Evaluation of Perceived Stress and Its Association with Dental Caries in 290 Undergraduate Medical Students

Introduction

Many psychiatric disorders with psychosomatic causes affect oral/paraoral structures, yet their common and limited symptoms have not been recognized [1]. Neuropsychiatric symptoms, such as delusions, depression, and anxiety, are linked to various diseases and conditions, inadequate clinical results, and increased socioeconomic burden [2]. Stress, a body response, has been linked to systemic disorders, such as gastric ulcers and diabetes [3], as well as oral lesions, including oral lichen planus, migratory glossitis, and aphthae [4]. The biopsychosocial model theory states that individual tension develops from an individual’s inability to effectively respond to both real and imagined mental or emotional demands [5]. Stress can be due to personality characteristics, including physiological, psychological, pathological (disease/deformity related), and cultural, or due to resources, including physical, personal, and social, with the type of stress mainly determined by the type of stressors [2,4]. Perceived stress is quite distinct from actual stressors in that it relates to an individual’s feelings regarding unpredictability and a lack of control. Scientists have considered personal stressors, irrespective of the type, to fall into categories that are exogenous or endogenous in nature [6]. Individuals confront stress in various social organizations, including families and offices [7]. The frequency and intensity of the stress varies according to the social environment. Professional training in schools of medicine and dentistry is known to generate significant academic and environmental stress [8,9], affecting students adversely on their performance, personal health, and competency [10,11]. The general health questionnaire scores (self-reported psychological disorder screening) of medical and dentistry students has been reported to be considerably higher (1.66; SD: 2.22) than those of nursing and physiotherapy students (1.22; SD: 1.87; t=2.3; P=0.022) [8]. Higher general health questionnaire scores identify the inability of an individual to conduct normal functions, while at the same time, high scores indicate the presence of new distressing phenomenon [8]. System-induced stress in such cases originates from school administration, interpersonal relationships (ragging and bullying), training, didactic atmosphere, living surroundings, unfair grades, financial burdens, and ethical issues, such as dehumanization and lack of team approach [12,13]. Medical students experience a change of lifestyle, which includes choices of eating and dressing. Less time is spent on personal care while more time is devoted to studies and patient care. The frequency of emotional exhaustion due to such stressors has been reported as high (66.2%) [13]. Alternately, studies found less personal stress among married students who constantly have spousal support (F[3.26]=18.12, P<0.001, adjusted Rc change=0.26) [14]. In the long run, negative outcomes related to higher education (choice of specialty), institute devotion, and patient care ability occur in those who were abused during training [15]. Students’ ability to cope with pressures brought on by the system are influenced by their coping mechanisms, potentially determining whether they respond positively or negatively to stressors [16]. The major components of student stress management include disengagement, which leads to negative outcomes, or engagement, which involves problem-solving, emotion expression, and collective support, with positive outcomes [13,17].

More than 2 billion people worldwide have dental caries, a chronic microbial oral disease that affects teeth [18]. Studies have demonstrated that stress enhances the vulnerability to caries in people [20] and animals [21], since Fauchard linked caries to stress [19]. Stress changes the way that caries can occur, through altered immune reactions [22], reducing salivary secretion (decline in amount and constituent) [23], impairing self-care habits, and increasing preference for unhealthy eating [24]. An increase of cigarette smoking (mean rate of 7.5 per day) and caffeine consumption (mean rate of 7 cups per week) due to examination stress has been reported [24]. Chronic stress affects autonomic nervous system control [25], which brings changes in the configuration of salivary constituents and related properties, in acute stress. Changes in oxygen reactiveness and uric acid antioxidant properties occur under stress [26]. Dental students in different grades, with either moderate of severe stress, have been found to have effects of salivary flow rate (mild stress=0.804 mL/min, severe stress=0.715 mL/min) and uric acid level (mild stress=5.142 mg/dL, severe stress=6.059 mg/dL) [27]. Caries, on the other hand, can themselves cause pain, substandard mastication, dietary changes, impaired aesthetics, and social inactivity, due to anterior tooth loss [28]. The indirect burden of disease amounts to intangible costs and loss of working hours and impacts other diseases [29]. The increase in the mean decayed, missing, and filled surfaces (DMFS) index in the oral cavity significantly increases the dental aesthetic index, suggesting dental caries as a cause. Studies have implicated dental caries as a potential cause of malocclusion, which later can take the shape of any of the forms of various temporomandibular disorders [30]. Malocclusion due to dental caries has been reported at early ages, of 12 to 15 years [31]. Medical students thus are prone to exaggerate their existing caries DMFS index under stressful conditions in medical schools. The ineffectiveness of conventional caries preventive education and social group variations in caries prevalence necessitate the development of new strategies for caries prevention.

