Perceptualand MotorSkills, 1992, 75, 796-798. O Perceptual and Motor Skills 1992
AROUSABILITY AND BRUXISM I N MALE A N D FEMALE COLLEGE STUDENTS ' DARRAH A. WESTRUP, S T E P H E N R. KELLER, TERRY A. NELLIS, A N D ROBERT A. H I C K S
Sun lose Slate University Summary.-The relationship between arousabilicy, as measured by the Arousal Predisposition Scale, and bruxism was computed for groups of 41 male and 75 female university undergraduates as o further test of the hypothesis that bruxism is a stresslinked disorder. Contrary to our prediction, arousability was not related to bruxism in men and the relationship between these variables for women was significant but relatively weak. W h e n considered with other studies, these data provide a clearer focus for further study 06 the stress-bruxism hypothesis.
A substantial number of adults are affected with bruxism (Hicks & Conti, 1989). This painful dental illness is characterized by the nonfunctional gritting, grinding, and clenching of the teeth, usually occurs during sleep, and if not checked, it can result in excessive irreversible toothwear, fractures of the teeth, and deterioration of the alveolar bone which may result in periodontal disease. I n addition, bruxism may be accompanied by severe chronic headaches, facial pain, and sensitive teeth. While the etiology of this widespread serious health problem is unknown, increasingly research points to links between stressful experience and bruxing behavior (e.g., Hicks, Conti, & Bragg, 1990; Hicks & Conti, 1991). The purpose of this study was to examine the relationships between stress-related variables and bruxism further by measuring the relationship between arousability and the self-reported incidence of bruxism for groups of male and female college students. Since arousability seems implicated in the consequences of exposure to stressful experience (e.g., Mathews, Weiss, Detre, Dembroski, Falkner, Manuck, & Williams, 1986; Hicks, Conti, & Nellis, 1992), we predicted that persons who reported bruxism would score higher on the Arousal Predisposition Scale than those who reported no symptoms of bruxism. METHOD To identify the groups of bruxers and nonbruxers, we administered a questionnaire to approximately 800 undergraduate students during regularly scheduled class periods. Embedded in this questionnaire was the critical item, "Do you experience bruxism (teeth grinding)." Based on a positive (yes) response to this question, 116 bruxers, 41 men and 75 women, were 'In part this research was supported by NIH-MBRS Grant G M 08192-13. Requests for reprints should be addressed to Robert A . Hicks, Department of Psychology, San Jose State University, San Jose, CA 95192-0189.
797
COLLEGE STUDENTS: AROUSABILITY, BRUXISM
identified. The nonbruxing group was formed from students who gave a negative (no) response to the critical item and who I d not check any bruxism-related items on a checklist of physical symptoms that included the common symptoms of bruxism. From those who were eligible for this group, we randomly selected 41 men and 75 women as the nonbruxing group. To measure arousability, we scored these students' responses to a 12item scale that Coren (1988, 1990) has recently developed and standardized, i.e., the Arousal Predisposition Scale. Of relevance to this study, scores have been shown to be positively correlated with the extent to which students report experience with stress-related physical symptoms (Hicks, et al., 1992) responsiveand with levels of electrodermal activity and ele~trom~ographic ness (Coren & Mah, 1992). I n responding to the scale, people are asked to select the response to each item (e.g., "I startle easily" and "I am a calm person") by selecting a response alternative (from five alternatives that range from "never" to "always") which best describes them and their behavior. These responses are then assigned a weight that ranges from 1 to 5 and then summed to yield a total arousabdity score.
Using the arousability score for each individual, the means and standard deviations for the male, female, and total bruxing and nonbruxing groups were computed. These results are summarized in Table 1. Also included in Table 1 are the t ratios that were computed to analvze the difference between the means for these groups. As can be seen by inspecting Table 1, the difference between the means for the male bruxers and nonbruxers was not significant ( p = 0.71) but the differences between the means for the female and total bruxer-nonbruxer groups were significant, with p < 0.001 and p < 0.004, respectively. Therefore, our hypothesis was confirmed only for wom. en, and the strength of this relationship is relatively weak, i.e., est. w 2= .068, which corresponds roughly to a correlation of .26 between arousability and bruxism. Thus, it seems prudent to conclude that, as it is reflected on the Arousal Predisposition Scale, arousability is not an important variable in the etiology of bruxism. The rationale for this study was the suspected link between stressful ex-
TABLE 1 MEANAROUSABILITY SCORES,STANDARD DEVIATIONS, A N D t & n o s BETWEEN BRUXISMGROUPSFOR MALE,FEMALE,AND TOTALSTUDENT SAMPLES Groups Men Women Total
