Assessment of oral health and habits in a group of school children with intellectual disabilities

Pages: 221-237

Konstantina Kritikou (1), Aneta Munteanu (2), Arina Vinereanu (3), Rodica Luca (4)

(1) Paediatric Dentistry resident, PhD student, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania(2) Assistant lecturer, Department of Paediatric Dentistry, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania(3) Private practice, Bucharest, Romania(4) Professor, Department of Paediatric Dentistry, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania


Aim. To asses the oral health status and habits in a sample of schoolchildren with intellectual disabilities.

Methods. Retrospective cross-sectional study conducted in 2019 on a sample of 75 schoolchildren (51 boys, 24 girls) aged 5 to 17 years (mean age= 10.81±2.85 years) from a school for special needs children in Bucharest. Data about oral hygiene habits, dental and periodontal status were collected through interviews and clinical examinations according to WHO criteria (1997). Prevalence index (Ip), restoration index (RI), plaque index by Silness&Loe (PI) and caries experience indexes (DMF-T/S, dmf-t/s) were evaluated for the whole sample and according to gender, age and intellectual disability (MID=mild, MoID=moderate, SID=severe). Data were processed using Microsoft Excel and SPSS 20.0 (p<0.05).

Results. : a) Ip= 92% (90.2% boys, 95.8% girls), (IpMID= 100%; IpMoID= 92.3%; IpSID= 87.5%); b) For the entire sample, DMF-T=4.32±3.40; DMF-S=6.22±6.19; dmf-t=3.53±2.39; dmf-s=7.87±6.58, the differences being non-statistically significant according to gender and intellectual disability; c) RI= 3.1%, d) sealants= 2.6% of the children, treated caries=5.3% e) PI=1.48 (PIMID=1.16; PIMoID=1.35); PISID=1.34) (p>0.05);  e) 60% of the children presented distinct signs of gingivitis; f) 85.33% of the children brushed their own teeth using manual toothbrushes; g) none of the children used fluoride products such as gels/solutions.

Conclusions. The oral health of the examined children was poor, regardless the degree of intellectual disability. Improvement of the oral health of children with intellectual disabilities can be achieved by implementing specific prevention programs and by increasing access to dental treatments.

Key words: intellectual disabilities, children, dental status, oral hygiene habits


Disability is the consequence of a deficiency that can be physical, cognitive, mental, sensory, emotional, developmental, or a combination of these [1]. Currently, according to the World Health Organization (WHO), about 15% of the global population has different types of disabilities (̴1 billion people) [2].

Intellectual disabilities are disorders characterized by a deficit of intellectual and adaptive function that begin in the developmental period of the individual. It is estimated that 1-3% of the entire population are people with intellectual disabilities. A child with a mild intellectual disability (MID) has an IQ level between 55 and 70, while moderate intellectual disability (MoID) is found in people with an IQ of 40 to 55. People with an IQ below 40 are considered to be severely intellectually disabled (SID) [3].

Dental caries is the most common oral pathology in children, including those with different types of disabilities [4]. In people with intellectual disabilities, oral health problems are more severe, one of the reasons being the reduced cognitive and motor skills. For these people, oral hygiene is more difficult to achieve, resulting in an increased risk of tooth decay and periodontal disease [5]. Various studies have shown that the access of children with disabilities to dental services is more restricted compared to healthy children and consequently many problems in the oral cavity remain unresolved [6].

During the last decade, several studies regarding the oral health of Romanian intellectually challenged Special Olympics athletes [7-11] were published. However, data about the oral health of Romanian children and adolescents with intellectual disabilities outside the Special Olympics program is scarce.

Given these aspects, the aim of the present study was to assess the dental status and oral hygiene habits of a group of school children with intellectual disabilities.

 Material and methods

In 2019, a cross-sectional retrospective clinical study was conducted on a sample of 75 intellectually challenged children (51 boys, 24 girls) aged between 5 and 17 years (mean age = 10.81±2.85 years), studying in a special school in Bucharest.

