Coronal computed tomography analysis of frontal cells

Background: Described by Schaefer in 1916, frontal cells have been implicated as a cause of frontal recess obstruction. In this cross-sectional study, we determine the prevalence of frontal cells and other anatomic variants and examine their relationships. Methods: Coronal computed tomography scans of the sinuses performed from January 2000 to June 2001 were evaluated for frontal cells, other anatomic variants, and sinus disease. Of 1009 scans evaluated, 768 scans were included for data collection. Frontal cells were classified. Results: In this population, 20.4% of individuals had frontal cells (14.9% had type I, 3.1% had type II, 1.7% had type III, and 2.1% had type IV). The presence of frontal cells was positively associated with hyperpneumatization of the frontal sinus (p = 0.01) and negatively associated with hypopneumatization of the frontal sinus (p < 0.01). Individuals with frontal cells had an increased prevalence of concha bullosa compared with individuals without frontal cells (41.4% versus 24.1%, p < 0.01). The prevalence of frontal mucosal thickening was increased in individuals with type III and type IV cells compared with individuals without frontal cells (38.5 and 69.0% versus 17.1%, p = 0.04 and p < 0.01). Conclusion: The prevalence of frontal cells among a population undergoing sinus computed tomography is 20.4%. Frontal cells are associated with other variants of sinonasal pneumatization and should be suspected when these variants are noted. The presence of frontal cells does not invariably lead to frontal sinusitis but may contribute to the mechanical obstruction of the frontal recess and should be appropriately addressed during the surgical management of frontal sinusitis.