Cross Cultural Adaptation, Reliability &Validity of The Arabic Version of 8_Item Jaw Functional Limitation Scale In Temporomandibular Joint Disorders
Temporomandibular Joint Disorders
What this study involves
The registry does not currently label this study as recruiting. Ask about its status before planning a screening visit.
- Study type
- Observational
- Phase
- Not applicable / not listed
- Age range
- 18 years - 65 years
- Sex eligible
- All sexes
- Healthy volunteers
- Not accepted
- Participants
- 100 Actual
These are starting points, not an eligibility decision. The research team must review the full requirements.
About the research
The purpose of this study is to test if the translated Arabic version of the (jaw functional limitation scale -8) JFLS\_8 , valid (face, content, feasibility) ,reliable (internal consistency, test retest) and culturally adapted enough to quantify the impact of temporomandibular joint (TMJ) disorders on jow function in arabic people or not?
Read the full description
Temporomandibular disorders (TMD) are relatively prevalent among adults, representing a considerable health concern. These disorders negatively affect psychological well-being and overall quality of life, highlighting the importance of accurate assessment and appropriate management strategies. Consequently, there is a growing need for reliable and efficient tools to assess functional limitations associated with TMD.
The Jaw Functional Limitation Scale with 8 items (JFLS-8) is a concise, valid, and reliable instrument used for the assessment of functional limitations related to the masticatory system. It was developed as a shorter version of the JFLS-20 and has been shown to be more practical for use in busy clinical settings while maintaining strong psychometric properties. The JFLS-8 has demonstrated excellent validity and reliability and has been successfully translated and culturally adapted into several languages, confirming its effectiveness as a clinical assessment tool.
Therefore, there is a clear need to translate the JFLS-8 into an Arabic version, perform cultural adaptation, and evaluate its validity and reliability among patients with temporomandibular disorders in Arabic-speaking populations.
Who may be able to participate?
The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.
Inclusion Criteria:
- Patients aged 18 to 65 years .
- Diagnosis of temporomandibular disorders ) jaw pain-popping sounds in the jaw -limited jaw movements - orofacial pain ) for one month at least, not receiving actual treatment for the orofacial region (splinting)
- Being conscious and oriented.
- Able to read and write in Arabic.
- Both Genders were included.
Exclusion Criteria:
- History of trauma (recent head or neck or TMJ severe trauma)
- Recent surgery at the neck, head or TMJ
- Diagnosed systemic and psychiatric diseases; diseases that may affect the TMJ, such as ankylosing spondylitis or rheumatoid arthritis; and pregnancy
Study population
Adult male and female patients diagnosed with temporomandibular disorders (TMD), aged 18 to 65 years, who are native Arabic speakers. Participants are recruited from El-Kasr Elainy jaw and dental clinics to evaluate the validity, reliability, feasibility, and cultural adaptation of the Arabic version of the 8-item Jaw Functional Limitation Scale (JFLS-8).
Understand screeningTreatment, groups and participation
The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.
- Assignment
- Not reported
- Masking
- Not reported
Questionnaire Administration OTHER
Participants complete the Arabic version of the 8-item Jaw Functional Limitation Scale (JFLS-8), along with reference measures (Visual Analogue Scale and Fonseca Anamnestic Index), to evaluate validity, reliability, feasibility, and cultural adaptation of the questionnaire.
A subset of participants completes the JFLS-8 again after 2 days to assess test-retest reliability.
What researchers are measuring
Outcome measures describe what is being studied. They are not proof that a treatment works.
Primary measures
Face Validity of the Arabic Version of the 8-item Jaw Functional Limitation Scale (JFLS-8)
Time frame: 30 minutes
It will be assessed using the Clarity Index and Expert Proportion of Clearance, judged by two expert panels (5 experts each) to evaluate whether the scale appears clear and relevant.
Content Validity of the Arabic Version of the 8-item Jaw Functional Limitation Scale (JFLS-8)
Time frame: 30 minutes
It will be assessed using the Content Validity Index (CVI) and Expert Proportion of Relevance, to confirm that the 8 items adequately cover the construct of jaw functional limitation.
Feasibility of the Arabic Version of the 8-item Jaw Functional Limitation Scale (JFLS-8)
Time frame: 30 minutes
It will be evaluated by two factors: time needed to complete the questionnaire and the missed item index (ratio of unanswered items).
Internal Consistency Reliability of the Arabic Version of the 8-item Jaw Functional Limitation Scale (JFLS-8)
Time frame: 30 minutes
It will be measured using Cronbach's alpha to confirm that all 8 items are measuring the same underlying construct.
Test-Retest Reliability of the Arabic Version of the 8-item Jaw Functional Limitation Scale (JFLS-8)
Time frame: 2 days
It will be assessed using Spearman's rank correlation coefficient, with a subset of patients completing the JFLS-8 again after 2 days under the same conditions.
Secondary measures
Visual Analogue Scale (VAS)
Time frame: 30 minutes
a 10 cm pain intensity scale measuring jaw pain during activity (recorded in cm), used to assess convergent validity with the JFLS-8.
Fonseca Anamnestic Index (FAI)
Time frame: 30 minutes
a 10-item questionnaire classifying TMD severity (scores: 0-15 = no TMD; 20-40 = mild; 45-65 = moderate; 70-100 = severe), also used for convergent/construct validity testing.
Review the complete result tables and limitations in the official record.
Open official results ↗Research locations (1)
The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.
1 locations
El-Kasr Elainy jaw and dental clinicsGiza, EgyptStatus unknown
Study team and timeline
- Lead sponsor
- Cairo University
- Study start
- Mar 7, 2026 Actual
- Primary completion
- May 7, 2026 Actual
- Study completion
- May 15, 2026 Actual
- First posted
- Mar 4, 2026 Actual
- Last updated
- Nov 10, 2026 Actual
Official study contacts
No central contact is listed. Check the locations and the official record.
Official study title
Cross Cultural Adaptation, Reliability &Validity of The Arabic Version of 8_Item Jaw Functional Limitation Scale In Temporomandibular Joint Disorders
Ask Wellness Clinical Research
Your message goes to WCR, including when this study is run by another organization. WCR may offer general guidance but may not operate this trial, have access to its team or be able to enroll you.
Source: ClinicalTrials.gov API v2. Information is submitted by sponsors and investigators. NLM does not approve the safety or science of all listed studies. Registry disclaimer.
Retrieved: Nov 12, 2026 · Last registry update: Nov 10, 2026