Formal permission for the study was obtained from the school management. Verbal consent from participating children was obtained and all their parents signed the informed consent.

Demographic data of each child included in the study (age, sex), as well as the level of their intellectual disability, were extracted from the medical records. Dental examination was performed in the classroom, according to WHO recommendations (1997) [12], using basic examination kit (mirror, probe), in natural light and with the help of a headlamp (Fig.1). Before clinical examination, the children attended an oral hygiene education class, with practical demonstrations of correct brushing technique (Fig.2). Dental status (sound/ decayed / sealed) and periodontal status (presence of dental plaque, gingivitis) were recorded. Caries were diagnosed exclusively by clinical examination, without radiographs. Permanent molars were recorded as “sealed” when sealant was present on at least 2/3 of the occlusal surface.

Based upon the recorded data the following parameters were calculated:

• Caries prevalence index (Ip)

• Caries experience indexes for permanent teeth (DMF-T, DMF-S) and primary teeth (dmf-t, dmf-s) for the whole sample and separately according to gender, age and degree of intellectual disability (MID, MoID, SID)

• Restoration Index (RI)

RI = [F / (F + D) x100] %, where F = filled teeth and D = teeth with untreated decay

• Plaque index Silness & Loe (PI) 

The children answered a questionnaire regarding their oral hygiene habits; answers were recorded by the examiner.

Data were processed using Microsoft Excel and SPSS 20.0; a level of statistical significance (ss) was set at p <0.05.

Fig. 1. Clinical examination in natural light and using a headlamp (according to WHO recommendations, 1997)
Fig. 2. Oral health class with practical demostration of brushing technique


a) Degree of intellectual disability

Most of the children who participated in the study had a moderate intellectual disability (69.3%). Severe intellectual disability was present in 21.4% of pupils and mild intellectual disability in 9.3% of them.

b) Caries prevalence

Only 8% of children were caries free. Caries prevalence (Ip) for the whole sample was 92%. Caries prevalence index was higher in girls (95.8%) compared to boys (90.2%), but the differences were not statistically significant (p> 0.05). Regarding the prevalence of caries according to the degree of intellectual disability, a score of 100% was observed for children with MID, 92.3% for those with MoID and 87.5% for children with SID, without statistically significant differences (p> 0.05).

c) Caries experience indexes

The examined children had on average 4 permanent and 3 primary teeth affected by caries. Caries experience indexes were not ss correlated with gender or with the degree of intellectual disability (p> 0.05) (Table I).

Table I. Caries experience indexes

d) Restoration index (RI)

Restorative treatments were found in only 5.3% of children. The calculated value for the restoration index (RI) was 3.1%.

Sealants were found in 2.6% of the examined subjects.

e) Plaque index

The mean value of the Silness & Loe (PI) plaque index for the whole sample was 1.48. Children with MoID had the highest plaque index mean value (1.35), followed by those with SID (1.34). The lowest PI value was found in children with MID (1.16). However, differences were not statistically significant (p> 0.05).

f) Signs of gingivitis

A proportion of 60% of the whole sample had different types and degrees of gingivitis. Gingival inflammation affected 81.25% of the children with SID, 55.76% of those with MoID and 14.28% of the children with MID.

Regarding oral hygiene habits, 85.33% of the children reported that they brushed their own teeth. The same percentage used manual toothbrushes (Table II).

Table II. Oral hygiene habits


Official data for Romania in 2018 reported a total number of 853 465 people with different degrees and types of disabilities, of which 8.16% were children (aged 1-18 years) and 15.75% had intellectual disabilities [13].

Various studies have shown that children with intellectual disabilities have poorer oral health, correlated with their limited abilities to recognize and perform proper oral hygiene [14], with less knowledge about the causes of oral diseases [15] or with an increased level of fear or anxiety [16].

On the other hand, some studies report non-significant differences or even better oral health in people with intellectual disabilities as compared to healthy subjects. Thus, people with Down syndrome frequently have dental abnormalities in number (agenesis), shape (“peg-shaped” teeth) and size that can act as favorable factors for better oral health, as proximal surfaces may become less retentive and thus more accessible to efficient self-cleaning and toothbrushing. Delayed tooth eruption in children with intellectual disabilities may also be regarded as a protective factor [17].

