Nitrous oxide inhalation sedation is widely used in dental practice as an effective means of mental sedation to reduce stress during dental treatment. Circulation dynamics are maintained and adjusted by baroreflex, but there is no information available regarding the sensitivity of baroreflex during N₂O inhalation. Therefore, we evaluated whether sympathetic baroreflex sensitivity（Sympathetic BRS）is decreased by nitrous oxide inhalation sedation. Arm cuff and beat-to-beat BP（finger plethysmography）, HR, cardiac output（CO）, stroke volume（SV）, and MSNA（microneurography）were measured during inhalation of room air, 100％ oxygen, 30％ and 40％ nitrous oxide, and recovery（room air）for 20 min through a mask, respectively, in 10 young men［age 31±2（SD）yrs］. Sympathetic BRS was analyzed from the spontaneous changes in beat-by-beat diastolic BP and corresponding MSNA（burst incidence）during the last 5 minutes of each condition. Systolic and diastolic BP did not differ among the inhalation conditions. HR, CO, and MSNA（burst frequency and total MSNA）were also similar between all conditions. Sympathetic BRS remained unchanged by inhalation sedation with any nitrous oxide concentration（burst incidence）. These results suggest that baroreflex function is maintained during nitrous oxide inhalation sedation and nitrous oxide itself does not directly affect BP regulation.

A questionnaire survey was conducted on JSDH-certified dentists of the Japanese Society of Dentists which focused on the selection factors of behavior management methods and whether dentists inform patients with disabilities about these methods before they obtain consent. The objective was to identify problems that may support decision-making in regards to patients with disabilities.

The subjects were 300 dentists randomly selected among 1,053 JSDH-certified dentists of the Japanese Society of Dentists in 2016. The behavior management methods that they could perform were behavior modification（94.7％）, body restraint（85.2％）, physical control（78.7％）, N₂O inhalation sedation（69.8％）, intravenous sedation（56.2％）, and general anesthesia（47.3％）. They were classified by the cluster analysis method as “the medicine group” and the “non-medicine group”. Dentists in the non-medicine group were significantly less likely to refer to the severity of the disorder, number of untreated teeth, wishes of the parents, and hospitalization time, than the medicine group. These results were attributed to the fact that the dentists in the non-medicine group had fewer behavior management methods, and it was inferred that the medical cooperation system for persons with disabilities was not established in the area. 12.4％ of the dentists do not always explain the suppression method to parents when the patient has the possibility of refusing the treatment. 40％ of dentists answered that sometimes they do not explain to parents the procedure of the treatment in order to perform general anesthesia or intravenous sedation in other medical institutions. In medical disputes, not explaining possible behavior management methods in order to obtain informed consent may be a violation of the duty to explain. Regarding “you explain the behavior adjustment method to the mentally handicapped yourself and ask for consent”, 33.7％ answered “occasionally”, 32.5％ “rarely”, and 17.2％ “never”. It is considered that decision support has not been provided in the field of dentistry for the disabled, and is not generally standardized in special needs dentistry. Guidance that standardizes the process of decision support is necessary.

Trachea osteomalacia is a condition in which the tracheal lumen is greatly collapsed during exhalation or intrathoracic pressure rise due to general or local fragility of the tracheal wall.

We performed dental treatment in an intubation patient with speech cannula for trachea osteomalacia. The patient had mental retardation and would not cooperate with maintaining the opening, so we used the nitrous oxide inhalation sedation method. Regarding respiratory management, special consideration for pneumonia prevention and trachea osteomalacia was necessary. Since the structure of the speech cannula is a non-rebreathing type circuit having a one-way valve and a side hole, care was taken to humidify the anesthetic gas and open air in the clinic supplied to the respirator. For trachea osteomalacia, caution was required to minimize mechanical compression stimulus from inside and outside the airway. In preparation for accidental symptoms, a circulatory anesthesia machine and a usual cuffed cannula were prepared for a suction catheter in the trachea and for positive pressure assisted respiration.

By minimizing the chair time, it was possible to avoid accidental symptoms.

A mouth stick（MS）is a self-help device for writing sentences, using electronic devices and so on. Frequently, an MS is applied to patients with spinal cord injury or cerebral palsy with dysfunction of the upper limbs. The present case was a female patient with cerebral palsy with quadriplegia（64 years old）. First, partial dentures were fabricated for the patient’s maxilla and mandible. Next, after the dentures had stabilized the mandibular position, an MS with replaceable shaft parts that can be used in several ways was fabricated. As a result, we succeeded in obtaining patient satisfaction, because by making the shaft part into an attachment-like form that could be easily changed, the MS could be more easily handled by the patient and assistants. This result suggests that the MS with replaceable shaft parts would be an effective self-help device for cerebral palsy patients with quadriplegia.

Impacted teeth are often treated with extraction, fenestration, orthodontic traction, surgical extrusion and reimplantation. If possible, it is desirable to guide the impacted tooth into the dentition, for which orthodontic traction is frequently used. However, when treating patients with disabilities, orthodontic treatment is sometimes not possible because of their condition. Here, we report a case of surgical extrusion performed for a patient with autistic spectrum disorder who had gemination of an impacted premolar, the occlusion of which was restored by the following procedure.

