Clinical Research Directory

Inclusion Criteria: * Aged 18 to 60 years, any gender * Meet the diagnostic criteria for oral commissure ptosis: bilateral oral commissure ptosis angle (angle between the oral commissure point and the horizontal line of the ipsilateral vermilion border) \> 1° at rest * Have clear aesthetic demand for oral commissure ptosis improvement and can complete full-cycle follow-up * No redness, swelling, ulcer, scar, deformity or active infection in the perioral and mental regions * Have not participated in other interventional clinical trials within 3 months before enrollment Exclusion Criteria: * Hypersensitivity to botulinum toxin type A, lidocaine or excipients of injection preparations; or contraindications to botulinum toxin injection (myasthenia gravis, Lambert-Eaton syndrome, motor neuron disease, severe liver and kidney dysfunction, coagulation disorders, uncontrolled autoimmune diseases, malignant tumors) * History of mid-lower facial botulinum toxin type A injection, soft tissue filling, laser/radiofrequency rejuvenation, perioral surgery or orthognathic treatment within 6 months before enrollment * Planned perioral treatment within 6 months after enrollment that may affect efficacy evaluation * Pregnant or lactating women, or those planning to become pregnant within 6 months * Acquired oral commissure ptosis caused by facial nerve palsy/sequelae, perioral scar traction, severe jaw deformity or severe alveolar bone resorption * Severe facial asymmetry (difference in bilateral oral commissure ptosis angle \> 2°) * History of botulinum toxin allergy or severe adverse reactions after previous botulinum toxin injection * Currently using aminoglycoside antibiotics, quinine, calcium channel blockers, anticoagulants or other drugs that may affect botulinum toxin efficacy or increase bleeding risk and cannot discontinue * History of mental illness, drug/alcohol abuse, or poor compliance unable to complete follow-up * Other conditions deemed unsuitable for enrollment by the investigator