Dental desensitization by dentists and occupational therapists for autistic adults: A pilot study

Introduction

References in the literature on the oral health of adults with autism are scarce, and most agree in that the prevalence of caries in these individuals is similar or even lower than that in the general population (Blomqvist et al., 2015; Loo et al., 2008; Orellana et al., 2012; Vajawat and Deepika, 2012). However, studies have indicated that these adults are more susceptible to periodontal disease, gingival recession, dental malocclusions, bruxism, self-inflicted oral injuries, and hyposalivation (Blomqvist et al., 2015; Orellana et al., 2012; Vajawat and Deepika, 2012).

Accordingly, most of these individuals have significant dental treatment needs (Mangione et al., 2020; Rada, 2013). It has been suggested that, among adults with autism but no intellectual disability, the most widely used health service after the family doctor is the dentist (Vogan et al., 2017). However, many of these patients are uncooperative (Loo et al., 2008), the dental treatment cannot be provided under conditions of consciousness (Mangione et al., 2020), and pharmaceutical sedation (both oral and inhaled with nitrous oxide) are less effective in adults than in children (Mangione et al., 2020). Therefore, a considerable percentage of adults with autism require general anesthesia when undergoing dental treatment (Loo et al., 2008; Mangione et al., 2020).

General anesthesia often causes disruptive behaviors in the hospital (Rada, 2013) and is not exempt from morbidity and mortality risks (Parry et al., 2021), especially if we consider that many adults with autism have comorbidities such as obesity, heart disease, diabetes, and toxic habits (Dumbuya et al., 2021; McNeil et al., 2023) and that a considerable percentage of dental treatment sessions under general anesthesia have to be repeated in 2 years (Parry et al., 2021).

The occupational therapists work with individuals with autism in various scenarios such as the home, school and community settings, where the therapists assess the factors that determine the skills and participation of these individuals in activities of daily living (including oral care) (Crabtree and Demchick, 2018). Their fundamental goal is to identify the individuals’ strengths and challenges, while simultaneously adapting and modifying activities to facilitate the participation of individuals with autism (Como et al., 2020). A number of previous experiences have been published on interdisciplinary collaboration between occupational therapists and dentists for planning changes in the dental setting and adapting dental protocols, with the aim of reducing some of the barriers for individuals with autism (Stein Duker et al., 2019). Desensitization is a structured teaching resource based on temporal and spatial organization, mainly through visual information, which has been used occasionally to help adults with autism tolerate oral examinations (Orellana et al., 2014). It has been suggested that occupational therapists could participate in these desensitization strategies for preparing the dental clinic visit (Como et al., 2020; Junnarkar et al., 2022); to date, however, the results of these interventions have not been published.

The aim of this pilot study was to assess the efficacy of a desensitization program in which dentists and occupational therapists participate, so that adults with autism could undergo an oral examination and a simple dental therapeutic procedure.

Methodology

The study group consisted of 18 users of the ASPANAES day center (Association of Parents of Individuals with Autism Spectrum Disorder, Santiago de Compostela, Spain), 10 of whom were men and 8 of whom were women, with a mean age of 24.5 years (range, 18–45 years). All patients satisfied the following inclusion criteria: a confirmed diagnosis of autism, 18 years of age or older, arriving while accompanied but voluntarily to the waiting room on the consultation days, not taking specific medication for encouraging collaboration on the consultation days, and authorization through the informed consent of their legal guardians. We did not consider the presence of comorbidities, the intellectual and verbal communication level, or previous experiences in the dental clinic.

The patients underwent a baseline examination, after which they were progressively exposed to oral examination maneuvers and ultimately dental procedures. To this end, the patients participated in a weekly desensitization session performed by one of the center’s occupational therapists (previously instructed by a dentist) and a monthly evaluation session by a dentist in the Special Care Dentistry Unit of the Faculty of Medicine and Odontology of the University of Santiago de Compostela (Spain), for a maximum period of 30 weeks.

