Sinonasal Anatomic Variations According to Frontal Sinus Pneumatization in a Korean Population

Background and Objectives It is necessary to understand the variations of the paranasalsinuses (PNS) and other anatomical structures during an endoscopic sinus surgery (ESS). Thepurpose of this study was to investigate any association between the degree of frontal sinus(FS) pneumatization and the development of the PNS structures.
Subjects and Method We analyzed 311 PNS computed tomography (CT) scans (622 sinuses,including the left and right sides). We classified FS into type I (aplasia), type II (hypoplasia),and type III (control). We assessed and compared the middle turbinate pneumatization(MTP), superior turbinate pneumatization (STP), agger nasi cell (ANC), infraorbital cell (IOC),optic nerve (ON) type, and vidian nerve (VN) type with the pneumatization of the FS. Wefurther studied for any association between the degree of pneumatization of the FS, maxillarysinus (MS), and sphenoid sinus (SS) and the lateral lamella length (LLL).
Results MTP, ANC, and IOC rates according to the FS types were not significant (p>0.05).
Both type II and III showed more frequent occurrences of STP than type I (p=0.005). The ONtype III and IV were significantly frequent in the FS type III (p<0.001). The occurrence ofVN type III in the FS type I was significant (p<0.001). When comparing the pneumatizationsof FS with MS or SS, there were no significant correlations between them (p>0.05). In the FStype II and III, the LLL was significantly greater than in type I (p<0.001).
Conclusion Increased FS pneumatization shows greater indentation of ON and VN into theSS, as well as increased LLL. During ESS, it is important to recognize the possibility of structuraldamage of ON, VN, and LLL according to FS pneumatization.