Recently, the “Metaverse” and “Generative AI” have attracted much attention. Authors have been conducting research based on the idea that the metaverse could be a key technology for solving problems in real space, rather than virtual space. Therefore, in this paper, we will introduce some current examples of solution developments that utilize the metaverse. In particular, the latest research results regarding the “Metaverse of Things” (MoT), which has created new added value by metaversing “things” in real space, will be introduced. In addition, by using specific examples, we will discuss how the use of generative AI can lead to more efficient and advanced problem solving.

  Anaphylaxis is one of the most serious adverse events that can occur during the perioperative period and presents with immunological or non-immunological reactions to the causative agent. Sufficient recognition of the diagnosis and treatment of anaphylaxis is necessary, as the disease can rapidly become severe if not treated promptly and accurately. The initial treatment for anaphylaxis, as with emergency resuscitation, is to secure the airway, assist ventilation, maintain hemodynamics, administer an appropriate dose of adrenaline, provide a high concentration of oxygen for inhalation, and maintain adequate infusion. The treatment of anaphylaxis during anesthesia is not particularly different from the general response ; the main difference is that the venous route will already have been secured during the induction of anesthesia.

  In February 2021, the Japanese Society of Anesthesiologists published the “Practical guideline for the response to perioperative anaphylaxis”. This practical guideline is divided into seven sections : 1) an “Essential summary,” followed by 2) “Introduction,” 3) “Epidemiology,” 4) “Preoperative diagnosis,” 5) “Diagnosis at disease onset,” 6) “Treatment,” and 7) “Postoperative diagnosis.” These guidelines provide explanations and guidance based on current research findings. It is hoped that this practical guideline will be revised and improves as further evidence accumulates.

  The article describes the suggested fields of study after a society member has become a Japanese Board of Dental Anesthesiologist (JBDA) member or a Board-Certified Dental Anesthesiology Specialist (BCDAS) member. Options include 1) becoming a university staff member, 2) practicing hospital dentistry, 3) acting as an open practitioner besides anesthetic specialities and 4) acting as a specialized dental anesthesiologist for dental implant surgery under intravenous sedation. However, future hurdles for dental anesthesia are expected to include 1) a decreasing number of active members, 2) fewer hospitals and poor recruitment, 3) fewer opportunities to utilize dental anesthesia as a specialty, and 4) reductions in the number of future cases. One possibility for the future engagement of dental anesthesiologists that would utilize their knowledge and dentistry techniques is the area of “Mobile dentistry.” Mobile dentistry is a new type of dental practice that has become more common in Japan over the past 10 years because of the increasing number of geriatric patients. Patients benefiting from mobile dentistry are mostly geriatric or medically compromised individuals, such as those with dementia or strokes arising from cerebral infarction, cerebral hemorrhage and cardiovascular diseases (such as ischemic heart diseases) or arrhythmia (such as atrial fibrillation). Dental anesthesiologists have the knowledge to cope with such serious symptoms safely. Using safe management derived from anesthetic knowledge and techniques in turn allows the patients to feel comfortable and safe. De novo monitoring devices, which are small and compact and can be used outside of dental offices, are also indicated for mobile dentistry. The health insurance system in Japan can adequately cover expenses related to dental treatments, suggesting that dental practitioners can expect better incomes. Since mobile dentistry is limited because of human and material resources, it requires anesthesiologists that are competent in both dental treatment and anesthetic tactics.

  A nationwide online survey of dental clinics and associations was conducted to assess the status of anesthesia management (general anesthesia and/or sedation) during dental treatment in Japan. The survey garnered responses from 482 dental clinics (30.4% response rate), 26 prefectural dental associations (55.3% response rate), and 327 county/city dental associations (42.7% response rate). Notably, 69.3% of dental clinics were partnered with hospitals to offer outpatient dental treatments under anesthesia.

  Dental clinics primarily referred patients to general (62.0%) and university hospitals (57.5%) for treatments requiring anesthesia, with most patients experiencing a wait of less than two months. However, about 40% of regions reported a mismatch in the supply and demand for anesthesia services, independent of the presence of university hospitals. This shortfall was echoed by over two-thirds of dental associations, citing a lack of hospitals equipped to provide dental anesthesia and a shortage of specialized dental anesthesiologists. The survey revealed a low awareness (＜25%) among patients and guardians regarding anesthesia management during dental treatment. Over half of the clinics and associations believed that promoting the capabilities of anesthesia could enhance its adoption and guide patients towards suitable hospitals. To expand access to dental treatment under anesthesia, increasing the number of hospitals and trained dental anesthesiologists, along with establishing a specialty designation in dental anesthesia, will be crucial.

  Background : Preoperative carbohydrate loading (CHO) is recommended to enhance recovery after elective surgery. However, most supporting data originate from studies conducted in fields of surgery other than oral and maxillofacial surgery.

