Frontal sinus anatomical variations with potential consequences for the orbit. Study on cadavers.

Anatomical variations of the frontal sinuses that may play a role in the correlation between frontal sinusitis and orbital complications are described. There were used 18 cadavers during routine educational cadaver dissections, one month after theirs withdrawal from the formol basin. The dissections of the cranial cavity and the orbits were performed so as to reveal the frontal sinuses. An unusual bilateral posterior extension of the frontal sinus mucosa was found in two of the cadavers. The projection of the mucosa was covering half of the orbital roof in a 60 year old male and one third of the orbital roof in a 59 year old male. Among the other cadavers that presented normal variations of the frontal sinuses, there was also a case of a 57 year old female with a complete aplasia of the frontal sinuses. Such anatomical variations with unusual extension of the frontal sinuses above orbital roof may support the correlation between frontal sinusitis and the possible complications from the orbit and these cases may be considered as 'high risk' cases for orbital complications during a frontal sinusitis.