Botulinum Toxin Type A Injection Sites for Oral Commissure Ptosis

Phase 4Not Yet RecruitingNCT07646886

Peking University266 enrolled

Overview

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.

Oral commissure ptosis is a common aesthetic concern that presents as abnormal downward displacement of the mouth corners at rest, leading to a sad, angry or aged appearance. Botulinum toxin type A (BTX-A) injection is the first-line treatment, but there is no consensus on the optimal injection site in the depressor anguli oris (DAO) muscle. This multicenter randomized controlled trial will enroll 266 subjects with oral commissure ptosis from 5 top Chinese stomatological hospitals. Subjects will be randomly assigned 1:1 to receive either upper DAO or lower DAO BTX-A injection. The primary endpoint is the improvement of oral commissure ptosis angle at 1 month post-treatment. Secondary endpoints include objective efficacy measures, subjective aesthetic evaluations, and safety profiles during a 6-month follow-up. This study aims to determine the optimal injection site for Chinese population, establish standardized operation specifications, and provide level I evidence for clinical practice.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Eligibility

Sex: ALLMin age: 18 YearsMax age: 60 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Improvement of Bilateral Oral Commissure Ptosis Angle from Baseline at 1 Month Post-Treatment

The primary endpoint is the change in bilateral oral commissure ptosis angle (∠oba) from baseline. The angle is measured on standardized frontal facial photographs at rest by 3 independent assessors who are completely blinded to group assignment. The average value of 3 measurements is used as the final result.

Time frame: 30±3 days after treatment

Secondary Outcomes

Improvement of Oral Commissure Ptosis Angle at Maximum Smile and Maximum Depression Position

Change in oral commissure ptosis angle from baseline measured at maximum smile without teeth exposure and maximum oral commissure depression position on standardized facial photographs.

Time frame: 1, 3, 6 months after treatment

Vertical Elevation Amplitude of the Oral Commissure

Change in the vertical distance from the oral commissure point to the ipsilateral pupil from baseline, measured on standardized frontal facial photographs.

Time frame: 1, 3, 6 months after treatment

Merz Facial Aesthetic Scale Score

Physician-assessed aesthetic improvement using the full Merz Facial Aesthetic Scale. Scale range: 0 (No aging) to 4 (Severe aging). Lower scores indicate better aesthetic outcome.

Time frame: 1, 3, 6 months after treatment

Global Aesthetic Improvement Scale (GAIS)

Patient-reported global aesthetic improvement using the full Global Aesthetic Improvement Scale (GAIS). Scale range: 1 (Much worse) to 5 (Much improved). Higher scores indicate better aesthetic outcome.

Time frame: 1, 3, 6 months after treatment

Patient Satisfaction Score (FACE-Q)

Patient-reported facial appearance satisfaction using the full FACE-Q Facial Appearance Module. Scale range: 0 (Worst possible appearance) to 100 (Best possible appearance). Higher scores indicate better outcome.

Time frame: 1, 3, 6 months after treatment

Incidence of Adverse Events (AEs)

Incidence, time of onset, clinical manifestation, severity, treatment measures and outcome of all adverse events during the study period. Severity is graded according to CTCAE 5.0.

Time frame: From enrollment to 6 months after treatment

Incidence of Toxin Diffusion-Related Adverse Events

Incidence of adverse events related to unintended botulinum toxin diffusion, including oral commissure asymmetry, lower lip movement disorder, salivation, dysarthria and abnormal smile.

Time frame: From enrollment to 6 months after treatment

Incidence of Serious Adverse Events (SAEs)

Incidence of serious adverse events that result in death, life-threatening condition, hospitalization, persistent or significant disability, or congenital anomaly/birth defect.

Time frame: From enrollment to 6 months after treatment

Patient Satisfaction Score (Visual Analog Scale, VAS)

Patient satisfaction measured by the 10-point Visual Analog Scale (VAS). Scale range: 0 (Completely dissatisfied) to 10 (Completely satisfied). Higher scores indicate higher satisfaction.

Time frame: 1, 3, 6 months after treatment

Botulinum Toxin Type A Injection Sites for Oral Commissure Ptosis

Overview

Conditions

Interventions

Eligibility

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts