Using Steiner analysis we examined the facial characteristics of 35 male and 35 female Chinese adults with maxillary protrusion selected from a clinic in New Taipei City. Angular and linear measurements were determined. In comparison with pre-existing measurement values for Chinese children, the SNA angle, SNB angle, SND angle, L1 to NB (angle), Interincisal angle, and SL values for our subjects were significantly greater while the U1 to NA (mm), U1 to NA (angle), and SE values were significantly smaller. Compared to measurement values for Japanese, the SNA angle, ANB angle, U1 to NA (mm), U1 to NA (angle), Pog to NB, and SE were larger, and the SNB angle, SND angle, Interincisal angle, Occl to SN, and SL were smaller. These results demonstrate that there was excessive growth in Chinese adults with maxillary protrusion. The mandibles showed retrusion, and the degree of clockwise rotation was found to be less than in Japanese. In addition, with respect to the occlusal plane, the inclination in Chinese was less than in Japanese. Based on the above findings, it was suggested that maxillary protrusion in Chinese adults is easier to treat than in Japanese. (J Osaka Dent Univ 2022; 56: 1-6)

We examined the facial characteristics of Chinese adults with high angle craniofacial morphology using Steiner and Downs analyses. Twenty-one males and 56 females were selected from a clinic in Tainan City, Taiwan. Angular and linear measurements were determined. In comparison with pre-existing measurement values for Chinese adults with maxillary protrusion, the L1 to NB (angle), ∠Occl to SN, and ∠GoGn to SN were significantly larger, while the SNA angle, SNB angle, SND angle, U1 to NA (mm), L1 to NB (mm), Interincisal angle, and SL were significantly smaller. Compared to measurement values of Chinese children in Hellman's developmental stage IIIC with maxillary protrusion, the SNA angle, SNB angle, ANB angle, SND angle, L1 to NB (angle), ∠Occl to SN, ∠GoGn to SN, and SL were significantly larger among subjects in the present study; while the U1 to NA (mm), U1 to NA (angle), L1 to NB (mm), Interincisal angle, and SE were significantly smaller. These results demonstrate that marked clockwise rotation of the mandible in the skeletal patterns was presumed to be the result of increased vertical growth. In regard to denture patterns, there was increasing labial inclination of the mandibular anterior teeth and the clockwise rotation of the occlusal plane as the dental compensation for the skeletal changes. (J Osaka Dent Univ 2022; 56: 7-12)

Periodontal disease is an inflammatory condition caused mainly by infection with periodontopathic bacteria. Plasmalogen (Pls) is glycerophospholipid that is one of the components of cell membranes and possesses various biological functions. We investigated the effect of Pls on intercellular adhesion molecule-1 (ICAM-1) expression in human gingival fibroblasts (HGF) stimulated with lipopolysaccharide (LPS) derived from Porphyromonas gingivalis (Pg). ICAM-1 expression was analyzed using real time PCR and flow cytometry. Pls decreased Pg-LPS-induced ICAM-1 gene expression in a dose-dependent manner in HGF. It was also revealed by flow cytometry that the addition of Pls decreased the cell surface expression of ICAM-1 in Pg-LPS-stimulated HGF. The results demonstrated that Pls suppressed Pg-LPS-induced ICAM-1 expression in HGF at the gene and protein levels. Our findings suggest that Pls may inhibit inflammatory reactions through the reduction of ICAM-1 expression in periodontal disease. (J Osaka Dent Univ 2022; 56: 13-17)

This report presents a case of denture fibroma excision, immediate denture repair, and new denture fabrication for a patient with dementia, which reduced the burden on the family caregivers. An 88-year-old woman with severe dementia presented with the chief complaint of swelling of the upper lip and decreased masticatory ability. Oral examination revealed an elastic, soft mass of 30 x 10 mm² on the upper lip. The maxillary and mandibular removable partial dentures were both fractured and ill-fitting. An excision of the upper lip mass and immediate repair of the dentures were performed at the first visit. Three months after the resection of the upper lip mass, we began fabricating new dentures. After completion of treatment, the patient's family reported that cleaning her mouth, as well as placing and removing her dentures, had become easier, and mealtimes had become shorter. Furthermore, the Zarit Burden Interview score revealed that the primary caregiver's burden of care was reduced from 28 points at baseline to 19 points at follow-up. This treatment enabled the patient's family to maintain her oral hygiene and shorten her mealtimes, thereby reducing the burden on the family caregivers. (J Osaka Dent Univ 2022; 56: 19-24)

