Anatomical Variation of Lacrimal Sac Fossa and Bony Nasolacrimal Duct among Adult Egyptians: Dry Bone and Radiological Study

Abdel Gawad, Fayza Abdel Raouf; Attia, Rasha Abdel Khalek; Elazab, Reham Farouk; Khaled, Bahaa Eldin Ali; Shuaib, Doaa Mahmoud

doi:10.21608/zumj.2022.131920.2545

Anatomical Variation of Lacrimal Sac Fossa and Bony Nasolacrimal Duct among Adult Egyptians: Dry Bone and Radiological Study

Document Type : Original Article

Authors

¹ Human Anatomy and Embryology Department, Faculty of Medicine, Cairo University, Egypt

² Human Anatomy and Embryology Department, Faculty of Medicine, Cairo University, Egypt Human Anatomy and Embryology Department, College of Medicine, Jouf University, Sakaka, Saudi Arabia

10.21608/zumj.2022.131920.2545

Abstract

Background: Successful lacrimal surgery begins with understanding the anatomy of the lacrimal drainage system. Detailed knowledge of the orientation of the bony lacrimal passages is a key feature for success of lacrimal probing and intubation. The present study was assigned to demonstrate the anatomy of the lacrimal drainage system and its variants among adult Egyptians. Material and methods: The study included 44 dry skulls and 83 multidetector computed tomography (MDCT) images of adults of both sexes. The anterior and posterior lacrimal crests were examined in dry bones. The length, width of the upper, middle and lower thirds of lacrimal sac fossa (LSF) were measured using the digital Vernier caliper. Radiological CT images were examined for anteroposterior and transverse diameters of the entrance, narrowest point and exit of nasolacrimal duct (NLD). The length of NLD and the angle between the longitudinal axis of the NLD and floor of the nose were measured. Results: The LSF was formed by the frontal process of maxilla and lacrimal bone at different proportions. The width of the middle and lower thirds of LSF were significantly greater in males than females. Radiological CT images showed that the anteroposterior and transverse diameters of the entrance of the NLD were significantly greater in females than males below 40 years. Conclusion: Sex and age of the patient should be considered while selecting the optimal NLD stent for patient with NLD obstruction. The precise dimensions of NLD can reduce the risk of injury during the transnasal operations

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