Classification of Mouth Corners in Asian Women

There is increasing interest in mouth corner lift (MCL), as well as lip augmentation. Procedures for lip corner lifting to create smiling lips include botulinum toxin, injectable filler, and surgery. However, there is no proper system to classify mouth corners, thereby causing difficulties in patient counseling, treatment planning, and communicating with medical staff. We developed a new classification system to analyze the shape of mouth corners in Asian women.

Lip shapes were classified as types I (arched upper lip) and II (flat upper lip), each of which was further classified as subtypes a (upturned mouth corner) and b (flat or downturned mouth corner). Atypical cases were classified as type III. The anterior-posterior view of facial photographs were taken of female patients aged 20-40 years who visited HB Plastic Surgery Clinic between January 2017 and December 2018. Patients who visited for surgery other than lip plastic surgery (group A) and those who visited for MCL (group B) were compared. Changes in mouth corner type across age were examined.

The most common type was IIb in group A and Ib in group B. IIa and IIb were more common in group A, whereas Ib was more common in group B, at a statistically significant level. With increasing age, the proportions of IIb and III tended to increase, and Ia and IIa tended to decrease.

This relatively simple classification system for mouth corners might be helpful in patient counseling and communication with medical staff during plastic surgery.