Seth M. Weinberg

Anthropometric precision and accuracy of digital three-dimensional photogrammetry: comparing the Genex and 3dMD imaging systems with one another and with direct anthropometry.

A variety of commercially available three-dimensional (3D) surface imaging systems are currently in use by craniofacial specialists. Little is known, however, about how measurement data generated from alternative 3D systems compare, specifically in terms of accuracy and precision. The purpose of this study was to compare anthropometric measurements obtained by way of two different digital 3D photogrammetry systems (Genex and 3dMD) as well as direct anthropometry and to evaluate intraobserver precision across these three methods. On a sample of 18 mannequin heads, 12 linear distances were measured twice by each method. A two-factor repeated measures analysis of variance was used to test simultaneously for mean differences in precision across methods. Additional descriptive statistics (e.g., technical error of measurement [TEM]) were used to quantify measurement error magnitude. Statistically significant (P < 0.05) mean differences were observed across methods for nine anthropometric variables; however, the magnitude of these differences was consistently at the submillimeter level. No significant differences were noted for precision. Moreover, the magnitude of imprecision was determined to be very small, with TEM scores well under 1 mm, and intraclass correlation coefficients ranging from 0.98 to 1. Results indicate that overall mean differences across these three methods were small enough to be of little practical importance. In terms of intraobserver precision, all methods fared equally well. This study is the first attempt to simultaneously compare 3D surface imaging systems directly with one another and with traditional anthropometry. Results suggest that craniofacial surface data obtained by way of alternative 3D photogrammetric systems can be combined or compared statistically.

Digital three-dimensional photogrammetry: evaluation of anthropometric precision and accuracy using a Genex 3D camera system.

Objective To determine the precision and accuracy of facial anthropometric measurements obtained through digital three-dimensional (3D) photogrammetry. Design Nineteen standard craniofacial measurements were repeatedly obtained on 20 subjects by two independent observers, using calipers and 3D photos (obtained with a Genex 3D camera system), both with and without facial landmarks labeled. Four different precision estimates were then calculated and compared statistically across techniques. In addition, mean measurements from 3D photos were compared statistically with those from direct anthropometry. Results In terms of measurement precision, the 3D photos were clearly better than direct anthropometry. In almost all cases, the 3D photo with landmarks labeled had the highest overall precision. In addition, labeling landmarks prior to taking measurements improved precision, regardless of method. Good congruence was observed between means derived from the 3D photos and direct anthropometry. Statistically significant differences were noted for seven measurements; however, the magnitude of these differences was often clinically insignificant (< 2 mm). Conclusions Digital 3D photogrammetry with the Genex camera system is sufficiently precise and accurate for the anthropometric needs of most medical and craniofacial research designs.

Mutations in BMP4 Are Associated with Subepithelial, Microform, and Overt Cleft Lip

Cleft lip with or without cleft palate (CL/P) is a complex trait with evidence that the clinical spectrum includes both microform and subepithelial lip defects. We identified missense and nonsense mutations in the BMP4 gene in 1 of 30 cases of microform clefts, 2 of 87 cases with subepithelial defects in the orbicularis oris muscle (OOM), 5 of 968 cases of overt CL/P, and 0 of 529 controls. These results provide confirmation that microforms and subepithelial OOM defects are part of the spectrum of CL/P and should be considered during clinical evaluation of families with clefts. Furthermore, we suggest a role for BMP4 in wound healing.

3D digital stereophotogrammetry: a practical guide to facial image acquisition

The use of 3D surface imaging technology is becoming increasingly common in craniofacial clinics and research centers. Due to fast capture speeds and ease of use, 3D digital stereophotogrammetry is quickly becoming the preferred facial surface imaging modality. These systems can serve as an unparalleled tool for craniofacial surgeons, proving an objective digital archive of the patients face without exposure to radiation. Acquiring consistent high-quality 3D facial captures requires planning and knowledge of the limitations of these devices. Currently, there are few resources available to help new users of this technology with the challenges they will inevitably confront. To address this deficit, this report will highlight a number of common issues that can interfere with the 3D capture process and offer practical solutions to optimize image quality.

Face shape of unaffected parents with cleft affected offspring: combining three‐dimensional surface imaging and geometric morphometrics

OBJECTIVE Various lines of evidence suggest that face shape may be a predisposing factor for non-syndromic cleft lip with or without cleft palate (CL/P). In the present study, 3D surface imaging and statistical shape analysis were used to evaluate face shape differences between the unaffected (non-cleft) parents of individuals with CL / P and unrelated controls. METHODS Sixteen facial landmarks were collected from 3D captures of 80 unaffected parents and 80 matched controls. Prior to analysis, each unaffected parent was assigned to a subgroup on the basis of prior family history (positive or negative). A geometric morphometric approach was utilized to scale and superimpose the landmark coordinate data (Procrustes analysis), test for omnibus group differences in face shape, and uncover specific modes of shape variation capable of discriminating unaffected parents from controls. RESULTS Significant disparity in face shape was observed between unaffected parents and controls (p < 0.01). Notably, these changes were specific to parents with a positive family history of CL/P. Shape changes associated with CL/P predisposition included marked flattening of the facial profile (midface retrusion), reduced upper facial height, increased lower facial height, and excess interorbital width. Additionally, a sex-specific pattern of parent-control difference was evident in the transverse dimensions of the nasolabial complex. CONCLUSIONS The faces of unaffected parents from multiplex cleft families displayed meaningful shape differences compared with the general population. Quantitative assessment of the facial phenotype in cleft families may enhance efforts to discover the root causes of CL/P.

