Figuring Out the Genetic Mutations That Lead to Lower Jaw Advancement More Than the Upper Jaw

Purpose of the Research:

To reveal the genetic cause for the occurrence of Class III malocclusion, or what may be described as a reverse bite (underbite).

Introduction and Detailed Procedures for the Patient (Work Plan):

1. The volunteer will rinse their mouth with chlorhexidine before taking the swab. 2. A saliva sample will be collected from the patient using a syringe, along with a frontal facial photograph and a lateral cephalometric X-ray. 3. DNA / genetic material will be extracted from the sample. 4. Screening will be conducted for genetic mutations that may be responsible for the occurrence of the underbite. 5. The photographs and X-rays will be analyzed and compared with the swab results. 6. This data will be analyzed to determine whether the detected mutations are the cause of the underbite. 7. The sample will be retained for use in future research studies.

Side Effects, Expected Risk Levels, and Management"

* Pain: Mild discomfort during swab collection, which does not require any painkillers. * Infection/Inflammation: Mild inflammation at the sample site or a secondary bacterial infection; in this case, antibiotics may be prescribed if necessary. * Risk Level: Low risk, estimated to be less than 5%.

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Key information

Conditions

Skeletal Class III Malocclusion

Age range

10 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Faculty of Dentistry, Cairo University

Cairo, Egypt

Who can participate

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

Inclusion criteria

for Control group:

Patients of Egyptian nationality.
ANB from 0° to 4.8°.ANB from 0° to 4.8°.
Wits appraisal no less than -3.0 mm.

Inclusion criteria

for Study group:

Patients of Egyptian nationality.
ANB (angle between point A, nasion and point B at nasion) angle (point A-nasion point B) of less than 0 degrees.
Negative Wits appraisal greater than -3.0 mm.

Exclusion criteria

The presence of any growth disturbances, syndromes, congenital abnormalities, & endocrine disorders.
Patients subjected to previous orthodontic, orthopedic, or orthognathic treatment.
Poor quality of radiographic records.
Consent form not signed.
Trauma.

Treatment and study plan

Primary outcomes

presence of single nucleotide polymorphism

Time frame: cross-sectional - results are assessed at one point of time (Preintervention)

difference in snps between control and study group

Secondary outcomes

lateral cephalometric measurements

Time frame: cross-sectional - results are assessed at one point of time (Preintervention)

if the snps found have a correlation with different linear and angular measurements
Frontal photos measurements

Time frame: cross-sectional - results are assessed at one point of time (Preintervention)

If the snps found have a correlation with different ratios on frontal photos:

Sponsors and collaborators

Lead sponsor

Cairo University

Other

Registry information

Official study title

Investigating Genetic Biomarkers in the Early Detection of Skeletal Class III Malocclusion: An Observational Study

Important dates

Study start: 2023
Primary completion: 2026
Study completion: 2026
First posted: Aug 6, 2026
Registry last updated: Aug 6, 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.

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Completed