From: Countering the poor oral health of people with intellectual and developmental disability: a scoping literature review
Authors, Year (Country)
I. Interventions – technical and educational
1a). Tooth brushing
García-Carrillo et al., 2016 (Spain) 
Single-blinded cluster RCT
Compare effect of sonic powered versus manual toothbrush in adults with ID on plaque (PlI) and gingival (GI) indices.
64 adults with ID (male n = 34, female n = 30) in six clusters.
No significant difference in PlI or GI between techniques. No adverse effect or technical problems observed.
Shin & Saeed, 2013 (USA) 
Prospective cohort study
Explore most difficult tasks during tooth brushing and the effect of Oral Health (OH) education on technique.
14 childrena with ID from a disability-specific day program.
Most difficult tasks were brushing off identified plaque and brushing front teeth. Following education, greatest improvements were opening toothpaste and placing toothpaste on brush. No significant change in PlI.
Zhou, Wong & MacGrath, 2019 (Hong Kong) 
Two-phase pre-post intervention study
Examine the effectiveness of a visual-verbal integration model (VVIM) in training parents and children with IDD to dispense a pea-sized amount of toothpaste.
370 pairs of preschool IDD children (71.6% male) and their parents.
Children with higher adaptive skills were more likely to benefit from VVIM training. Parents should be motivated and reinforced to control toothpaste amount.
1b). Caregiver OH education programs
Binkley et al., 2014 (USA) 
Measure effect of agreed carer action, training, environment changes and, ongoing coaching on paid caregivers’ self-efficacy, support provision, oral hygiene practice, and OH status of residents
21 paid caregivers (male n = 6; female n = 15) and 25 adults with ID (male n = 16; female n = 9).
No change in caregiver self-efficacy. Support provision to residents increased especially regarding supervision and environmental adaptation. Use of dental floss and disclosing solution increased in residents, but total time spent brushing teeth did not change. People with ID had a 50% plaque reduction.
Faulks & Hennequin, 2000 (France) 
Evaluate impact of OH education program on OH attitudes and behaviours.
Carersa (n = 69 pre, n = 28 post) and residentsa (n = 67 pre, n = 25 post) from three centres for people with ID.
Frequency of teeth cleaning more than once a day rose by 28% (p < 0.05). More carers were able to clean all teeth of their residents (36% increase, p < 0.05), and 24% more found tooth cleaning easy (p > 0.05).
Fickert & Ross, 2012 (USA) 
Determine effectiveness of an OH educational program on paid caregivers’ knowledge and skills.
52 paid caregivers (male n = 7, female n = 45)
Oral hygiene knowledge significantly improved. Oral hygiene skills and compliance improved but this was not statistically assessed. Intervention may improve OH of people with ID requiring oral hygiene assistance.
Mac Giolla Phadraig, Guerin, & Nunn, 2013 (Ireland) 
Explore effect of OH train the trainer program on knowledge, behaviour, attitude and self-efficacy of paid caregivers.
25 care homes (n = 183) (21 trained (n = 159), 17 returned post questionnaire (n = 76))
Knowledge, reported behaviour and self-efficacy significantly increased among the intervention group. Multi-tiered training can be effective for caregivers.
Mac Giolla Phadraig, Guerin, & Nunn, 2015 (Ireland) 
Evaluate impact of OH train the trainer program on OH status and hygiene of people with ID in community based care homes.
76 caregivers (male n = 42, female n = 43) of adults with ID.
No statistically significant differences in PlI and the GI between control and intervention. Accuracy of outcome measures may be affected by difficulty of oral examination among people with ID.
Phlypo et al., 2018 (Belgium) 
Pre-post intervention study.
Explore effect of a dental student developed OH education program for caregivers in a residential facility for people with IDD.
Residents with severe to profound ID (intervention n = 18; control n = 19). Caregivers (intervention n = 12; control n = 22).
Change of PlI and GI from pre to post did not significantly differ between intervention and control. Intervention and control post GI scores were significantly different (p = 0.02).
1c). Dentist interventions - sedation, GA, and other procedures
Chang, Patton, & Kim, 2014 (Korea) 
Assess primary caregiver perceptions of the effect of dental treatment under GA on OH-related quality of life (OHRQoL) and family dynamics.
102 Primary family caregivers (male n = 66; female n = 36)
Percieved OHRQoL of patients with IDD was significantly improved by dental treatment under GA for patients older than 30 years, originally eating soft meals, displaying no or very low levels of cooperation, or receiving endodontic treatment.
