Investigation of the structure and variations of lamina papyracea on CT images

Lamina papyracea(LP) is a thin bone structure located on the face of os ethmoidale that faces the orbit and contributes to the formation of the medial wall of the orbital wall. In endoscopic sinus surgery (ESS), the LP can be broken iatrogenically and entered into the orbit and serious complications can occur. It is important to know the structure and variations of LP in order to prevent possible complications. For this reason, in our study, the structure and variations of the LP were examined using CT images. Patients who underwent face, cranium, sinus paranasales CT between September 2021 and June 2022 at Düzce University Research and Application Hospital were included in the study. The 101 randomly selected female and 102 male patients were identified and measured for the right and left side of LP. Data were analyzed with SPSS program (version 23.0). Among the 203 patients we included in the study, 3 individuals were found to have LP dehiscence. Patients with dehiscence were not included in the measurements. A total of 400 LPs, including the right and left sides, were measured in 200 patients. It was observed that Type I was the most common in LP, followed by Type IIa, Type IIb, Type IIIa and Type IIIb, respectively. The incidence of left LP types varied depending on gender (p<0.05), but the incidence of right LP types did not change depending on gender (p>0.05). The left LP types were compared with the right LP types, and the incidence of LP types did not change based on the presence on the right or left side (p>0,05). When all types of LP were examined, it was seen that the type changed depending on age (p<0.05). While there is no age-related change in the right LP type (p>0.05), there is an age-related change in the left LP type (p<0.05). The incidence of the types of LP we found in our study was consistent with the rates reported in the literature. The rate of LP dehiscence in our study was found to be compatible with the rates of dehiscence reported in the literature. Statistical evaluation of whether LP dehiscence chooses gender, age and parties could not be done because the data were insufficient. Our study will help to avoid serious complications that may occur in ESS with better knowledge of the structure of LP.