Objective:
To provide a normal comparison group against which to judge symmetry results after
cleft surgery and to introduce the thin lip correction (TLC) feature in SymNose. A
lip–aspect ratio algorithm has been added to the latest version of SymNose to compensate
for the higher degree of overlap in thicker lips when compared to thin lips.
Design:
Retrospective analysis of symmetry in healthy participants, using the computer-based
program SymNose on both anteroposterior (AP) and base view images. Photographs of 91
noncleft children were traced twice by 3 independent investigators experienced with
SymNose.
Participants:
Five-year-old healthy participants from a local state school in Tavistock (West Devon,
United Kingdom).
Main Outcome Measure:
Asymmetry expressed as the perimeter mismatch percentage for nose and lip features on
AP view images and for nose features on base view images.
Results:
The perimeter mismatch reference range for the nose (AP view) was 2.65% to 30.91%, for
the lip 2.13% to 15.44%, for the nose (base view) 1.69% to 14.84%, for the nostrils
4.68% to 26.6%, and for the width–height ratio 1.15% to 1.80%. The perimeter mismatch
percentage for the lip without TLC was significantly higher compared to the perimeter
mismatch percentage with TLC (
P
< .001).
Conclusion:
This article provides a noncleft reference range for all perimeters drawn from SymNose
against which to compare results after cleft surgery at 5 years of age. Furthermore, it
shows the importance of correcting for variance in lip volume per child.