It is important to select appropriate toothbrushes for special needs patients. However, there is no objective functional index for toothbrush selection.

In this study, we created a new method for in vitro functional evaluation of toothbrushes with a new model (SHC model). The SHC model consists of a semi-circular rod with a diameter of 8.0mm fixed to a flat plate. This method is simple to reproduce, and is easy and useful for evaluating the function of a toothbrush. We used three kinds of toothbrush：type I：three rows of bristles and a flat profile, type II：four rows of super-tapered bristles, and type III：four rows of bristle and multi-tufts.

According to our research, the conformity was highest in the following order：type II, type III, and type I. The cleaning performance of type III was higher than that of type II. For Type I, it is difficult for those with physical disability to clean the areas that require conformity. Type II requires a long tooth-brushing time because of the poor cleaning performance. Type III needs a shorter tooth-brushing time than type I and type II.

The evaluation combining the results of the conforming and cleaning performance using the SHC model could identify the differences in toothbrushes. It is suggested that our method might serve as a useful functional index when selecting a toothbrush for special needs patients.

Epidermolysis bullosa is a hereditary disease with blistering of the dermal mucosa. The blister formation and its healing may cause narrowing of the oral vestibule or reduction of mouth opening, through the adhesion and scarring of the skin and mucosa. It is hard to maintain oral hygiene due to ulceration which is easily caused by external force, and the deterioration of skill due to finger adhesion and joint contracture. Enamel hypoplasia may be observed. There are many sporadic reports on dental findings, but there are few reports that summarize the characteristics inside and outside the oral cavity and the dental findings.

Results : We report on our investigation of dental findings in patients with recessive dystrophic epidermolysis bullosa (RDEB). Systemic findings included mucocutaneous ulcers and scars, adhesions, and contractures associated with healing. Oral findings were reduction of mouth opening, enamel hypoplasia, and narrowing of the oral vestibule, and caries tended to occur frequently.

Conclusions : In cases with recessive dystrophic epidermolysis bullosa, damage of the mucosa around the oral cavity and scarring and contraction associated with healing result in reduction of mouth opening and narrowing of the oral vestibule. For this reason, oral hygiene worsens and caries tends to occur frequently.

To alleviate increased muscle tone during dental treatment, sedation with nitrous oxide inhalation was performed successfully in a patient with severe motor and intellectual disabilities who underwent surgical closure of the tracheoinnominate artery. The patient was a 35-year-old man who underwent laryngotracheal separation surgery. He had previously received periodic dental checkups and oral cleaning without sedation. This time, the patient received sedation with nitrous oxide inhalation because of an increase in muscle tone during dental treatment. Nitrous oxide gas was applied to the patient through the tube connected to the tracheotomy hole. Appropriate sedation was then achieved and the increase in muscle tone was alleviated, which enabled dental treatment. Sedation with nitrous oxide inhalation can be easily used in patients who have undergone laryngotracheal separation surgery, although precautions should be taken for possible respiratory depression during the procedure. Dental treatment in patients who have undergone surgical closure of the tracheoinnominate artery should be performed with close monitoring for changes in the patient’s head position, excessive load on the neck, and vibration of the tracheal cannula.

Many special needs patients who are maladapted to dental treatment have difficulty undergoing endodontic treatment in particular.

The purpose of this study was to investigate the prognosis of endodontic treatment in special needs patients. Among the special needs patients who visited our dental clinic during the three-month period from December 2019 to February 2020, those who had received endodontic treatment at our dental clinic in the past were studied, and the prognosis was judged from clinical findings and radiological findings. The subjects were 150 teeth of 48 patients (average age 47.3±12.0 years). The diagnosis was pulpitis in 61 (40.7%) and apical periodontitis in 89 (59.3%). By disorder, there were 15 persons with intellectual disability (31.3%), 11 persons with autism spectrum disorder (22.9%), 7 persons with sequelae of cerebrovascular disorder (14.6%), and others including cerebral palsy, Down syndrome, and psychiatric disorders. Behavioral adjustment included 13 physical restraints (27.1%) and 4 intravenous sedation (8.3%). The number of teeth judged to have a good prognosis was 136 (90.7%)：pulpitis 96.7% and apical periodontitis 86.5%. Of the patients with apical periodontitis, 38 (63.3%) had apical transmission loss after treatment, and 8 (13.3%) had reduced size.

As a result of a prognostic survey on endodontic treatment in special needs patients, the results were as good as those reported in healthy subjects. It seems to be possible to maintain oral health in special needs patients for a long time by faithfully carrying out accurate endodontic treatment rather than simply extracting the tooth because of failure or difficulty of treatment.

It is generally recognized that individuals with disabilities are at an increased risk of experiencing medical incidents；however, few reports have been published on this issue. The purpose of the present study was to investigate whether the type of incident was associated with the type of disability and whether the frequency of incidents varies depending on the type of disability.

Medical incident reports by the dentist and the dental hygienist of our clinic from April 2008 to March 2019 were collected and analyzed. The disability type, patient age, severity level and incident details were identified from these reports.

The total number of incident reports was 120, of which 72 were associated with patients and 48 were not. The most frequently occurring type of medical incident was the falling of an extracted tooth or an appliance in the oral cavity (23 cases). Among physically disabled patients, the most frequently occurring type of medical incident was the falling of a tooth or a small appliance in the oral cavity (8 cases), followed by teeth trauma or appliance destruction due to unexpected biting (7 cases). Among those with development disorders, the most frequent type of medical incident was panic/self-harm/breaking of appliances (10 cases). Among intellectually disabled patients, the most frequent type of medical incident was the falling of a tooth or a small appliance in the oral cavity (9 cases), followed by damage to the soft tissue during a treatment procedure (6 cases). Among those with development disorders, medical incidents occurred during and after treatment, whereas in other patient groups, most cases occurred during treatment.

These results revealed a unique pattern of medical incidents for each type of disability. Therefore, it is necessary to understand that the type of disability affects medical safety considerations.

Objective : To determine caries experience and number of teeth present in people using facilities for the intellectually disabled with and without a family dentist.

Materials and Methods : We performed dental checkups at three facilities for people with intellectual disabilities to assess the number of untreated cavities, treated teeth, and remaining teeth. In addition, we interviewed the staff to determine whether the facility users had a family dentist or not. The study sample comprised patients with intellectual or developmental disorders and Down’s syndrome.

Results : The mean number of untreated cavities in people using facilities for the intellectually disabled was less than that found by a national survey of dental diseases conducted by the Ministry of Health, Labour and Welfare in 2016, except for those aged 50-54 and 60-64 years old. Similarly, individuals using facilities for the intellectually disabled had a lower mean number of treated teeth than the Japanese population, except for those aged 45-54 years. In people using facilities for the intellectually disabled who had a family dentist, the mean number of untreated cavities and treated teeth were 0.4±1.2 and 8.2±6.4, respectively；in contrast, among those without a family dentist, the numbers were 1.0±1.8 and 6.0±4.9, respectively. The mean number of remaining teeth was less than that of those aged 35-39 years or older in the national survey of dental diseases conducted by the Ministry of Health Labour and Welfare in 2016, which was also notably less than that for those older than 60 years old. The mean number of remaining teeth of people using facilities with a family dentist was 21.3±9.6, while the number for those using facilities without a family dentist was 27.5±3.2.

Discussion : The experience of caries in people in facilities for the intellectually disabled is comparable with typical people without intellectual disability. However, the number of teeth decreases in those aged>60 years old. Therefore, to prevent tooth loss, prolonged maintenance by a family dentist is required.