Prevalence and predictors of early periodontal disease among adolescents.

BACKGROUND: Periodic estimation of periodontal disease burden is essential for formulating new treatment strategies, for evaluating preventive strategies, and for framing of new policies. The previous national-level survey among adolescents was held 15 years ago. The objective of this study was to estimate the prevalence of periodontal disease among older adolescent students and to analyze its predictors as part of an oral health assessment survey conducted in Kerala.
MATERIALS AND METHODS: A multistage cluster sampling was employed among five districts of Kerala to examine 1065 students in the age group of 15-18 years from government and private schools of selected urban and rural areas. Sociodemographic and oral health behavioral data, modified Community Periodontal Index, Oral Hygiene Index Simplified, and Dental Aesthetic Index were taken. Descriptive statistics and bivariate and multivariate logistic regression analyses were done to identify the predictors of gingival bleeding and periodontal pockets.
RESULTS: The prevalence of gingival bleeding, periodontal pockets, and loss of attachment was 42%, 13.4%, and 2.7%, respectively. In the adjusted multivariate model for predictors of gingival bleeding, rural location of residence, studying in government schools, high mother's education and their working status, orthodontic treatment need, oral hygiene frequency, and poor oral hygiene status emerged as significant predictors of gingival bleeding. In the multivariate model for periodontal pockets, bleeding on probing emerged as the strongest predictor with an odds ratio of 12.85 when adjusted to poor oral hygiene.
CONCLUSION: The prevalence of early periodontal disease among adolescents is significant. Sociodemographic factors, poor oral hygiene, and malocclusion are significant predictors for periodontal disease among adolescents.

INTRODUCTION

Severe periodontitis, one of the highly prevalent conditions affecting about 11% of humans, is considered as a public health problem since it leads to disability and thereby impairs quality of life.[12] Age is a recognized risk determinant for periodontitis and children, and adolescents are universally affected with milder forms of the disease with varying degrees of gingival inflammation. Even though severe destructive periodontitis is less common among adolescents, inflammatory changes associated with early periodontal disease set in during this period. Periodic estimation of disease burden is essential for appraisal of the preventive strategies, for formulating new treatment strategies, and for framing of new policies. The last national oral health survey (NOHS) was done almost 15 years ago, and hence, there is a paucity of information about the prevalence of periodontal disease among adolescents in India.[3]

Periodontitis represents a range of clinical manifestations from mild subclinical inflammation to advanced destructive forms, leading to tooth loss. Diagnosis is based mainly on clinical assessment of surrogate markers such as probing pocket depth (PD) and clinical attachment level (CAL) and radiographic evidence of alveolar bone loss. Several factors influence the estimation of periodontitis prevalence including examination protocol (full mouth/partial mouth), age group, source population, and case definitions.[4] The WHO advocates the use of Community Periodontal Index (CPI) for disease estimation. At present, a modified CPI criteria is suggested which includes examination and reporting of all teeth for gingival bleeding and periodontal pockets and six index teeth for loss of attachment (LoA) and does not consider the presence of calculus.[5]

The present study aimed to estimate the prevalence of periodontal disease among the older adolescent students and analyze its predictors, as part of an oral health assessment survey conducted across five districts of Kerala.

