title: Prevalence and Severity of Temporomandibular Disorders among Undergraduate Medical Students in Association with Khat Chewing.
abstract: The aim of this study was to assess the prevalence and severity of temporomandibular joint disorders (TMDs) among undergraduate medical students in the presence of khat chewing over a period of time.
  
  
  
  Totally, 186 medical college students (age < 20 years) were randomly selected for the present study. The study subjects were divided into two groups according to age, under 20 and above 20 years. The study was based on Fonseca's anamnestic index and its questionnaire, which is composed of 10 questions and classifies the severity of TMDs. The obtained data were coded and entered into Statistical Package for the Social Sciences (SPSS) program for analysis using chi-square test at significance level of 5%.
  
  
  
  Most of the participants were male (68.8%) students and older than 20 years (63%). Those who reported with khat chewing comprised 31.7%. From the total samples, only 38.0% was classified as having mild TMD and 0.50% were classified as having severe TMD. Poor dental articulation, grinding of teeth, headaches, tense personalities, and temporomandibular joint (TMJ) clicking were the most common clinical findings. The mean scores showed no significant difference among gender (p < 0.29) and the khat chewing (p < 0.531) groups for the 10 questions. However, it showed significant difference among age groups (p < 0.025).
  
  
  
  The majority of subjects complained of mild TMD, while only a few cases showed a moderate TMD among different age groups. The most frequently reported dysfunctions were related to poor dental articulation and grinding of the teeth, frequent headaches, the clicking of joint, and tense personalities. No significant difference was found between gender and khat and nonkhat chewing groups.
  
  
  
  Khat chewing is a parafunctional habit and affects dental occlusion (especially cuspal wear) in terms of anterior guidance. Such alterations in occlusion are known to be one of the causative (predisposing) factors of TMD.
authors.affiliation: Department of Prosthetic Dental Science, College of Dentistry Jazan University, Jazan, Kingdom of Saudi Arabia, e-mail: drmoaleem2014@gmail.com.
authors.forename: Mohammed M
authors.initials: MM
authors.lastname: Al Moaleem
authors.affiliation: Department of Prosthodontics, Bernhard-Gottlieb University Clinic of Dentistry, Medical University of Vienna, Vienna Austria Department of Dental Technology, College of Applied Medical Science, King Khalid University, Abha, Kingdom of Saudi Arabia.
authors.forename: Abdulmajeed S
authors.initials: AS
authors.lastname: Okshah
authors.affiliation: Department of Dental Technology, College of Applied Medical Science, King Khalid University, Abha, Kingdom of Saudi Arabia Department of Prosthodontics, Indiana University-Purdue University Indianapolis, Indiana, USA.
authors.forename: Ahid A
authors.initials: AA
authors.lastname: Al-Shahrani
authors.affiliation: Department of Dental Technology, College of Applied Medical Science, King Khalid University, Abha, Kingdom of Saudi Arabia.
authors.forename: Abdulkhaliq Ali F
authors.initials: AA
authors.lastname: Alshadidi
authors.affiliation: Saudi Board, King Abdulaziz University Training Center Jeddah, Kingdom of Saudi Arabia.
authors.forename: Fawzia I
authors.initials: FI
authors.lastname: Shaabi
authors.affiliation: College of Dentistry, Jazan University, Jazan, Kingdom of Saudi Arabia.
authors.forename: Abdulaziz H
authors.initials: AH
authors.lastname: Mobark
authors.affiliation: Department of Prosthetic Dental Science, College of Dentistry Jazan University, Jazan, Kingdom of Saudi Arabia.
authors.forename: Khurshid A
authors.initials: KA
authors.lastname: Mattoo
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002012:Bruxism; D029754:Catha / Q000009:adverse effects; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004504:Education, Medical, Undergraduate; D005260:Female; D006261:Headache; D006801:Humans; D008297:Male; D008409:Mastication / Q000502:physiology*; D010551:Personality; D015995:Prevalence; D012720:Severity of Illness Index; D013337:Students, Medical / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013705:Temporomandibular Joint Disorders / Q000453:epidemiology* / Q000209:etiology*; D055815:Young Adult
keywords: Catha edulis; Dental occlusion; Fonseca's anamnestic index; Fonseca's questionnaire; Medical students Saudi Arabia.