Juvenile Facial Growth and Mimicry: A Preliminary 3D Study.

Studies focused on facial development during childhood have been conducted by means of 3D technology to provide modifications of anthropometric parameters. Facial mobility was also considered. This study proposed a 3D approach to facial growth changes. Facial surface data of 6 subjects were acquired in T1 (age 7-14 years) and after 7 years (T2), in rest position, and during voluntary movements, by a 3D laser scanner. Linear and angular measurements on rest position scans at T1 and T2 were compared. Each mimic scan was superimposed with the corresponding rest scan. Displacement of significant anthropometric points was measured for each facial gesture and at T1 and T2 statistically compared. Vertical measurements were those most influenced by aging. Some measurements of central facial area were consistent over time. The pattern of soft tissues displacement for each expression was consistent in T1 and T2. These results may be helpful for missing children identification.

Facial Mobility after Maxilla-Mandibular Advancement in Patients with Severe Obstructive Sleep Apnea Syndrome: A Three-Dimensional Study.

Introduction. The functional results of surgery in terms of facial mobility are key elements in the treatment of patients. Little is actually known about changes in facial mobility following surgical treatment with maxillomandibular advancement (MMA). Objectives. The three-dimensional (3D) methods study of basic facial movements in typical OSAS patients treated with MMA was the topic of the present research. Materials and Methods. Ten patients affected by severe obstructive sleep apnea syndrome (OSAS) were engaged for the study. Their facial surface data was acquired using a 3D laser scanner one week before (T1) and 12 months after (T2) orthognathic surgery. The facial movements were frowning, grimace, smiling, and lip purse. They were described in terms of surface and landmark displacements (mm). The mean landmark displacement was calculated for right and left sides of the face, at T1 and at T2. Results. One year after surgery, facial movements were similar to presurgical registrations. No modifications of symmetry were present. Conclusions. Despite the skeletal maxilla-mandible expansion, orthognathic surgical treatment (MMA) of OSAS patients does not seem to modify facial mobility. Only an enhancement of amplitude in smiling and knitting brows was observed. These results could have reliable medical and surgical applications.

Quantification of facial movements by optical instruments: surface laser scanning and optoelectronic three-dimensional motion analyzer.

The objective of this study was to assess the accuracy of displacements of tracing landmarks in standardized facial movements. Forty healthy persons were evaluated in 2 different groups (20 men and 20 women, aged 18-30 years) with optoelectronic motion analyzer and surface laser scanning. The displacements of tracing landmarks in brow lift and smile were calculated, and the 2 methods (optoelectronic motion analyzer and surface laser scanning) were compared in healthy persons. Side-related differences were found in the tracing landmark (superciliare) during brow lift movements between both methods (the largest movements were found on the right side, P = 0.044), whereas in smile movements the tracing landmark cheilion did not show significant differences between the 2 sides. In both movements, the differences of the tracing landmark displacements between the 2 systems and sexes were on average less than 2 mm, without statistically significant differences (P > 0.05). In conclusion, normal young adult men and women had similar standardized facial movements. The 2 analyzed movements can be measured by both optical instruments with comparable results.

Facial mobility after bimaxillary surgery in class III patients: a three-dimensional study.

Quantifying soft tissue changes after orthognathic surgery is increasingly important in surgical planning, but little is actually known about the changes in facial mobility after surgery. In the current study, we investigated facial mimics in patients before and after orthognathic surgery. Eleven patients with jaw discrepancy requiring maxillary and/or mandibular surgery were considered. Facial landmarks were applied, and facial surface data were acquired using a three-dimensional laser scanner before surgery and after 3, 6, and 12 months. The facial movements were frowning, eye closure, grimace, smiling, and lip purse. They were described in terms of surface and landmark displacements. Mean and SD were calculated for the right and left sides of the face and compared with normal values previously obtained in control subjects. We compared the results in 4 groups of patients: all the patients together (group A), bimaxillary surgery (group B), basal surgery without ancillary procedures (group C), and basal surgery plus rhinoplasty and/or genioplasty (group D). After surgery, modifications of symmetry were evident in many subjects, but after 1 year, facial movements were statistically similar to presurgical registrations. In smiling, the single case observations revealed a postsurgical improvement of amplitude in 8 subjects. In conclusion, orthognathic surgery did not significantly modify facial mobility in the long term. On the contrary, the amplitude of movement during smiling seems to increase in the majority of subjects. Our evaluation of three-dimensional laser scanning of facial movement showed that it can detect small posttreatment changes on soft tissues.