MATERIALS AND METHODS

Permission (order No.M/02/2011/DCK) was obtained from the ethics committee of Govt. Dental College, Kottayam, and from the heads of respective schools which took part in the study. Oral examination and data collection were done from February 2016 to March 2017. For dental examination and data recording, informed consent was obtained from the parents and verbal consent from the students. A multistage cluster sampling was employed among five districts as shown in Figure 1. Based on the list of schools in the urban and rural areas, obtained from the department of higher secondary education, the schools were categorized into public sector and private. From each location, three schools were randomly selected, the students in one class in the age group of 15–18 years who were systemically healthy to undergo detailed oral examination formed the cluster. Examination proceeded from the first school to the next until getting the required sample from the location. Children with mental disability or learning disorder, history of scaling within 3 months, and those with current or previous fixed or removable orthodontic treatment were excluded from the study. Data of 1080 students from 40 schools were obtained, 1065 were taken up for analysis, and the rest were avoided due to incomplete information. Sociodemographic (place of residence, school type, family income, mother's education, and employment) and oral health behavioral data (brushing technique, frequency, and timing of last dental visit) were collected. For diagnosing periodontal disease, gingival bleeding (BoP) and periodontal pockets (PD) around all teeth and LoA around the six index teeth according to the modified CPI criteria (WHO, 2013) were employed. Dental Aesthetic Index was employed to determine orthodontic treatment need and Oral Hygiene Index Simplified for oral hygiene status. Mean and standard deviation was estimated for continuous variables and proportions for categorical variables. Bivariate analysis of predictors was done with gingival bleeding and periodontal pockets. The significant variables were taken up for the multivariate logistic regression model building for both conditions. Nagelkerke R2 and a statistically nonsignificant (P > 0.05) Hosmer and Lemeshow statistic were employed for the goodness of fit analysis of the final model. For all other comparisons, P < 0.05 was considered as statistically significant.

Figure 1

Multistage sampling strategy employed across five districts in Kerala

RESULTS

The descriptives of the population are given in Table 1. The prevalence of gingival bleeding was 42% (39.2–44.9). Adolescents from rural background had a greater proportion of gingival bleeding when compared to their urban counterparts. Gingival bleeding was more prevalent among the students in government schools when compared to students in private schools which was statistically significant [Table 2]. Place of residence, school type, orthodontic treatment need, oral hygiene status, and oral hygiene frequency were statistically significant in the bivariate analysis [Table 2]. In the adjusted analysis, the sociodemographic factors – place of residence, school type, and mother's education and the clinical variables – orthodontic treatment need, oral hygiene frequency, and oral hygiene status emerged as significant predictors of gingival bleeding [Table 3]. Oral hygiene status demonstrated the highest odds ratio (OR) of 3.34 (2.53–4.41).

Table 1

Descriptives of the population

Variable	n (%)
Gender
Male	458 (43.1)
Female	607 (56.9)
Place of residence
Urban	553 (51.9)
Rural	512 (48.1)
Family income
High income	573 (53.8)
Low income	492 (46.2)
School type
Government/aided	630 (59.2)
Private	435 (40.8)
Timing of last dental visit (year)
Within 1	231 (21.7)
>1	834 (78.3)
Mother’s education
Low	324 (30.4)
High	741 (69.6)
Orthodontic treatment need
No need (DAI Score up to 25)	758 (71.2)
Need (DAI 26 and above)	307 (28.8)
Gingival bleeding (BoP)
No bleeding sites (CPI bleeding score 0)	617 (58)
Gingival bleeding (CPI bleeding score 1 and above)	448 (42)
Periodontal pockets (PD)
No pockets (pockets up to 3 mm)	918 (86.6)
Pockets (4 mm and above)	147 (13.4)
LoA
Absent (LoA up to 3 mm)	1036 (97.3)
Present (4 mm and above)	29 (2.7)

DAI – Dental Esthetic Index; CPI – Community Periodontal Index; LoA – Loss of attachment; PD – Pocket depth; BoP – Bleeding on probing; n – Number of subjects

Table 2

Predictors of gingival bleeding among adolescents-unadjusted analysis

Predictor	Gingival bleeding, n (%)		Crude OR	95% CI	P
	Absent	Present
Place of residence
Urban	342 (61.8)	211 (38.2)	1.40	1.10-1.78	0.007*
Rural	275 (53.7)	237 (46.3)
Socioeconomic status
Low family income	279 (56.7)	213 (43.3)	1.09	0.86-1.40	0.452
High family income	338 (59)	235 (41)
School
Government/aided	341 (53.4)	298 (46.6)	1.61	1.25-2.07	<0.001*
Private	276 (64.8)	150 (35.2)
Last dental visit (year)
>1	490 (58.8)	344 (41.2)	1.17	0.87-1.16	0.304
Within 1	127 (55)	104 (45)
Orthodontic treatment need
Absent	488 (64.4)	270 (35.6)	2.49	1.90-3.27	<0.001*
Present	129 (42)	178 (58)
Oral hygiene
Good	340 (72.5)	129 (27.5)	3.03	2.34-3.93	<0.001*
Poor	277 (46.5)	319 (53.5)
Oral hygiene frequency
Once daily	248 (54)	211 (46)	0.76	0.59-0.96	0.025*
Twice or more	369 (60.9)	237 (39.1)
Gender
Male	264 (57.6)	194 (42.4)	0.98	0.76-1.25	0.857
Female	353 (58.2)	254 (41.8)
Mother’s education
College	25 (50)	25 (50)
Higher secondary	130 (56.8)	99 (38.5	0.675	0.37	1.21
School	462 (58.8)	324 (41.2)	0.807	0.464	1.403

