The Average Facial Expressions: A Range of Motion Analysis for Different Sex and Age Groups.

Facial expressions are ubiquitous in communication. Therefore, assessment of mimic function is essential in facial surgery, but no reference standards are currently available. This prospective study aims to create reference values of three-dimensional landmark displacement for different sex and age groups. Methods: Three-dimensional photographs were taken from healthy subjects in rest, maximum closed smile, and pouting. Displacement for both exercises of perioral landmarks was analyzed with MATLAB as absolute displacement and as the ratio of mouth width. Additionally, displacement in three planes was analyzed for each landmark. Averages were calculated for both genders in four age groups: 4-8, 8-12, 12-16, and >16 years. Results: In total, 328 subjects were included. Oral landmarks predominantly moved forward and backward for both exercises. Nasal landmarks predominantly moved vertically. Growing up, oral landmark displacement decreased for smiling, whereas nasal landmark displacement increased. For pouting, oral landmark displacement increased while growing up, whereas nasal landmark displacement decreased. Conclusions: The present study creates reference values for movement of perioral structures for different sex and age groups, for two facial expressions. These data are of great value for the assessment of mimic function and give insight into the development of facial animation over time.

Identification of the Peri-oral Mimic Muscles on Cadaver Slices and 3 and 7 Tesla MRI Scans.

Decreased smile dynamics is reported as an unwanted side effect after Le Fort I osteotomies. It is assumed that this negative sequela might be caused by postoperative changes in the anatomy of peri-oral mimic muscles. Due to a lack of specific anatomical knowledge, the exact mechanism is not yet clarified. This makes prevention of the undesired changes in smile dynamics difficult. The first aim of this study is to increase basic anatomical and radiological MRI knowledge of the peri-oral mimic muscles. The second aim is to investigate if 7 Tesla MRI scans are better suited to identify these muscles than 3 Tesla MRI scans. METHODS: Eleven peri-oral mimic muscles were chosen as subjects of the present study. Three and 7 Tesla MRI scans of a cadaver head were made. The same head was cut in axial slices using a cryomacrotome. Every second slice was digitally photographed. A three-dimensional model was created utilizing EMAC software, which served as gold standard for the identification and comparison of the chosen peri-oral mimic muscles on both MRI scans. RESULTS: All predetermined peri-oral mimic muscles could be identified in the cadaver head, and a detailed radiological atlas was created. The ease of identification and separation of the peri-oral mimic muscles was significantly higher on the 7 Tesla MRI than on the 3 Tesla MRI scan (P < 0.001). CONCLUSION: A 7 Tesla MRI scanner offers great improvement in the identification of peri-oral mimic muscles compared with a 3 Tesla scanner.

Finding the Ledge: Sagittal Analysis of Bony Landmarks of the Orbit.

PURPOSE: This study determined the average distances and angles between anatomic landmarks within the orbit, with an emphasis on localization of the orbital process of the palatine bone. This information will help the surgeon with treatment planning and surgical procedures. PATIENTS AND METHODS: Four anatomic landmarks were identified retrospectively on computed tomograms of 100 adult Caucasian patients (50 men and 50 women): the top of the infraorbital margin superior to the infraorbital foramen (point A), the top of the orbital process of the palatine bone (point B), the anteriormost bony portion of the superior orbital fissure (point C), and the ventrolateral aspect of the bony entrance of the optic canal (point D). The distances between these points were measured, as were the angle between the medial wall of the orbit and a line connecting points A to D at the level of the optic nerve. RESULTS: The mean distances between the orbital rim (point A) and the orbital process of the palatine bone (point B) were 33.8 mm in men and 32.7 mm in women. Men had markedly larger bony orbits than women; however, women had a larger angle than men for the 2 orbits. CONCLUSION: Obtaining these measurements preoperatively can enable a safer and more predictable surgical approach to the orbit, which can help lower the risk of damaging important neighboring structures. A preformed reconstruction plate can be manufactured or a standard reconstruction plate can be customized according to these measurements; during reconstruction, they also can help adequately localize the posterior ledge, specifically the orbital process of the palatine bone. These 2 aspects could ensure a more precise reconstruction of the orbital floor.

A prospective study on the effect of modified alar cinch sutures and V-Y closure versus simple closing sutures on nasolabial changes after Le Fort I intrusion and advancement osteotomies.

PURPOSE: The purpose of this study was to determine whether a modified alar cinch suture and V-Y closure (mACVY) have a beneficial effect on labial form after Le Fort I intrusion and advancement osteotomies and whether they result in excessive upward nasal tip rotation. Both are possible effects compared with simple closing sutures (SCS). PATIENTS AND METHODS: A prospective study was carried out on 56 patients, 31 with mACVY and 25 with SCS. Lateral cephalograms taken immediately before and 18 months after operation were used, measuring horizontal and vertical changes of the following landmarks: anterior and posterior nasal spine, A-point, incision superior, pronasale, subnasale, labiale superior, and stomion superior, as well as angular changes of sella-nasion-pronasale, and changes in upper vermilion exposure. Statistical analysis was performed on intragroup, paired t test, and intergroup differences, unpaired t test (P < .05). RESULTS: The horizontal and vertical changes of labiale superior were significantly larger for mACVY versus SCS, and the angle sella-nasion-pronasale increased in mACVY versus SCS. However, no significant difference was found for vertical changes of the nasal tip. Upper vermilion exposure increased with mACVY versus SCS. CONCLUSION: mACVY has a beneficial effect on labial form, and excessive upward rotation of the nasal tip is prevented.