In the desensitization sessions in the day center, the participants underwent three types of scenarios: (1) Familiarization with the environment and the basic dental instrumentation (simulated waiting room, simulated dental chair, intraoral mirror, tongue depressor, examination probe, and saliva ejector); to this end, we developed image-object and image-image association activities, dental instrument classification activities, and recreational activities (the “Dental Health” board game); (2) Simulated oral examination sessions, performed by the occupational therapist (simulated orthopantomography, sitting down in a stretcher with the backrest raised, leaning back on the backrest of the stretcher and lying down, tolerating a protective bib around the neck, tolerating light shining directly on the face, tolerating the invasion of personal space, allowing perioral manipulation with gloves, opening the mouth, tolerating intraoral manipulation with gloves, tolerating intraoral examination with the basic dental instrumentation, tolerating the intraoral application of a stream of pressurized air and allowing the simulated performance of intraoral radiography); to this end, we used the same strategies described in the instrumentation familiarization phase; (3) Simulated sessions of simple dental treatments, performed by the occupational therapist and using portable dental equipment (tolerating a mouth opener, tolerating the noise of the vacuum and of the dental handpiece, allowing intraoral contact with the vacuum and with the dental handpiece (with and without water), allowing the intraoral contact with an anesthesia syringe without needle, and simulating the placement of a rubber dam in the mouth); to this end, the patients watched a video with the sound of the vacuum and of the dental handpiece, a video of a simulated dental procedure performed on one of their companions, and role-playing activities.

In the visits to the Special Care Dentistry Unit, the participants were accompanied by the occupational therapist who performed the desensitization and were provided visual support of the picture book that they had used in the facility. The dental examinations and procedures were always performed in the same dental office (except the simulated performance of an orthopantomograph in the radiodiagnosis room) and always by the same dentist with the help of an assistant. In the more advanced sessions for evaluating a single dental procedure, the participants underwent a local anesthesia injection (with a conventional syringe and needle), placement of the rubber dam (which they had to maintain for 10 min), and finally application of a resin-based sealant of cracks and tartar removal.

The patients’ behavior was assessed using the Frankl scale (Frankl et al., 1962), dichotomously recoded (unfavorable: definitely negative or negative in the original scale; favorable: positive or definitely positive in the original scale). If the behavior while conducting a specific process was unfavorable, the four desensitization sessions were repeated in the day center, and the process was subsequently reassessed in the dental clinic.

The research study and the use of this information with purposes of disclosure were approved by the Ethics Committee of the University of Santiago de Compostela, Spain (approval number: USC 07/2022).

Results

During the first session (baseline) in the Special Care Dentistry Unit, 44% of the participants completed all of the oral examination procedures, reaching 100% by the seventh visit (Figure 1).

OPEN IN VIEWER

Figure 1.

Percentage of participants who in each monthly session completed all of the oral examination procedures in the visit to the Special Care Dentistry Unit.

In the first visit, more than 80% of the participants behaved favorably when the following procedures were performed: simulated performance of an orthopantomograph, entering the dental office and sitting down in the chair with the backrest raised. A total of 60%–80% of the participants behaved favorably during the first visit for the following procedures: lying down in the dental chair with the backrest reclined, tolerating a protective bib around the neck, tolerating light shining directly on the face, tolerating the invasion of personal space, allowing perioral manipulation with gloves, and opening the mouth and allowing intraoral manipulation with gloves. The least tolerated procedures during the first visit (40%–50% of the participants) were as follows: the intraoral examination with basic dental instrumentation, the intraoral application of a stream of pressurized air, and allowing the simulated implementation of intraoral radiography.

Most of the oral examination procedures were tolerated by the entire study group starting the fourth visit, except for sitting down voluntarily in the dental chair with the backrest reclined (fifth visit) and allowing the simulated performance of intraoral radiography (fifth visit). With the described visit schedule (a weekly desensitization session and a monthly evaluation session) and considering all visits as a whole (baseline, desensitization sessions, and evaluation sessions), the average number of visits required to tolerate an oral examination was 7.