Three-dimensional Surface Imaging: Limitations and Considerations From the Anthropometric Perspective

The use of three-dimensional (3D) surface imaging for clinical measurement purposes has increased considerably as the technology has become more affordable. Like any measurement technique, 3D surface-based anthropometry is subject to a number of limitations and methodological caveats and thus should not be applied without sufficient consideration of its potential strengths and weaknesses. In this brief report, the authors consider 3D surface imaging from the anthropometric perspective, specifically focusing on issues related to the capture of reliable quantitative information from the head and face.

The FaceBase Consortium: a comprehensive program to facilitate craniofacial research.

The FaceBase Consortium consists of ten interlinked research and technology projects whose goal is to generate craniofacial research data and technology for use by the research community through a central data management and integrated bioinformatics hub. Funded by the National Institute of Dental and Craniofacial Research (NIDCR) and currently focused on studying the development of the middle region of the face, the Consortium will produce comprehensive datasets of global gene expression patterns, regulatory elements and sequencing; will generate anatomical and molecular atlases; will provide human normative facial data and other phenotypes; conduct follow up studies of a completed genome-wide association study; generate independent data on the genetics of craniofacial development, build repositories of animal models and of human samples and data for community access and analysis; and will develop software tools and animal models for analyzing and functionally testing and integrating these data. The FaceBase website (http://www.facebase.org) will serve as a web home for these efforts, providing interactive tools for exploring these datasets, together with discussion forums and other services to support and foster collaboration within the craniofacial research community.

Orbicularis oris muscle defects as an expanded phenotypic feature in nonsyndromic cleft lip with or without cleft palate

Nonsyndromic cleft lip ± cleft palate is a complex disease with a wide phenotypic spectrum; occult defects of the superior orbicularis oris muscle may represent the mildest subclinical form of the lip portion of the phenotype. This study used high‐resolution ultrasonography to compare the frequency of discontinuities in the OO muscle in 525 unaffected relatives of individuals with nonsyndromic cleft lip  ±  cleft palate versus 257 unaffected controls. OO muscle discontinuities were observed in 54 (10.3%) of the non‐cleft relatives, compared to 15 (5.8%) of the controls—a statistically significant increase (P = 0.04). Male relatives had a significantly higher rate of discontinuities than male controls (12.0% vs. 3.2%; P = 0.01); female relatives also had a higher rate of discontinuities than female controls, but the increase was not statistically significant (8.9% vs. 7.4%; P = 0.56). These data confirm the hypothesis that subepithelial OO muscle defects are a mild manifestation of the cleft lip phenotype. Identification of subepithelial OO muscle defects may be important in a clinical setting, as a means of providing more accurate recurrence risk estimates to relatives in cleft families. Furthermore, the expansion of the cleft lip  ±  cleft palate phenotypic spectrum should improve the power of genetic studies.

Facial Phenotype in Children and Young Adults with PHOX2B-Determined Congenital Central Hypoventilation Syndrome: Quantitative Pattern of Dysmorphology

Congenital central hypoventilation syndrome (CCHS) is caused by mutations in PHOX2B, which is essential for maturation of the neural crest into the autonomic nervous system and is expressed in the dorsal rhombencephalon, a region that gives rise to facial structures. Digital photographs of 45 individuals with PHOX2B-confirmed CCHS, and 45 matched controls were analyzed for 17 linear and 6 angular measurements, and 9 derived indices. Paired t tests were used to compare group means, correlation was calculated between PHOX2B polyalanine expansion number and facial measures, and stepwise logistic regression was used to predict case-control and genotype status. CCHS cases differed significantly from controls on 13 variables (6 after p value correction: nasolabial angle, upper lip height, lateral lip height, facial index, upper facial index, and presence of inferior inflection of the lateral segment of the upper lip vermillion border). Five variables were able to predict correctly 85.7% of CCHS cases and 82.2% of controls: upper lip height, biocular width, upper facial height, nasal tip protrusion, and inferior inflection of the upper lip vermillion border. A negative relationship between number of repeats and four anthropometric measures was observed: mandible breadth, nasolabial angle, lateral lip height, and mandible-face width index. These results suggest a characteristic facial phenotype in children and young adults with CCHS, due to an expansion mutation in PHOX2B.

Rethinking isolated cleft palate: Evidence of occult lip defects in a subset of cases†

Emerging research suggests that subepithelial defects of the upper lip musculature are part of the phenotypic spectrum of cleft lip and/or palate (CL/P) and may represent an occult, subclinical manifestation of the anomaly. The present study investigates whether similar occult lip defects are present in individuals affected with isolated cleft palate (CP). To this end, upper lip ultrasounds of 33 CP cases (12 males, 21 females) were evaluated retrospectively for the presence of discontinuities (i.e., breaks) within the orbicularis oris muscle (OOM). In four CP cases (2 males, 2 females), distinct discontinuities of the OOM were identified. Of the remaining CP individuals, 23 demonstrated normal lip morphology on ultrasound (7 males, 16 females), while, in 6 cases (3 males, 3 females), a definitive evaluation was not possible. As CP and CL/P are traditionally thought to be etiologically distinct, these findings raise the possibility that some CP cases may be misclassified. Such diagnostic errors could have important implications for recurrence risk estimation and studies aimed at discovering etiology.