Evaluation of Regio Temporalis in 3 Steps in Terms of Interventional Procedures

Abstract

Regio temporalis is a site where botulinum neurotoxin is applied for various medical reasons, such as migraine, bruxism, and myofascial pain syndrome. The region is also one of the target regions in flap surgery. This study aimed to define the region topographically. In addition, it was aimed to reveal the intramuscular nerve distribution of the temporalis.11 fixed cephalus (cadaver head) and 2 fresh cephalus were used. The lateral canthus of the eye was marked as point A, and the middle of the ear tragus as point B. The transverse and vertical distances of the branching point of the superficial temporal artery to the A and B points were measured. Transverse distances of the superficial temporal artery and superficial temporal vein to A and B points were measured. The muscle was examined in 5 equal parts (L0–L1–L2–L3–L4), and each part’s vertical muscle and tendon lengths were examined. Intramuscular nerve density was demonstrated by applying the modified Sihler staining to fresh temporalis’. Superficial temporal artery had an average transverse distance of 8.56±1.9 mm in women and 12.56±1.94 mm in men from the middle of the ear tragus. The artery was 64.21±5.59 mm posterior in females and 63.48±6.53 mm in males from the lateral canthus of the eye. Our study determined that the branching point of the superficial temporal artery was below the upper level of the arcus zygomaticus in 10% of cases and above it in 90% of cases. In our study, the L2 point had the highest vertical muscle length at 45.67 mm, while the L3 point had the highest vertical tendon length at 41.25 mm. The point where the muscle length had the highest ratio with 1.49 compared to the tendon length, was the L2 point. The temporalis’ for which the modified Sihler staining was applied was examined in 5 quadrants. It was determined that the nerve densities were in the second and third quadrants from anterior to posterior. The distance of superficial landmarks to neurovascular structures is extremely important in interventions to the regio temporalis. Considering the average distances given in our study is important in avoiding damage in surgical procedures and not injecting into vascular structures. The point where the muscle length had the highest ratio of 1.49 compared to the tendon length was the L2 point. The area in line with this point is the most suitable area for injection. The L2 point is also the most suitable area for injection as it has the highest muscle length. Since the nerve densities were observed in the modified Sihler staining applied temporalis’ 2 and 3 quadrants from anterior to posterior, botulinum neurotoxin injections to these areas will give more effective results.