Risk factors associated with incidence and persistence of frequent headaches.
OBJECTIVE
Headaches represent a significant public health problem, but the knowledge of factors specifically related to incidence and persistence of headaches is still limited. The aim of this study was to evaluate whether gender, self-reported bruxism and variations in the dental occlusion contribute to onset and persistence of frequent headaches.


METHODS
The study population comprised 280 dental students, examined annually in a 2-year prospective study with a questionnaire and a clinical examination of the jaw function. In the analysis subjects were dichotomized into cases with frequent (once a week or more) or without frequent headaches (controls). The 2-year cumulative incidence was based on subjects without frequent headaches at baseline. Cases with 2-year persistent headaches reported such symptoms at all three examinations. Self-reported bruxism and factors in the dental occlusion at baseline were used as independent variables in logistic regression analyses.


RESULTS
The 2-year cumulative incidence of frequent headaches was 21%. Female gender (OR = 2.6; CI = 1.3-5.4), self-reported bruxism (OR = 2.3; CI = 1.2-4.4) and mandibular instability in intercuspal position (OR = 3.2; CI = 1.4-7.5) were associated with incidence of frequent headaches. Persistent headaches during the observation period were present in 12 individuals (4%) and significantly related to mandibular instability in intercuspal position (OR = 6.1; CI = 1.6-22.6).


CONCLUSIONS
The results indicate that female gender, self-reported bruxism and mandibular instability in intercuspal position are of importance in the development of frequent headaches. In management of these patients a multidisciplinary approach including dentists may be important and, thus, advocated.
Department of Odontology, Clinical Oral Physiology, Faculty of Medicine, Umeå University , Umeå , Sweden.
Susanna
S
Marklund
Birgitta
B
Häggman-Henrikson
Anders
A
Wänman
D000293:Adolescent; D000328:Adult; D002012:Bruxism / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D003766:Dental Occlusion; D005260:Female; D006261:Headache / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008310:Malocclusion / Q000453:epidemiology; D008334:Mandible / Q000503:physiopathology; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D057566:Self Report; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
bruxism; dental occlusion; gender; prospective; risk