Istemihan Coban1, Kaan Yucel2, Yelda Pinar3. 1. Department of Anatomy, Faculty of Medicine, Izmir Democracy University, Göztepe, Konak, Izmir, Turkey. istemihancoban@gmail.com. 2. Department of Anatomy, Faculty of Medicine, Izmir Democracy University, Göztepe, Konak, Izmir, Turkey. 3. Department of Anatomy, Faculty of Medicine, Ege University, Izmir, Turkey.
Abstract
PURPOSE: The masseteric nerve, which is a branch of the mandibular nerve, passes lateral to the mandibular notch and then spreads in the muscle to achieve motor innervation. The muscle entry points of these motor branches are the target points of minimally invasive interventions preferred in the treatment of masseter hypertrophy. The aim of this study was to reveal the areas where the motor entry points are concentrated in the muscle by dividing the muscle into topographic regions using reliable anatomic landmarks. METHODS: Bilateral 20 masseter muscles (40 in total) belonging to 20 formalin-fixed cadavers (10 female and 10 male) were examined. The distribution of the nerve in the muscle and its motor entry points were demonstrated and marked on the muscle surface. The masseter muscle was divided into six areas by lines passing through reliable anatomical landmarks (Areas 1-6). RESULTS: The total number of MEPs was 231.The mean distance of the MEPs from the Line-1 was 27.4 ± 11 mm, and the same distance from the Line-6 was 30.32 ± 7.2 mm. Most of the MEPs (123/231) were located in Area-4. Area-6 was the second (82/231) and Area-5 (19/231) was the third. CONCLUSION: We suggest that interventions in Area-4 (especially in the middle part) may have less complications as a result of less relationship with surrounding anatomical structures and more effective with high MEP number.
PURPOSE: The masseteric nerve, which is a branch of the mandibular nerve, passes lateral to the mandibular notch and then spreads in the muscle to achieve motor innervation. The muscle entry points of these motor branches are the target points of minimally invasive interventions preferred in the treatment of masseter hypertrophy. The aim of this study was to reveal the areas where the motor entry points are concentrated in the muscle by dividing the muscle into topographic regions using reliable anatomic landmarks. METHODS: Bilateral 20 masseter muscles (40 in total) belonging to 20 formalin-fixed cadavers (10 female and 10 male) were examined. The distribution of the nerve in the muscle and its motor entry points were demonstrated and marked on the muscle surface. The masseter muscle was divided into six areas by lines passing through reliable anatomical landmarks (Areas 1-6). RESULTS: The total number of MEPs was 231.The mean distance of the MEPs from the Line-1 was 27.4 ± 11 mm, and the same distance from the Line-6 was 30.32 ± 7.2 mm. Most of the MEPs (123/231) were located in Area-4. Area-6 was the second (82/231) and Area-5 (19/231) was the third. CONCLUSION: We suggest that interventions in Area-4 (especially in the middle part) may have less complications as a result of less relationship with surrounding anatomical structures and more effective with high MEP number.
Authors: Joe Iwanaga; Vishram Singh; Aiji Ohtsuka; Youngil Hwang; Hee-Jin Kim; Janusz Moryś; Kumar Satish Ravi; Domenico Ribatti; Paul A Trainor; José Ramón Sañudo; Nihal Apaydin; Gülgün Şengül; Kurt H Albertine; Jerzy A Walocha; Marios Loukas; Fabrice Duparc; Friedrich Paulsen; Mariano Del Sol; Philip Adds; Ahmed Hegazy; R Shane Tubbs Journal: Clin Anat Date: 2020-09-09 Impact factor: 2.414