Goodwin, Patricia Mary; (2001) A three dimensional comparison of the facial morphology of unilateral cleft lip and palate patients with a control group. Doctoral thesis (Ph.D), UCL (University College London).

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Abstract

The quest to describe and quantify three-dimensional (3D) facial form has spanned many centuries, ancient Greek sculptors designed frames for recording facial shape in order to faithfully reproduce likenesses in stone, and also contemplated the aesthetic significance of various proportionate measures. Greek mathematicians and philosophers attempted to interpret beauty in terms of divine proportions (Huntley 1970). Historically, it has long been recognised that two-dimensional (2D) representations of human anatomy are limited. The human body is three-dimensional, and not comprised of regular geometric structures. It has no obvious internal reference system and there is no easy way of applying an external reference system, therefore the measurement of the body and its representation in 3D is not an easy task. The need for accurate measurement and representation of the face is particularly acute because of the vital importance of appearance, and this is especially so for those born with a craniofacial anomaly such as unilateral cleft lip and palate (UCLP) (Shaw 1988). The need to objectively quantify face shape in those born with facial anomalies such as UCLP is necessary, not just in terms of clinical audit, but to determine the best treatment regimes for good aesthetic outcome. This is a subject of debate within both the orthodontic and surgical community with many inter-centre studies being carried out (Shaw et al. 1992; MacKay et al. 1994, Roberts-Harry et al. 1996). A great deal of research on facial growth has been undertaken using, on the whole, 2D methods of data collection, such as lateral cephalometric radiographs and photography. The motivation for this work has arisen from the need to quantify objectively in 3D the differences in the facial soft tissue morphology between a group of children born with UCLP and an equivalent control group. This thesis studies the work of one surgeon and compares the facial morphology of those children born with UCLP with a normal population of the same age, sex and ethnic origin using a method of 3D analysis. Recent reports suggest the need to quantify surgical outcome of children born with UCLP and assess the aesthetic and functional effects of surgery (Shaw et al. 1992, Shaw et al. 1996, Williams et al 1996) If we want to characterise the shape of the face and its changes with growth the whole facial surface needs to be recorded in 3D. A finely sampled recording of the face in 3D is also required if the shape of the facial surface is to be determined and analysed. The hypothesis of this thesis is that there is no difference in the soft tissue facial morphology of UCLP patients who have been carefully operated on by one surgeon, compared with a control group. In order to test the hypothesis the facial soft tissue morphology of a control group and a group of children with UCLP were studied. There were a total of 73 children in the UCLP group and 245 in the control group. The control group and the UCLP group were divided by age and sex, so that differences in soft tissue facial morphology which occur at different ages could be investigated. The facial morphology of the female and male UCLP group were then compared with each other. The female and male cleft groups were also compared to the equivalent female and male control group. One surgeon operated on all the UCLP groups. The majority of the clefts being studied were left-sided, those with a right-sided cleft were mirror-imaged to make them left sided and were included in this study. The control groups were all Skeletal I (glossary) cases, with no history of orthodontic treatment or tooth extraction. The children in this study were all Caucasians (glossary) and the facial data were collected from our clinical centres in East and Central London. The data used in both the UCLP and control group is cross-sectional and were collected using the non-invasive, no contact system of 3D optical surface scanning developed at University College London (UCL), (Moss et al 1989). This method of data collection is ideally suited to measurement and comparison of soft tissues and also allows direct reference to equivalent control populations. The scanning of faces produces sufficient 3D co-ordinate measurements of the facial surface to allow the use of computer graphics to produce a photo-realistic image of the 3D surface, which may be, analysed and manipulated. All the facial datasets within each group were averaged to produce an average face for each group. Averaging all the individual facial data in this way permits comparison between the groups. The average facial scans were then registered, which provides an objective, quantitative comparison between each group. In order to quantify the changes, the nose and specific facial distances were also measured. Summary of Results Female cleft compared with male cleft: The noses of the male cleft group at ages 4-8 were longer and wider than that of the female cleft group of the same age. At age 9-12 the nose of the female group was longer and wider than that of the equivalent male group. At age 13-16 the female nose was still slightly longer than that of the equivalent male group. The chin was more prominent in the male cleft group at ages 4-8 and 13-16 years, whereas at age 9-12 the chin, cheeks and lips of the female cleft group were more prominent than those of the males. Female cleft compared with female control: The soft tissues of the female cleft groups were more retropositioned than the female control groups at all ages. The noses of the female clefts were flatter than those of the controls, alar base width was also greater in the female cleft groups. Male cleft compared with male control: The tip of the male cleft noses in all age groups was flatter than that of the controls, alar base width was variable within the groups. The cheeks and lips of the male cleft group at all ages were more retropositioned than the controls. The chin was more prominent at ages 4-8 and 9-12 but at age 13-16 it was the same as that of the equivalent control group. Conclusion There was a significant difference in the facial morphology of unilateral cleft lip and palate patients compared with controls at all ages.

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