1. Background
Periodontitis has several etiological factors, among which dental plaque that harbors specific periodontal pathogens is the primary etiology. Chronic stress negatively affects immune response efficacy, which in turn causes an imbalance between host and parasites and leads to periodontal break-down (1). However, studies show that psychosocial variables can also be risk factors for periodontitis (1-4).
Currently, stress and depression affect many people. Moreover, the immune response is affected by emotional states, and behavioral factors may lead to a health imbalance favoring the onset of periodontal disease (3). Hugoson et al. reported the association between severe periodontal disease and a poor ability to cope with stress. This relationship was explained as an appropriate brain-neuro-endocrine response to plaque–induced inflammation in the gingival connective tissue (4). To date, most studies on the relationship between periodontal disease and psychosocial factors have focused mainly on stress and depression (5-9).
2. Objectives
In the present study, we evaluated the relationship between periodontitis and 9 different types of psychological disorders.
3. Patients and Methods
In a cross-sectional study, 80 literate individuals referred to the periodontics department of Zahedan school of dentistry (Eastern Iran) in 2011 were included in the study. All the participants had a similar level of education (high school diploma).
After a periodontal examination using a mirror and a Williams probe with 1 mm accuracy, a periodontal chart was prepared for each patient. Next, 40 patients with severe chronic periodontitis and 40 clinically healthy individuals between 20 and 40 years old were selected. The healthy individuals did not have any sign of inflammation on the gingiva, had an evidence of plaque score of less than 20%, and didn’t have bleeding on probing. The criteria for severe chronic periodontitis were: slow rate of disease progression and clinical attachment loss ≥ 5 mm in at least two teeth. Patients with aggressive forms of periodontitis were excluded from the study.
Informed consent was obtained from the participants, and the patients with periodontitis received necessary treatments. Then, the subjects were given a set of psychosocial questionnaires which were completed in a private setting in the clinic. Professional staff were available to answer any questions regarding the questionnaire. The participants were assured that their answers would be kept strictly confidential, to help encourage complete and truthful self-reporting.
To evaluate a broad range of psychological problems and symptoms, we used the symptom checklist-90-revised (SCL-90-R) questionnaire (10). It consists of 90 items and takes 15 - 20 minutes to administer, yielding nine scores along primary symptom dimensions. Many studies have shown the reliability, validity, and utility of this questionnaire (2, 10, 11). Psychological and somatic symptom patterns assessed by SCL-90-R questionnaire include the following 9 symptom dimensions: anxiety (10 items), depression (13 items), hostility (6 items), somatization (12 items), phobic anxiety (7 items), psychotism (10 items), obsessive compulsive disorder (10 items), interpersonal sensitivity (9 items), paranoid ideas (6 items), and additional questions (7 items) (2).
3.1. Statistical Analysis
All statistical analyses were performed using the SPSS software, version 19, then described by means and standard deviations. The comparison between groups was performed using a Mann-Whitney U test.
4. Results
A total of 80 individuals (37 men and 43 women) participated in this study. The findings showed that there was a significant statistical difference between the two groups in the average scores on 9 dimensional aspects (somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideas, and psychotism) (P < 0.001, Table 1). In other words, patients with severe chronic periodontitis had more evident psychological disorders than healthy people.
Table 1. Mean Scores and Standard Deviations for 9 Psychological Dimensions in Study Groups
| Study Groups Psychological Dimension | Patients | Healthy Individuals | P Valuea |
|---|---|---|---|
| Anxiety | 0.81 ± 0.64 | 0.17 ± 0.27 | < 0.001 |
| Somatization | 0.62 ± 0.50 | 0.22 ± 0.33 | < 0.001 |
| Obsessive-compulsive | 0.71 ± 0.50 | 0.18 ± 0.34 | < 0.001 |
| Depression | 0.96 ± 0.58 | 0.27 ± 0.30 | < 0.001 |
| Hostility | 0.61 ± 0.43 | 0.22 ± 0.25 | < 0.001 |
| Phobic anxiety | 0.72 ± 0.50 | 0.15 ± 0.28 | < 0.001 |
| Paranoid ideas | 0.75 ± 0.61 | 0.16 ± 0.28 | < 0.001 |
| Psychotism | 0.66 ± 0.48 | 0.11 ± 0.22 | < 0.001 |
| Interpersonal sensitivity | 0.84 ± 0.57 | 0.22 ± 0.27 | < 0.001 |
aMann-Whitney Test.
Results also indicated that the mean score for GSI was higher in patients than in healthy people, and this difference was statistically significant (P < 0.001) (Table 2).