Bruxers M
SD
32.9 37.4 35.8
7.6 8.2 8.2
Nonbruxers M SD 32.3 33.1 32.8
7.8 6.9 7.2
t
P
.37 3.47 2.94
0.71 CO.001 c0.004
798
D. A . WESTRUP, ETAL.
perience and bruxism. These results should not be viewed as questioning the validity of that hypothesis, but rather they serve to sharpen the focus of research designed to test it. Clearly these data reinforce the need to consider gender as a variable in attempts to identify the psychological factorb) that may contribute to bruxism. In addition, when these data are considered together with those of an earlier study which yielded a relationship between Type A behavior scores and bruxism (Hicks & Chancellor, 1987), they suggest that stress-related changes in state that seem to be correlated with arousability may be less important to the etiology of bruxism than certain coping styles that are more likely among Type A scorers. REFERENCES COREN,S. (1988) Prediction of insomnia from arousability predisposition scores: scale development and cross-validation. Behavior Research and Therapy, 26, 415-420. COREN,S. (1990) The Arousal Predisposition Scale: normative data. Bulletin of the Psychonomic Society, 28, 551-552. COREN,S., & MAH,K. B. (1992) Prediction of physiolo ical arousability: a validation of the Arousal Predisposition Scale. Behavior Research a n j ~ h e r a p y in , press. C. (1987) Nocturnal bruxisrn and Type A-B behavior in college HICKS,R. A,, & CHANCELLOR, studencs. Psychological Reporfs, 60, 1211-1214. HICKS,R . A , , & C o ~ n I?, A. (1989) Changes in the incidence of nocturnal bruxism in college students 1966-1989. Perceptuai and Motor Skills, 69, 481-482. HICKS, R. A , , & CONTI,I? A. (1991) Nocturnal bruxism and self-reports of stress-related symptoms. Perceptual and Motor Skills, 72, 1182. HICKS, R. A , , CONTI,P. A . , & BRAGG, H . R. (1990) Increases in nocturnal bruxism among college students implicate stress. Medical Hypothesis, 33, 239-240. HICKS, R. A,, C o ~ n P. , A , , & NELLIS, T. A. (1992) Arousability and stress-related physical symptoms: a validation of Coren's Arousal Predisposition Scale. Perceptual and Motor Skills, 74, 659-662. MATHEWS,K. A., WEISS, S. M., DETRE, T., DEMBROSKI,T. M., FALKNER,B . , MANUCK,S. B . , & WILLIAMS,R. B. (Eds.) (1986) Handbook of stress, reactivity and cardiovascular disease. New York: Wiley. Accepted August 24, 1992
AROUSABILITY AND BRUXISM I N MALE A N D FEMALE COLLEGE STUDENTS ' DARRAH A. WESTRUP, S T E P H E N R. KELLER, TERRY A. NELLIS, A N D ROBERT A. H I C K S
Sun lose Slate University Summary.-The relationship between arousabilicy, as measured by the Arousal Predisposition Scale, and bruxism was computed for groups of 41 male and 75 female university undergraduates as o further test of the hypothesis that bruxism is a stresslinked disorder. Contrary to our prediction, arousability was not related to bruxism in men and the relationship between these variables for women was significant but relatively weak. W h e n considered with other studies, these data provide a clearer focus for further study 06 the stress-bruxism hypothesis.
A substantial number of adults are affected with bruxism (Hicks & Conti, 1989). This painful dental illness is characterized by the nonfunctional gritting, grinding, and clenching of the teeth, usually occurs during sleep, and if not checked, it can result in excessive irreversible toothwear, fractures of the teeth, and deterioration of the alveolar bone which may result in periodontal disease. I n addition, bruxism may be accompanied by severe chronic headaches, facial pain, and sensitive teeth. While the etiology of this widespread serious health problem is unknown, increasingly research points to links between stressful experience and bruxing behavior (e.g., Hicks, Conti, & Bragg, 1990; Hicks & Conti, 1991). The purpose of this study was to examine the relationships between stress-related variables and bruxism further by measuring the relationship between arousability and the self-reported incidence of bruxism for groups of male and female college students. Since arousability seems implicated in the consequences of exposure to stressful experience (e.g., Mathews, Weiss, Detre, Dembroski, Falkner, Manuck, & Williams, 1986; Hicks, Conti, & Nellis, 1992), we predicted that persons who reported bruxism would score higher on the Arousal Predisposition Scale than those who reported no symptoms of bruxism. METHOD To identify the groups of bruxers and nonbruxers, we administered a questionnaire to approximately 800 undergraduate students during regularly scheduled class periods. Embedded in this questionnaire was the critical item, "Do you experience bruxism (teeth grinding)." Based on a positive (yes) response to this question, 116 bruxers, 41 men and 75 women, were 'In part this research was supported by NIH-MBRS Grant G M 08192-13. Requests for reprints should be addressed to Robert A . Hicks, Department of Psychology, San Jose State University, San Jose, CA 95192-0189.
