Oral health and quality of life: an epidemiological survey of adolescents from settlement in Pontal do Paranapanema/SP, Brazil

This study aimed to verify oral health, treatment needs, dental service accessibility, and impact of oral health on quality of life (QL) of subjects from settlement in Pontal do Paranapanema/SP, Brazil. In this epidemiological survey, 180 10-to 19- years old adolescents enrolled in the school that attend this population in settlement underwent oral examination, to verify caries index (DMFT- decayed, missing and filled teeth) and periodontal condition (CPI), and were interviewed using the World Health Organization Quality of Life (WHOQOL-Bref) and Oral Impact Daily Performance (OIDP) instruments to evaluate QL, and the Global School-Based Health Survey (GSHS) about dental service accessibility. DMFT average was 5.49 (± 3.33). Overall, 37.2% of participants showed periodontal problems, mainly CPI = 1 (77.7%). Treatment needs were mainly restorations. GSHS showed that the last dental consultation occurred > 1 year previously for 58.3% of participants at a public health center (78.9%). The average WHOQOL-Bref was 87.59 (± 15.23). Social relationships were related to dental caries and health service type. The average OIDP was 6.49 (± 9.15). The prevalence of caries was high and observed periodontal problems were reversible. The social relationships of adolescents from settlement were influenced by caries and health services type.


Introduction
Recent research has examined adolescents' conceptualizations of and satisfaction with quality of life, as well as their well-being 1,2 .Well-being and health-related quality of life are measured using the physical, social relationships, psychological, and environmental domains 2 .
Oral health is an important indicator of adolescents' quality of life independently of domains, but especially in the social relationships domain due to halitosis and concern with appearance 1,3 .Dental caries and periodontal disease are the oral health factors that cause the most pain and embarrassment among adolescents.Rural populations have shown extremely poor oral health characterized additionally by early tooth loss, despite public health policies and technological advances in dentistry 4 .The psychological and social impacts of oral health problems can compromise adolescents' quality of life 5 .
In Brazil, oral health is worse in rural than in urban populations, posing a major burden on the public health system 6 .In the state of São Paulo, the decayed, missing, and filled teeth (DMFT) index was found to increase three-fold between the ages of 11 and 19 years (2 vs. 6), reflecting the worsening of oral health during adolescence 4 .However, national surveys have documented a decline in the DMFT index from 6.1 in 2003 to 4.2 in 2010 among 15-19-year-olds 7,8 .
The high caries index and prevalence of periodontal disease suggest that inequality of access to dental services affects rural adolescents, who can be considered to be a socially excluded population due to residence in remote areas 9 .Despite the presence of health centers in rural areas, the difficulty of transport to these centers, lack of capable professionals, and suboptimal center infrastructure can pose barriers that negatively impact adolescents' health 9 , similarly in rural settlements because of geographic setting.
Rural settlements in Brazil have been built with land reform, involving national government, the landless and farmers front many violent conflicts.In anticipation of land reform, families invade land considered to be unproductive and live there without sanitary services.In this manner, settlements are created and populations organize to seek the right of access to public health services.However, they are located in remote areas and must overcome obstacles to health care access 10 .
In this context, the aims of this study were to determine the oral health conditions, access to dental services, self-perceived quality of life, and impact of oral health on quality of life among Brazilian adolescents from rural settlement.

Study design and participants
All 349 adolescents aged 10-19 years old who lived in rural settlement in Caiuá, São Paulo State, Brazil, were invited to take part in this cross-sectional epidemiological study.São Paulo Lake Project School is the only educational institution which attends this community that is also located into rural settlement.Considering that all of adolescents were participants in the Family Aid financial national incentive program, which requires regular school attendance, this school was considered the better setting to find all adolescents and to conduct this research.
After approval by the Committee for Ethics in Human Research of Univ.Estadual Paulista -UNESP, School of Dentistry -Araçatuba, the study purpose and procedure were explained to adolescents' parents.Parents provided written informed consent to adolescents' participation and the study was conducted in accordance with all ethical guidelines.Adolescents who agreed to take part in the research, answered all questions, and permitted oral examination were included in the study.
Data collection was performed through oral examination and interviews.

