# Orthognathic speech pathology: Understanding how jaw disharmonies and their surgical correction influence speech

> **NIH NIH K08** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2021 · $166,960

## Abstract

ABSTRACT
Scientific Approach: Patients with severe dentofacial disharmonies (DFD; jaw disharmonies) seek orthognathic
surgery and orthodontic care to address issues with mastication, esthetics and speech. Preliminary data from
thousands of DFD patients generated by our colleagues at UNC-CH indicate speech concerns surpass impaired
chewing function as a motivator for surgery. Due to limited studies, we, as providers, are unable to give evidence-
based recommendations as to whether our orthodontic and surgical interventions will address speech disorders
associated with DFD. Despite limited data, patients undergo invasive jaw surgery in hopes of speech
improvement. To address this gap in knowledge, we have gathered surgical records and pre-operative audio
recordings of patients with DFD to quantitatively characterize their speech. In this proposal, we present
preliminary data identifying anatomical thresholds for significant articulation errors. Based on these data, we
hypothesize that speech distortions correlate with severity of anterior-posterior and vertical jaw
disharmonies, and that corrective surgery yields long-term improvement in speech. We propose the
following aims to address this hypothesis and explore the relationship between correction of jaw disharmonies
and speech. Aim 1: To examine the relationship between underbite (Class III) and open bite jaw disharmonies,
and speech distortion. Aim 2: To assess short- and long-term effects of corrective orthognathic surgery on
speech distortion in patients with underbite and open bite.
Training approach: Dr. Jacox is a dual-trained clinician-scientist, who completed dental school in parallel with
graduate school at Harvard School of Dental Medicine (HSDM- DMD) and Graduate School of Arts and Sciences
(GSAS- PhD). In addition, she is a certified diplomate of the American Board of Orthodontics. Her research
program and focus of this application was inspired by a patient seeking treatment `to help her talk
normally', whereby an evidence-based treatment option was not clear. The mentoring plan for this K08
award is designed to ensure Dr. Jacox will be a well-rounded and successful independent clinician-scientist
following completion of the activities in this proposal. Dr. Jacox has assembled a strong mentoring team to guide
her professional development and the establishment of her independent research program. Two co-mentors and
four consultants from diverse yet appropriate scientific and professional backgrounds will assist in the completion
of the training and scientific activities. Scientific interactions as well as didactic training in speech science and
technologies of speech science will add to Dr. Jacox's strong foundation in clinical orthodontics and the biology
of dentofacial disharmonies. These growth opportunities will allow for successful completion of the proposed
experiments, while the professional development activities will complement the training activities and provide Dr.
Jacox wit...

## Key facts

- **NIH application ID:** 10301902
- **Project number:** 1K08DE030235-01A1
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Laura Anne Jacox
- **Activity code:** K08 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $166,960
- **Award type:** 1
- **Project period:** 2021-08-01 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10301902

## Citation

> US National Institutes of Health, RePORTER application 10301902, Orthognathic speech pathology: Understanding how jaw disharmonies and their surgical correction influence speech (1K08DE030235-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10301902. Licensed CC0.

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