Quantitative Measurement of Symmetry from Photographs following Surgery for Unilateral Cleft Lip and Palate

Abstract

A computer-based program is presented to be used with digitized frontal and basal photographs. SymNose enables the user to quantify asymmetry of the front view of the lip and nose and of the nose from the base view, using the area of mismatch of one side reflected over the other. There is a facility to transfer results to a spreadsheet. The program is simple and quick to use and runs on Apple Macintosh OSX 10.4 or later, power and Intel-based systems. The outline of a feature can be drawn using the mouse or digitizing pad. The program, together with Help files, is available from the authors.

The use of SymNose for quantitative assessment of lip symmetry following repair of complete bilateral cleft lip and palate

“…To account for these factors, a precise protocol was followed to standardise the images, and tracings were carried out twice by each assessor on separate days. The accuracy of SymNose has been documented previously (McKearney et al, 2012;Pigott and Pigott, 2010) with the latter authors producing high levels of intra-observer (r ¼ 0.76) and interobserver (r ¼ 0.67) reliability. Even higher values were found in this study, leading to the conclusion that one set of tracings would be adequate to achieve a high level of accuracy.…”

“…This challenges previous opinion that those with bilateral defects would be relatively symmetrical. Nose symmetry was found to differ little between both groups, although a basal view as used by Pigott and Pigott (2010) may provide more information in this area. One of the main concerns regarding use of SymNose is the inherent element of subjectivity involved.…”

“…The SymNose computer program designed by Pigott and Pigott (2010) utilises 2-D images to evaluate symmetry of both nose and lip. Until recently, computer-aided methods of measuring facial symmetry had focused mainly on the nose and nostrils (Coghlan et al, 1987;Yamada et al, 1999) without reference to the lip.…”

“…One of the main concerns regarding use of SymNose is the inherent element of subjectivity involved. The placement of roundels and subsequent tracing is dependent on the performance of the user as well as the quality of the image, which makes it, at best, a "semi-objective" process (Pigott and Pigott, 2010). To account for these factors, a precise protocol was followed to standardise the images, and tracings were carried out twice by each assessor on separate days.…”

“…A method of objective facial assessment was developed by Pigott and Pigott (2010) in the form of the SymNose computer program. The SymNose program uses two-dimensional (2-D) digital images of faces and requires the user to mark important anatomical landmarks including the medial canthi, nasal bridge, nose tip and middle upper lip.…”