Prevalence of Bilateral Frontal Sinus Absence in Cadaveric Specimens: A Cross-Sectional Study


Purpose: The frontal sinus is one of four pairs of paranasal sinuses, developed early in gestation and continuing pneumatization into teenage years. Due to the differences in pneumatization, large variability exists in the size and dimensions of the frontal sinus, with the majority of radiologic studies showing prevalence of bilateral frontal sinus agenesis to be between 3-5%. While frontal sinus agenesis has not been identified as a frequent cause of patient complaints, it has contributed to worsening symptoms in certain diseases, and this anatomical variation may pose complicated risks to patient treatments, such as surgery. This study aims to demonstrate the prevalence of bilateral frontal sinus agenesis in a population of fixed cadavers from the United States.

Methods: The sagittally hemisected skulls of forty-eight cadavers donors of the HSC Willed Body Program were used for this study, and were not separated based on sex, race, or age. All donors were above the age of 35, allowing for complete pneumatization of the frontal sinuses at the time of hemisection. Initial gross observation of the frontal sinus was performed by the researchers at the midline site of hemisection. If the hollow frontal sinus was not identifiable, sagittal cuts with a bone shear were performed in the bilateral supraorbital regions laterally up to two centimeters from the site of midline hemisection in order to determine if the frontal sinus was present. This method was performed on each of the forty-eight cadaveric skulls. During gross observation and further dissection of the supraorbital regions of the skulls, bilateral presence or absence of the frontal sinuses was noted.

Results: Three of the forty-eight donors exhibited bilateral agenesis of the frontal sinus leaving forty-five to exhibit unilateral or bilateral presence of frontal sinuses. This correlates to a prevalence of bilateral frontal sinus absence in 6.25% of the population.

Conclusion: This study contributes valuable insights to variations and developmental sequences of the frontal sinus. Literature is consistent regarding prevalence of frontal sinus agenesis in various populations, ranging from 2% to 8% depending on the country of origin; the prevalence of bilateral frontal sinus absence in the sample population of this study was 6.25%. Our findings contribute to current data highlighting prevalence rates, which highlights the importance of noting radiologically determined frontal sinus abnormalities in patient histories, ensuring appropriate care during surgeries and future treatments of conditions such as chronic sinusitis and primary ciliary dyskinesia (PCD).