Morphometric Properties of the Whitnall's Tubercle and Its Relationship With Neighboring Bony Structures

Abstract

ABSTRACTObjective: Whitnall’s tubercle is used as an Anatomical landmark in surgical approaches toorbit and periorbital structures. Therefore, in order to increase the success of invasiveprocedures and minimize surgical complications, it was aimed to determine localization ofWhitnall’s tubercle by using some palpable bony landmarks and to reveal its morphologicaland morphometric features.Materials and method: Ethics committee approval was obtained from the Istanbul MedicalFaculty Clinical Research Ethics Committee. 322 zygomatic bones (167 right, 155 left) ofDepartment of Anatomy of Istanbul Faculty of Medicine belonging to adults of unknowngender, were examined to reveal Whitnall’s tubercle and morphological features of thetubercle were identified. An acetate prepared by drawing a clock with a dial and an apparatuson which this acetate was located was used in order to determine localization of Whitnall'stubercle. By means of this acetate, positions of this tubercle relative to marginal tubercle andanterior point of the zygomatic arch were determined. Distances between Whitnall’s tubercleand frontozygomatic suture and lateral margin of orbital rim were measured with a digitalcalipers.Results: Whitnall's tubercle was determined in 284 zygomatic bones, and this tubercle wasabsent in 38 bones. Of determined tubercles, 181 were classified as small, 10 as medium, and93 as large. Position of Whitnall's tubercle according to marginal tubercle was at 8, 9, and 10o'clock on the left, and at 2, 3, and 4 o'clock on the right. Position of the Whitnall's tubercleaccording to anterior point of zygomatic arch was at 9,10 and 11 o'clock on the left, and at 1and 2 o'clock on the right. Distances between Whitnall’s tubercle and lateral margin of orbitalrim and frontozygomatic suture were measured as 1.94±0.31mm and 8.17±5.82mm,respectively.Conclusion: We think that findings obtained regarding Whitnall’s tubercle will contribute toanatomy of the related region and surgical procedures applied to this area.Keywords: lateral canthus; marginal tubercle; zygomatic bone; Whitnall’s tubercle;zygomatic arch