title: Bilateral asymmetry in dental discrete traits in human isolates: south Sinai Bedouin tribes.
abstract: Data are presented on dental morphology as adjudged from dental casts of children (boys and girls) 6-13 years of age from four Bedouin tribes of Southern Sinai (Gebeliya, Muzeina, Hamada and Aliquat) and a mixed group designated as "other tribes", (Awlad Said, Gararsha, Sawalcha, Haweitat and Beni-Wassal). Alginate was the impression material used and the casts were made of artificial stone poured into the irreversible hydrocolloid impression. A total of 352 casts were available for study. In the maxilla, 29 dental discrete traits of permanent teeth and 2 traits of deciduous teeth were observed, and in the mandible, 24 traits of permanent teeth and 2 traits of deciduous teeth; in all, 57 traits were observed. Only clear traits were considered. From the studied 57 traits only 30 morphological traits were used for the estimation of the asymmetry. Total symmetry was observed in 2 mandibular teeth and traits: a) Lateral incisor-LI-slight inclination; b) Canine-Cn-no lingual cingulum and in 3 maxillary teeth and traits a) Central incisor-CI-slight convexity of labial profile curvature; b) First premolar-PM1-intercuspal distance more than 3 mm; and c) Second molar,-M2-pit groove pattern similar to the first molar. Low values of asymmetry (1-5.1%) were observed in traits describing outline form and shape, surface outline, and number of cusps in three maxillary and two mandibular teeth (nine discrete traits). High values of asymmetry (12.7-37.0%) were observed regarding traits describing styles on slopes, ridges, pits, grooves and lingual tubercles in three maxillary and one mandibular teeth (15 discrete traits). The high rate in molars was higher than that in the incisors. A higher rate of asymmetry occurred in the maxilla than in the mandible.
authors.affiliation: School of Dental Medicine, Tel Aviv University, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Moskona
authors.forename: M
authors.initials: M
authors.lastname: Vainder
authors.forename: I
authors.initials: I
authors.lastname: Hershkovitz
authors.forename: E
authors.initials: E
authors.lastname: Kobyliansky
mesh_terms: D000293:Adolescent; D002648:Child; D003431:Cross-Cultural Comparison; D003818:Dentition, Mixed; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D005828:Genetics, Population; D006801:Humans; D008297:Male; D008877:Middle East