Periodontal status of students living with disability in Amhara region, Ethiopia: a cross-sectional study

The study was conducted in special needs schools in the Amhara Regional State of Ethiopia. In Amhara regional state, there are eight special needs schools located in; Gondar, Bahir-Dar, Debre-Markos, and Dessie town. Six hundred ninety-six disabled students are attending special needs schools in the region, and half of them (341) were hearing-impaired students. students who met the following inclusion criteria were included in the study; agreed and signed the consent form (parents gave written consent), attending a special needs school in the region during the data collection period. However, the critically ill, who didn’t give full data due to their disability, uncooperative students, and students living with HIV/AIDS and Diabetic Mellitus were excluded from the study.

A school-based cross-sectional study was conducted from November 30, 2020, to April 10, 2021, among students living with disability and attending special needs schools in the Amhara region, Ethiopia. The study design and reporting was in agreement with the ‘strengthening the reporting of observational studies in Epidemiology (STROBE) statement for cross-sectional studies.

The sample size was calculated using the single population proportion formula. Assuming; a 50% prevalence (since no past national data exist), 95% confidence interval, 5% margin of error, and a 15% non-response rate. The final sample size was 443. A simple random sampling technique using a computer random generator was employed to recruit the study participants.

A pre-tested structured interview administered questionnaire adapted from the WHO oral health survey tool was implemented [21]. The questionnaire was prepared in English and translated into the local language, Amharic. To check the consistency of the questionnaire, the Amharic version was then translated back to English. Data collected were demographic data, oral health practice, medical condition, type of disability, and presence of oral habits (finger sucking, mouth breathing, etc.). Data regarding the type of disability was obtained from the coordinator of special needs education of each school. The disability condition and demographic data were collected before the intra-oral examination. Data were collected from the selected students with the assistance of their parents or legal guardian. For the intellectually disabled students, parents were interviewed regarding sociodemographic characteristics and other habits of their children.

Data was collected under strict supervision by 8 dental surgeons and two special needs experts. The data collectors received a five-day training on the study's objectives, research ethics, approach to the interviewee, data collection tools and techniques, and confidentiality during study selection of study participants and data collection. The data collectors wrote all answers to the questionnaires. The supervisors (AM, KA) had onsite supervision during the whole data collection period and checked the data daily to ensure its completeness and consistency.

Four qualified dentists were involved in the clinical examination with the aid of special needs experts and other health professionals. The dentists were trained and calibrated using the WHO oral health survey tool by the investigator. The calibration and standardization of the evaluators were done through a series of training that includes; a theoretical overview, and discuss issues and questions encountered during the examination period. Moreover, a pretest was done on 45 disabled students at Injibara before the actual study to validate the diagnostic criteria. The clinical examination was conducted in the classroom using normal light and students' chairs. Participants suffering from severe physical handicaps and confined to a wheelchair were examined in their wheelchairs. The examinations were conducted with the aid of a mouth mirror, and periodontal probe. The periodontal status, bleeding on probing (BOP) and periodontal pocket depth (PD) around all teeth, and loss of attachment around the six index teeth were evaluated according to the modified community periodontal index criteria (CPI). Moreover, “Guidelines for Periodontal Screening and Management of Children and Adolescents Under 18 Years of Age” was used for evaluation of the periodontal status of under 18 years of age children [22]. Students with a dental emergency were linked to the nearby dental center for treatment. A maximum infection prevention mechanism was implemented by the data collectors to avoid COVID-19 infection.

Permission (Ref. No: V/P/RCS/05/541/2020) was obtained from the institutional ethical review board of the University of Gondar, and educational admins of respective zones and heads of schools. The objective of the study was explained to the students, parents, and special needs teachers. Written Informed consent was obtained from all participants and/or their parents/legal guardians for study participation. To ensure confidentiality of data, study subjects were identified using codes and unauthorized persons would not access the collected data.

