Dentofacial AbnormalitiesOSPNCT04117360
Orthognathic Speech Pathology: Phonetic Contrasts of Patients With Dental Discrepancies Pre- and Post-Treatment Analyses
An observational study of Dentofacial Abnormalities and Dentofacial Deformities, run by University of North Carolina, Chapel Hill at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 15 to 40 years
- Conditions the study is for
- Dentofacial Abnormalities, Dentofacial Deformities, Dentofacial Anomalies, Including Malocclusion
- What is being tested?
- Orthognathic surgery and Orthodontics
- Type of treatment
- Pill or oral medicine
- How many people
- 180 participants
- Where
- 1 siteUnited States
- Study dates
- 11 Sep 2019to Mar 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 15 to 40 years
- All sexes
- No healthy volunteers
- Child, Adult
Study population: The study population includes healthy patients who present in our oral surgery and/or orthodontic dentofacial disharmony clinics with skeletal underbites, open bites, and/or excessive overjet. These patients have decided (prior to our study) to pursue orthodontic treatment combined with orthognathic surgery to address their jaw disproportions.
Who may be able to join
- Jaw surgery patient at UNC with a skeletal open bite, underbite or overjet greater than 5mm.
- Age 15-40 years
Who cannot join
- 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
Show all 9Show fewer
- history of craniofacial trauma
- history of prior craniofacial surgery (excluding extractions and dental procedures)
- Jaw surgery without fixed orthodontic appliances
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Sherrill T Phillips, BS contact
United States1 site, 1 recruiting
- Recruiting
University of North Carolina
Chapel Hill, North Carolina, 27514
Laura A Jacox, DMD, PhD, MS, 847-702-0988, LJacox@ad.unc.edu
Laura A Jacox, DMD, PhD, MS
About this study
Official title: Orthognathic Speech Pathology: Phonetic Contrasts of Patients With Dentofacial Discrepancies With Pre- and Post-Treatment Analyses
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.
Read the detailed description
Purpose: The investigators are studying how phoneme distortion is effected by jaw disproportions in dentofacial disharmony (DFD) patients and whether speech improves after orthognathic surgery and orthodontic treatment. Spectral moment and tongue gestural analysis are being used to mechanistically determine how jaw position effects speech. The investigators hypothesize that skeletal open and underbites contribute to phoneme distortion and tongue gestural changes that improve following surgical correction of jaw position. All DFD patients are already seeking treatment from orthodontics and oral surgery. The study will observe how their speech changes before and after treatment. There is no randomization or intervention involved.
Aim 1: Qualify the prevalence of auditory and visual speech distortions in the DFD population. Aim 2: Quantitatively evaluate the first spectral moment (kHz) of four articulating consonant sounds (/t/, /k/, /s/, and /?/ pronounced "sh"). Quantify and analyze the changes in speech distortions for orthognathic patients pre and post-operation. Aim 3: Evaluate tongue posture during speech with patients from Aim 2 pre and post-operation.
Participants:
Participants: Patients of the UNC dentofacial disharmony (DFD) clinic who have undergone orthognathic surgery for correction of jaw disharmonies.
Procedures (methods):
Patients will be recorded pronouncing a series of words highlighting a range of phonetic contrasts including --/s-sh/ and t-k/. words each presented on a screen using PowerPoint, 3 times each with carrier phrases). Recordings include an acoustic feed, a profile video of the jaws plus lips, and ultrasound imaging of the tongue relative to the palate and jaws. Research staff will score audio recordings according to their spectral moments and ultrasound recordings according to tongue movement and associate findings with degree of dental discrepancy. Prospective recordings will be collected at three timepoints: 1-3 months prior to jaw surgery, 3-8 months and 9-15 months post-operation for 60 overbite, 60 openbite and 60 underbite DFD patients. These time points were selected to co-occur with patients' surgical check-ups to ensure reliable data collection while minimizing confounding factors such as severe facial swelling and splint placement which occur immediately after surgery.
- Conditions
- Dentofacial Abnormalities, Dentofacial Deformities, Dentofacial Anomalies, Including Malocclusion, Malocclusion, Malocclusion in Children, Dentofacial Disharmony
- Being tested
- Orthognathic surgery and Orthodontics
- Keywords
- Dentofacial Disharmony, Skeletal malocclusion, Speech Sound Disorder, Spectral Moment Analysis, Tongue Ultrasound, Orthognathic Surgery
- Medical subject headings
- Dentofacial Deformities, Malocclusion, Speech Sound Disorder, Speech Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Orthognathic surgery and OrthodonticsOther
This study is observational. All subjects identified to participate will be undergoing orthognathic jaw surgery and orthodontic treatment.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Other: Orthognathic surgery and Orthodontics |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Speech Distortion Phonemes over Time
Audio recordings of consonant phonemes will be quantitatively analyzed using spectral moment analysis yielding mean values.
Measured: pre-operation through 9-15 months post-operation
Change in Quantitative Tongue Gestures over Time
Ultrasound analysis of tongue posture to quantitatively describe tongue position during speech.
Measured: pre-operation through 9-15 months post-operation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Oct 2019
- Study start11 Sep 2019
- Primary completionMar 2028 (estimated)
- Study completionMar 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Dentofacial AbnormalitiesStudies of the same condition, open and under way.
