title: The relationship between mandibular arch length and widths in a sample of Yemeni subjects with normal dento-Skeletal relationship.
abstract: OBJECTIVE
  To assess the relationship between mandibular arch length and widths in a sample of Yemeni subjects aged (18-25) years.
  
  
  METHODS
  The investigation involved clinical examination of (765) adults; only 214 (101 females, 113 males) out of the total sample were selected to fulfill the criteria for the study sample (normal dento-skeletal relationship). Study models were constructed and evaluated to measure mandibular arch dimensions. The Spearman's correlation coefficient (r) was calculated between the measurements of arch widths and lengths.
  
  
  RESULTS
  Overall, the male group demonstrated greater transverse and sagittal mandibular dimensions; However, this was only statistically significant for measurements of inter-first and second molar distances and anterior arch length (P < 0.05). Relatively stronger linear relationships were observed between the inter-canine distance and mandibular arch lengths (P < 0.05, Spearman's r ranged between 0.17 to 0.50).
  
  
  CONCLUSIONS
  Among studied mandibular dimensions in subjects with normal dento-skeletal relationship, only the inter-canine distance demonstrated a week to moderate linear relationship with the mandibular arch lengths.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Sana'a University, Sana'a, Yemen.
authors.forename: Nabil Muhsen
authors.initials: NM
authors.lastname: Al-Zubair
keywords: Arch length; Yemeni norms; arch width; dental cast analysis; mandible