Each questionnaire was evaluated for completeness and entered into Epi-data (version 4.6) and then transferred to SPSS 26 for coding, storing, and further analysis. Descriptive statistics of categorical variables were presented in terms of frequency and percentage, and continuous variables were presented in terms of mean and standard deviation (SD). Binary logistic regression analyses were done to determine the relationship between the independent variables and periodontal disease. those variables with a P value of ≤ 0.2 in the bivariable analysis were transferred to the multivariable logistic regression model to decrease the confounders. An adjusted odds ratio was determined along with its 95% confidence interval and a significant level of P < 0.05 was considered for all analyses.

Four hundred forty-three study participants were involved in the study and provided a 100% response rate. The mean age of the subjects was 15.84 ± 3.882 years. About 64.3% of the study participants were within the 13–18 years age range. Two hundred thirty-seven (53.5%) of the study participants were males. Almost three-fourths (69.8%) of the study participants were orthodox Christians. Regarding their educational status, 53.3% of the study participants were in grades 1–4. The family monthly income of the study participants showed nearly 2/3rd (62.1%) of them had a monthly income of less than 2500 Ethiopian Birr. Regarding the type of disability, 33.6% of the participants were hearing impaired and 30.9% had a mental disability (Table 1).

Of 443 study participants, 76.1% had a habit of tooth brushing and 7.9% had brushed their teeth twice and more. Among the students who brushed their teeth, 82.6% had no family support; 13.2% received some support and 4.2% had received frequent support during their tooth brushing. The physically disabled group received slightly higher support (30.4%) than others did while mentally disabled students received low family support (8.5%). Of all students included in the study, 46.7% had poor oral health status. Mentally disabled students had a high frequency of poor oral hygiene status (66.4%) (Table 2).

Of the total disabled students, only 28.7% had a health periodontium. More than half of the study participants had calculus deposition. Periodontal disease was present in 27.5% of the participants (18.5% had shallow pockets and 9% in deep pockets). Moreover, more than half (56.7%) of the study participants had bleeding on probing (BOP). Mentally disabled students were more affected by periodontal disease than others were. Males had a slightly higher prevalence of shallow periodontal pocket (PPD 4–5 mm) than females (52.2% vs. 47.8%). Twenty-three students (57.5%) of 13–18 years and thirteen (32.5%) of 19–30 years had deep periodontal pockets (periodontal pocket depth of ≥ 6 mm) (Table 3).

To identify the factors that affect periodontal disease, a univariate chi-square test was done on data collected in the questionnaires such as demographic, oral hygiene practice, other oral health problems (malocclusion, dental caries), and carbohydrate intake habits. The results showed that age (P = 0.008), monthly family income (P = 0.001), oral health status (P = 0.000), dental caries (P = 0.015), and malocclusion (P = 0.001) significantly affected the periodontal status of disabled students (Table 4).

Age, family monthly income, carbohydrate intake, oral health status, malocclusion, and dental caries were statistically significant during the bivariate analysis and entered into the multivariate logistic regression model as independent variables for the outcomes of periodontal disease. The multivariate logistic regression analysis showed that age, family monthly income, malocclusion, class-2 malocclusion, oral health status, and dental caries were the risk factors for periodontal disease (shallow and deep pocket). Students above 18 years old were 3.41 folds at risk of having periodontal disease than 7–12 years students (AOR = 3.41(95%CI 1.40, 8.23). Moreover, students from low family income had a high risk of acquiring periodontal infection (AOR = 2.21; 95%CI 1.22, 4.03). Students with a malocclusion were 1.59 times more likely to have periodontal disease than students who had normal occlusion (AOR = 1.59 (95%CI 1.01, 2.54), and the odds of having the periodontal disease were high in class-2 malocclusion students (AOR = 2.39 (1.30, 4.42). Poor oral health status was the major risk factor for periodontal disease among special needs students (AOR = 9.41; 95%CI 4.92, 17.98) (Table 5).

To the best of our knowledge, this is the first study that tried to assess the periodontal status of students living with disability in Ethiopia. Moreover, the study was done by multi-professionals; dental professionals, public health professionals, internists, behavioral science professionals, special needs experts, and other professionals were involved. However, we have faced the following difficulties; first, the study only included students attending special needs schools, and disabled students who do not attend special needs education were excluded. Moreover, the self-reported nature of the oral health behavior of the questionnaire has some limitations for disabled participants.