An anatomical study on the position of the summit of the zygoma: Theoretical bases for reduction malarplasty

Background: To achieve optimal outcomes in reduction malarplasty, the area of zygoma from which volume should be reduced must be accurately identified. This anatomical study aims to evaluate the location of the zygoma region that contributes most to the protrusion of the cheek. MethodS: The morphology of the zygoma was studied on 121 Japanese adults (73 men and 48 women). The midpoint of the inferior orbital rim, zygomaticomaxillary junction, the junction between the frontal process and the zygomatic arch, and the lateral orbital rim were marked to be used as anatomical reference points. Then, a vertical plane intersecting the anterior and posterior edges of the zygoma was marked. The point of the zygoma most distant from the plane was defined as the summit of the zygoma. Three-dimensional measurement using graphic software was performed, and the positional relationships between the summit and the four reference points were evaluated. Results: In terms of horizontal position, the summit is located lateral to the lateral orbital rim and medial to the junction between the frontal process and the zygomatic arch. Regarding vertical position, the summit exists at higher positions in men than in women. Conclusions: The summit of the zygoma is located medial to the junction of the frontal process and zygomatic arch. Therefore, bone incision lines should be placed medial to the posterior edge of the frontal process in reduction malarplasty; effective correction of the protrusion cannot be achieved solely by detachment of the zygomatic arch. The summit is located higher for men than for women. Therefore, bone incision lines should be placed higher for men than for women.