Table 2. Mean Scores and Standard Deviations of GSI Index in Study Groupsa
| Study Groups | Healthy Individuals | Patients | P Valueb |
|---|---|---|---|
| Sex | |||
| Men | 60.7 ± 40.3 | 18.6 ± 16.5 | < 0.001 |
| Women | 88.1 ± 41.4 | 24.6 ± 33.25 | < 0.001 |
| Age group, y | |||
| 20 - 25 | 63.9 ± 35.2 | 15.7 ± 14.8 | < 0.001 |
| 26 - 30 | 77.4 ± 44.8 | 32.2 ± 41.6 | 0.03 |
| 31 - 35 | 99.3 ± 38.6 | 20.1 ± 21.5 | 0.004 |
| 36 - 40 | 82.00 ± 49.1 | 20.8 ± 23.1 | 0.002 |
| Total | 77.1 ± 42.6 | 21.4 ± 25.6 | < 0.001 |
aValues are expressed as mean ± SD.
bMann-Whitney Test.
All the psychological symptoms were statistically different between the study groups after gender analysis (Table 3).
Table 3. Mean Scores and Standard Deviations of 9 Psychological Dimensions in Study Groups, by Gendera
| Psychological Dimension | Gender | Patients | Healthy Individuals | P Valueb |
|---|---|---|---|---|
| Anxiety | Women | 0.95 ± 0.60 | 0.22 ± 0.36 | < 0.001 |
| Men | 0.59 ± 0.65 | 0.13 ± 0.15 | 0.002 | |
| Somatization | Women | 0.72 ± .52 | 0.26 ± 0.44 | 0.001 |
| Men | 0.49 ± 0.45 | 0.18 ± 0.18 | 0.002 | |
| Obsessive compulsive | Women | 0.74 ± 0.52 | 0.23 ± 0.43 | < 0.001 |
| Men | 0.66 ± 0.48 | 0.13 ± 0.23 | < 0.001 | |
| Depression | Women | 1.07 ± 0.57 | 0.31 ± .33 | < 0.001 |
| Men | 0.78 ± 0.56 | 0.24 ± 0.27 | < 0.001 | |
| Hostility | Women | 0.71 ± 0.43 | 0.23 ± 0.31 | < 0.001 |
| Men | 0.46 ± 0.40 | 0.21 ± 0.17 | 0.03 | |
| Phobic Anxiety | Women | 0.82 ± 0.43 | 0.18 ± 0.39 | < 0.001 |
| Men | 0.56 ± 0.56 | 0.12 ± 0.18 | 0.001 | |
| Paranoid Ideas | Women | 0.82 ± 0.44 | 0.24 ± 0.34 | < 0.001 |
| Men | 0.56 ± 0.50 | 0.09 ± 0.19 | < 0.001 | |
| Psychotism | Women | 0.79 ± 0.44 | 0.13 ± 0.26 | < 0.001 |
| Men | 0.47 ± 0.49 | 0.09 ± 0.18 | 0.001 | |
| Interpersonal Sensitivity | Women | 0.99 ± 0.54 | 0.25 ± 0.35 | <0.001 |
| Men | 0.63 ± 0.56 | 0.19 ± 0.18 | 0.001 |
aValues are expressed as mean ± SD.
bMann-Whitney Test.
We next distributed the participants into four age groups: 20 - 25 years old (group 1), 26 - 30 years old (group 2), 31 - 35 years old (group 3), and 36 - 40 years old (group 4). Using a Mann-Whitney U test, we found that in group 1, chronic periodontitis patients had more psychological symptoms than healthy individuals, and in group 2, the anxiety, somatization, depression, and hostility dimensions were not statistically different between patients and healthy participants, but the other dimensions were more evident in patients. Furthermore, in group 3 the interpersonal sensitivity dimension was not different between groups , but other dimensions were more evident in the chronic periodontitis group, and in group 4, somatization and hostility didn’t show a statistically significant difference between study groups, but the other psychological symptoms were more evident in patients (Table 4).