We evaluated the modifications and possible perforations of the sinus mucosa lining and the implant surfaces after sinus floor elevation. Eighteen New Zealand rabbits received bilateral sinus floor elevation using deproteinized bovine bone mineral (DBBM) with granule dimensions of either 0.125-1 mm (small group) or 1-2 mm (large group). Perforations and thinned mucosa sites of less than 40 μm were evaluated in the sinus mucosa in contact with graft and implants after 2, 4 and 8 weeks in six animals for each period. The mean width of the pristine mucosa during these periods was between 113 μm to 76 μm. All sinuses in both the small and large groups had several thinned mucosa sites around the xenograft granules with the mean incidence ranging between six to ten in each sinus. Twenty-one sinuses out of thirty-six examined had perforations, especially at the 2- and 8-week evaluation periods. No differences were found among the groups. A lower number of thinned mucosa sites were seen at the implant sites compared to the graft sites, and there were no perforations. We found that sinus mucosa in close contact with the graft particles and implant surface underwent thinning and perforations after the sinus floor elevation. (J Osaka Dent Univ 2022; 56: 25-33)

We examined the facial characteristics of Chinese children with high angle craniofacial morphology using Steiner analysis. Sixty-four boys and 61 girls were selected from a clinic in Hangzhou, Zhejiang Province, China. The Chinese children with high angle craniofacial morphology had significantly larger U1 to NA (mm), U1 to NA (angle), L1 to NB (mm), and SE, and significantly smaller ∠SNA, ∠SNB, ∠ANB, ∠SND, L1 to NB (angle), Interincisal angle, ∠Occl to SN, ∠GoGn to SN, and SL compared with Chinese adult high angle cases. Compared to measurements of Chinese at developmental stage IIIC skeletal 1 cases, ∠ANB, U1 to NA (mm), U1 to NA (angle), L1 to NB (mm), ∠Occl to SN, ∠GoGn to SN, and SE were significantly larger, and SNA, ∠SNB, ∠SND, Interincisal angle, and SL were significantly smaller. These results demonstrated a skeletal pattern of maxillary and mandibular growth in the anterior direction, and the mandible in particular exhibited vigorous downward growth and retrusion due to clockwise rotation. Regarding the denture pattern, although we found that the excessive labial inclination of the maxillary and mandibular anterior teeth improved with age, the cant of the occlusal plane increased. (J Osaka Dent Univ 2022; 56: 35-41)

Using Steiner analysis and Wits appraisal, we examined the facial characteristics of 21 male and 19 female Chinese adults with reverse occlusion selected from a clinic in Ningbo City in Zhejiang, China. Angular and linear measurements were determined. In comparison with pre-existing measurement values of Chinese adults with skeletal 2 malocclusion, all measurement items indicated significant differences. Compared to Japanese, the ∠SNA, ∠SNB, U1 to NA (mm), U1 to NA (angle) and the Interincisal angle were larger and ∠ANB, L1 to NB (mm), L1 to NB (angle), ∠Occl to SN and ∠GoGn to SN were smaller. These results demonstrate that although maxillary undergrowth was not observed, overgrowth was seen in the mandible. We found that, vertically, compared to Chinese adults with a skeletal 1 malocclusion, those with a skeletal 3 had a short anterior facial height and a low angle in their maxillofacial morphology. It was also found that although the lower anterior facial height was shorter than that of Japanese, it was longer than that of Caucasians. In the denture pattern, Chinese adults with a skeletal 3 malocclusion, when compared to a skeletal 1, had more pronounced labial inclination of the maxillary incisors and lingual inclination of the mandibular incisors. (J Osaka Dent Univ 2022; 56: 43-49)

Tumor progression and metastasis occur by a variety of mechanisms, including epithelial-mesenchymal transition (EMT) and PD-1/PD-L1 signaling. In addition, hepatocyte growth factor (HGF) induces EMT in cancer, so the HGF/c-Met pathway is being elucidated. Epidermal growth factor (EGF) is overexpressed in cancer cells and is considered to be a poor prognosis factor for cancer. Furthermore, it has been reported that PD-L1 expression is associated with HGF/c-Met and EGF/EGFR. Therefore, in this study, we investigated the relationship between HGF/c-Met signal and PD-L1 expression using oral squamous cell carcinoma (OSCC) cell lines. PD-L1 expression was enhanced by HGF and EGF treatments alone using Western Blotting. However, c-Met inhibitory treatment did not suppress the PD-L1 expression. In addition, PD-L1 was suppressed by EGFR inhibitor treatment. Therefore, it was investigated whether treatment with SU11274, which is a c-Met inhibitor, acts on the activity of EGF receptor, p-EGFR in HSC3 and SAS. As a result, high expression of p-EGFR was observed.