  Methods : This retrospective cohort study explored the effect of CHO on the rate of postoperative complications, including the time to return of bowel function (ROBF) and the incidences of vomiting, hyperglycemia, and hypoproteinemia, in consecutive patients who underwent a Le Fort 1 and sagittal splitting ramus osteotomy under general anesthesia with total intravenous anesthesia at the Nihon University School of Dentistry Dental Hospital between October 2022 and June 2023. A multivariate linear regression analysis was used to investigate the relationship between CHO and the time to ROBF.

  Results : The final cohort included 87 patients. Forty-one patients (47%) consumed 400 mL of a 12.5% carbohydrate drink (50 g carbohydrate) between the time of waking and 2 hours before surgery. The remaining patients (n＝46, 53%) drank water only from the time of waking until at least 2 hours before surgery. The results showed that CHO decreased the number of postoperative days until ROBF (β, −0.72 ; 95% confidence interval, −1.18 to −0.26 ; P＝0.002). Sex, preoperative defecation frequency, and incidence of postoperative diarrhea were not significantly associated with the time until postoperative defecation.

  Conclusions : CHO reduces the time to ROBF, which may result in a reduced incidence of postoperative constipation and increased comfort after bimaxillary osteotomy, although the present assessment was limited by the relatively small patient cohort.

  The incidence of postoperative nausea and vomiting (PONV) in patients undergoing orthognathic surgery is high. Moreover, PONV persist despite using total intravenous anesthesia (TIVA) featuring propofol. We investigated the incidence of PONV after orthognathic surgery conducted under TIVA using propofol along with ondansetron, compared to that without using ondansetron. Patients with ASA physical status of Ⅰ or Ⅱ, who underwent orthognathic surgery under TIVA using propofol between April 2020 and March 2023, were enrolled. Patients who underwent awake intubation or postoperative ventilatory management, who were not administered betamethasone intraoperatively, were excluded. The following data were extracted from the electronic medical record : age, sex, body mass index, operation time, blood loss, awake intubation, dose of fentanyl and ondansetron, history of smoking and PONV, and postoperative headache. Postoperative nausea, vomiting, and use of antiemetics within 24 hours after surgery were also extracted. The primary outcome was that PONV is defined as the presence of at least one of these parameters. We divided patients into ondansetron and control groups. We compared the incidence of PONV between groups using Pearson’s chi-square test after propensity-score matching. Among the 291 eligible patients, 78 patients were included in each group after propensity-score matching. Baseline patient characteristics were acceptably balanced between the groups. The incidence of PONV in the ondansetron group was significantly lower than that in the control group (21% vs. 36%, p＝0.033), whereas postoperative headache was comparable between the groups. Ondansetron effectively reduces PONV in patients undergoing orthognathic surgery under TIVA without an increase in headache.

  A 6-year-old girl (height, 102 cm ; weight, 14 kg) with epilepsy and intellectual disability was scheduled to undergo a dental procedure for managing caries under ambulatory general anesthesia. The patient was induced with sevoflurane and intubated nasally with a 5.0 mm inner diameter cuffless tube. Some resistance was encountered during tube passage through the glottis. Anesthesia was maintained using intravenous propofol and remifentanil. Postoperatively, spontaneous respiration was confirmed, and the patient was extubated. However, 20 min post-extubation, the patient developed stridor in the recovery room. No skin symptoms were observed, and her oxygen saturation was 96-98% (room air). Fibroscopy revealed edema and worsening vocal cord movement ; therefore, the patient underwent oral reintubation under general anesthesia using a 3.5-mm cuffed tube. Following reintubation, the patient was admitted to the intensive care unit and managed with mechanical ventilation under sedation. Hereditary angioedema was rule out based on negative blood test results. Five days later, the edema and vocal cord movement improved, and the patient was successfully extubated. In this case, a tracheal tube with a 5.0-mm internal diameter was selected based on Cole’s formula and other factors. Since the patient was younger than the average 6-year-old, the relatively large-diameter tube may have led to the development of the edema. Notably, a standardized method for selecting tracheal tubes in children has not yet been established ; therefore, early detection and treatment of airway stenosis hold significant importance.

