A Guide to Bilateral Cleft Lip Markings: An Anthropometric Study of the Normal Cupid's Bow.

Objective: The aim of this study was to define the ratio of the heights of the vermilion between the peaks and trough of the Cupid's bow and hence assist in defining the point of closure on the lateral lip element to achieve a balanced Cupid's bow in bilateral lip repair based on our findings.

Design: This study is a retrospective observational study of the anthropometrics of the upper lip's Cupid's bow. Three-dimensional (3D) images of toddlers between 2009 and 2016 were extracted from a normative 3D image database of toddlers at the Royal Children's Hospital, Melbourne.

Patients: Participants from the normative 3D image database at the age of 1 year were studied. This excluded any patients with prior trauma or surgical intervention of the nasolabial region.

Intervention: Landmarks measured were right and left crista philtri (cphR and cphL), labial superius (ls), stomion (sto), right and left chelion, and labial fissure (lf).

Outcome: Vermilion height of the right peak, trough, and left peak of the Cupid's bow was calculated by analyzing the vertical linear distance between cphR-lf, ls-sto, and cphL-lf. The ratio between the median and paramedian heights were recorded.

Results: The paramedian height of the upper lip vermilion is consistently greater than the midline height. There was no significant sexual dysmorphism between ratio of paramedian to midline height on the right (P = .538) and left (P = .410).

Conclusion: We describe an anthropometric observation of the vermilion relationship at the Cupid's bow and define a specific lateral lip marking for bilateral cleft lip repair based on our anthropometric findings.