Maeda et al., 2005 (Japan) 
Explore if ICF codes can be used to assess tolerability of dental treatment for people with ID and determine its influence on application of GA or IVS.
Paid caregiversa of 49 patients with ID (male n = 32; female n = 17)
The ICF codes were a useful guide for patient treatment tolerability and enabled easy interviewing.
Meurs, Rutten, & de Jongh, 2010 (The Netherlands) 
Assess effect of background information for patients with ID on level of cooperation during first dental visit.
57 patients with ID (male n = 40, female n = 17) (control n = 28, intervention n = 29)
No significant difference was found in patient cooperation between groups regardless of degree of ID and function.
Miyawaki et al., 2004 (Japan) 
Compare sedative doses required for patients with ID to those required for patients without ID.
73 dental patients with ID (male n = 63; female n = 10); 19 patients without ID (n = 19; male n = 8, female n = 11).
Required dose of propofol in subjects with ID was significantly higher than for other subjects. This could be attributed to the use of anticonvulsants in the ID group.
Mori, Amano, Akiyama, & Morisaki, 2000 (Japan) 
Evaluate effectiveness of a 6-week Professional Mechanical Tooth Cleaning Program (weekly cleaning using dental teeth cleaners and polishers) in improving OH and caries susceptibility.
Ten young adults with ID (male n = 9, female n = 1) with periodontal inflammation.
OH improved; probing depth and bleeding sites were reduced, however number of bleeding sites returned to baseline after 3 months. No change in susceptibility to dental caries. Mechanical tooth cleaning can be effective in improving OH for people with ID.
Sakaguchi et al., 2011 (Japan) 
Investigate use of propofol sedation using Bispectral Index (BIS)-guided target-controlled pump infusion (TCI) in dental patients with ID when compared to manual control
Intervention group: n = 20 (male n = 12; female n = 8) and Manual control group: n = 20 (male n = 15; female n = 5).
The BIS-TCI group had significantly reduced doses of propofol and shortened recovery times. BIS-TCI can reduce the dose and length of sedation for people with ID.
Silva et al., 2018 (Portugal) 
Analyse the utility of Bispectral Index (BIS) for anaesthetic depth monitoring in paediatric dental patients with IDD.
17 patients with ID (female n = 7, male n = 10).
The BIS correlated with end-tidal sedative concentration and had good prediction probability except in patients with Lennox-Gastaut, West syndrome, cerebral palsy and epilepsy. BIS may be able to reflect anaesthetic depth in patients with some types of ID.
Vaessen, Schouten, van der Hoeve & Knape, 2017 (The Netherlands) 
Evaluate safety and effectiveness of propofol sedation by trained nonmedical sedation practitioners in dental patients with ID in an office-based setting.
Participantsa with ID; mild (n = 21); moderate (n = 56) and severe (n = 47).
Propofol sedation was effective, allowing a sufficient sedation level without moderate or severe complications. The intervention allowed successful dental treatment in safe, familiar home surroundings.
Yeganegi & Tandon, 2008 (India) 
Assess the efficacy and retention of Fuji VII Glass Ionomer Cements (GIC) for surface protection in plaque-prone areas of teeth
100 patients with ID (male n = 48; female n = 52).
Mean plaque scores at follow up were significantly lower in the intervention group when compared to the comparison group. GIC helps to reduce plaque accumulation, although retention of the GIC on tooth surfaces was inadequate.
1d). Dental clinic setting
Kim, Carrico, Ivey & Wunsch, 2019 (USA) 
Explore impact of a sensory adapted dental environment (SADE) on behavioural and physiological changes when compared to routine dental environment (RDE).
Children with developmental disability (male n = 14, female n = 8)
No significant difference in physiological scores (heart rate and oxygen saturation) between the two groups. The SADE group had significantly better observed behaviour scores compared to the routine dental environment group.
Potter, Wetzel & Learman, 2018 (USA) 
Examine whether a SADE had an effect on anxiety and agitation in adults with IDD when compared to RDE.
Adults with IDD (male n = 22; female n = 19) mainly with severe to profound IDD.
There was a significant reduction in the frequency and duration of observed agitation after SADE. There was also a significant reduction in anxiety after SADE as measured by heart rate and blood pressure.
Shapiro, Sgan-Cohen, Parush, & Melmed, 2009 (Israel) 
Examine the influence of a SADE compared to RDE on the behaviour and arousal levels of children with and without DD.
16 children with DD (male n = 11, female n = 5); 19 children without DD (male n = 13, female n = 6).
Both groups performed better in the SADE compared to the RDE, however the difference between the 2 environments was greater in children with DD.
Zhou et al., 2014 (UK) 
Explore the applicability of the Verona coding definitions of emotional sequences (VR-CoDES) to assess emotional distress of patients with ID in a dental context.
14 patients with ID and complex communication needs (male n = 6, female n = 8).
Cues of emotional distress were reliably identified during seven of the 14 consultations. Although cues and responses were reliably identified, improving coding accuracy of responses is required through further guidance.
II. Perspectives – people with IDD, Caregivers, and Dentists
2a). Perspectives of people with IDD
Blaizot et al., 2017 (France) 
Qualitative study using focus groups (FG)
Explore ethical tensions in OH care management reported by adults with ID and then confirm these with family and paid caregivers
FG 1: Adults with IDa (n = 8)
FG 2: Family caregiversa (n = 6)
FG 3: Paid caregiversa (n = 6)
Participants wanted a dentist competent to meet their specific needs, with a positive attitude toward people with ID, and the confidence to adjust their communication style for people with ID. Access barriers included the need for environmental adaptations, and cost.
Lees, Poole, Brennan & Irvine, 2017 (UK) 
Explore experiences of people with ID and their carers who accessed community dental services.
Adults with IDa (n = 4) an their caregiversa (n = 6)
Participants valued the dental practitioners with ID-specific knowledge and positive attitudes. Dissatisfaction was attributed to poor communication, the transition form child to adult services and cost.
Mac Giolla Phadraig et al., 2016 (Ireland) 
Determine the priorities of people with ID regarding oral health services
Six participants (male n = 5, female n = 1) with mild-moderate ID.
Participants were disempowered in their interactions with dental services. They prioritised issues relating to control, empowerment and choice.
2b). Perspectives of caregivers
Chadwick, Chapman & Davies, 2018 (UK) 
Descriptive phenomenological study
Identify factors influencing engagement of adults with ID in daily oral and dental care.
372 adults with ID (male n = 159, female n = 213)
Two global themes were identified:
1) Personal and lifestyle influences: physical, sensory, cognitive, behavioural and affective factors
2) Social and environmental factors: caregiver support, equipment/adaptations used and oral hygiene routine.
Eijsink, Schipper & Vermaire, 2018 (The Netherlands) 
Explore all prevailing viewpoints that caregivers of institutionalised persons with ID have about oral hygiene.
Caregivers of people with ID living in institutions n = 40 (women n = 27).
Participants either: 1) recognised the consequences of poor dental care and took responsibility; 2) prioritised dental care as a way of promoting the social acceptability of their clients, 3) were highly motivated to promote OH but perceived obstacles; or 4) wanted to provide OH care but had insecurities about how to do so effectively.
Gerreth & Borysewicz-Lewicka, 2016 (Poland) 
Evaluate unpaid caregiver views about access to and satisfaction with dental health care of their children with ID.
Parents/caregiversa (n = 264) of children with ID.
31.8% parents/caregivers did not have any problems with access to dental care. The most commonly reported barrier to obtaining dental care was waiting time for a visit (36.7%). Most commonly, children were treated in dental surgery conditions (90.1%). Only 42.1% respondents were satisfied with their children’s dental care.
Kahabuka & Ndalahwa, 2006 (Tanzania) 
Investigate oral hygiene practices and OH care given by parents of individuals with ID.
100 parents (male n = 48, female n = 52) of 100 individuals with ID (male n = 55, female n = 45)
65% of the individuals with ID were able to independently brush their teeth. Children who brushed less frequently experience significantly more bleeding. Few parents took their children to a dentist for dental pain (26%) or bleeding gums (37%).
Minihan et al., 2014 (USA) 
Describe the experiences of caregivers (paid and family) supporting the at-home OH of adults with IDD.
Caregiversa (paid n = 683; unpaid family n = 125) of adults with IDD.
Most adults with IDD required assistance with oral hygiene with behavioural problems interfering with OH care. Paid caregivers were significantly more confident in providing support.
Oliveira, Paiva, & Pordeus 2007 (Brazil) 
Analyse parental acceptance regarding physical and chemical restraint for patients with ID during dental care.