*Significance P<0.05. OR – Odds ratio; CI – Confidence interval; n – Number of subjects; P – Probability value

Table 3

Multivariate logistic regression model showing predictors of gingival bleeding among adolescents-adjusted analysis

Predictor	Adjusted OR	95% CI	P
Place of residence
Urban*
Rural	1.37	1.04-1.78	0.024
Socioeconomic status
High income*
Low income	0.74	0.55-1.01	0.05
School
Private*
Government	2.05	1.54-2.73	<0.001
Oral hygiene status
Good*
Poor	3.28	2.49-4.32	<0.001
Orthodontic treatment need
Absent*
Present	2.77	2.07-3.71	<0.001
Oral hygiene frequency
Once daily
Twice or more*	1.33	1.01-1.74	0.038
Gender
Male*
Female	1.07	0.82-1.41	0.594
Mother’s education
College*
Higher secondary	0.64	0.35-1.18	0.155
School	0.51	0.27-0.96	0.039

*Reference category, significance P<0.05. (Goodness of fit of model: R2=0.182, Hosmer and Lemeshow Χ2=8.354; P=0.400). OR – Odds ratio; CI – Confidence interval; n – Number of subjects; P – Probability value

Periodontal pocketing was less prevalent among Kerala adolescents, with 13.4% (11.4–15.4) having at least one pocket deeper than 3 mm, and the prevalence of LoA was even lower, 2.7% [Table 1]. Among students from a rural background, 16.2% had periodontal pockets whereas among those from an urban background 11.6% had pockets, this difference was statistically significant [Table 4]. There was no statistically significant difference in the prevalence of periodontal pockets among the socioeconomic classes and the school types [Table 4]. Among those students with poor oral hygiene, 18.8% reported having periodontal pockets, whereas among those with good oral hygiene 7.5% had periodontal pockets, the difference was statistically significant [Table 4]. Orthodontic treatment need and periodontal pockets had a statistically significant relation with more participants with PD having definite orthodontic treatment need as compared to those without PD [Table 4]. The presence of gingival bleeding was strongly associated with PD, as among those with no BoP, only 2.6% had periodontal pockets [Table 4]. In the bivariate analysis, rural location of residence, poor oral hygiene, presence of gingival bleeding, and need for orthodontic treatment were significant predictors of periodontal pockets [Table 4]. In the final multivariate model of predictors of PD, BoP emerged as the strongest predictor with an OR of 12.85 (7.46–22.14) when adjusted to poor oral hygiene [Table 5].

Table 4

Predictors of periodontal pockets among adolescents-unadjusted analysis

Predictors	Periodontal pockets, n (%)		Crude OR	95% CI	P
	Absent (CPI score 0)	Present (CPI score 1)
Place of residence
Urban	489 (88.4)	64 (11.6)	1.48	1.04-2.10	0.028
Rural	429 (83.8)	83 (16.2)
Socioeconomic status
High Income	429 (83.8)	83 (16.2)	0.91	0.64-1.29	0.604
Low income	489 (88.4)	64 (11.6)
School
Private	367 (86.2)	59 (13.8)	1.01	0.71-1.43	0.971
Government	551 (86.2)	88 (13.8)
Oral hygiene status
Good	434 (92.5)	35 (7.5)	2.87	1.92-4.28	<0.001
Poor	484 (81.2)	112 (18.8)
Gingival bleeding
Absent	600 (97.4)	16 (2.6)	15.45	9.03-26.41	<0.001
Present	318 (70.8)	131 (29.2)
Malocclusion
Absent	673 (88.8)	85 (11.2)	2.01	1.40-2.86	<0.001
Present	245 (79.8)	62 (20.2)
Dental visit (year)
<1	200 (86.6)	31 (13.4)	1.04	0.68-1.59	0.849
>1	718 (86.1)	116 (13.9)