Oral examination
Oral examinations were conducted to calculate DMFT caries index (decayed, missing and filled teeth) and a community periodontal index (CPI) for each adolescent participant.The CPI was used to classify periodontal conditions in sextants of the maxilla and mandible as healthy (0) or to indicate the presence of gingival bleeding (1), dental calculus (2), periodontal pocket of 4-5-mm depth (3), and periodontal pocket of ≥ 6 mm depth (4).
A pilot study was conducted earlier this research with adolescents who lived in other settlement in Presidente Venceslau-SP, aiming to test questionnaires and to train the researcher who had 0.88 in Kappa test for dental caries.
The oral examinations were conducted by this trained researcher, who was properly attired, using mirror and probe to verify caries index and periodontal condition.These examinations were performed under the World Health Organization's (WHO's) recommendations for epidemiological surveys.

Measures
The same researcher conducted the interviews of students during class periods at the schools, in local reserved to avoid embarrassment and coercion.It was previously scheduled and when some student was not present, three consecutive attempts were executed.The absence of student in all of attempts, result in exclusion of sample.
The validated Portuguese versions of the World Health Organization Quality of Life (Brief) questionnaire (WHOQOL-Bref) 11 , Oral Impacts on Daily Performance (OIDP) index 12 , and the World Health Organization's Global School-Based Student Health Survey (GSHS) 13 questionnaires were used to guide interviews.Although these instruments can be self-administered, the researchers administered them in an interview setting to ensure participants' comprehension and reduce the possibility of false answers, thereby controlling for common biases.
The WHOQOL-Bref is a 26-item instrument developed by the WHO to evaluate quality of life in the physical, psychological, social relationships, and environmental domains, with two additional questions about self-perceived quality of life and health.Responses to all items are structured by a five-point Likert scale ranging from 1 (never/nothing/very dissatisfied) to 5 (always/ completely/very satisfied).Higher scores indicate better quality of life, except for items related to pain and discomfort, negative feelings, and medication dependence, which have inverted scales.Domain scores are calculated by summing responses to all items in that domain 11 .
The OIDP index measures the impact of oral health on quality of life.It was developed originally for children and was later adapted for use in older populations, including adolescents.The instrument has two components: the first section solicits information about adolescents' self-reported oral problems in the past 3 months using a list of 17 problems and an open "other" item, and the second component is used to evaluate the effects of problems reported in the first section on eight daily activities of adolescents (eating, speaking, cleaning the mouth, sleeping, maintaining an emotional repertoire, smiling, doing homework, and engaging in social socializing).
The impacts of oral problems on quality of life are measured according to severity (none, few, moderate, severe) and frequency (always, sometimes, never) using a Likert scale ranging from 0 (none/never) to 3. Severity scores are multiplied by frequency scores to obtain an index for each daily activity (range, 0-9).The total OIDP score (range, 0-72) is obtained by summing all totals for the eight daily activities; the overall OIDP index is calculated by multiplying by this score by 100 and dividing by 72 to create a scale ranging from 0 to 100.Higher scores indicate a greater impact of oral health on quality of life 12 .
The WHO developed the GSHS in 2003 and improved it in 2009 13 to evaluate health risk behaviors among adolescents according to demographic profile, with the aim of collecting data to support the planning and implementation of new programs and policies focused on adolescent populations, mainly in school environments.In this study, 27 GSHS items on oral hygiene habits and dental service accessibility were used.It has no score, but show behaviors of study population.

Statistical analysis
Descriptive analysis about DMFT and CPI index, all questions of GSHS, WHOQOL-Bref and OIDP instruments, was first conducted to characterize the study sample.The normality of data distribution related to WHOQOL-Bref and OIDP was examined using the Shapiro-Wilk test.Bivariate analyses were conducted using the chisquared, Fisher's, and Mann-Whitney tests, with calculation of 95% confidence intervals, which outcomes were variables related to quality of life.The independent variables were all question of dental services accessibility, DMFT and CPI indices.The same testes were applied in other bivariate analysis to test the influence of dental services accessibility on oral health condition (DMFT and CPI).A multivariate logistic regression model was constructed using variables showing statistical significance of 95% confidence intervals in bivariate analyses.All analyses were performed using BioEstat 5.3 and SPSS 20.0 software.

