Preliminary Analysis of the 3-Dimensional Morphology of the Upper Lip Configuration at the Completion of Facial Expressions in Healthy Japanese Young Adults and Patients With Cleft Lip

Three-Dimensional Dynamic Analysis of the Reproducibility of Verbal and Nonverbal Facial Expressions

OBJECTIVE

The aim of this study is to compare the short- and long-term reproducibility of verbal and nonverbal facial expressions of normal people using dynamic 3-dimensional (3-D) imaging.

DESIGN

Prospective, cross-sectional, controlled study.

SETTING

Peking University School and Hospital of Stomatology, Beijing, China.

PATIENTS AND PARTICIPANTS

Twenty-seven participants, 12 males and 15 females, were recruited for this study.

METHODS

A 3-D dynamic system was applied to capture the process of 4 nonverbal facial expressions (smile lips closed, smile lips open, lip purse, cheek puff) and 2 verbal facial expressions (/i:/, /u:/) at an initial time point, 15 minutes later, and 1 week later. Key frames were selected from each expression recording sequence.

MAIN OUTCOME MEASURES

The root mean square (RMS) between each key frame and its corresponding frame at rest was calculated. ΔRMS reflected the difference of the same key frames between the different sessions of the same expression of the same participant. The reproducibility of different facial expressions at different time intervals were analyzed.

RESULTS

There was no significant difference in verbal and nonverbal expression repeatability during a 15-minute interval, except for cheek puff motion. Following a 1-week interval, verbal expression repeatability was superior to that of nonverbal expressions (P < .01). Compared with nonverbal expressions, the repeatability of verbal expressions did not obviously decrease with the increase in recording interval.

CONCLUSIONS

Dynamic 3-D imaging is a useful technique for facial expression analysis. Verbal expressions showed greater reproducibility than nonverbal expressions.

Nasolabial shape and aesthetics in unilateral cleft lip and palate: an analysis of nasolabial shape using a mean 3D facial template

The aim of this study was to determine the amount of deviation in nasolabial shape in patients with a cleft compared with an average non-cleft face, and to assess whether this difference is related to nasolabial aesthetics. Three-dimensional stereophotogrammetric images of 60 patients with a unilateral cleft were used. To quantify shape differences, four average non-cleft faces were constructed from stereophotogrammetric images of 141 girls and 60 boys. Three-dimensional shape differences were calculated between superimposed cleft faces and the average non-cleft face for the same sex and age group. Nasolabial aesthetics were rated with the modified Asher-McDade Aesthetic Index using a visual analogue scale (VAS). Mean VAS scores ranged from 51.44 to 60.21 for clefts, with lower aesthetic ratings associated with increasing cleft severity. Shape differences were found between cleft faces and the average non-cleft face. No relationship was found for the VAS, age, and sex, except that a lower VAS was related to a higher nose and lip distance between the superimposed cleft and average non-cleft faces for nasal profile (P= 0.02), but the explained variance was low (R²=0.066). In conclusion, except for nasal profile, nasolabial aesthetics were not influenced by the extent of shape differences from the average non-cleft face.

The effect of resting morphological lip shape during lip movement: A three-dimensional motion analysis study

Purpose

The aim of this study was to determine the influence of different morphological lip shape during lip movement.

Method

A sample of 80 individuals with three-dimensional facial images at rest and during speech were recorded. Subjects were asked to pronounce four bilabial words in a relaxed manner and scanned using the 3dMDFace™ Dynamic System at 48 frames per second. Six lip landmarks were identified at rest and the landmark displacement vectors for the frame of maximal lip movement for all six visemes were recorded. Principal component analysis was applied to isolate relationship between lip traits and their registered coordinates. Eight specific resting morphological lip traits were identified for each individual. The principal component (PC) scores for each viseme were labelled by lip morphological trait and were graphically visualized as ellipses to discriminate any differences in lip movement.

Results

The first five PCs accounted for up to 95% of the total variance in lip shape during movement, with PC1 accounting for at least 38%. There was no clear discrimination between PC1, PC2 and PC3 for any of the resting morphological lip traits.

Conclusion

Lip shapes during movement are more uniform between individuals and resting morphological lip shape does not influence movement of the lips.

Volumetric comparison of maxillofacial soft tissue morphology: computed tomography in the supine position versus three-dimensional optical scanning in the sitting position

OBJECTIVE

Three-dimensional (3-D) surgical simulation has become popular, but the accuracy of such simulation is difficult to assess. Because maxillofacial soft tissue profiles vary with posture, we compared such profiles obtained in the supine and sitting positions.

STUDY DESIGN

In total, 28 patients with skeletal Class III jaw deformities underwent computed tomography in the supine position and 3-D optical scanning in the sitting position. The 2 sets of 3-D data were superimposed, and linear and volumetric differences were calculated. We evaluated the cheeks, the subauricular and infraorbital regions, the nose, the lips, and the chin. Statistical analyses were performed by using paired Student's t tests. Differences with P < .05 were considered significant.

RESULTS

Patients were divided into 3 groups based on body mass index. The facial profiles of the cheeks and subauricular areas differed significantly between the sitting and supine positions. The extent of variation increased with body mass index.

CONCLUSIONS

When a patient moves from the sitting position to the supine position, maxillofacial soft tissue migrates from the cheeks to the subauricular regions. Thus, simulations for surgery based on supine computed tomography alone do not accurately model the cheeks and subauricular areas.