A Reliable Method to Measure Lip Height Using Photogrammetry in Unilateral Cleft Lip Patients

There is still no reliable tool to determine the outcome of the repaired unilateral cleft lip (UCL). The aim of this study was therefore to develop an accurate, reliable tool to measure vertical lip height from photographs. The authors measured the vertical height of the cutaneous and vermilion parts of the lip in 72 anterior-posterior view photographs of 17 patients with repairs to a UCL. Points on the lip's white roll and vermillion were marked on both the cleft and the noncleft sides on each image. Two new concepts were tested. First, photographs were standardized using the horizontal (medial to lateral) eye fissure width (EFW) for calibration. Second, the authors tested the interpupillary line (IPL) and the alar base line (ABL) for their reliability as horizontal lines of reference. Measurements were taken by 2 independent researchers, at 2 different time points each. Overall 2304 data points were obtained and analyzed. Results showed that the method was very effective in measuring the height of the lip on the cleft side with the noncleft side. When using the IPL, inter- and intra-rater reliability was 0.99 to 1.0, with the ABL it varied from 0.91 to 0.99 with one exception at 0.84. The IPL was easier to define because in some subjects the overhanging nasal tip obscured the alar base and gave more consistent measurements possibly because the reconstructed alar base was sometimes indistinct. However, measurements from the IPL can only give the percentage difference between the left and right sides of the lip, whereas those from the ABL can also give exact measurements. Patient examples were given that show how the measurements correlate with clinical assessment. The authors propose this method of photogrammetry with the innovative use of the IPL as a reliable horizontal plane and use of the EFW for calibration as a useful and reliable tool to assess the outcome of UCL repair.