A study to understand chewing and swallowing difficulties in older adults using a simple video-based method

ISRCTN	ISRCTN11010971
DOI	https://doi.org/10.1186/ISRCTN11010971
ClinicalTrials.gov (NCT)	Nil known
Clinical Trials Information System (CTIS)	Nil known
Protocol serial number	Nil known
Sponsor	Kaohsiung Medical University
Funder	Investigator initiated and funded

Submission date: 17/04/2025
Registration date: 17/04/2025
Last edited: 20/10/2025

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Digestive System

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
Chewing and swallowing difficulties (dysphagia) are common but frequently underdiagnosed in older adults. This study aims to develop a non-contact, video-based screening approach to detect early signs of dysphagia by analyzing mandibular (jaw) movement and diadochokinetic (DDK) speech performance.

Who can participate?
Older adults aged 65 to 95 years who are capable of following instructions and performing basic oral motor tasks

What does the study involve?
Participants are asked to perform jaw opening and closing movements and to rapidly repeat the syllables /pa/, /ta/, and /ka/ in a single breath. These tasks are recorded using non-contact video and audio equipment. The recordings are analyzed to extract features such as jaw movement velocity and DDK rate.

What are the possible benefits and risks of participating?
Participants may gain early awareness of potential chewing and swallowing difficulties. The procedures involve minimal risk and are similar to routine speech and movement assessments.

Where is the study run from?
The study is led by researchers from the Department of Sports Medicine at Kaohsiung Medical University. Data were collected at selected community health and elder care centers in Kaohsiung City, Taiwan.

When is the study starting and how long is it expected to run for?
April 2022 to February 2023

Who is funding the study?
Investigator initiated and funded

Who is the main contact?
Dr Lan-Yuen Guo, yuen@kmu.edu.tw

Contact information

Mr Lan-Yuen Guo
Public, Scientific, Principal investigator

No. 100, Shiquan 1st Rd
Sanmin Dist.
Kaohsiung City
807378
Taiwan

Phone	+886 (0)7 312 1101#2646
Email	yuen@kmu.edu.tw

Study information

Primary study design	Observational
Study design	Single-centre observational cross-sectional study
Secondary study design	Cross sectional study
Study type	Participant information sheet
Scientific title	To explore the correlation between chewing and swallowing difficulties during oral preparation in the elderly through non-contact imaging analysis of mandibular movement trajectory and oral movement rate
Study acronym	JAWS
Study objectives	It is hypothesised that older adults with chewing and swallowing difficulties will demonstrate significantly different mandibular movement parameters (e.g., distance, angle, velocity) and diadochokinetic performance compared to those without such difficulties, as measured using non-contact video-based motion analysis and audio-based articulation assessment.
Ethics approval(s)	Approved 20/04/2022, Kaohsiung Medical University Chung-Ho Memorial Hospital Institutional Review Board (No. 100, Tzyou 1st Road, Kaohsiung, 807, Taiwan; +886 (0)7 3121101 ext 6646; irb@kmuh.org.tw), ref: KMUHIRB-E(II)-20210396
Health condition(s) or problem(s) studied	Chewing and swallowing difficulties (dysphagia)
Intervention	Participants will undergo non-contact video recording of mandibular movements during chewing tasks, and audio recording of diadochokinesis (/pa/, /ta/, /ka/) for speech motor assessment. Swallowing function is classified using the Repetitive Saliva Swallowing Test (RSST). No treatment or intervention is administered.
Intervention type	Behavioural
Primary outcome measure(s)	Mandibular movement parameters (average jaw opening/closing angle, distance, and velocity) and diadochokinetic rate (/pa/, /ta/, /ka/) are measured using non-contact video and audio analysis at a single timepoint
Key secondary outcome measure(s)	1. RSST score measured using the Repetitive Saliva Swallowing Test at a single timepoint to classify participants into normal and impaired swallowing groups 2. Diadochokinetic rate (syllables per second) for /pa/, /ta/, and /ka/ syllables measured using the fixed-count method (10 and 15 syllables per trial) and maximum-performance method (maximum number of syllables in a single breath), based on audio recordings analyzed in Audacity at a single timepoint 3. Average mouth opening distance measured using Kinovea software from non-contact video recordings at a single timepoint 4. Average mouth opening angle measured using Kinovea software from non-contact video recordings at a single timepoint 5. Average jaw opening velocity measured using Kinovea software from non-contact video recordings at a single time point 6. Average jaw closing velocity measured using Kinovea software from non-contact video recordings at a single timepoint
Completion date	17/02/2023

Eligibility

Participant type(s)	Healthy volunteer
Age group	Senior
Lower age limit	65 Years
Upper age limit	95 Years
Sex	All
Target sample size at registration	115
Total final enrolment	100
Key inclusion criteria	1. Community-dwelling older adults aged between 65 and 95 years 2. Able to complete the required speech and mandibular movement tasks correctly after a brief instruction session 3. No obvious impairment in lip closure, dentition (including the use of dentures), or jaw mobility 4. Able to open and close the mouth adequately without pain or discomfort 5. Willing to participate and provide written informed consent 6. Able to comply with the study procedures and complete all required recordings
Key exclusion criteria	1. Presence of temporomandibular joint disorders (e.g., pain, limited range of motion, joint noise) 2. Neurological conditions that may affect orofacial motor control (e.g., Parkinson’s disease, stroke, ALS) 3. Severe cognitive impairment that affects the ability to understand instructions or perform the tasks 4. Recent oral surgery or facial trauma within the past 6 months 5. Unwillingness to participate or inability to complete the study protocol
Date of first enrolment	20/04/2022
Date of final enrolment	17/02/2023

Locations

Countries of recruitment

Taiwan

Study participating centre

Kaohsiung Medical University

No. 100, Shiquan 1st Rd
Sanmin Dist.
Kaohsiung City
807378
Taiwan

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Data sharing statement to be made available at a later date
IPD sharing plan	The data-sharing plans for the current study are unknown and will be made available at a later date

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article		08/10/2025	20/10/2025	Yes	No
Basic results		10/05/2025	12/05/2025	No	No
Other files			17/04/2025	No	No
Other files			17/04/2025	No	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes
Protocol file			17/04/2025	No	No

Additional files

47202_PROTOCOL.pdf: Protocol file
47202_AssessmentForm.pdf: Other files
47202_ConsentForm.pdf: Other files
ISRCTN11010971 BasicResults 10May2025.pdf: Basic results

Editorial Notes

20/10/2025: Publication reference added.
12/05/2025: The basic results have been uploaded as an additional file.
17/04/2025: Study's existence confirmed by Kaohsiung Medical University Chung-Ho Memorial Hospital Institutional Review Board.