A female outpatient in her 80s suffered sudden vomiting and loss of consciousness in our university dental hospital. Medicine was not given and surgery has not been performed yet. Her Japan Coma Scale levels were in the 3-figure range, her systolic blood pressure had decreased to 90 mmHg, and SpO₂ had decreased to 90%. Therefore, the in-hospital medical emergency call system was activated. Cerebral CT scans showed bilateral lacunar infarctions. No neurological findings were observed. The suspected diagnosis was vasovagal syncope. The incidence of medical emergencies among outpatients is 0.003 to 0.009% in Japan, The most common causes of medical emergency calls are elevation of blood pressure, accidental ingestion of a foreign body, vasovagal reflux, and hyperventilation. Immediate and adequate treatment would improve the prognosis, hence knowledge and skills maintenance for the management of medical emergencies are required for all medical staff.

We planned a tooth extraction of the bilateral mandibular first molar teeth under day anesthesia. But the general anesthesia was canceled because a large amount of stomach contents was aspirated after the induction of anesthesia. The patient was a 25-year-old man, 185.5 cm in height, and 73.4 kg in weight. His disabilities were autism, mental retardation, and suspected epilepsy. General anesthesia was begun with slow induction, and maintained by an intravenous anesthetic after the placement of an intravenous catheter. Since a lot of the patientʼs stomach contents were sucked through the stomach tube, we interrupted the general anesthesia. We confirmed the contents of the patientʼs supper from the day before and found out that it was much more than our supposed range of meal amounts. We think that eating a large amount of high calorie food in a short time caused inadequate digestion for the patient. In day anesthesia, it is necessary for the patientʼs parents or facility staff to restrict feeding in the perianesthetic period, and consequently, explanations that anyone can understand are required for safe anesthetic administration.

Previously, we have elucidated the role of insulin-like growth factor-I （IGF-I） during the early stages of tooth root formation in mandibular first molars of 5-day-old mice. We reported that IGF-I stimulates the mitotic activity in the outer enamel epithelium of the Hertwig's epithelial root sheath （HERS）, resulting in the elongation of the root. In the present study, we used mandibular first molars from 20-day-old mice in order to further elucidate the role of IGF-I during the later stages of tooth root formation. The control explants showed normal development of the HERS, similar to that in vivo. But the explants treated with 100 ng/ml of IGF-I showed diminished cell proliferation in the inner and outer layers of the HERS. In addition, obvious disintegration of the root sheath along with the appearance of cellular cementogenesis was noted. It was considered that IGF-I signaling accelerated the changing rate, from the maintenance of the length via cell proliferation to the disintegration of the HERS layer, eventually facilitating the differentiation of cementoblasts and cellular cementogenesis. These findings indicated that IGF-I is one of the important regulatory factors throughout root formation.