Results
Of 349 eligible participants, 32.9% moved, 7.5% withdrew from the study, 1.1% died, 4.0% refused study participation, and 2.9% did not answer all interview questions or did not allow oral examination.The final study population thus comprised 180 (51.6%) adolescents.
The mean DMFT index was 5.49 ± 3.33; 6.7% of adolescents had DMFT indices of 0 Dental caries was associated with age (p < 0.001) according to the Mann-Whitney test, but the regression model showed no linear progression (p = 0.67).
Table 1 shows adolescents' access to dental services according to caries experience and periodontal condition.
The health services type of last consultation with a dentist was related to the need for restoration of one tooth surface (p = 0.03).There cause for the last consultation was associated with the same treatment need according to the chi-squared test (p = 0.01).
Table 2 shows WHOQOL-Bref domain scores according to quality of life measures.
WHOQOL-Bref variables are distributed symmetrically, but OIDP indices are characterized by an asymmetrical distribution with many outliers.The Shapiro-Wilk test confirmed the asymmetrical distribution of OIDP scores in relation to the presence (p < 0.001) and absence (p = 0.04) of caries.Table 3 shows descriptive statistics for WHOQOL-Bref total and domain scores and the OIDP index; Mann-Whitney tests revealed that dental caries had a major impact on social relationships.
WHOQOL-BREF scores (average = 85.4) were higher among adolescents who sought dental treatment in the past 12 months than among those who consulted a dentist more than 1 year ago (average = 80.1).
WHOQOL-BREF social domain scores were higher among adolescents who obtained private dental services (average = 61.3)than among whose received public services (average = 54.5), and higher among those who classified the last consultation as "good" (average = 57.0)than among those who classified it as "bad" (average = 53.4).The health service type and quality of the last consultation thus influenced adolescents' social life (Table 4).
WHOQOL-BREF environmental domain scores were higher among adolescents who had received education about oral disease prevention (average = 77.4)than among those who reported receiving no health education (average = 70.16;Table 4).

