Carroll-Ann Trotman

Sexual dimorphism in normal craniofacial growth.

The purpose of this investigation is to re-evaluate an existing sample of Caucasian individuals, of mostly Northern European ancestry and undefined ethnic origins, who have been characterized as having excellent occlusions and balanced facial proportions (from a subjective assessment). The focus is the emergence of sexual dimorphism in the skeletal and dental relationships. Serial lateral cephalograms of 51 subjects were obtained from the Bolton-Brush Study at ages 6, 9, 12, 14, 16 and 18 yrs. At each age, the records of 16 males and 16 females were selected. Cephalometric evaluation indicated that the length of the anterior cranial base was larger in males but the cranial base angle was similar for both sexes at all age intervals studied. The effective lengths of the maxilla and mandible were similar in both sexes up to 14 years; thereafter in females this length remained relatively constant while in males it increased. The direction of facial growth was similar for both sexes, with a tendency towards a more horizontal growth pattern in females.

Three Dimensional Analysis of Facial Movement in Normal Adults: Influence of Sex and Facial Shape

The aim of this study was to quantify facial movements in a sample of normal adults and to investigate the influence of sex and facial shape on these movements. The study sample consisted of 50 healthy adult subjects, 25 males and 25 females (age: mean = 27.3 years; range = 23-39 years). A video-based tracking system was used to track small-diameter retroreflective markers positioned at specific facial sites. Subjects were instructed to make 7 maximum facial animations from rest, and the facial movements for each animation were characterized as the vectors of maximum displacement. Hotellings T2 was used to test for significant sex differences in facial movements. In order to determine the effects of facial shape on facial movements, an index of facial shape was first calculated for each subject, and then a mixed-model ANOVA was used with facial shape (index), sex, and the interaction between facial shape and sex as fixed effects and subject as a random effect. The results demonstrated specific movement patterns for each animation. In general, males had larger movements than females and facial shape had a small but significant effect on facial movements. By comparing patient movements with the data from this large normative sample, the utility of this method to assess region-specific movement deficits was demonstrated.

A comparison of three-dimensional and two-dimensional analyses of facial motion

The purpose of this study was to compare the amplitude of facial motion obtained using three-dimensional (3-D) and two-dimensional (2-D) methods. The amplitude of motion of fifteen facial landmarks during five maximal animations (smile, lip-purse, grimace, eye closure, and cheek-puff) was quantified in 3-D and 2-D using a video-based system. Results showed that the 3-D amplitudes were significantly larger than the 2-D amplitudes, especially for landmarks on the lower face during the smile animation. In the latter instance, the 2-D amplitudes underestimated the 3-D amplitudes by as much as 43%. The difference between 3-D and 2-D amplitudes was greater for 2-D amplitudes obtained from one camera rather than from multiple cameras. The results suggest that a 2-D analysis may not be adequate to assess facial motion during maximal animations, and that a 3-D analysis may be more appropriate for detecting clinical differences in facial function.

Measurement of facial soft tissue mobility in man

OBJECTIVE The assessment of facial mobility is a key element in the treatment of patients with facial motor deficits. In this study, we explored the utility of a three-dimensional tracking system in the measurement of facial movements. METHODS AND RESULTS First, the three-dimensional movement of potentially stable facial soft-tissue, headcap, and dental landmarks was measured with respect to a fixed space frame. Based on the assumption that the dental landmarks are stable, their motion during a series of standardized facial animations was subtracted from that of the facial and headcap landmarks to estimate their movement within the face. This residual movement was used to determine which points are relatively stable (< or = 1.5 mm of movement) and which are not (> or = 1.5 mm of movement). Headcap landmarks were found to be suitable as references during smile, cheek puff, and lip purse animations, and during talking. In contrast, skin-based landmarks were unsuitable as references because of their considerable and highly variable movement during facial animation. Second, the facial movements of patients with obvious facial deformities were compared with those of matched controls to characterize the face validity of three-dimensional tracking. In all instances, pictures that appear to be characteristic of the various functional deficits emerged. CONCLUSIONS Our results argue that tracking instrumentation is a potentially useful tool in the measurement of facial mobility.

