Al-Omari,I.; Millett,D.T.; Ayoub,A.F. Methods of assessment of cleft-related facial deformity: a review. Cleft Palate.Craniofac.J., 2005, 42, 2, 145-156, United States

Clinical Assessment

Quantitative ancl qualitative means have been used. Severa! studies used anthropometry, which provicles a means of quantitative analysis of the extent of ab normal morphology ancl the clegree of clisproportion associatecl with the repaired cleft lip and palate (Lindsey and Farkas, 1972; Farkas et al., 1993; Lazarus et al., 199g). Farkas et al. ( 1993) established many anthropometric measurements of the cleft lip and nasal complex through direct lin·ar and propor tional measurements. These data were comparecl with similar assessments made in normal children of similar age. Friede et al. (1980), however, measured angular, linear, and surface mea surements using a plaster cast of the miclface of patients with unilateral cleft lip ancl palate. These elata were usecl to evaluate the results of different surgical techniques.

Assessment Using Two-Dimensional Media Only

Recently developments in digital photography and computerized image analysis have facilitated direct measurements from on-screen digital images (Becker et al., 1998; Gotfredsen et al., 1999). Becker et al. ( 1998) reported excellent intra- and interexaminer reproducibility when measurements of distances, angles, and areas, as well as subjective on-screen evaluation of surgical results in patients with cleft lip and palate, were made from digital photographs. The accuracy of on-screen im age analysis program measurements has yet to be determined. Furthermore, measurement errors were reported because of the magnification factor.

Assessment Using Three-Dimensional Media

Laser scanning has been employed recently in the analysis of the craniofacial area and provides quantitative three-dimen sional information on the facial surface. The system has proved reliable and accurate in the identification and measure ment of facial landmarks and dimension s (Moss et al., 1995; Foong et al., 1999; Duffy at al., 2000). Only two studies, how ever, used a three-dimensional scanner to evaluate the cleft related deformity (Table 3). Duffy et al. (2000) found this tech nique to be capable of disclosing and quantifying effectively the surface characteristics of the face of a child with a cleft.

Similar results were reported by Foong et al. (1999). In their study, a plaster cast of each infant with unilateral cleft lip and palate was scanned by a surface laser scanner; online inter active computer landmark localization permitted the assess ment of three-dimensional coordinates of each landmark. The laser-scanning technique was accurate to less than 0.06 mm in ali three (x, y, z) axes. The main disadvantage of the laser scanning technique is that it takes 10 seconds

for full-surface capture that may be difficult in maintaining cooperation in infants and young children.

Ras et al. (1994a, 1994b) used a three-dimensional orthogonal coordinate system to study asymmetry of the surface of the face in three dimensions in individuals with repaired com plete unilateral cleft lip and palate. A three-dimensional image of the face was reconstructed from two photographs taken with two semimetric cameras from a stereo pair. Three-dimensional coordinates of 26 landmarks were calculatecl and identified semiautomatically on the three-dimensional irnages.

Some currently available imaging systems may have poten-tial use in the analysis of the soft tissues in the craniofacial region such as moiré topography (Takasaki, 1970; Kawai et al., 1990), telecentric photography (Robertson, 1981), and three-dimensional morphoanalysis (Ferrario et al., l 997; Ras et al., 1994a, 1994b).

A computer-aided diagnostic system was developed by Yamada et al. (1998, 1999). Facial forms were measured with a three-dimensional optical scanner and three-dimensional co ordinates were obtained. A special program was developed to automatically extract the landmarks. The spatial accuracy of this system has been reported to be within 0.5 mm.

Stereophotogrammetry is based on the principie of photographing a three-dimensional object from two pairs of identical cameras separated by a known base distance. The result is a stereo pair of photographs of the face taken from two different positions at the same instant. The basis of ali methods of mea surement is the fusion of the two photo images to form a three dimensional model. Previous stereophotogrammetric systems suffered from many limitations in terms of the elaborate, sophisticated, and expensive machine (Burke and Beard, 1967). Three-dimensional facial analysis is now a possi bility with contemporary developments in modern stereophotogrammetry (Ayoub et al., 1996, 1998; Hajeer et al., 2002). This technique permits acquisition of a true representation of the human face without exposure to ionizing radiation.