Furthermore, when SU11274 and AG1478 were used together, PD-L1 was significantly reduced in both HSC3 and SAS. Immunostaining showed that SU11274 alone did not change the expression of PD-L1 found mainly in the cell membrane, but the AG1478 treatment tended to significantly reduce the expression of PD-L1. Furthermore, the expression of PD-L1 was significantly reduced when both were added. These results suggested that the expression of PD-L1 in the OSCC cell line is regulated by the mutual balance between the HGF/c-Met and the EGF/EGFR signal. From the regulating the expression of PD-L1 point of view, it is effective to use the potent EGFR tyrosine kinase inhibitor AG1478 in combination with c-Met inhibition. (J Osaka Dent Univ 2022; 56: 51-61)

The purpose of this study was to clarify from which part of the smile, of different intensities, positive impressions are obtained using an eye tracker.

The subjects were 60 young adults (23 males and 37 females, mean age 22.6 ± 2.3 years). The stimulus images used for eye tracking were the average faces of 10 adult males (mean age: 24.5 ± 2.4 years) and 10 adult females (mean age: 25.9 ± 1.3 years) synthesized from their respective face photographs in order to eliminate individuality. The stimulus images were three average faces of males and females: a neutral face with a closed mouth, a smile with a closed mouth, and a grin with exposed teeth. The measurement sites were the eyes, nose, and mouth. Gaze fixation time at each measurement site was measured during the questioning session using pairs of adjectives that were considered important in a previous study for the impression evaluation of stimulus images of both sexes. The median gaze fixation time was then compared between stimulus images. Although there was no substantial change in gaze fixation time on the eye and nose areas in the average face of both sexes, a characteristic change in gaze fixation time on the mouth area was noted when a grin was shown.

In a previous study in which factor analysis of impressions from a neutral face, smile, and grin was performed, the factor score was highest for a grin with exposed teeth in stimulus images of both sexes, with improvements noted in positive impressions such as "sociable," "active," "friendly," and "elegant." This study revealed that positive impressions are gained by looking at the mouth with exposed teeth among dental students. (J Osaka Dent Univ 2022; 56: 63-70)

Using Steiner, Downs and Northwestern analysis and Tweed triangle's parameters, we examined the facial characteristics of 20 male and 23 female Chinese adults with skeletal 1 malocclusion selected from an orthodontic clinic at Guangdong Pharmaceutical University, in China. Angular and linear measurements were determined. In comparison with pre-existing measurement values of Chinese children with skeletal 1 craniofacial morphology, maxilla showed more protruded and mandible showed more retruded. Mandibular anterior teeth showed more lingual inclination. Lower facial height was shorter. Compared to Japanese adults with skeletal 1 craniofacial morphology, mandible showed more retruded. Maxillary anterior teeth showed more labial inclination. Lower facial height was shorter. Compared to Caucasian adults with skeletal 1, maxilla showed more protruded and mandible showed more retruded. Maxillary and mandibular anterior teeth showed more labial inclination. Lower facial height was shorter. These results demonstrate that Chinese adults with skeletal 1 malocclusion tend to have forwardly positioned maxilla, mandible, and smaller facial height than the Japanese and Caucasians. In addition, the occlusal plane was found to have less inclination in the Chinese than in the Japanese, suggesting that the orthodontic treatment of Japanese individuals with skeletal 1 malocclusion will be easier than that of the Chinese. (J Osaka Dent Univ 2022; 56: 71-77)

We examined the influence of masticatory function on central nervous system regeneration after the onset of cerebral infarction. For this experiment, we used a CB17 mouse cerebral ischemia model, which has high reproducibility. The mice were divided into two groups: the hard diet group (the left middle cerebral artery was occluded, and hard, solid food was given after the ischemic operation), and the soft diet group (the left middle cerebral artery was occluded, the upper and lower incisors were extracted, and powdery food was given after the ischemic operation). Brain tissue sections were prepared in both groups at 3, 7 and 14 days after the ischemic operation, and the pattern of nerve, glial and neural stem cell expression was investigated using immunohistochemical staining.