  Methemoglobinemia is reportedly caused by propitocaine administration. According to the clinical statement from the Japanese Dental Society of Anesthesiology, the maximum dose of propitocaine is 400-600 mg (6-8 mg/kg). We experienced a case of propitocaine-induced methemoglobinemia at a dose of 4.3 mg/kg in a 28-year-old woman with a height of 152.8 cm and weight of 50.8 kg. Surgery for placement of a dental implant was scheduled under intravenous sedation. The patient had a diagnosis of schizophrenia and took aripiprazole regularly. We planned to inject 3% propitocaine and 0.03 IU/mL felypressin as local anesthetic because aripiprazole is contraindicated for combined administration of adrenaline. Intravenous sedation was maintained with midazolam and propofol. The patient’s initial SpO₂ was 96% under air, but rose to 94% after administration of 7.2 mL propitocaine. Administration of oxygen resulted in recovery of SpO₂ to 100%, and her final SpO₂ was 96% under air after the need for sedation. However, SpO₂ rose to 91% after 20 min in the recovery room. We started to monitor the hemoglobin concentration ; SpMet^® using a pulse CO oximeter (Rainbow^®, MASIMO Inc.), which was 4.6%. We diagnosed the patient with methemoglobinemia and continued to measure the hemoglobin concentration and this measurement decreased to 2.5% 4h and 25 min after propitocaine injection. We decided to discharge the patient from the hospital because the hemoglobin concentration was lower than normal value ; <3% and the patient strongly wished to be discharged. The patient was ultimately discharged from the hospital without any symptoms of methemoglobinemia.

  When a preoperative examination reveals an elevated creatine kinase (CK) level, the cause of the elevation is usually sought before planning general anesthesia. However, a definitive diagnosis may not always be possible ; in such cases, careful attention must be paid to general anesthesia management. Here, a 6-month-old girl with bilateral cleft lip and palate is reported. No other remarkable clinical or family history findings were noted. However, blood tests showed persistently high CK levels, strongly suggesting the presence of a disease involving muscle tissue ; nevertheless, a definitive diagnosis could not be made. Therefore, considering the risk of complications (such as malignant hyperthermia), cleft lip corrective surgery was performed under total intravenous anesthesia (TIVA). The patient’s intraoperative vital signs were stable. No postoperative respiratory complications were noted. She was subsequently found to be a carrier of Duchenne muscular dystrophy (DMD). DMD carriers can have the same pathophysiology as DMD patients. Therefore, a thorough preoperative evaluation and measures to prevent intraoperative and postoperative complications were considered important in the present case.

  This case report describes the use of ultrasound-guided glossopharyngeal nerve block (UGPNB) and intravenous sedation (IVS) to control a gag reflex (GR). A 45-year-old man (178 cm, 102 kg) with a severe GR attended our hospital to receive dental treatments under anesthetic management. The patient did not have any comorbidities other than obesity (body mass index of 32.2 kg/m²) and was not taking any medications. We used IVS for the first treatment but experienced difficulty inserting the dental suction cannula and controlling the GR. Subsequently, we used UGPNB with IVS for the remaining treatments and were able to insert the dental suction cannula and control the GR successfully. For UGPNB, the ultrasonic probe was positioned in the posterior mandibular ramus and set parallel to the sternocleidomastoid muscle. The resulting ultrasound images clearly delineated the sternocleidomastoid muscle and stylohyoid muscle. A 25-gauge, 25-mm needle was inserted under the stylohyoid muscle through the sternocleidomastoid muscle using an out-of-plane technique. No complications related to the UGPNB occurred. Conventional UGPNB targets an area in the vicinity of the styloid process. This area contains the internal carotid artery, internal jugular vein, external jugular vein, vagus nerve, hypoglossal nerve, and facial nerve. Other approaches target the distal parapharyngeal space ; however, these approaches are associated with a risk of puncturing the facial artery and infecting the submandibular salivary gland. Our sternocleidomastoid muscle approach enabled blood vessel punctures and infection of the salivary gland to be avoided. Therefore, this approach to nerve block has advantages for the management of dental treatments that are repeatedly performed in outpatient settings. The collection of additional patient data is needed for the dissemination of this new approach to performing nerve blocks.

  Nonodontogenic toothache is a condition characterized by pain in the oral cavity that is not caused by the teeth or periodontal tissues and for which no evidence of organic problems exists. The diagnosis of nonodontogenic toothache is known to be difficult, leading to misdiagnosis and overtreatment. Nonodontogenic toothache includes the following : 1. toothache arising from myofascial pain, 2. maxillary sinus pain, 3. cardiac toothache, 4. neurovascular toothache, 5. toothache arising from neuropathic pain, 6. persistent idiopathic toothache, and 7. toothache arising from psychiatric disorders or psychosocial factors. Recently, pain has been categorized as nociceptive pain, neuropathic pain, and nociplastic pain. Major nonodontogenic toothaches can also be differentiated according to these three categories of pain. In addition, burning mouth syndrome is considered to be a representative disorder of nociplastic pain. To differentiate unexplained pain in the oral cavity, the proper classification of pain must be understood and patients must be examined and diagnosed appropriately.

  The majority of patients receiving daily medical care are adults, and the number of medical personnel involved in pediatric care is relatively small. Children are in the process of growth and development and require different considerations during anesthesia than adults. Dental anesthesia and pediatric anesthesia share many similarities in terms of patient background and anesthetic management. Perioperative management and anesthesia for children have not yet been standardized. Safe and painless general anesthesia or sedation should be performed based on an understanding of pediatric anatomy and physiology. This article describes the perioperative management of children and management specifics related to pediatric anesthesia.