The Precise Location of the Stylomastoid Foramen and Clinical Implication for Facial Nerve Block

Abstract

Aim: We aimed to develop linear regression formulas for determining the precise localization of the stylomastoid foramen on the base of the morphometric features of the person’s own skull. 
 Material and Method: The study was conducted on 22 stylomastoid foramina (11 skulls). The 10 parameters determined for the stylomastoid foramen were measured on the photographs taken from the skull base and the 17 parameters determined for the morphometric features of the skull were measured on the photographs taken from the anterior plane, lateral plane, and posterior plan using Image J measurement software. The data obtained were evaluated with SPSS 20.0 statistical software. 
 Results: To determine the morphometric and topographic features of the stylomastoid foramen the equations have been developed such as; P1 (The distance between stylomastoid foramen and root of the zygomatic arch)=18.758+(0.472xP12)-(2.092x P16)+(0.831xP17)–(0.390xP18)–(0.101x P20); Adjusted R2=0.865, Standard Error of the Estimation=1.389. 
 Conclusion: Mean values can give misleading information in determining the topographical relationship between the stylomastoid foramen and the surrounding anatomical structures. We have developed regression formulas that will estimate the accurate location of the stylomastoid foramen and the accurate distances between other surrounding anatomical structures, taking into account the morphometric characteristics of the person’s own skull.