Skip to main content
OpenTrials
Recruiting

NCT Number: NCT06075134

EMG-guided Botox Injection Versus Conventional Botox Injection in Gummy Smile Patients

The goal of this clinical trial is to compare the effect of EMG-guided Botox injection with conventional Botox injection in Yonsei point, in patients with excessive gingival display.

The main question it aims to answer is:

• Does the use of electromyography (EMG) as a guide during Botox injection for patients with gummy smile has better effect than conventional injection in Yonsei point?

Participants will be randomized in equal proportions between intervention and control groups.

* Preoperative assessment of amount of gingival display, lip length (philtrum and vermilion length), and smile type. * For the intervention group, EMG readings will be done in Clinical Neurophysiology Department, Kasr Al-Ainy Hospital EMG-guided Botox injection (Intervention group). Conventional Botox injection in Yonsei point (Control group).

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Excessive Gingival Display

Age range

18 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Faculty of Dentistry, Cairo University

Cairo, Egypt

Location status: Recruiting

Location contact

Sherry Fayez Akhnokh

CONTACT

[email protected]

+2 01284857175

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with excessive gingival display.
  • Patients with esthetic concerns.
  • Patients with mild to moderate VME (vertical maxillary excess).
  • Normal clinical crown dimensions.
  • Patients aged 18 to 50.
  • Systemically healthy patients.
  • Non-smokers.

Exclusion criteria

  • Patients with severe VME (vertical maxillary excess).
  • Pregnant and breastfeeding women.
  • Patients with gingival inflammation and/or enlargement.
  • Inflammation or infection at the site of injection.
  • Patients with known allergy to any of the components of Botox (i.e., saline, human albumin, lactose and sodium succinate).
  • Patients using anticholinesterase or other agents affecting neuromuscular transmission.
  • Psychologically unstable patients or those who have unrealistic expectations and questionable motives.
  • Patients with neuromuscular disorders (e.g., myasthenia gravis, Eaton-Lambert syndrome).

Treatment and study plan

botox injection

Procedure

Botox injection

Other names: Botulinum toxin injection

EMG

Device

Quantitative Electromyography

Other names: Electromyography

Zinc Supplement

Drug

To increase efficacy of Botox

Other names: Zinc supplement in the form of tablets

Primary outcomes

  1. Change in amount of gingival display

    Time frame: Baseline, One-week, One-month, three-months, and six-months follow-up

    Will be measured using ruler in mm.

Secondary outcomes

  1. Quantitative EMG

    Time frame: Baseline, One-week and six-months follow-up

    Will be measured using EMG in mv.

  2. Patient satisfaction

    Time frame: Baseline, One-week, One-month, three-months, and six-months follow-up

    Will be assessed using questionnaire, on a scale from 1 to 5, where 1 is completely not satisfied and 5 is completely satisfied.

  3. Post-operative pain

    Time frame: Baseline, One-week, and One-month follow-up

    Will be measured using visual analogue scale (VAS) from 1 to 10.

  4. Smile type

    Time frame: Baseline, One-week, One-month, three-months, and six-months follow-up

    Qualitative, by Rubin (1974). Smile is classified into 1. Corner of the mouth (Mona Lisa) smile, 2. Canine Smile, and 3. Full denture smile

  5. Change in lip length

    Time frame: Baseline, One-week, One-month, three-months, and six-months follow-up

    Will be measured using UNC (University of North Carolina) -15 periodontal probe in mm.

  6. Esthetics (Symmetry) for operators

    Time frame: Baseline, One-week, One-month, three-months, and six-months follow-up

    Will be measured using 5-point Likert scale, where 1 is significantly asymmetrical and 5 is completely symmetrical.

Study contacts

Contact information is provided by the study sponsor or research team.

Nesma Shemais, PhD

CONTACT

[email protected]

Sherry Fayez Akhnokh, BSc

CONTACT

[email protected]

+0201284857175

Sponsors and collaborators

Lead sponsor

Cairo University

Other

Registry information

Official study title

EMG-guided Botox Injection Versus Conventional Injection in Yonsei Point in Gummy Smile Patients: A Randomized Clinical Trial

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Oct 10, 2023
Registry last updated
Mar 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.