Park WB, et al. - To assess the clinical consequence of nonrepair of perforated maxillary sinus membrane as compared to nonperforated cases, investigators performed a retrospective comparative study among 63 candidates with 65 sinuses. A significant relationship was noted between the presence of sinus pathoses prior to surgery and the occurrence of Schneiderian membrane perforation. Significantly thicker Schneiderian membrane was reported in subjects with perforation when compared to the cases without perforation. They found no association of the size of the perforation with the thickness of the Schneiderian membrane. An occurrence of most of the perforations (83%) was noticed at the mesial and middle part of the lateral window. They found that the Schneiderian membrane thickness was reduced significantly in both groups subsequent to the sinus elevation procedure.