The patient was a 12-year-old boy with autistic spectrum disorder. Radiographic findings revealed impaction of the maxillary left first premolar. In CT images, the premolar was found to be a fused normal premolar tooth and a supernumerary tooth. Moreover, it was confirmed that the distal part of the first premolar was interfered with by the crown of the second premolar, which inhibited its eruption. An orthodontic traction procedure was considered to be inapplicable due to the patient’s disability, so we chose surgical extrusion under general anesthesia for guiding and fixing the premolar into the dentition. Following surgery, the patient did not complain about pain in particular. Tooth mobility disappeared 1 month later and the premolar was making steady progress. 2 years after surgery, the patient has no discomfort and there is no evidence of root resorption, with good occlusion. Surgical extrusion of an impacted tooth is a reasonable option when treating a disabled patient for whom an orthodontic guidance approach would be difficult.

1p36 deletion syndrome is caused by submicroscopic deletion in the subtelomeric region of chromosome 1. The features of the syndrome are characteristic facial appearance（straight eye-brows, deep-set eyes, flat nasal bridge, unsymmetrical shape of earflap and pointed chin）, cardiac anomaly, intellectual disability, epilepsy, cleft lip and palate, and cleft soft palate. We investigated four cases of 1p36 deletion syndrome.

Patient 1 was a 7-year-old girl who had intellectual disability, characteristic facial appearance, ventricular septal defect, cardiac anomaly and epilepsy. Three congenital missing teeth were observed at #53, 63 and 73 and one pegged tooth was also observed at #83. In addition, open bite was observed.

Patient 2 was a 13-year-old girl who had intellectual disability, characteristic facial appearance, cardiac anomaly and epilepsy. One congenital missing tooth was observed at #41 and four pegged teeth were observed at #12, 22, 53 and 63. In addition, cleft palate and crowding of teeth were observed.

Patient 3 was a 15-year-old boy who had intellectual disability, characteristic facial appearance, ventricular septal defect and epilepsy. Fused teeth of #71 and 72 were observed, one congenital missing tooth was observed at #32 and one pegged tooth was observed at #13. In addition, cleft soft palate and crowding of teeth were observed.

Patient 4 was a 21-year-old female who had intellectual disability, characteristic facial appearance, cardiac anomaly and epilepsy. Fused teeth of #72 and 73, and 83 and 84 were observed. Two congenital missing teeth were observed at #32 and 42. In addition, open bite was observed.

The frequency of congenital missing teeth and pegged teeth in cases with 1p36 deletion syndrome was found to be high, and we consider that these might be features of the syndrome. Open bite was observed in patients 1 and 3. However, both patients with open bite also had a tongue-thrusting habit, therefore the relation was not clear.

All four patients had intellectual disability, so self-brushing was impossible. We consider that professional care is very important.

Excessive fear（dental phobia：DP）and gag reflex（GR）experienced by patients during dental treatment may have negative effects on treatment. When providing dental care for patients with these disorders, various behavior control methods are used while taking into consideration their psychological factors. However, some patients discontinue treatment and their oral condition worsens. A survey was conducted involving DP or GR patients who had consulted the Department of Dentistry to examine their psychological factors and oral findings at the initial consultation. The results were as follows：

1. The psychological factors of all patients solely with GR could not be identified. The largest number of patients with solely DP had “fear of pain（53.6％）”, and “fear that gag reflex may be induced during dental treatment（92.0％）” was the most common psychological factor among patients with both DP and GR. These factors were associated with their uncomfortable experiences.

2. In comparison with the results of a national dental health survey conducted by the Ministry of Health, Labor and Welfare, the mean DMFT scores of DP and GR patients in the present survey were higher. The number of decayed teeth in particular was significantly higher among most of those DP and GR patients, excluding patients in their 70s, which suggests that their oral environment was poor.

3. Although approximately 70％ of the patients completed treatment, less than 40％ were under regular dental health management.

Dental care for DP or GR patients should be continued even after the completion of treatment. It is necessary to implement dental health management programs for these patients on a regular basis to address or reduce their psychological factors, maintain a healthy oral environment, and improve it while using desensitization approaches.

Introduction： The Services and Support for Persons with Disabilities Act came into effect in 2006, making it necessary to enhance the family dentist system for special needs patients in the community, and to establish a community-based dental care system for special needs patients so that dental care can be provided seamlessly in close cooperation with advanced medical institutions.

Therefore, in 2007 the Aichi Dental Association launched “the system of accredited cooperation dentists for special needs patients” for the purpose of developing human resources who can continue to provide community-based dental care for such patients；11 years have already passed since the workshop to train accredited cooperation dentists for special needs patients was opened. We summarized the results of questionnaires distributed after workshops in order to sum up the workshops so far and to examine future issues, and clarified the following：

1. With reference to the number of parsons with disabilities separately in secondary medical care areas, it is necessary to examine the appropriate number of cooperation dentists in accordance with the population of special needs patients in the community.

2. Since some burden on attendant trainees is unavoidable for clinical practice training at advanced medical institutions, it will also be necessary to discuss training at local dental clinics for special needs patients in the future.