In the hard diet group, although the expression of astrocytes and nestin-positive neural stem cells was confirmed in infarcted foci up to 7 days after the ischemic operation, there was no expression of astrocytes or neural stem cells in infarcted foci at 14 days after the operation. On the other hand, in the soft diet group, although the expression of astrocytes was confirmed in infarcted foci up to 14 days after the ischemic operation, nestin-positive neural stem cells were confirmed in infarcted foci 3 days after ischemia. In the penumbra area, neural stem cell expression was noted in the two groups, suggesting that the nerve regeneration capacity was maintained.

In the hippocampal dentate gyrus, nestin-positive and GFAP-positive cells were observed up to 14 days after ischemia in both groups. In the hard diet group, the expressions of nestin-positive and GFAP-positive cells reached a peak at 14 days after the ischemic operation, confirming the enhancement of reactive astrocyte expression. On the other hand, in the soft diet group, the expressions of nestin-positive and GFAP-positive cells reached a peak at 7 days after the ischemic operation.

The results of this experiment confirmed that intrinsic neural stem cells were induced in the infarcted area and hippocampal dentate gyrus in the acute phase of cerebral infarction, suggesting that the nerve regeneration capacity in the hippocampal dentate gyrus is enhanced during the early phase in the presence of masticatory hypofunction, in comparison with a state in which the masticatory function is maintained. In addition, we found that reactive astrocytes were closely involved in the mechanism of nerve regeneration in the hippocampal area. (J Osaka Dent Univ 2022; 56: 79-86)

We investigated the reliability, validity, and responsiveness of the mandibular activity measurement of mastication initiation training foods using a three-axis accelerometer of patients with dysphagia after a stroke. The reliability and validity were examined in 16 healthy dentate subjects (12 males and 4 females, with a mean age of 47.7 ± 18.7 years, healthy group) and in 16 dentate patients with dysphagia after a stroke (10 males and 6 females, with a mean age of 62.3 ± 16.9 years, patient group). Ten patients (7 males and 3 females, 57.1 ± 15.6years) who underwent mastication training for approximately 1 month were included in the study for responsiveness. The test food was 6g of food for mastication initiation training (Process LeadⓇ, Otsuka Pharmaceutical, Tokushima, Japan). A three-axis acceleration sensor (UB-301 BT, A&D, Tokyo, Japan) was used to measure mandibular activity. The measurement conditions in this study were found to be reliable and valid for a cross-sectional comparison between healthy subjects and patients. However, it was not possible to determine the effect of chewing training (responsiveness). (J Osaka Dent Univ 2022; 56: 87-98)

Artesunate (ART) is an anti-malarial drug that is used worldwide. It also inhibits the proliferation of various types of cancer cells. Specifically, ART induces intracellular iron-dependent reactive oxygen species (ROS) production, which causes cell death due to oxidative stress. Little is known about the potential of ART as a treatment for oral squamous cell carcinoma (OSCC). We investigated the anti-tumor effects of ART against OSCC cells. OSCC cell, Ca9-22, was cultured and treated with different concentrations of ART. Control group was treating DMSO only. The effects of the ART on cell viability, intracellular ROS production, DNA damage and anti-oxidative stress mechanism were assessed.

Results: ART specifically inhibited the growth of OSCC cells compared with normal human keratinocytes, and apoptosis was induced in the OSCC cells through iron-dependent ROS production. The transcription factor NF-E2-related factor 2 (NRF2), whose activity was increased by ART, played an important role in the induction of anti-oxidative stress mechanisms in OSCC cells by ART. Furthermore, hemeoxygenase-1 was activated by the activation of NRF2. Anti-oxidative stress mechanisms are considered to be an important molecular target of cancer treatment. Within the limitation of this study, it can be concluded that ART could be inhibited the growth of OSCC cells. This suggests that ART induced apoptosis by upregulating iron-dependent ROS production, resulting in the activation of anti-oxidative stress mechanisms in OSCC cells. These results suggested that ART may be a useful treatment for OSCC. (J Osaka Dent Univ 2022; 56: 99-105)

