mice. We attempted to improve this method in mice using the mandibular gland and the dorsum of the tongue. A high-precision syringe pump was used in the mice for the mechanical injection of low-viscosity acrylic resin, followed by high-viscosity acrylic resin, which was heat-cured. Observation under a scanning electron microscope confirmed that sufficient acrylic resin had been injected into the capillary vessels of both the mandibular gland and lingual dorsum. In the mandibular gland, arterioles were apparent near the surface layer, and a reticular structure was observed in which the capillary-level vessels continued from a region corresponding to the roots of the lobules to the surface layer. In the lingual dorsum, the hairpin capillary loop structures of the filiform papillae and the reticular structures of the fungiform papillae were apparent. We were able to prepare vascular corrosion casts of the mandibular gland and lingual dorsum in mice, one of the most widely used laboratory animals. This will aid the research on microvessels in mice. (J Osaka Dent Univ 2022; 56: 223-227)