Most of the children who participated in this study had moderate intellectual disability (approximately 7 children out of 10), while 2 children out of 10 had severe intellectual challenge.

Caries prevalence in our study group was very high, higher than values reported by previous studies for people with disabilities (Table III).

Table III. Caries prevalence indexes in people with intellectual disabilities – comparative data

Similar results in terms of caries prevalence are reported for Romanian Special Olympics athletes for 2018 [9] (Table III). However, it is important to emphasize that the relevance of comparisons is limited by age differences between the different study groups.

Carious experience indexes showed much higher values as ​​compared to the target set by the WHO for the year 2000 (DMF-T <3 at age 12) [20]. This target has not been reached so far and it appears even more difficult to achieve from the perspective of the child with intellectual disabilities.

However, carious experience indexes calculated for our group were comparable to values previously ​​reported (Table IV).

 Table IV. Caries experience indexes in people with intellectual disabilities – comparative data

Concern for caries prevention was very scarce in our study group (sealants in a small percentage, non-use of fluoride products).

Most of the examined children had not received any prophylactic or curative dental treatments by the time of the examination (Table V).

Table V. Preventive and restoration treatments in people with intellectual disabilities – comparative data

This situation could be due to limited access to dental treatment caused by reduced ability to cooperate with medical staff, reluctance or even refusal of treatment by the practitioner due to insufficient professional training in this direction. Parents’ low level of literacy regarding the importance of oral health and regular check-ups is another contributing factor. Financial reasons may also induce limitation of dental treatments in people with disabilities, especially in case of late presentation, with already complex pathologies, needing treatments with a higher level of difficulty. Dental treatment in people with disabilities may require 2-5 times more time, more materials and resources to provide treatment under special circumstances like sedation or general anesthesia [23].

Compared to previous studies performed on athletes with intellectual disabilities who participated in Romanian Special Olympics games and were examined in the Special Smiles Program, the present study shows a lower percentage of subjects who had already benefited from dental treatments at the time of the examination. For example, the average value of the restoration index (RI) calculated during the present study was 3.1%, versus 20.06% reported for Romanian Special Olympics athletes examined in 2018 [9]. Part of this difference can probably be due to the age difference between the two study groups. However, Special Olympics athletes can be considered ‘favored’ in the community of people with various disabilities, as they benefit not only from social integration through sports, which can enhance communication abilities and medical compliance, but also from preventive programs such as Special Smiles Romania. This statement is supported by the difference between the reported 14.4% SOR athletes with sealants (4.4% pre-existing + 10% applied during the Special Smiles event) [9] and the 2.6% found in the present study.

Inadequate oral hygiene and absence of regular professional hygiene favor the accumulation of bacterial plaque, affecting the marginal periodontium. In children with disabilities, chronic gingivitis caused by lack of oral hygiene is common and this is an aspect also noticed in the present study. More than half of the examined children showed signs of gingivitis; other studies reported comparable results (Table VI).

Table VI. Signs of gingivitis in persons with intellectual disabilities – comparative data

Although various studies may report contradictory results with regard to carious damage in patients with intellectual disabilities [17], restrained access of these patients to dental service is a reality that is difficult to dispute, therefore the need to implement prevention programs and improve access to dental treatment for this category of population.

For proper oral hygiene, all children need – at least up to 9-10 years of age- the help and / or supervision of an adult. For children with intellectual disabilities, this kind of need may sometimes be lifelong. Understanding this need by parents and caregivers is essential for these children’s oral health and overall wellbeing. For this reason, preventive programs specifically designed for people with disabilities must also include parents as target groups.


The oral health status of the examined children was poor, regardless the degree of intellectual disability. Improvement of the oral health of children with intellectual disabilities can be achieved by implementing specific preventive programs and by increasing access to dental treatments.


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