Significance P<0.05. CPI – Community Periodontal Index; OR – Odds ratio; CI – Confidence interval; n – Number of subjects; P – Probability value

Table 5

Multivariate regression model showing predictors of periodontal pockets among Kerala adolescents

Predictor	Adjusted OR	95% CI	P
Place of residence
Urban*
Rural	1.29	0.88-1.89	0.19
Oral hygiene status
Good*
Poor	1.91	1.24-2.94	0.003
Gingival bleeding
Absent*
Present	12.85	7.46-22.14	<0.001
Orthodontic treatment need
Absent*
Present	1.45	0.98-2.15	0.063

*Reference category, significance P<0.05. (Goodness of fit of model: R2=0.278, Hosmer and Lemeshow test χ2=15.06, P=0.058). OR – Odds ratio; CI – Confidence interval; P – Probability value

DISCUSSION

Periodontal disease manifestation ranges from subclinical change in color of gingival to advanced LoA and bone loss leading to loss of teeth and edentulism. Various epidemiological studies have employed different diagnostic criteria from mere presence of subgingival calculus to radiographic bone loss. Thus, the prevalence estimates vary across studies. This study employed the modified CPI criteria for the assessment of BoP, PD, and LoA.[5] The original CPI criteria had a few shortcomings including assessment of periodontal pockets and not considering LoA.[678]

Majority of the students (56%) reported poor oral hygiene. However, the majority used toothbrush (98.6%) and toothpaste (93.45) for cleaning. This is in accordance with the oral hygiene behavior reported among adolescents from Kozhikode city in a recent study.[9] Statistically significant differences could not be found between groups with different oral hygiene frequencies, different materials used for teeth cleaning, and different oral hygiene methods. Similar findings were reported by Das et al. among adolescent students.[9] The presence of BoP from at least one tooth site was considered as the presence of gingival bleeding for that student. BoP observed among Kerala adolescents in this study (42%) was much less when compared to a recent report among 15–17-year-old students (72%), which employed the original CPI criteria among 15–17-year-old students.[9] The observed prevalence is less than reported from other parts of the country, 84.3% in Rajasthan and 59% in Bhopal schoolchildren.[1011] Gingival bleeding was more in those from a rural background and those enrolled in government schools. Poor oral hygiene and orthodontic treatment need strongly predicted the presence of gingival bleeding among those who had the problems. Gingival bleeding was more commonly associated with lower anterior teeth. Lower anterior crowding and presence of calculus around these teeth might have contributed for this association. Similar finding was reported by Lagana et al.[12] Several studies from various populations have reported that crowded and malposed teeth contribute to gingival inflammation and periodontal destruction.[131415] It was also shown that the treatment of crowding improves gingival and periodontal conditions.[14] No gender differential could be noticed in the study. A common type of gingivitis seen among adolescents is mouth breather's gingivitis.[1617] Plaque-induced inflammation due to poor oral hygiene and hormonal influence due to puberty and mouth breathing could have contributed to the overall prevalence of gingivitis among adolescent students in Kerala. Frequency of dental visiting did not influence gingival bleeding. It has been reported from several populations that the dental treatment-seeking behavior is closely linked to dental pain.[181920] The primary reason for seeking dental treatment was for dental pain or sensitivity due to dental caries. Treatment was sought only when they perceive a need.[21] Dental visiting for preventive health checkups or oral prophylaxis was not common. However, Krustrup and Petersen have observed a greater prevalence of periodontal pockets among adults who visited dentists more frequently in Denmark.[22] Mother's higher educational status was associated with their employment status (P < 0.05). Mothers still play the primary and major role in the oral health care of children.[23] Working mothers could devote less time for children which could have negatively influenced their gingival health. In the adjusted multivariate model, poor oral hygiene emerged as the strongest predictor of gingival bleeding (OR: 3.34, 95% confidence interval [CI]: 2.53–4.41), followed by orthodontic treatment need (OR: 2.77, 95% CI: 2.04–3.76). There is unequivocal evidence that poor oral hygiene and presence of visible plaque are strong predictors of gingivitis.[24] In the adjusted model too, students from rural background, those studying in government school, tooth brushing only once a day and higher educational status and working mothers predicted a higher risk for gingival bleeding.