Discussion
This research revealed high caries index and the treatment needs concentrated on restoration and endodontics procedures suggesting the lack of dental care, which problem started in health system or through neglect of oral health by patients.
Preventive and educational measures can avoid the worsening of oral health, but their absence can result in the need for endodontic procedures, provisional restorations, and drug prescription in urgent dental clinics to address severe dental problems and avoid extraction 14 .First molars are most commonly affected because they are the first posterior teeth to erupt, even with deciduous permanence 15 .It is important to highlight that the highest prevalence of decayed component of caries index and gingival bleeding predominance in the present study suggested that there was failed treatment and preventive dental services for that excluded population.
The neglect of oral hygiene, consumption of a cariogenic diet, and non-regularity of consultation with a dentist make the first molars more susceptible to extraction 15 .Considering that the settlement stayed in rural area, it is important to emphasize that rural population which present adolescents with high caries index tend to have a future with tooth loss in adulthood 4 .
In the present research the prevalence of caries was higher among adolescents who sought dental treatment because of pain than among those who presented for routine consultation.Preventive care can avoid dental caries, but it is rarely a part of public health services, which are the main source of dental care for rural and remote populations to maintain oral health 15 , that express the same situation of studied population who live at rural settlement.
Important to observe that the need for restoration of one tooth surface was greater among adolescents who attended public services than among those who consulted dentists in the private sector and adolescents who sought treatment because of pain perceived a greater need for restoration of one tooth surface than did those who made preventive routine dental visits.
These findings showed that adolescents attend public service used not to do a preventive dental treatment and the pain is the main reason for seeking care.In rural and remote communities, dental caries is a common event in children's life on their mothers' view, showing the lack of information regarding preventive measures 16 .
Adolescents perceive that a large number of decayed and un-treated teeth, severe gingivitis, and the presence of dental calculus are reasons to need dental treatment 1 .Unfortunately, adolescents seek dental treatment because of dental problems, instead of seeking regular and preventive consultation 17,18 .The expected outcome of this attitude, which is part of rural culture, in addition to the difficulty of access to dental services and shortage of capable professionals 9 , is poor oral health, with negative effects on learning and academic development 19 .The prevalence of conditions causing toothache among adolescents demonstrates the need for public health policies that consider the difficulties faced by these socially excluded populations and aim to reduce caries prevalence and promote oral health maintenance through preventive, educational, and interventional measures focused on quality of life 20 .
Fear may be one reason for rare treatment seeking and may also explain the high caries index because it can prevent individuals from ob- Adolescents' conceptualization and valuation of oral health must also be considered such as the social representation of oral problems among them 16 ; those who do not value oral health tend to have the worst hygiene habits, lowest frequency of consultations, and, thus, worst oral health 15,21 .Tooth loss and large and numerous carious lesions are common in patients who experience fear or high levels of anxiety during dental consultation 19 .
Health education should begin in childhood because conceptualization of the meaning of health and the importance of maintaining systemic health and preventive habits persists into adulthood.Adolescents who lack health information, particularly those in rural communities, are more likely to experience severe tooth loss in adulthood with negative effects on quality of life 4,21 .
Poor oral health affects individuals' social life, chewing, and tooth cleaning 21 .However, despite these effects on many aspects of quality of life, individuals' satisfaction with their dental appearance worsens from adolescence to adulthood, suggesting worsening oral health conditions and lack of care 22 .In the transition to adulthood, individuals acquire harmful habits such as tobacco use, alcohol consumption, and impoverishment of oral hygiene, making the oral condition more vulnerable to dental problems 22 .OIDP indices were low in the present study, demonstrating that oral health impacted adolescents' quality of life The relation found between presence of caries and social relationships in the present study indicated the mild impact of oral health on quality of life.
The negative effects of oral health on quality of life are due mainly to gingivitis and dental calculus, which prevent adolescents from smiling because of embarrassment about their appearance and halitosis.In addition, severe untreated caries cause pain, suffering, and discomfort, preventing individuals from relaxing, making them more sentimental, and making concentration on their studies difficult; in other words, these oral health problems clearly damage adolescents' social life 1 .The oral problems measured by the OIDP index cause difficulties with smiling, sleeping, eating, and tooth cleaning due to pain and discomfort 14 .
Another relevant problem caused by the worsening of caries, lack of preventive care, and rarity of dental consultation among adolescents is absenteeism from school, which increases the impact of oral health on quality of life 1 .This situation is worse in adolescents who lives in rural communities, given the difficulty of accessing schools and the severe pain resulting from poor oral health; in addition to the effects of poor valuation of oral health, these factors combine to make school absenteeism normal fin this population 1 , like the studied adolescents from settlement.Teenagers with severe caries and toothache due to large numbers of decayed and untreated teeth tend to be absent from school more than those with low caries indices 1 .
