Three-dimensional Morphological Analysis of the Upper Lip Configuration During Facial Expressions
The desired outcome of a cleft lip surgery includes a symmetrical lip and nose and a surgical wound with limited scarring. Recently, an improvement has been observed in the outcomes of cleft lip surgery. The number of cases with good symmetrical forms has also increased. However, in certain cases, the irregularity of the upper lip form is visible while smiling or during upper lip protrusion. Therefore, a three-dimensional (3D) morphological analysis of the upper lip form is required during different facial expressions. In this study, two 3D scanners capable of consecutive image taking were used for three-dimensional analyses of upper lip configurations during facial expression in 20 healthy subjects. The configuration observed in healthy people was then compared to that of patients with a unilateral cleft lip after surgery.
Materials and Methods
This study included 20 healthy subjects (10 women and 10 men) and one with a cleft lip who underwent secondary correction of the lip in our department.
3D measurements were carried out from two different vertical directions using two 3D scanners capable of shooting 15 consecutive frames per second. The scanned images were then analyzed using 3D-Rugle V®software.
Images obtained at rest as well as two facial expressions images (smile and protrusion) were superimposed at the T-zone area (from the forehead to the nasal root). We used texture and normal vector images to reveal the orbicularis oris muscle of the upper lip and analyzed the upper lip form in facial expressions after setting up 32 points on the upper lip. The cross-section form at the central part of the upper lip was then analyzed. Finally, we compared the upper lip configuration between healthy subjects and patients with a unilateral cleft lip.
Results
The T-zone area overlapping within ±0.25 mm was found to be 63.1 ± 23.4% during smiling and 74.4 ± 23.8% at lip protrusion. Some of the set points in the upper lip moved to a posterosuperior position during smiling and to a forward position at lip protrusion. The movements observed were symmetrical. The cleft form was asymmetrical in the patient with the cleft lip as compared to healthy subjects.
Conclusions
The findings of this study indicate that it is possible to use 3D analysis for evaluation of upper lip forms during formation of facial expressions.
References
1.Trotman.C-A, J.J. Faraway, C. Phillips and J. van Aalst. Effects of Lip Revision Surgery in Cleft Lip/Palate Patients. J DENT RES. 2010;89(7):728-732
2. K Mishima, T Yamada, A Sugii, T Matsumura and T Sugahara. Production of a range image for facial motion analysis: A method for analyzing lip motion. Computerized Medical Imaging and Graphics. 2006;30:53–59