Three-dimensional nasolabial displacement during movement in repaired cleft lip and palate patients

The objective of this study was two‐fold: (1) to explore the suitability of a novel modified Procrustes fit method to adjust data for head motion during instructed facial movements, and (2) to compare the adjusted data among repaired unilateral (n = 4) and bilateral (n = 5) cleft lip and palate patients and noncleft control subjects (n = 50). Using a video‐based tracking system, three‐dimensional displacement of 14 well‐defined nasolabial landmarks was measured during four set facial animations without controlling for head motion. The modified Procrustes fit method eliminated the contributions of head motion by matching the most stable landmarks of each video‐recorded frame of the face during function to frames at rest. Its effectiveness was found to approximate that of a previous method (i.e., use of a maxillary occlusal splint to which stable dentition‐based markers were attached). Data from both the unilateral and bilateral cleft lip and palate patients fell outside the normal range of maximum displacements and of asymmetry, and individual patients demonstrated greater right‐versus‐left asymmetry in maximum displacement than did individual noncleft subjects. It is concluded that the modified Procrustes fit method is fast, is easy to apply, and allows subjects to move the head naturally without the inconvenience of a splint while facial movement data are being collected. Results obtained using this method support the view that facial movements in cleft patients may be severely hampered and that assessment of facial animation should be strongly considered when contemplating surgical lip revisions. (Plast. Reconstr. Surg. 105: 1273, 2000.)

Sensitivity of a Method for the Analysis of Facial Mobility. I. Vector of Displacement

OBJECTIVE (1) To determine which facial landmarks show the greatest movement during specific facial animations and (2) to determine the sensitivity of our instrument in using these landmarks to detect putatively abnormal facial movements. DESIGN Movements of an array of skin-based landmarks on five healthy human subjects (2 men and 3 women; mean age, 27.6 years; range, 26 to 29 years) were observed during the execution of specific facial animations. To investigate the instrument sensitivity, we analyzed facial movements during maximal smile animations in six patients with different types of functional problems. In parallel, a panel was asked to view video recordings of the patients and to rate the degree of motor impairment. Comparisons were made between the panel scores and those of the measurement instrument. RESULTS Specific regions of the face display movement that is representative of specific animations. During the smile animation, landmarks on the mid- and lower facial regions demonstrated the greatest movement. A similar pattern of movement was seen during the cheek puff animation, except that the infraorbital and chin regions demonstrated minimal movement. For the grimace and eye closure animations, the upper, mid-facial, and upper-lip regions exhibited the greatest movement. During eye opening, the upper and mid-facial regions, excluding the upper lip and cheek, moved the most, and during lip purse, markers on the mid- and lower face demonstrated the most movement. We used the smile-sensitive landmarks to evaluate individuals with functional impairment and found good agreement between instrument rankings based on the data from these landmarks and the panel rankings. CONCLUSION The present method of three-dimensional tracking has the potential to detect and characterize a range of clinically significant functional deficits.

Maxillary Growth in Patients with Clefts Following Secondary Alveolar Bone Grafting

OBJECTIVE This investigation evaluated the effects of secondary alveolar bone grafting on subsequent maxillary growth in cleft patients. DESIGN This was a retrospective longitudinal cephalometric study. Nineteen patients who had received secondary alveolar bone grafts were matched to a control sample by sex, cleft, availability of longitudinal records, and presurgical cranial base dimensions and growth direction. All patients had at least two lateral cephalometric radiographs before surgery and two radiographs after surgery. SETTING The records were obtained from the Longitudinal Growth Study of the Lancaster (Pennsylvania) Cleft Palate Clinic. INTERVENTIONS All patients had received similar primary surgical procedures by the same surgeon, no orthopedics, and similar mixed-dentition orthodontics. Secondary alveolar bone grafting was the only surgical intervention different between the two groups. MAIN OUTCOME MEASURES Six measures of maxillary sagittal and vertical growth were taken from 235 radiographs. Slopes of the regression lines for each growth dimension were compared between groups both pre- and postsurgically. RESULTS There were no significant between-group differences in maxillary sagittal or vertical growth following the grafting procedure. Anterior maxillary vertical growth rates decreased in the grafted group when their pre- and postsurgical rates were compared. Several growth trends in the postsurgical period were found to be continuations of the rates documented presurgically and unrelated to the grafting procedure. CONCLUSIONS When evaluated longitudinally, maxillary growth in patients having received secondary alveolar bone grafting did not differ from a group of matched controls.

