Recruiting

Observational Study

Sponsor:

University of North Carolina, Chapel Hill

Code:

NCT04117360

Conditions

Dentofacial Abnormalities

Dentofacial Deformities

Dentofacial Anomalies, Including Malocclusion

Malocclusion

Malocclusion in Children

Eligibility Criteria

Sex: All

Age: 15 - 40

Healthy Volunteers: Not accepted

Interventions

Orthognathic surgery and Orthodontics

Study Details

Brief summary:

The investigators are studying how speech is effected by jaw and tooth position in jaw surgery patients. Eighty percent of our jaw surgery patients have speech pathologies, compared to five percent of the general population, but speech pathologists do not understand why. The investigators hypothesize that open bites and underbites prevent most patients from being able to pronounce words normally and surgical correction will lead to improvement in speech. Patients will be audio recorded speaking and patients' tongue gestures ultrasound recorded before and after their jaw surgeries to observe what changes occur in their speech and tongue movements.

Conditions

Dentofacial Abnormalities

Dentofacial Deformities

Dentofacial Anomalies, Including Malocclusion

Malocclusion

Malocclusion in Children

Study ID

NCT04117360

Start date

Sep 11, 2019

Status verified date

Jun, 2026

Completion date

Mar, 2028

Anticipated

Primary completion date

Mar, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 15 - 40

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Jaw surgery patient at UNC with a skeletal open bite, underbite or overjet greater than 5mm.
  • Age 15-40 years

Exclusion Criteria:

  • Hearing loss
  • Learned English as a second language
  • Significant regional accent, as characterized by a speech pathologist
  • Developmental delay, performing several grade levels below age bracket
  • history of craniofacial disorder
  • genetic syndrome associated with known craniofacial presentation
  • history of craniofacial trauma
  • history of prior craniofacial surgery (excluding extractions and dental procedures)
  • Jaw surgery without fixed orthodontic appliances

Study Design

Enrollment

180 participants

Anticipated

Interventions and Outcome Measures

Arms

Dentofacial Disharmony Patients

Dentofacial disharmony patients who are seeking jaw surgery in UNC oral and maxillofacial surgery department and are seen in UNC orthodontic dentofacial disharmony clinic.

Interventions

Orthognathic surgery and Orthodontics

This study is observational. All subjects identified to participate will be undergoing orthognathic jaw surgery and orthodontic treatment.

Primary outcome measure

  • Change in Speech Distortion Phonemes over Time [ Time Frame: pre-operation through 9-15 months post-operation ]
  • Change in Quantitative Tongue Gestures over Time [ Time Frame: pre-operation through 9-15 months post-operation ]

Central Contacts and Locations

Central contacts

Laura A Jacox, PhD, DMD, MS

847- 702-0988ljacox@ad.unc.edu

Sherrill T Phillips, BS

sherrill_phillips@unc.edu

Locations

University of North Carolina

Recruiting

Chapel Hill, North Carolina, United States, 27514

Contacts

Laura A Jacox, DMD, PhD, MS

847-702-0988LJacox@ad.unc.edu

Principal Investigator:

Laura A Jacox, DMD, PhD, MS

More Information

Sponsor

University of North Carolina, Chapel Hill

Last update posted

Jun 12, 2026

Last verified

Jun, 2026

Keywords

  • Dentofacial Disharmony
  • Skeletal malocclusion
  • Speech Sound Disorder
  • Spectral Moment Analysis
  • Tongue Ultrasound
  • Orthognathic Surgery

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of North Carolina, Chapel Hill on 2026-06-12.