title: Seasonal variation in maxillary antral pseudocysts in a general clinic population.
abstract: OBJECTIVE
  To determine overall prevalence of maxillary antral pseudocysts and the effect of seasonal variation, allergies, asthma and current smoking status.
  
  
  METHODS
  Panoramic radiographs of 1175 dental clinic outpatients were examined. Data on the prevalence of allergies, asthma and smoking status was obtained from the medical records and age- and gender-matched controls. chi-square tests were used to determine the relationship between these factors and seasonal variation in prevalence.
  
  
  RESULTS
  Pseudocysts were found in 114 (9.7%) patients. Eleven patients (9.7%) reported a history of environmental allergies, nine (7.9%) were asthmatic and 21 (19.6%) current cigarette smokers. Compared with controls, the association between each of these findings and the presence of pseudocysts was not significant. 44.3% of the pseudocysts were detected in November, December and January compared with only 8.6% in April, May and June: this variation was significant (alpha = 0.01).
  
  
  CONCLUSIONS
  The marked increase in the prevalence of pseudocysts during cold winter months supports the concept that seasonal variation may be related to an increased incidence in viremias or irritation from dry forced air heating during this period.
authors.affiliation: Department of Oral Diagnostic Sciences, School of Dental Medicine, State University of New York at Buffalo 14214-3008, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Carter
authors.forename: A
authors.initials: A
authors.lastname: Calamel
authors.forename: A
authors.initials: A
authors.lastname: Haller
authors.forename: A
authors.initials: A
authors.lastname: Aguirre
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000150:complications; D002648:Child; D003560:Cysts / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D008297:Male; D008443:Maxillary Sinus / Q000000981:diagnostic imaging; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D010254:Paranasal Sinus Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015995:Prevalence; D011862:Radiography, Panoramic / Q000295:instrumentation / Q000379:methods; D012621:Seasons; D012907:Smoking / Q000009:adverse effects