797
COLLEGE STUDENTS: AROUSABILITY, BRUXISM
identified. The nonbruxing group was formed from students who gave a negative (no) response to the critical item and who I d not check any bruxism-related items on a checklist of physical symptoms that included the common symptoms of bruxism. From those who were eligible for this group, we randomly selected 41 men and 75 women as the nonbruxing group. To measure arousability, we scored these students' responses to a 12item scale that Coren (1988, 1990) has recently developed and standardized, i.e., the Arousal Predisposition Scale. Of relevance to this study, scores have been shown to be positively correlated with the extent to which students report experience with stress-related physical symptoms (Hicks, et al., 1992) responsiveand with levels of electrodermal activity and ele~trom~ographic ness (Coren & Mah, 1992). I n responding to the scale, people are asked to select the response to each item (e.g., "I startle easily" and "I am a calm person") by selecting a response alternative (from five alternatives that range from "never" to "always") which best describes them and their behavior. These responses are then assigned a weight that ranges from 1 to 5 and then summed to yield a total arousabdity score.
Using the arousability score for each individual, the means and standard deviations for the male, female, and total bruxing and nonbruxing groups were computed. These results are summarized in Table 1. Also included in Table 1 are the t ratios that were computed to analvze the difference between the means for these groups. As can be seen by inspecting Table 1, the difference between the means for the male bruxers and nonbruxers was not significant ( p = 0.71) but the differences between the means for the female and total bruxer-nonbruxer groups were significant, with p < 0.001 and p < 0.004, respectively. Therefore, our hypothesis was confirmed only for wom. en, and the strength of this relationship is relatively weak, i.e., est. w 2= .068, which corresponds roughly to a correlation of .26 between arousability and bruxism. Thus, it seems prudent to conclude that, as it is reflected on the Arousal Predisposition Scale, arousability is not an important variable in the etiology of bruxism. The rationale for this study was the suspected link between stressful ex-
TABLE 1 MEANAROUSABILITY SCORES,STANDARD DEVIATIONS, A N D t & n o s BETWEEN BRUXISMGROUPSFOR MALE,FEMALE,AND TOTALSTUDENT SAMPLES Groups Men Women Total
Bruxers M
SD
32.9 37.4 35.8
7.6 8.2 8.2
Nonbruxers M SD 32.3 33.1 32.8
7.8 6.9 7.2
t
P
.37 3.47 2.94
0.71 CO.001 c0.004
798
D. A . WESTRUP, ETAL.
perience and bruxism. These results should not be viewed as questioning the validity of that hypothesis, but rather they serve to sharpen the focus of research designed to test it. Clearly these data reinforce the need to consider gender as a variable in attempts to identify the psychological factorb) that may contribute to bruxism. In addition, when these data are considered together with those of an earlier study which yielded a relationship between Type A behavior scores and bruxism (Hicks & Chancellor, 1987), they suggest that stress-related changes in state that seem to be correlated with arousability may be less important to the etiology of bruxism than certain coping styles that are more likely among Type A scorers. REFERENCES COREN,S. (1988) Prediction of insomnia from arousability predisposition scores: scale development and cross-validation. Behavior Research and Therapy, 26, 415-420. COREN,S. (1990) The Arousal Predisposition Scale: normative data. Bulletin of the Psychonomic Society, 28, 551-552. COREN,S., & MAH,K. B. (1992) Prediction of physiolo ical arousability: a validation of the Arousal Predisposition Scale. Behavior Research a n j ~ h e r a p y in , press. C. (1987) Nocturnal bruxisrn and Type A-B behavior in college HICKS,R. A,, & CHANCELLOR, studencs. Psychological Reporfs, 60, 1211-1214. HICKS,R . A , , & C o ~ n I?, A. (1989) Changes in the incidence of nocturnal bruxism in college students 1966-1989. Perceptuai and Motor Skills, 69, 481-482. HICKS, R. A , , & CONTI,I? A. (1991) Nocturnal bruxism and self-reports of stress-related symptoms. Perceptual and Motor Skills, 72, 1182. HICKS, R. A , , CONTI,P. A . , & BRAGG, H . R. (1990) Increases in nocturnal bruxism among college students implicate stress. Medical Hypothesis, 33, 239-240. HICKS, R. A,, C o ~ n P. , A , , & NELLIS, T. A. (1992) Arousability and stress-related physical symptoms: a validation of Coren's Arousal Predisposition Scale. Perceptual and Motor Skills, 74, 659-662. MATHEWS,K. A., WEISS, S. M., DETRE, T., DEMBROSKI,T. M., FALKNER,B . , MANUCK,S. B . , & WILLIAMS,R. B. (Eds.) (1986) Handbook of stress, reactivity and cardiovascular disease. New York: Wiley. Accepted August 24, 1992