- More trials run by University of North Carolina, Chapel HillThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 180 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of North Carolina, Chapel Hill
- Sponsor type
- University, hospital or other
- Collaborators
- North Carolina State University
- Responsible party
- Sponsor
- Investigators
- Laura A Jacox, PhD, DMD, MS, Principal investigator, Professor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04117360
- Sponsor's protocol ID
- 19-1196
- Acronym
- OSP
- Status last verified
- Jun 2026
- First submitted
- 3 Oct 2019
- Last updated
- 12 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Our data includes video, audio and ultrasound recordings. This is not data that can be shared and maintained confidentially while meeting HIPAA guidelines.
Study at a glance
From the registry record, last updated by the sponsor on 12 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Orthognathic Speech Pathology: Phonetic Contrasts of Patients With Dentofacial Discrepancies With Pre- and Post-Treatment Analyses
- ClinicalTrials.gov ID
- NCT04117360
- Acronym / sponsor ID
- OSP / 19-1196
- Conditions
- Dentofacial Abnormalities, Dentofacial Deformities, Dentofacial Anomalies, Including Malocclusion, Malocclusion, Malocclusion in Children, Dentofacial Disharmony
- Keywords
- Dentofacial Disharmony, Skeletal malocclusion, Speech Sound Disorder, Spectral Moment Analysis, Tongue Ultrasound, Orthognathic Surgery
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 180 participants (estimated)
- Lead sponsor
- University of North Carolina, Chapel HillUniversity, hospital or other
- Collaborators
- North Carolina State University
- Study start
- 11 Sep 2019 (actual)
- Primary completion
- Mar 2028 (estimated)
- Study completion
- Mar 2028 (estimated)
- First posted
- 7 Oct 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Purpose: The investigators are studying how phoneme distortion is effected by jaw disproportions in dentofacial disharmony (DFD) patients and whether speech improves after orthognathic surgery and orthodontic treatment. Spectral moment and tongue gestural analysis are being used to mechanistically determine how jaw position effects speech. The investigators hypothesize that skeletal open and underbites contribute to phoneme distortion and tongue gestural changes that improve following surgical correction of jaw position. All DFD patients are already seeking treatment from orthodontics and oral surgery. The study will observe how their speech changes before and after treatment. There is no randomization or intervention involved.
Aim 1: Qualify the prevalence of auditory and visual speech distortions in the DFD population. Aim 2: Quantitatively evaluate the first spectral moment (kHz) of four articulating consonant sounds (/t/, /k/, /s/, and /?/ pronounced "sh"). Quantify and analyze the changes in speech distortions for orthognathic patients pre and post-operation. Aim 3: Evaluate tongue posture during speech with patients from Aim 2 pre and post-operation.
Participants:
Participants: Patients of the UNC dentofacial disharmony (DFD) clinic who have undergone orthognathic surgery for correction of jaw disharmonies.
Procedures (methods):
Patients will be recorded pronouncing a series of words highlighting a range of phonetic contrasts including --/s-sh/ and t-k/. words each presented on a screen using PowerPoint, 3 times each with carrier phrases). Recordings include an acoustic feed, a profile video of the jaws plus lips, and ultrasound imaging of the tongue relative to the palate and jaws. Research staff will score audio recordings according to their spectral moments and ultrasound recordings according to tongue movement and associate findings with degree of dental discrepancy. Prospective recordings will be collected at three timepoints: 1-3 months prior to jaw surgery, 3-8 months and 9-15 months post-operation for 60 overbite, 60 openbite and 60 underbite DFD patients. These time points were selected to co-occur with patients' surgical check-ups to ensure reliable data collection while minimizing confounding factors such as severe facial swelling and splint placement which occur immediately after surgery.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Dentofacial Disharmony Patients | – | Other: Orthognathic surgery and OrthodonticsDentofacial disharmony patients who are seeking jaw surgery in UNC oral and maxillofacial surgery department and are seen in UNC orthodontic dentofacial disharmony clinic. |
Who may qualify
- Ages
- 15 to 40 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
- Study population
- The study population includes healthy patients who present in our oral surgery and/or orthodontic dentofacial disharmony clinics with skeletal underbites, open bites, and/or excessive overjet. These patients have decided (prior to our study) to pursue orthodontic treatment combined with orthognathic surgery to address their jaw disproportions.
Key inclusion criteria (2 listed)
- Jaw surgery patient at UNC with a skeletal open bite, underbite or overjet greater than 5mm.
- Age 15-40 years
Key exclusion criteria (9 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Orthognathic surgery and OrthodonticsThis study is observational. All subjects identified to participate will be undergoing orthognathic jaw surgery and orthodontic treatment. | Other | Dentofacial Disharmony Patients |
Primary outcome
Change in Speech Distortion Phonemes over Time
Time frame: pre-operation through 9-15 months post-operation
Audio recordings of consonant phonemes will be quantitatively analyzed using spectral moment analysis yielding mean values.
Change in Quantitative Tongue Gestures over Time
Time frame: pre-operation through 9-15 months post-operation
Ultrasound analysis of tongue posture to quantitatively describe tongue position during speech.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jun 2026.
- Individual participant dataSharing planned: No. Our data includes video, audio and ultrasound recordings. This is not data that can be shared and maintained confidentially while meeting HIPAA guidelines.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Sherrill T Phillips, BS contact
Laura A Jacox, PhD, DMD, MS principal investigator
Professor
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Dentofacial Abnormalities and Dentofacial Deformities, run by University of North Carolina, Chapel Hill at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 12 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Laura A Jacox, PhD, DMD, MS (847- 702-0988, ljacox@ad.unc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Speech Distortion Phonemes over Time (time frame: pre-operation through 9-15 months post-operation). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jun 2026.