Botulinum Toxin Type A Injection Sites for Oral Commissure Ptosis

This multicenter, prospective, randomized parallel-controlled, assessor-blinded clinical trial aims to address the core clinical pain point of lack of high-level evidence and non-standardized operation in injection site selection for BTX-A treatment of oral commissure ptosis. A total of 266 eligible subjects will be randomly assigned in a 1:1 ratio to receive either upper DAO or lower DAO BTX-A injection. The study will compare the clinical efficacy, time-effect characteristics and safety profiles of the two regimens, and conduct stratified analysis of treatment response in different patient subtypes. The results will determine the optimal injection site for Chinese population, establish standardized operation specifications, fill the international evidence gap, and provide level I evidence for clinical practice.

NCT Number	NCT07646886
Lead Sponsor	Peking University
Conditions	Facial Aging, Melomental Folds, Oral Commissure Ptosis
Enrollment	266 participants
Start Date	2026-07-01
Primary Completion	2027-06-01 (estimated)
Study Completion	2027-12-01 (estimated)
Updated on ClinicalTrials.gov	2026-07-07