None of the participants completed a simple dental treatment up to the third session, subsequently increasing the percentage progressively, with a substantial inflection between the sixth and seventh sessions, until reaching a maximum of 61% (Figure 2). In the seventh visit, most of the dental treatment procedures were tolerated by 77%–88% of the participants, including the local anesthesia injection (83%). The highest acceptance rate corresponded to intraoral contact with the dental handpiece without water (94%), while the lowest rate was achieved with the placement of the rubber dam (72%), which only 61% of the participants tolerated for 10 min. Considering all visits as a whole (baseline, desensitization sessions, and evaluation sessions), the average number of visits required to tolerate a simple therapeutic procedure was 27.

OPEN IN VIEWER

Figure 2.

Percentage of participants who in each monthly session completed all of the simple dental therapeutic procedures in the visit to the Special Care Dentistry Unit.

Discussion

This study showed that virtually all of the adults with autism who underwent a specific desensitization program can tolerate an oral examination and that more than 60% can tolerate a simple dental therapeutic procedure, without having to apply pharmacological behavioral control techniques.

In a study with similar characteristics performed in Spain in which 34 adults with autism participated, 67.3% were reluctant to undergo the oral examination in the baseline visit. After completing five desensitization sessions conducted by the dentist, however, the patients showed similar results to those of our study; the oral examination was completed in all participants (Orellana et al., 2014). In children, especially older children, the efficacy of desensitization has also been confirmed, given that a study conducted at the University of Washington in Seattle in which 168 children aged 4–18 years participated, 80% of the children aged 13–18 years tolerated an oral examination in the first or second visit, and 96% tolerated it by the fifth visit (Nelson et al., 2017).

We found no references in the literature as to the efficacy of desensitization programs regarding therapeutic dental procedures. Sensory processing difficulties in the dental setting have been well documented in individuals with autism (Stein et al., 2011). It is therefore especially striking that most participants managed to tolerate the direct application of light on the face and the use of the dental handpiece (without water) and that 77.7% tolerated the performance of ultrasonic dental cleaning. We also did not expect that more than 80% of the patients would tolerate a local anesthesia injection, probably because the avoidance behaviors in individuals with autism respond more to the pain-related anxiety and fear than to differences in the pain threshold compared with the general population (Failla et al., 2020). Placing the rubber dam and having the patient endure it for at least 10 min is a challenge, probably related to the difficulties in sensory processing among individuals with autism (Stein et al., 2011). Although working with the rubber dam entails advantages both for the practitioner and the patient, its use in certain patients with autism should be avoided because it can be difficult to tolerate (Diekamp et al., 2020).

The dental procedures performed most often in individuals with autism are of a diagnostic and preventive nature (Dumbuya et al., 2021; Mangione et al., 2020), although only one in every three adults with autism attends a preventive visit with the dentist at least once a year (McNeil et al., 2023). The incorporation of occupational therapists into dental desensitization programs can not only facilitate visits to the dentist but also help plan favorable dental environments, adapt oral hygiene strategies, eliminate a number of barriers, and refer patients with oral disease or harmful habits to the dentist (Como et al., 2020; Junnarkar et al., 2022).

In addition to the sample size, this pilot study has other potential limitations, such as omitting the severity of the participants’ autism. Although it has been suggested that the heterogeneity of autism spectrum disorders complicates the preparation of oral care guidelines (Mangione et al., 2020), the response of the adults with autism to the dental desensitization sessions appears not to have been determined by their level of cognitive development (Orellana et al., 2014). We also did not analyze the variables that could determine the results of the desensitization. In children, it has been suggested that participating in group activities, preserving verbal communication, having a moderate versus severe level of autism, and being autonomous for dressing are predisposing factors for the success of desensitization (Nelson et al., 2017).

Conclusion

Taking into account the study’s limitations, this dental desensitization program implemented by dentists and occupational therapists could help in performing oral examinations and simple dental therapeutic procedures for a considerable percentage of adults with autism, without having to resort to pharmacological behavioral control techniques.