Application of Botulinum Toxin at the Yonsei Point for the Treatment of Gummy Smile: a Randomized Controlled Trial
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 48
- Locations
- 1
- Primary Endpoint
- the dynamic measurements anterior gingival exposure (mm)
Study Overview
Brief Summary
The purpose of the present study will be to evaluate the efficacy of a single dose of botulinum toxin (BTX) at the Yonsei point for the treatment of gummy smile (GS).
In this double-blind single-site randomized clinical trial, A total number of 36 patients with gummy smile will be enrolled in the study at Peking University School and Hospital of Stomatology over a period of 12 months. Patients will be included and randomized 1:1 to two groups for BTX-A treatment at different injection point. For experimental group, Three units of onabotulinumtoxinA (BTX-A) per site (90 hemifaces) will be initially injected at the Yonsei point. For control group，the same dose of BTX will be injected into the levator labii superioris alaeque nasi muscle, and the injection point is located 3 to 5 mm lateral to each nostril, which was a classical injection point of this treatment. The patients will be then assessed at 2, 4, 12, 36 and 72 weeks postinjection. All subjects underwent standardized measurements by a single examiner, including dynamic and static measurements and a lateral cephalometric radiograph. In addition, facial photos and videos and a questionnaire of self-assessment will be obtained. The primary outcome measurement is the anterior gingival exposure measurements when the subject get an achieve full, unrestricted, spontaneous smiles 2 weeks postinjection.
Detailed Description
BACKGROUND:
Gummy smile (GS), also known as excessive gingival display, is a common unaesthetic clinical condition. Recent evidence showed that botulinum type A (BTX-A) injection is a promising, simple, corrective method for GS. However, Currently, there is no standardized approach for the treatment of excessive gingival exposure with botulinum toxin, and controversies still exist and due to different injection methods, the efficiency of BTX-A for GS treatment shows great variation in different studies, with the improvement rate of gingival exposure (GE) ranging from 62% to 98%.
The treatment goal is to identify a consistent, minimally invasive alternative for the correction of GS caused by hyperfunctional upper lip elevator muscles. In 2009, Hwang et. al. described the Yonsei point, which is the confluence of three muscles - the levator labii superioris (LLS), the levator labii superioris alaeque nasi (LLSAN), and the zygomaticus minor (Zm). These three muscles are primarily responsible for the smile.
In order to minimize the complications associated with multiple injections of BTX, the present study is designed with the prime purpose of evaluating the efficacy of one injection of BTX at the Yonsei point as a minimally invasive approach in the treatment of GS.
In this double-blind single-site randomized clinical trial, A total number of 36 patients with gummy smile will be enrolled in the study at Peking University School and Hospital of Stomatology over a period of 12 months. Patients will be included and randomized 1:1 to two groups for BTX-A treatment at different injection point. For experimental group, Three units of onabotulinumtoxinA (BTX-A) per site (90 hemifaces) will be initially injected at the Yonsei point. For control group，the same dose of BTX will be injected into the levator labii superioris alaeque nasi muscle, and the injection point is located 3 to 5 mm lateral to each nostril, which was a classical injection point of this treatment. The patients will be then assessed at 2, 4, 12, 36 and 72 weeks postinjection.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Double (Participant, Outcomes Assessor)
Masking Description
The participant and the outcomes assessor will be prevented from having knowledge of the interventions assigned to individual participants.
Eligibility Criteria
- Ages
- 18 Years to 60 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Gingival exposure ≥3.0mm upon unrestricted "full-blown" smiling
- •Age: 18-60 years
Exclusion Criteria
- •Contraindication of BTX-A
- •Previous diseases or treatments affecting the position of the gingiva or upper lips
- •History of BTX-A injections to the head or neck region
- •Facial paralysis
- •Subject's refusal to participate.
Arms & Interventions
the Yonsei point group
Three units of onabotulinumtoxinA (BTX-A) per site (90 hemifaces) will be initially injected at the Yonsei point.
Intervention: the injection of onabotulinumtoxinA at different point (Procedure)
the levator labii superioris alaeque nasi muscle group
For control group，the same dose of BTX will be injected into the levator labii superioris alaeque nasi muscle, and the injection point is located 3 to 5 mm lateral to each nostril, which was a classical injection point of this treatment.
Intervention: the injection of onabotulinumtoxinA at different point (Procedure)
Outcomes
Primary Outcomes
the dynamic measurements anterior gingival exposure (mm)
Time Frame: 2 weeks postinjection
anterior gingival exposure, defined as the distance between the superior margin point of the right incisor and the lower margin of the upper lip, measured when the subject get an achieve full, unrestricted, spontaneous smiles using the vernier caliper
Secondary Outcomes
- the dynamic measurements bilateral posterior gingival exposure (mm)(2 weeks postinjection)
Investigators
Gong Xi
principal investigator
Peking University