209 parents/legal guardians (male n = 44, female n = 165) of children with ID.
Participants were more likely to accept physical restraints for their child when parents were over the age of 35 and from an underprivileged economic class, and when the children had previously experienced physical restraints.
Pradhan, Slade, & Spencer, 2009 (Australia) 
Compare access to dental care for adults with ID living in family homes, institutions and community housing.
484 caregivers (male n = 276, female n = 206) of adults with ID.
43.6% of respondents reported problems accessing dental care. Adults with ID living at home were more likely to have irregular dental visits than people with ID living in institutions.
Thole, Chalmers, Ettinger, & Warren, 2010 (USA) 
Investigate the OH care activities and attitudes of care providers for people with ID.
138 paid caregivers (male n = 21, female n = 117).
Providing OHC to people with ID was rated as important to extremely important for 98% of respondents. Barriers include a lack of time and lack of staff. Behavioural issues were common (64.9%).
Versloot et al., 2008 (Canada) 
Determine If the Dental Discomfort Questionnaire (DDQ) can identify dental pain in children with ID, and if two added items can increase its sensitivity.
Parents of 58 children with ID (male n = 40, female n = 18) completed the DDQ after dental examination.
There was a non-significant trend between having caries and parents reporting toothache. There was a significant association between mean DDQ scores and the presence or absence of caries. The standard DDQ has good predictive value in determining the presence or absence of caries and dental pain in children with ID.
Weckwerth et al., 2016 (Brazil) 
To evaluate the parents’ perception of dental caries in children with ID.
Schoolchildrena (n = 100) with (n = 50) without (n = 50) ID diagnoses, and their parents.
Both groups had a similar prevalence of caries free children. Parents of children with ID rated impact of caries on drinking, eating and pronunciation as more important than for parents of children without ID.
Wiener et al., 2016 (USA) 
Explore if finances, employment and time burdens are associated with perceived need for and receipt of dental care.
Secondary analysis of 16,323 caregivers of children (male = 65.2%) who have CASD/DD/MHC.
Unmet need for preventative dental care was associated with employment and financial burdens of caregivers. Parents with either private or public health insurance policies were more likely to self-report that their children had all their OH needs met.
2c). Perspectives of dentists
Byrappagari, Jung & Chen, 2018 (USA) 
Examine level of access individuals with DD have to dental care and explore the dentists’ practices, attitudes and barriers to providing care to this population.
279 dentists (male 75.6%)
Most dentists provided care for people with DD (80.3%) and 58% were confident to do so. All dentists identified training and better reimbursement for services as key to improving care for these patients. Behaviour, inadequate training, and severity of patient’s condition were the most common reasons for not treating patients with DD.
Grant, Carlson, & Cullen-Erickson, 2004 (Australia) 
Explore the experiences and strategies involved in achieving positive OH outcomes for people with ID.
10 professionalsa (support worker n = 3; dental professional n = 4; other professional n = 3) caring for four adults with ID.
Direct support workers defined positive outcomes as acceptance of treatment, whereas professionals thought in terms of improvements in dental condition/oral hygiene. Strategies for better outcomes were consistent personnel and procedure, positive feedback to people with ID, exercising patience, and respecting their choices.
III. Non-clinical service delivery contexts
Lo et al., 2004 (Hong Kong) 
Describe the appropriateness, efficiency and acceptance of an OH outreach service for marginalised sub-populations including people with IDD.
1030 (male n = 618, female n = 412) adolescents and adults with ID
Mean numbers of decayed teeth were 1.8; mean numbers of missing teeth were 1.6. Problems with access, financial stress, and under-estimating the severity of the problem were the main barriers to OH service provision. The outreach service was viewed positively with more services and more frequent OH reviews requested.
Shyama, Al-Mutawa, Honkala, & Honkala, 2003 (Kuwait) 
Evaluate the effectiveness of a school-based, supervised tooth-brushing program.
112 children with Down syndrome and ID (males n = 45, females n = 67).
Mean PlI and GI showed significantly decreased after the intervention. A supervised toothbrushing program can be effective in reducing PlI and GI.
York & Holtzman, 2004 (USA) 
Mixed methods design
Design and assess the effect of a school-based dental program for students with IDD.
Parents/guardians (n = 131) of students with IDD (male children n = 97, female children n = 34).
Two years after first dental visit, an increase was observed in parent/guardian consent, and the number of children seen by a dentist.