Using Steiner analysis and Tweed's analysis, we examined the facial characteristics and determined angular and linear measurements for 19 male and 16 female Chinese children with mandibular prognathism selected from a clinic in Guangzhou, Guangdong Province, China. The skeletal pattern findings showed that the maxilla was more undergrown in Chinese children with skeletal Class III malocclusion than in Chinese children with skeletal Class I malocclusion. Although Chinese children with skeletal Class III malocclusion did not demonstrate horizontal hypergrowth in the mandible, vertical hypergrowth was observed. Regarding dental patterns, Chinese children with skeletal Class III malocclusion demonstrated lingual inclination of the maxillary and mandibular anterior teeth. In comparison with Japanese children with skeletal Class I malocclusion, Chinese children with skeletal Class III malocclusion demonstrated maxillary hypogrowth, mandibular hypergrowth, a low anterior facial height, a low angle maxillofacial morphology, and marked lingual inclination of the maxillary and mandibular anterior teeth. (J Osaka Dent Univ 2022; 56: 107-113)

Enamel matrix derivative (EMD) is used in periodontal tissue regeneration therapy. In our previous study, we constructed a synthetic oligopeptide (SP) derived from EMD that enhanced the cell proliferation of gingival fibroblasts and periodontal ligament cells. SP also induced hard tissue formation in artificial periodontal tissue defects in a rat experimental model. Mesenchymal stem cells (MSCs) are highly proliferative and have a high potential of osteogenic differentiation, and thus contribute to the regeneration of hard tissues. However, the molecular effect of SP is not fully understood. In this study, we investigated the effect of SP on cell proliferation and osteogenic differentiation of human MSCs. Additionally, we examined the activation of the extracellular signal-related kinases (ERK) 1/2 pathway to investigate its molecular biological mechanism. Our results indicated that SP promotes cell proliferation and osteogenic differentiation, and induces ERK 1/2 activation in MSCs. Therefore, SP might promote cell proliferation and osteogenic differentiation through the ERK 1/2 pathway in MSCs, thus possibly contributing to periodontal tissue regeneration. (J Osaka Dent Univ 2022; 56: 115-120)

We studied the questionnaires filled out by 20 patients who received autotransplantation of teeth between March 2016 and November 2020 at Osaka Dental University Hospital. The patients were 8 males and 12 females, and the mean age was 44 years. The transplant survival rate was 100%, and the success rate was 85%. Most patients remembered the transplant surgery and said that it was relatively easy to decide to have the treatment. However, most felt that transplant surgery was very uncomfortable. Most patients thought that the transplanted tooth was in the ideal position, and said that it was as good as the original. However more than half of the patients who had unsuccessful cases noted that the transplanted tooth were slightly different from the original. Most cases of functional dissatisfaction or pain around the transplanted tooth were confirmed clinically for the unsuccessful cases. In conclusion, transplantation for missing teeth at our hospital had a relatively high success rate and resulted in subjective patient satisfaction. (J Osaka Dent Univ 2022; 56: 121-126)

To understand the importance of preoperative blood tests, we investigated the positive rate of hepatitis B (HBs antigen), hepatitis C (HCVIII antibody), and syphilis (RPR) in 3,277 cases at Osaka Dental University during the past five years. This is an important part of a patient's medical history. We also examined the self-assessment rate from questionnaires and medical interviews. The self-assessment rates for the questionnaires were 20% for RPR, 25% for HBs antigen, and 44% for HCVIII antibody. The prior determination rates, by questionnaires and medical interview, were RPR 20%, HBs antigen 50%, and HCVIII antibody 70%. The positive rates for the preoperative blood tests for syphilis, hepatitis B, and hepatitis C were 0.61%, 0.61% and 2.44% respectively. We found that it was difficult to grasp the positive cases for these infectious diseases by questionnaires and medical interviews, confirming the need for preoperative blood tests. (J Osaka Dent Univ 2022; 56: 127-129)

In the age of COVID-19, health literacy education with an emphasis on the prevention of the spread of infections is essential for expanding the public's range of activities and increasing their satisfaction with life, which includes participating in local events and enjoying travel with peace of mind. We conducted a questionnaire-based survey of event organizers in the fields of culture, arts, and sports to promote and establish events that take measures to prevent the spread of COVID-19 during the era of new lifestyles created by the disease. We found a tendency for the questionnaire items to be rated less important for matters where specific measures and support from the national and local governments were not available, and for matters where basic knowledge of virology and infectious diseases were not adequate. By understanding the knowledge and actions of event organizers regarding the prevention of the spread of COVID-19, it may be possible to supplement this knowledge, allowing them to hold events while lowering the risk of infection. (J Osaka Dent Univ 2022; 56: 131-141)