Interstitial brachytherapy (ISBT) has been performed for a long time and has a high local control rate for oral cancer. One feature of ISBT is excellent dose concentration in the tumor. Other advantages include a 50% dose reduction at 10 mm from the source when using a spacer.ISBT is particularly indicated for carcinoma of the tongue.The use of Ir-192 (half-life 74 days) hair pins and single pins were introduced in Osaka University Hospital in 1973. It is a form of low dose rate interstitial brachytherapy (LDR).This treatment was used from 1973 to 1991, replacing the Ra-226 source.We began using the microSelectron-HDR (MS-HDR) from Nucletron remote controlled after-loading system using Ir-192 in the Hospital in 1991. It is a high dose rate interstitial brachytherapy (HDR) system.

We concluded that HDR and LDR are important options for both the patients choosing treatment and the healthcare professionals.Also, HDR is an excellent treatment, comparable to LDR, because there is no need for isolation wards and no radiation exposure to the medical staff.It is expected that in the future HDR will be indicated for advanced T3 cases. Shika Igaku (J Osaka Odontol Soc) 2020; Oct; 83(2): 61-67.

We investigated the current state of employment of dental hygienists in Japan and their supply and demand, including dental hygienists doing procedures and giving instructions in medical and nursing care practice. In addition, we investigated the supply-demand balance for the profession. Analysis was based on the results of national statistic surveys and job postings for which there was recruitment at Osaka Dental University School of Dental Hygienists. The results showed that the number of dental hygienist colleges in Japan increased by nine in the ten-year period from 2010 to 2019, to 163 colleges. We estimated that half of those trained as dental hygienists were not employed in the profession. The number employed increased after age 30, and this trend was especially pronounced after age 50. Although 90% of dental hygienists worked for dental clinics, the number who were practicing in general hospitals and facilities covered by long-term care insurance are increasing considerably. According to the analysis of job postings, the number of recruiting institutions more than doubled from 443 in 2010 to 944 in 2017. In particular, the number of recruiting hospitals rose dramatically from 6 in 2010 to 31 in 2017.

These results suggest that the demand for dental hygienists is growing. This demand can be expected to continue growing with the increase in the recognition of the importance of perioperative oral health management and the needs of nursing care facilities. We found that about half of those who passed the National Dental Hygienist Examinations are not employed as dental hygienists and that the number of employed dental hygienists is slightly lower among those in their 20s compared to other age groups. When considering the future demand for dental hygienists, one important task will be to understand what working conditions enable qualified individuals to contribute to dental health, such as improvement in work-life balance. Also, their education should allow them to use their qualifications throughout life, to incorporate medical and dental care and to promote oral function management for older adults. Shika Igaku (J Osaka Odontol Soc) 2020; Oct; 83(2): 68-75.

We retrospectively studied the cases of 32 patients who received autotransplantation of third molars with complete root formation at Osaka Dental University Hospital from April 2013 to March 2018. Age, sex, recipient site, donor tooth, transplantation method, duration of observation, and postoperative course were elicited from patient clinical records. The subjects were 4 males and 28 females with an average age of 39 years. A mandibular first molar site was the most common recipient (25% for each side) and the mandibular left third molar was the most common donor (41%). Immediate transplantation was the most common transplantation method (78%). The one-year survival rate was 96.9%, while the three-year rate was 85.7%. Only one transplant tooth (3.1%) was lost one month after the operation because of a failure of wound healing. Only 4 cases (12.5%) were detected with a periodontal pocket of more than 4mm around the transplanted tooth. The survival rate for autotransplanted third molars with complete root formation at our hospital is high. Tooth autotransplantation is a valuable treatment for recovering the occlusal function of missing teeth. Shika Igaku (J Osaka Odontol Soc) 2020; Oct; 83(2):76-82.

1. Takahisa Fukuhara, Takashi Doi and Tatsuro Miyake. Evaluation of early caries activity and risk by the International Caries Detection and Assessment System (ICDAS) for deciduous dentition.