Functional Outcomes of Cleft Lip Surgery. Part I: Study Design and Surgeon Ratings of Lip Disability and Need for Lip Revision

Objective: Children with a cleft of the upper lip exhibit obvious facial disfigurement. Many require multiple lip surgeries for an optimal esthetic result. However, because the decision for lip revision is based on subjective clinical criteria, clinicians may disagree on whether these surgeries should be performed. To establish more reliable, functionally relevant outcome criteria for evaluation and treatment planning, a clinical trial currently is in progress. In this article, the design of the clinical trial is described and results of a study on subjective evaluations of facial form by surgeons for or against the need for lip revision surgery are presented. Design: Parallel, three-group, nonrandomized clinical trial and subjective evaluations/ratings of facial views by surgeons. Subjects: For the clinical trial, children with repaired cleft lip and palate scheduled for a secondary lip revision, children with repaired cleft lip and palate who did not have lip revision, and noncleft children. For the subjective evaluations, surgeons’ facial ratings of 21 children with repaired cleft lip. Analysis: Descriptive and Kappa statistics assessing the concordance of surgeons’ ratings of (a) repeated facial views and (b) a recommendation of revision on viewing the prerevision and postrevision views. Results: The surgeons’ consistency in rating repeated views was moderate to excellent; however, agreement among the surgeons when rating individual participants was low to moderate. Conclusions: The findings suggest that the agreement among surgeons was poor and support the need for more objective measures to assess the need for revision surgery.

Visual and statistical modeling of facial movement in patients with cleft lip and palate

Objective To analyze and display facial movement data from noncleft subjects and from patients with cleft lip and palate by using a new dynamic approach. The hypothesis was that there are differences in facial movement between the patients with cleft lip and palate and the noncleft subjects. Setting Subjects were recruited from the University of North Carolina School of Dentistry Orthodontic and Craniofacial Clinics. Patients, Participants Sixteen patients with cleft lip and palate and eight noncleft “control” subjects. Interventions Video recordings and measurements in three dimensions of facial movement. Main Outcome Measures Principal component (PC) scores for each of six animations or movements and dynamic modeling of mean animations. Statistics Multivariate statistics were used to test for significant differences in the PC mean scores between the patient groups and the noncleft groups. Results No statistically significant differences were found in PC mean scores between the patient groups and the noncleft groups; however, the variability of the effect of clefting on the soft tissues during animation was noted when the noncleft data were used to establish a “normal” scale of movement. Compensatory movements were seen in some of the patients with cleft lip and palate, and the compensation was not unidirectional. Conclusion Measures of mean movement differences as summarized by PC scores between patients with cleft lip and palate and noncleft subjects may be misleading because of extreme variations about the mean in the patient group that may neutralize group differences. It may be more appropriate to compare patients to a noncleft normal scale of movement.

Comparison of facial form in primary alveolar bone-grafted and nongrafted unilateral cleft lip and palate patients: intercenter retrospective study.

The purpose of this study was to describe and compare posttreatment craniofacial morphology in samples of complete unilateral cleft lip and palate (CUCLP) patients treated at two leading clinics: The Childrens Memorial Hospital Cleft Palate Clinic, Chicago, Illinois, and the Lancaster Cleft Palate Clinic, Lancaster, Pennsylvania. These centers have well-defined treatment protocols that allow the long-term effects on craniofacial form of the following treatment regimes to be contrasted: (1) Chicago--primary alveolar bone grafting, with definitive lip repair at age 4 to 6 months and hard and soft palate repair at 6 to 12 months; and (2) Lancaster--definitive triangular-flap lip repair at 3 months of age, followed by staged surgeries of the hard and soft palates, both completed by 18 months of age, but without primary alveolar bone grafting. Although the Lancaster center now performs secondary alveolar bone grafting, the majority of the patients studied here were treated before this procedure became part of their protocol. Patients were eligible for inclusion if they had no other congenital anomalies and no previous orthodontic treatment. A sample of 43 (24 male, 19 female) CUCLP patients was obtained from the Chicago Center, each of which was then matched to a nongrafted Lancaster CUCLP patient. The matching criteria were age, sex, and sella-nasion distance (to control, at least in part, for size differences). Lateral cephalometric radiographs of these 86 CUCLP patients were traced, digitized, and analyzed. Additionally, all linear data were adjusted to a standard magnification of 8% because the cephalograms from each center featured different enlargements. The Chicago and Lancaster samples had mean posttreatment ages of 10.32 years (SD = 1.96) and 10.40 years (SD = 2.18), respectively. The grafted Chicago group had faces that were on average less maxillary protrusive compared with the nongrafted Lancaster sample; it appeared, however, that the mandible compensated for the maxillary position by downward and backward rotation. As a result, a similar maxillomandibular relationship was noted in both groups, although, in the Chicago group, the lower anterior facial height increased.