Therefore, in this study, we aimed to identify the correlation between perceived stress and caries DMFS index among medical students who, under the circumstances of a medical course of study, are more vulnerable to neglecting their oral health. The main objective of the study was to establish the type of correlation, positive, negative, linear, or nonlinear, among the 2 independent variables, stress and caries index. The results obtained can guide and recommend other studies and/or preventive measures to be taken in medical schools. We also aimed to substantiate already existing data regarding the prevalence of different stress levels among medical students in India. The study’s premise is that there are different amounts of stress experienced by medical students and that there is a positive correlation between stress and the caries index. Alternatively, the study’s null hypothesis states that there is no stress among medical students and that there is no correlation between the 2 variables.

Material and Methods

ETHICS:

This clinical study was approved by the institutional ethics committee at one of the postgraduate medical schools in north India (vide reference XI-PGTSC-II B BDS-S/P 13). All participants were accordingly educated about the study method and benefits and provided written informed consent.

STUDY DESIGN:

The study followed a mixed-method prospective study design approach that used a survey to identify potential participants in whom 3 independent variables, perceived stress, temporomandibular disorder, and DMFS caries index, were assessed. The study followed a double-blind procedure on the cross-sectional student population sample (purposive). Categorical and numerical data collection measures were used for formal analysis. To determine the reliability and validity of the measuring tools, a pilot study was conducted prior to the main study on a different set of medical students.

OPERATIONAL DEFINITION:

Academic stress is defined as an unbalanced or unsatisfactory relationship between a student and their environment, which exceeds their resources and causes altered biological and behavioral responses [32]. Perceived stress refers to an individual’s perception of the amount of stress they have been exposed to over a specific period [33]. The number of permanent natural teeth that are filled, missing, or decaying as a result of caries is represented numerically by the DMFS index, also referred to as the “caries index” [34].

STUDY POPULATION SAMPLE: SELECTION, ORGANIZATION, AND INFERENCE:

The study’s sample size was guided by previous similar research and a software calculator (Epi-Info V 7, Atlanta, GA, USA) [15,23]. The sample calculations were based on precision level (±), 95% confidence level, and 0.5 estimated proportion for the student population in the concerned region. The sample was calculated using the Cochran equation, which also corrects population variance while calculating sample size. The study included 290 eligible students, with a 15% inclusion to cover those who withdrew due to personal reasons or were not considered eligible. The study involved voluntary, first- to fourth-year regular students from a medical college with similar clinical training and didactic course duration who were willing to undergo a thorough clinical examination of permanent natural dentition. The study included participants aged 18 to 30 years, with a minimum of a 6-month course, a complete set of natural permanent dentition, and no history of teeth correction, surgical corrective measures, congenitally missing teeth, regular drug use, drug/alcohol abuse, or history of systemic diseases. Students excluded from the study were pregnant students, those with internships, day students, and repeated failures. Two questionnaires, a demographic questionnaire and the perceived stress scale (PSS), were used to collect data.

MEASUREMENT, DATA COLLECTION AND ANALYSIS:

Socio-demographic attributes: Using an online platform, demographic information was gathered from 343 students, 290 of whom were enrolled in the study. Sex, age, academic year, birth year, habits, height, weight, and physical activity were among the collected parameters.

:

A pilot study performed on a separate set of 40 medical students tested the validity and reliability of the pre-validated PSS questionnaire [36]. For the main study, a self-administered questionnaire measured the PSS. This 10-item questionnaire-based instrument assesses an individual’s personal stress (self-evaluation) and divides it into 5 different stress levels, with each level rated on a scale of 0 (never), 1 (almost never or less often), 2 (sometimes), 3 (pretty often), and 4 (very often). The purpose of the questions is to gauge respondents’ present stress levels as well as their sense of uncontrollability, unpredictability, and overload. The key advantage of this instrument in the study context is that 2 different individuals (students) who had the identical events (training) and experiences would be rated differently depending on their perception. As a result, a particular incident may harm one individual while leaving the other unscathed. This instrument’s scaled questions enquire about current feelings and thoughts in a variety of social situations. Four items are scored in reverse order (0=4, 1=3, 2=2, 3=1), while the remaining 6 items are scored directly. The scores for each item level are then added to determine the person’s perceived stress score, which is a number between 0 and 40. Subsequently, the total score is divided into 3 stress levels: low stress (0 to 13), moderate stress (14 to 26), and high stress (27 to 40).

