Regular and effective oral hygiene is important to prevent increases in the level and variety of dental bacteria that make up dental plaque. Dental plaque has a major role in the development of periodontal disease and caries. A higher prevalence and severity of periodontal disease is seen in people with intellectual disability (ID). The World Health Organization’s (WHO) definition of disability is the most widely used and incorporates the complex interactions between health conditions, environmental factors and personal factors.  For people with ID three elements are common; a significant impairment of intelligence, a resultant significant reduction in adaptive behaviour/social functioning and the development of the condition (which persists throughout life) before the age of 18 years.

The aim of this Cochrane review was to assess the benefits and harms of oral hygiene interventions for people with intellectual difficulties.

Methods

Searches were conducted in the Cochrane Oral Health’s Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, PsychoINFO and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials.  Conference abstracts from the International Association of Disability and Oral Health (2006 to 2016) were hand searched.  There were no limitations on language or publication status or date.

Randomised controlled trials (RCTs) and some types of non-randomised studies (NRS) non-randomised controlled trials (NRCTs), controlled before-after studies, interrupted time series studies (ITS) and repeated measures studies evaluating oral hygiene interventions targeted at people with ID or their carers, or both were considered. At least two reviewers selected studies, extracted data and assess risk of bias. RCTs and NRSs were reported separately. The GRADE criteria were used to assess the certainty of evidence.  Studies were categorised as short (≤ 6 weeks), medium term (between 6 weeks and 12 months) and long term (>12 months).

Results

• 19 RCTs and 15 NRSs involving 1795 adults and children with ID and 354 carers were included.
• 9 comparisons of different types of oral hygiene interventions were included; special manual toothbrushes, electric toothbrushes, oral hygiene training, scheduled dental visits plus supervised toothbrushing, discussion of clinical photographs showing plaque, varied frequency of toothbrushing, plaque‐disclosing agents and individualised care plans.
• Most studies were small and at high or unclear risk of bias.
• Very low-certainty evidence suggested carers brushing wit a special manual toothbrush (the Superbrush) reduced gingival inflammation (GI), and possibly plaque, more than a conventional toothbrush in the medium term  (GI: mean difference (MD) -12.40 (95%CI; -24.31 to -0.49)[1 RCT, 18 participants]. Neither toothbrush showed superiority in the short term [low- to very low-certainty evidence]
• In the medium term, moderate and low-certainty evidence (2 RCTs, 120 participants) found no difference between electric and manual toothbrushes for reducing GI [ MD= 0.02 (95%CI; -0.06 to 0.09)] or plaque [standardised mean difference 0.29 (95%CI; -0.07 to 0.65)]. Findings were inconsistent for the short-term.
• There was low-certainty evidence suggesting that training carers in oral hygiene care had no detectable effect on levels of GI or plaque in the medium term. Oral hygiene knowledge of carers was better in the medium term after training but not found in the short term; MD= 0.69 (95%CI; 0.31 to 1.06).    [2 RCTs, 189 participants, low-certainty evidence].
• 1 RCT (10 participants) found that training people with ID in oral hygiene care reduced plaque but not GI in the short term; [very low-certainty evidence].
• Scheduled dental recall visits (at 1-, 3- or 6-month intervals) plus supervised daily toothbrushing were more likely than usual care to reduce GI (pocketing but not bleeding) and plaque in the long term (1 RCT, 304 participants, low-certainty evidence).
• Motivating people with ID about oral hygiene by discussing photographs of their teeth with plaque highlighted by a plaque-disclosing agent, did not reduce plaque in the medium term (1 RCT, 29 participants, very low-certainty evidence).
• Daily toothbrushing by dental students was more effective for reducing plaque in people with ID than once- or twice-weekly toothbrushing in the short term (1 RCT, 80 participants, low-certainty evidence).
• A benefit to gingival health was found by one NRS that evaluated toothpaste with a plaque-disclosing agent and one that evaluated individualised oral care plans (very low-certainty evidence).
• Most studies did not report adverse effects; of those that did, only one study considered them as a formal outcome. Some studies reported participant difficulties using the electric or special manual toothbrushes.

Conclusions

The authors concluded: –

Although some oral hygiene interventions for people with ID show benefits, the clinical importance of these benefits is unclear. The evidence is mainly low or very low certainty. Moderate-certainty evidence was available for only one finding: electric and manual toothbrushes were similarly effective for reducing gingival inflammation in people with ID in the medium term. Larger, higher-quality RCTs are recommended to endorse or refute the findings of this review. In the meantime, oral hygiene care and advice should be based on professional expertise and the needs and preferences of the individual with ID and their carers.

Comments

This well conducted Cochrane review demonstrates some evidence of benefit for some oral hygiene interventions for patients with ID. However, benefits for individual’s oral health and hygiene are unclear. While a majority of the included studies were RCTs the quality of the certainty of the evidence was moderate to very low and very low for the NRS studies.  The authors highlight that the outcomes assessed in the NRS studies would all have been amenable to investigation using RCT methodology.  The authors attempted to map the behavioural change aspect of the interventions using the COM-B system (Michie 2011) and suggest this could be used in understanding interventions in future studies. It is also suggested that future RCTs should be of appropriate size well conducted and reported focusing either on one level of ID or differentiating between levels and use common outcome sets (COMET Initative).

Links

Primary Paper

Waldron C, Nunn J, Mac Giolla Phadraig C, Comiskey C, Guerin S, van Harten MT, Donnelly‐Swift E, Clarke MJ. Oral hygiene interventions for people with intellectual disabilities. Cochrane Database of Systematic Reviews 2019, Issue 5. Art. No.: CD012628. DOI: 10.1002/14651858.CD012628.pub2

Other references

Michie S, Van Stralen MM, West R. The behaviour change wheel: a new method for characterising and designing behaviour change interventions. Implementation Science 2011;6(1):42.