The present analysis showed no significant association between quality of life indices and variables measuring the need for dental treatment and periodontal condition, perhaps due to the small amount of discomfort caused by gingival bleeding.Tooth brushing at least twice a day and daily use of dental floss are directly related to good oral hygiene and periodontal condition 23 .Parents' education level is not associated with their children's periodontitis, and this disease is usually not a reason for dental consultation 23 .
The association between timing of the last consultation and quality of life was higher among adolescents who made frequent visits to the dentist suggesting that routine dental consultations can improve the quality of life.
Infrequent dental visits and lengthy intervals before individuals seek treatment are directly related to the pronounced impacts of oral health on quality of life, high caries index, and dissatisfaction with oral health 17 .Parents who have taken their children to the dentist since childhood tend to encourage their children to continue this habit in adolescence, promoting better valuation of oral health and preventive actions 24 .
The studied adolescents who attended public health services presented worst quality of life than those who seek for private services, demonstrating that the type of care offered to population is important to maintenance of their quality of life.
Rural communities tend to use more public health services than the urban, likely due to the shortage of private services in rural and remote areas 17 , similarly the study population who sought dental treatment in public services.Generally, the poor environment domain is related to low social and economic classes 25 , but in the study population all of participants belonged to the same class, which suggested differences in dental consultations between public and private services.
Professionals find working in rural areas very difficult because of the limited social life, professional isolation, workload, dissatisfaction with health center infrastructure, difficulty of attending educational courses, and lack of information about other job opportunities 26 .Thus, health care providers working in remote communities tend to demonstrate professional unpreparedness, lack of affinity with this kind of work, and lack of professional commitment to promote health, all of which contribute further to social exclusion.
The difficulty of accessing dental services, whether public or private, is not the only factor contributing to poor dental and periodontal conditions in adolescents.Education level, receipt of information about oral health, frequency and quality of tooth brushing, regularity of dental visits, and sugar ingestion are also worst in rural communities, especially those far from urban capitals 17 .For these reasons, dental caries is more prevalent among adolescents from rural and remote areas than among urban adolescents 27 , with decayed and untreated teeth suggesting lack of care and harmful habits that directly affect quality of life, principally in the psychological, social, and physical domains 17 .
The negative influence found of environment in oral health education for the studied adolescents from settlement suggested some failing in preventive works in public health services.
Satisfaction with one's environment, educational level, and positive perception of parents' health seem to be associated with better oral health conditions and less psychological impact of poor oral health among adolescents.Conversely, the damage caused by worsening dental problems negatively affects quality of life and limits dental function, resulting in poor self-perceived oral health and worse self-esteem 28,29 .Self-esteem is related to self-efficiency in oral care, which is better in boys than in girls; in addition, this self-efficiency seems to be worse in adolescents who live with a single parent than in those who live with both parents 30 .
The impact of oral health, especially regarding decayed and missing teeth, on the psychological domain can be sufficiently large to contribute to depression 31 .This situation has gained attention from researchers because oral health is directly linked to health related quality of life.A high caries index reflects the urgent need for immediate care to avoid worsening of the condition and irreparable loss 30 , especially in socially excluded populations, which typically have the worst oral health conditions and show the greatest impacts on quality of life 2 .
Although, there are few works investigating oral health and quality of life of populations from rural settlement, mainly with adolescents.New studies focused on them would clarify some peculiarities, like their life style and habits, to help the health professionals comprehending them and also to support new public health policies which would make easier the dental service accessibility and consequently, contribute to better quality of life of these adolescents.
It was concluded that the caries index was high among adolescents from rural settlement in Pontal do Paranapanema (SP).The most evident periodontal change was gingival bleeding, which is a reversible condition.Dental treatment needs included restoration and instruction in oral hygiene and prophylaxis.Adolescents from settlement continue to face inequity in access to dental services; in the majority of the study population, the last dental consultation occurred more than 12 months previously, in the public sector, due to toothache.Although participants reported good quality of life and a low impact of oral health, the social relationships of these socially excluded adolescents were influenced by the presence of dental caries and type and quality of the last consultation.

Collaborations
MM Leão contributed to design of study, acquisition of data, analysis and interpretation of data, and in drafting the manuscript.CAS Garbin contributed to design and acquisition of data, mainly concerning ethical aspects; was involved in drafting the manuscript, revising it critically for important intellectual content and contributed to analysis and interpretation of data.SAS Moimaz contributed to design and acquisition of data, mainly concerning epidemiological aspects; contributed to analysis and interpretation of data and gave the final approval of the version to be published.TAS Rovida contributed to conception and design of research, in drafting the manuscript, analysis and interpretation of data, and gave final approval of version to be published.All authors read and approved the final manuscript.

Table 1 .
Dental service accessibility according to caries experience and periodontal condition among adolescents from settlement.

Table 2 .
Score according scales of measurements of quality of life.

Table 3 .
WHOQOL-BREF domain scores and OIDP index according to DMFT index.

Table 4 .
Associations of quality of life with dental service accessibility.