DMFT/DMFS INDEX:

The decay, missing, filled surface/teeth (DMFS/T) index (World Health Organization) [37] was used to determine the presence of caries on permanent dentition. The DMFS is more precise and sensitive to represent severity, as it represents the number of tooth surfaces affected by dental caries. Four anterior tooth surfaces were observed (mesial, distal, facial, lingual), and 5 posterior were observed (buccal, occlusal, mesial, distal, lingual). To ensure reliable data estimation, only 28 permanent teeth were evaluated, with 80 posterior surfaces on 16 teeth and 48 anterior surfaces on 12 teeth, totaling 128 surfaces. Each individual’s total score was classified as very low (0 to 1.1), low (1.2 to 2.6), moderate (2.7 to 4.4), high (4.5 to 6.5), or very high (>6.6) [38]. A noninvasive dental examination was performed by 2 calibrated dentists who were also double-blinded to purpose and outcome. All participants were examined in a well-equipped dental clinic in the Department of Oral Diagnosis and Radiology. Routine clinical protocols were followed at all stages of examination. When examination and reexamination were conducted 60 min apart to verify inter-examiner constancy, a considerable level of agreement was obtained (kappa value of 0.791). A visual and tactile examination, based on certain characteristics (cavitation, discoloration, opacification, catch or roughness, softened enamel), was used to detect caries. If a participant’s overall score was zero, they were said to have no dental caries; if it was greater than zero, they were said to have dental caries.

STATISTICAL ANALYSIS:

After inputting the data into Microsoft Excel sheets (version 20H2, OS build 19042.1466, Windows 11 Pro, Microsoft Corp), data correction, refinement, and coding were conducted. The coded data was then entered into SPSS version 24.0 (SPSS 24.0; IBM Corp, Armonk, NY, USA) for statistical analysis and testing. All categorical variables related to demographic characteristics were expressed in distribution frequencies, while numerical variables were derived as means and their standard deviations. Distribution of data for testing of normality was achieved by the Kolmogorov-Smirnov test. A chi-square test of independence was used to determine the relationships between the various obtained scores (PSS, DMFS, age). A 2-tailed Pearson correlation was used to assess the relationship between age, PSS, and DMFS scores. P values less than or equal to 0.01 were considered significant (P≤0.01) for the correlation coefficient.

Results

DEMOGRAPHIC CHARACTERISTICS:

Table 1 shows the sociodemographic characteristics of this study’s participants. In the study sample (n=290, age=18 to 30 years, mean age=21.48), there were more female participants than males. The second-year female medical students participated in greater numbers, with fourth-year female students having the lowest participation. With a mean BMI of 24.71, a significant proportion of students reported a lack of physical exercise.

PSS AND DMFS:

The distribution frequency of every PSS questionnaire item and the graded stress scored in 3 different categories – low, moderate, and high – are presented in Table 2. Stress was perceived by most participants in the previous month. The results revealed that low stress was perceived by a smaller number of participants (8.6%), while most participants experienced moderate (73.8%) to high stress (17.6%). Overall calculated scores for each variable (PSS and DMFS) and relative distribution of DMFS scores according to stress levels (low, moderate, high) are shown in Table 3. According to respective scale scores, moderate scoring levels were present for both PSS (m=21±3.61) and DMFS (m=3.20±3.61). Higher PSS scores were observed in women (m=21.52) than men (m=20.43), while higher DMFS scores were observed in men (m=3.27) than women (3.13), when sex differences were estimated. Participants who scored low PSS (0 to 13) were had low DMFS scores (0 to 1.1), while those who scored high on PSS (27 to 40) were found to have higher DMFS scores (4.5 to 6.5) (Table 3).

CORRELATION: AGE, STRESS, AND DMFS:

The Pearson correlation results between the evaluated continuous variables (stress, age, DMFS score) are displayed in Table 4. Stress (r=−0.072, P=0.219) and DMFS (r=−0.023, P=0.695) scores were negatively associated with age, with no noteworthy differences in the scores indicating no correlation between the variables. Stress and DMFS scores showed a positive link (r=0.41), but a modest correlation in terms of correlation size. The differences were significant (P≤0.01), suggesting a linear positive correlation. Although the variables under analysis were positively correlated, these results do not suggest any causal relationship between them. The 2 scores, when depicted graphically, showed a linear positive correlation between the 2 variables (Figure 1).

Discussion

STRENGTHS AND LIMITATIONS:

This study links DMFS as a potential marker that can be treated early on, offering a novel strategy to address preventive measures for the risk of developing caries-associated malocclusion. Regardless of the person experiencing stress, early management in cases of caries can avoid the development of parafunction, since the condition alters the structure of teeth and their relative occlusion. One of the study’s limitation is that only association, and not causality, has been shown. Another limitation is that the PSS, which is used to measure stress, does not permit the diagnosis of a particular stress disorder; rather, it assesses an individual’s sensitivity to stressful situations. Subjective perceptions vary from person to person as well as occasionally within the same individual. Furthermore, PSS validity is restricted to those who experience stress in non-academic environments, which limits its applicability to other social groups or organizations.

Conclusions

According to the study’s findings, there was a significant positive linear correlation between perceived stress and dental caries risk, and participants with higher stress had a greater incidence of caries. This study sheds light on how to prevent caries and its consequences by using DMFS as an early warning sign, particularly in medical students. Accordingly, the study recommends that people who perceive more stress should practice better oral hygiene to prevent dental caries. This will lessen the likelihood that those who are under a lot of stress will acquire or aggravate dental caries.