Original scientific paper
Multiple Lingual Cusps Trait on Mandibular Premolars and Hypoconulid Reduction Trait on Mandibular First Molar in Living Jordanian Population. Intra- and Inter-trait Interactions
Ameen Khraisat
; University of Jordan, Faculty of Dentistry, Department of Conservative Dentistry and Fixed Prosthodontics, Amman, Jordan
Firas Alsoleihat
; University of Jordan, Faculty of Dentistry, Department of Conservative Dentistry and Fixed Prosthodontics, Amman, Jordan
Karthikeyan Subramani
; University of Amsterdam and VU University Amsterdam, Academic Centre for Dentistry Amsterdam, Department of Oral Implantology and Prosthodontics, Amsterdam, The Netherlands
Mohammad A. Al-Rabab’ah
; University of Jordan, Faculty of Dentistry, Department of Conservative Dentistry and Fixed Prosthodontics, Amman, Jordan
Mahmoud K. Al-Omiri
; University of Jordan, Faculty of Dentistry, Department of Prosthodontics, Amman, Jorda
Ibrahim Abu-Tahun
; University of Jordan, Faculty of Dentistry, Department of Conservative Dentistry and Fixed Prosthodontics, Amman, Jordan
Abstract
The objective was to determine the expression and fluctuating asymmetry of two dental morphological traits in the living Jordanians: The lingual cusp number on the lower premolars (LP1 and LP2) and the hypoconulid (distal cusp) reduction on the lower first molar (LM1). In addition, both intra- trait and inter- trait interactions were analyzed. Three hundred school children (15.5± 0.4 years) were involved. Impressions for the mandibular dental arches were taken, and dental casts were reproduced. The above-mentioned traits were observed. Paired sample t test and nonparametric corre- lation analysis were used for data analysis. Three-cusped LP1 was found in 11.40 % of the examined students, while the two-cusped LP1 was found in 88.60%. In comparison, the Three-cusped LP2 was found in 61.40% while the two-cusped LP2 was found in 38.60% of the observed subjects. The frequencies of the 4-cusped and 5-cusped LM1 were found to be 8.65% and 91.35%, respectively. Nonparametric correlation analysis revealed positive and statistically significant asso- ciation between the expression of two lingual cusps on LP1 and on LP2 in both genders (p<0.01), while there was no sig- nificant correlation between expression of two lingual cusps on either LP1 or LP2 and the hypoconulid loss on LM1 in both genders (p>0.05). Bilateralism was highly significant in the tested traits in both genders (p<0.001).This finding might be a sign of relatively low environmental stresses experienced by the living Jordanians and/or great ability of its individuals to buffer the adverse effects of such stresses on dental development. This study is a useful addition to the ex- isting literature in that it examines a previously poorly characterized population and assists in placing the contemporary Jordanian population within the current framework of human population groups globally.
Keywords
left-right fluctuating asymmetry; buccolingual diameter; mesiodistal diameter; sexual dimorphism; bilateralism
Hrčak ID:
118287
URI
Publication date:
30.9.2013.
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