The NOHS reported the prevalence of calculus, bleeding, and pockets (53.2%) using the original CPITN criteria.[3] The present study assessed gingival bleeding and pockets around each tooth. Gingival bleeding was scored as present or absent, and the number of sites that bled were counted. Pockets were categorized as pockets 4–5 mm deep and more than 6 mm deep.[5] The number of sites in each category was counted. The prevalence of periodontal pockets was less among adolescents when compared to gingival bleeding. Using the CPI criteria, 86.2% had pockets up to 3 mm which is considered as normal whereas 13.8% had pockets more than 4 mm. In the overall prevalence of pockets, majority (13.4%) were 4–5 mm deep. Only four students (0.4%) reported pockets 6 mm or deeper, two of them had one site each and two others had two sites of 6 mm or deeper. Majority of the pockets (83%) were located around upper and lower first and second molars. This could be due to delay in passive eruption or false pockets. Students from a rural background reported more periodontal pockets than from urban. Lopez et al. report that socioeconomic factors and periodontal disease are closely related.[25] Statistically significant association was observed with poor oral hygiene status, presence of gingival bleeding sites, need for orthodontic treatment, and periodontal pockets. Only 1.8% of the students reported that they use tobacco products. Since tobacco use was assessed based on self-report only and the proportion of users was very limited, it was not considered for further analysis. No other relevant risk factor for periodontal disease among adolescents could be assessed in this school-based survey.

At least one site with LOA 4 mm or more was diagnosed as having periodontitis in this study, based on the CPI modified criteria.[5] The prevalence of periodontitis (LoA) observed was 2.7%. Only 48 sites demonstrated attachment loss of more than 4–5 mm, of which only 3 sites demonstrated LoA of 6–8 mm. Among which, 12 sites were seen around upper and lower incisors and the remaining 46 sites in the interproximal aspects of first molars. Das et al. reported a 3% prevalence of periodontitis among 15–17-year-old schoolchildren in Kozhikode.[9] In the USA, 2.75% of the participants aged 16–17 had chronic periodontitis.[26] Much higher prevalence was reported by various studies from other parts of the country, among adolescents. NOHS reported a prevalence of 9.7% among 15-year olds in Kerala.[3] Since 2000, surveys conducted in India generally utilized the CPITN criteria for estimating the prevalence of periodontitis.[272829] The estimated prevalence ranged from 15% to 43.2% and severe periodontitis ranged from 2.6% to 22.9%. To our knowledge, this is the first report employing the modified CPI criteria among adolescents from India.

Early stages of periodontal disease seen in adolescents are reversible if adequate oral hygiene is instituted.[30] Epidemiological studies point to a potential link between periodontal disease and many systemic diseases. Moreover, if young individuals display higher prevalence estimates, it is a matter of concern for the future as the disease is irreversible and the burden will be carried forward to adulthood leading onto early partial or complete edentulism affecting their oral and general health and well-being. Oral health awareness among adolescents and dentist population ratio of Kerala is similar to that of the developed world. Therefore, periodic surveillance of periodontal disease shall facilitate its early identification and prompt treatment.

CONCLUSION

This is the first report of early periodontal disease among adolescents from India that utilized the modified CPI criteria (2013) of the WHO. Early periodontal disease was significantly prevalent among adolescents in Kerala. Sociodemographic factors, poor oral hygiene, and malocclusion are significant predictors for periodontal disease among adolescents.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.