Analysis of the reliability of the Italian version of the Oral Behaviours Checklist and the relationship between oral behaviours and trait anxiety in healthy individuals

Summary Background The Oral Behaviours Checklist (OBC) is a valid 21‐item instrument quantifying the self‐reported frequency of oral behaviours. An Italian version (OBC‐It) has been released recently. Anxiety and oral behaviours are known to be associated in individuals with oro‐facial pain due to temporomandibular disorders (TMD). However, information about this relationship in pain‐free individuals is still limited. Objectives The aim of this study was to test the reliability of the OBC‐It and its reduced version (OBC‐It 6), focusing on tooth clenching‐related wake‐time oral behaviours, and the effect of patient instructions on reliability. A second aim was to test the association between trait anxiety and oral behaviours in pain‐free individuals. Methods Two hundred and eighty‐two TMD‐free students, divided into 2 groups (Group A, n = 139, mean age ± SD = 22.6 ± 5.4 years; Group B, n = 143, 23.7 ± 4.2 years), filled in the State‐Trait Anxiety Inventory and the OBC‐It. Group B received instructions about the OBC‐It, while Group A did not. After 2 weeks, both groups filled in the OBC‐It again. However, Group B was further divided into 2 subgroups, B1 and B2. The first received the same instructions again, while B2 did not. Results The test‐retest reliability of the OBC‐It (A: ICC = .87; B1: ICC = .94; B2: ICC = .95) and OBC‐It 6 (A: ICC = .85; B1: ICC = .89; B2: ICC = .93) was excellent in all groups. Trait anxiety was weakly associated with OBC‐It only in women (R2 = .043, P = .021). Conclusions The OBC‐It is a reliable tool but further subjects’ instructions might be needed. Trait anxiety has a limited effect on oral behaviours in TMD‐free subjects.