Anatomical Study of the Zygomaticotemporal Branch Inside the Orbit

The location of the opening of the zygomaticotemporal branch (ZTb) of the zygomatic nerve inside the orbit (ZTF(IN)) has significant surgical implications. This study was conducted to locate the ZTF(IN) and investigate the variations of the ZTb inside the orbit. A total of 20 sides from 10 fresh frozen cadaveric Caucasian heads were used in this study. The vertical distance between the inferior margin of the orbit and ZTF(IN )(V-ZTF(IN)), the horizontal distance between the lateral margin of the orbit and ZTF(IN) (H-ZTF(IN)), and the diameter of the ZTF(IN) (D-ZTF(IN)) were measured. The patterns of the ZTb inside the orbit were classified into five different groups: both ZTb and LN innervating the lacrimal gland independently (Group A), both ZTb and LN innervating the lacrimal gland with a communicating branch (Group B), ZTb joining the LN without a branch to the lacrimal gland (Group C), the ZTb going outside the orbit through ZTF(IN) without a branch to the lacrimal gland nor LN (Group D), and absence of the ZTb (Group E). The D-ZTF(IN) V-ZTF(IN) H-ZTF(IN) ranged from 0.2 to 1.1 mm, 6.6 to 21.5 mm, 2.0 to 11.3 mm, respectively. The number of sides in Groups A, B, C, D, and E were 13 sides (65%), three sides (15%), none (0%), two sides (10%), and two sides (10%), respectively. Such anatomical knowledge might reduce complications following surgery in and around the ZTb.