Table 4. Mean Scores and Standard Deviations of 9 Psychological Dimensions of Study Groups, According to Age Distributiona
| Psychologic Dimension | Age Group, y | ||||
|---|---|---|---|---|---|
| 36 - 40 | 31 - 35 | 26 - 30 | 20 - 25 | ||
| Anxiety | Patients | 0.87 ± 0.69 | 1.00±0.68 | 0.83 ± 0.65 | 0.66 ± 0.60 |
| Healthy Group | 0.12 ± 0.20 | 0.14 ± 0.17 | 0.26 ± 0.42 | 0.16 ± 0.26 | |
| P valueb | 0.001 | 0.004 | 0.07 | 0.01 | |
| Somatization | Patients | 0.72 ± 0.63 | 0.87 ± 0.41 | 0.74 ± 0.49 | 0.39 ± 0.30 |
| Healthy Group | 0.30 ± 0.44 | 0.21 ± 0.25 | 0.31 ± 0.49 | 0.12 ± 0.10 | |
| P value | 0.06 | 0.007 | 0.07 | 0.002 | |
| Obsessive Compulsive | Patients | 0.65 ± 0.55 | 0.98 ± 0.64 | 0.68 ± 0.42 | 0.68 ± 0.45 |
| Healthy Group | 0.16 ± 0.29 | 0.14 ± 0.29 | 0.32 ± 0.58 | 0.11 ± 0.15 | |
| P value | 0.008 | 0.004 | 0.04 | <0.001 | |
| Depression | Patients | 1.12 ± 0.60 | 1.43 ± 0.32 | 0.58 ± 0.37 | 0.79 ± 0.56 |
| Healthy Group | 0.27 ± 0.28 | 0.27 ± 0.34 | 038 ± 0.37 | 0.20 ± 0.23 | |
| P value | 0.002 | 0.002 | 0.22 | 0.001 | |
| Hostility | Patients | 0.54 ± 0.46 | 0.77 ± 0.45 | 0.69 ± 0.63 | 0.59 ± 0.32 |
| Healthy Group | 0.23 ± 0.22 | 0.22 ± 0.19 | 0.28 ± 0.38 | 0.17 ± 0.19 | |
| P value | 0.07 | 0.03 | 0.18 | 0.001 | |
| Phobic Anxiety | Patients | 0.72 ± 0.48 | 1.09 ± 0.47 | 0.90 ± 0.57 | 0.50 ± 0.44 |
| Healthy Group | 0.12 ± 0.14 | 0.12 ± 0.19 | 0.32 ± 0.57 | 0.06 ± 0.09 | |
| P value | 0.002 | 0.002 | 0.05 | 0.001 | |
| Paranoid Ideas | Patients | 0.85 ± 0.70 | 0.73 ± 0.53 | 0.75 ± 0.63 | 0.65 ± 0.56 |
| Healthy Group | 0.19 ± 0.26 | 0.09 ± 0.28 | 0.20 ± 0.38 | 0.15 ± 0.24 | |
| P value | 0.008 | 0.004 | 0.05 | 0.001 | |
| Psychotism | Patients | 0.61 ± 0.48 | 0.76 ± 0.60 | 0.88 ± 0.62 | 0.59 ± 0.40 |
| Healthy Group | 0.07 ± 0.17 | 0.04 ± 0.13 | 0.21 ± 0.35 | 0.10 ± 0.18 | |
| P value | 0.002 | 0.004 | 0.02 | <0.001 | |
| Interpersonal Sensitivity | Patients | 0.94 ± 0.62 | 0.87 ± 0.74 | 0.83 ± 0.43 | 0.74 ± 0.54 |
| Healthy Group | 0.17 ± 0.21 | 0.19 ± 0.19 | 0.35 ± 0.39 | 0.18 ± 0.26 | |
| P value | 0.001 | 0.15 | 0.03 | 0.001 | |
aValues are expressed as mean ± SD.
bMann-Whitney Test.
5. Discussion
In the present study we examined the relationship between 9 different psychological items and periodontitis. We found that all the measured psychological factors were more evident in chronic periodontitis patients than in healthy people, results that partly supported previous studies (4, 8, 9). Screening for only 9 disorders may have limited our results, but more in-depth studies on individual symptoms, with the assistance of psychologists, could produce more reliable results. In the present study, when we analyzed each symptom separately, we found a statistically significant association between psychological factors and periodontal disease. Also, when considering all nine psychological signs with GSI scores, people with severe chronic periodontitis had a significantly higher level of psychological disorders than healthy participants.
From a psychological point of view, the results were in accordance with Castro (3) and Solis (7). whose studies showed significant differences in anxiety and depression scores between periodontal patient and control groups. The relationship between psychological symptoms and periodontitis was not related to gender. This finding is in accordance with Johansen (8), who also showed depression could compromise periodontal health. Also, our results are in accordance to Mannem (12), who showed chronic periodontitis was associated with psychological stress. Zhao’s study (13) also showed a periodontal healing delay in rats. Stress results in periodontal healing delays, and the cause may be a down expression of bFGF in PDL.
Overall, periodontal disease has a long-term health outcome, and therefore it is likely that a chronic pattern of adverse psychological effects is required to affect and promote a measurable disease. Since our results are derived from a case-control study, they need to be complemented by further studies, particularly longitudinal ones, to confirm the findings. However, the result of this study may be used as a guide to decide on which measurements to include in longitudinal studies, especially for the 31 - 35 years old group, because this group has more psychologically significant symptoms. Another shortcoming of our article is that our results are based on questionnaires, so future studies should add psychologist consultations to the questionnaire data for better results.
