Size relationships among permanent mandibular molars in Aboriginal Australians and Papua New Guinea Highlanders

Abstract

Size relationships among crown units of permanent mandibular molars were investigated in two Sahul-Pacific samples: Aboriginal Australians (Yuendumu) and Papua New Guinea Highlanders (Wabag). Measurements of first, second, and third molars (M1, M2, and M3), including overall mesiodistal and buccolingual diameters as well as the mesiodistal and buccolingual diameters of the trigonid and talonid, were obtained from dental casts using a sliding caliper. Molar reduction was noted in talonid dimensions within both samples, but the trigonid mesiodistal diameter was not reduced in M2 or M3 compared with M1, indicating that the later-developing crown unit (talonid) was more reduced than the early-developing unit (trigonid). M2 was most reduced in size mesiodistally of the three molars, but its buccolingual diameter was not reduced. M3 was the most reduced tooth in trigonid buccolingual diameter. The percentage sexual dimorphism values were greater for the size of the talonid than for the trigonid, indicating that male values exceeded those for females by a greater amount in the later-developing crown unit. Crown dimensions were larger generally in the Aboriginal Australians from Yuendumu than in the Papua New Guinea Highlanders from Wabag, with differences being more evident in M2 and M3 than M1, especially in talonid dimensions. The trigonid, which develops early both phylogenetically and ontogenetically, tended to be relatively stable in size, whereas the later-forming talonid displayed size reduction when comparisons were made both within and between groups.

Odontometric sex discrimination in the herculaneum sample (79 AD, Naples, Italy), with application to juveniles

“…As a method of sex determination, odontometric analysis has been investigated over a long period of time (Garn et al,1967,1977; Sciulli et al,1977; Rösing,1983; Rao et al,1989; De Vito and Saunders,1990; Beyer‐Olsen and Alexandersen,1995; Lund,1999; Muller et al,2001; Pettenati‐Soubayroux et al,2002; Işcan and Kedici,2003; Kondo et al,2005; Okazaki,2005; Ateş et al,2006; Karaman,2006; Acharya and Mainali,2007; Vodanovíc et al,2007; Cardoso,2008), demonstrating that dental dimensions can be used successfully in sexual diagnosis in both living individuals and in skeletal remains in poor and/or fragmented condition.…”

Three‐dimensional (3D) geometric morphometric analysis of human premolars to assess sexual dimorphism and biological ancestry in Australian populations

“…For example, Yuendumu Aboriginals in Central Australia have relatively small teeth compared with other Indigenous groups (Brace, ). Nonetheless, Indigenous Australians generally show “megadontic” characteristics of their teeth (Kondo and Townsend, ), with larger deciduous and permanent teeth when compared to other populations (Brown, Margetts & Townsend, ; Margetts and Brown, ). For example, Yuendumu Aboriginals, who practiced a hunter‐gatherer lifestyle before moving onto a settlement, had larger teeth in all tooth classes when compared to Australians of European ancestry (Ashar et al, ).…”

Molar crown height: not always a reliable method for the evaluation of age-at-death

“…Size relationships among crown dimension of teeth, mainly based on bucco-lingual (BL) and mesio-distal (MD) dimensions, have been frequently considered a suitable solution for discriminating several human populations (Harris and Lease, 2005;Kondo et al, 2005), for evaluating secular trends in crown size between parents and their offspring (Harris et al, 2001) and for investigating sexual dimorphism inside specific human populations (PettenatiSoubayroux et al, 2002;Is¸can and Kedici, 2003).…”

“…The third molar was not considered because of the marked shape and size variability in the study population (Kondo et al, 2005) and because some authors consider it less reliable than the first and second molars for the assessment of age-at-death (Tomenchuk and Mayhall, 1979;Richards and Miller, 1991).…”