While participating in dental anthropol- ogy sessions at the past two American Asso- ciation of Physical Anthropologists meet- ings, we observed cases of ...
AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 99:357-359 (1996)
Notes and Comments a
Technical Note: Canine Mesial Ridge (Bushman Canine) Dental Trait Definition
b
Joel D. Irish and Donald H. Morris Department of Anthropology, University of New Mexico, Albuquerque, New Mexico 87131-1086 (J.D.I.), and Department of Anthropology, Arizona State University, Tempe, Arizona 85287-2402 (D.H.M.)
Fig. 1. Maxillary right normal (a)and Bushman canine (b).Note (1) hypertrophied mesial lingual ridge coalesced with tuberculum dentale, and (2) distally positioned lingual sulcus on affected tooth. Redrawn from Morris (1975).
While participating in dental anthropology sessions a t the past two American Association of Physical Anthropologists meetings, we observed cases of misidentification of the dental morphological variant known phied mesial ridge and tubercle, which have coalesced as the Bushman canine, or canine mesial so completely that they cannot be identified separately. The feature is not a cingulum because it is ridge, in non-African human dental samples. neither a ring or rim of enamel, nor is it confined to Numerous studies have shown that the trait the gingival portion of the tooth. Canines may have is entirely absent or occurs in very low frelarge tubercles or large mesial ridges yet not be simiquencies in non-African populations (e.g., lar to the Bushman canine. I consider a tooth to be affected ifthe hypertrophied area and a single distally Morris, 1975; Turner 1985, 1992a,b; Irish, positioned lingual sulcus are present (see Figs. 1 n.d.; Hawkey, personal communication, and 2). 1994; Hemphill, personal communication, 1994). However, it occurs in up to 40+ perSubsequently, Turner et al. (1991:16) decent of southern African Khoisan-speaking scribed the canine variant: peoples (i.e., San and Khoikhoi),and exhibits a significant Pan-African distribution (see Normally, the mesiolingual marginal ridge of the upper canine is similar in size to the distolingual Morris, 1975; Sakuma et al., 1991; Irish, marginal ridge. Occasionally, the mesial ridge is 1993, 1994, 1995; Irish and Turner, 1990). larger than the distal, and, in pronounced cases, i t Therefore, we feel that the trait’s definition possesses a distal deflection approximately twoshould be reiterated to help prevent future thirds of the way down from the occlusal surface due to its attachment to the tuberculum dentale. misidentification by dental researchers and thus maintain its utility as part of a diagnosTurner et al. (1991:16-17) also divided the tic suite of African dental attributes (see trait into four rank-scale grades (Fig. 3) of Irish, 1993, 1994, 1995). The unique “premo1ariform”-shaped ca- expression (0-3) for the ASU Dental Anthronine was first noted in African samples by pology System: Oranje (1934) and Galloway (1937, 1959). 0. Mesial and distal lingual ridges are the However, it was not systematically studied until Morris’ 1975 investigation. His (1975:334) original definition of the trait states: Received November 10, 1994; accepted July 24, 1995. . , . the lingual surface [of the maxillary canine] is
Address reprint requests to Dr. Joel D. Irish, Department of Anthropology, University of New Mexico, Albuquerque, NM
dominated by what one might consider a hypertro-
87131-1086.
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J.D. IRISH AND D.H. MORRIS
Fig. 2. Bushman canine present in a cast from a male Chewa individual from Malawi. Cast by M. Sakuma.
Fig. 3. Bushman canine plaque from Arizona State University Dental Anthropology System
same size. Neither is attached to the tuberculum dentale if present. 1. Mesiolingual ridge is larger than distolingual, and is weakly attached to the tuberculum dentale. 2. Mesiolingual ridge is larger than the distolingual, and is moderately attached to the tuberculum dentale.
3. Morris’ type form. Mesiolingual ridge is much larger than the distolingual, and is fully incoporated into the tuberculum dentale.
In the ASU System, the trait is considered to be present if the tooth is assigned a grade of 1-3. We feel that these grades, which arbi-
NOTES AND COMMENTS
trarily partition a continuum of expression from a normal canine to a fully formed Bushman canine, appropriately describe the variation seen in the Africans that we have studied. However, a s stressed by Turner (n.d.; Turner et al., 1991) for all traits, the plaques must be used in conjunction with the accompanying written definitions. In the case of the Bushman caninelcanine mesial ridge, the plaque’s grades 1and 3 clearly represent expressions of the trait. However, the grade 2 example is not a s obvious-if used without the written grade 2 definition. Thus, this situation may lead to some of the confusion, although many errors are likely due to simple misidentification; and misidentification may particularly be a problem in samples which have low or no occurrence of the trait, where the worker may, after repeatedly observing unaffected canines, mistakenly “see” the feature. ACKNOWLEDGMENTS We thank Ms. Diane Hawkey and Dr. Christy Turner from Arizona State University and Dr. Brian Hemphill from Vanderbilt University for their input. This research was supported by the National Science Foundation (BNS-9013942), the Arizona State University Research Development Program, and the American Museum of Natural History. LITERATURE CITED Galloway A (1937) The skeletal remains of Mapungubwe. In L. Fouche (ed.): Mapungubwe: Ancient Bantu Civilization on the Limpopo. Cambridge: University Press, pp. 127-174. Galloway A (1959)The Skeletal Remains of Bambandyanalo. Johannesburg: Witwatersrand University Press.
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Irish J D (n.d.) Incidence of the Bushman canine trait in Latte period (AD 1000) Micronesians from Guam. Manuscript in possession of the author. Irish J D (1993) Biological Affinities of Late Pleistocene through Modern African Aboriginal Populations: The Dental Evidence. Ph.D. dissertation, Arizona State University, Tempe. Irish J D (1994) The African dental complex: Diagnostic morphological variants of modern sub-Saharan populations. Am. J . Phys. Anthropol. Supplement 18:112. Irish J D (1995) High frequency archaic dental traits in modern sub-Saharan African populations. Am. J . Phys. Anthropol. Supplement 20:117. Irish JD, and Turner CG I1 (1990) West African dental affinity of late Pleistocene Nubians: Peopling of the Eurafrican-South Asian triangle 11. Homo 41:42-53. Morris DH (1975) Bushman maxillary canine polymorphism. S. Afr. J . Sci. 71:333-335. Oranje P (1934) The dentition of the Bush race. S. Afr. J . Sci. 31.576. Sakuma M, Irish JD, and Morris DH (1991) The Bushman maxillary canine of the Chewa Tribe in eastcentral Africa. J . Anthropol. SOC.Nippon 99:411-417. Turner CG I1 (n.d.1 ASU Dental Anthropology System: Scoring Procedures for Key Morhological Traits of the Permanent Dentition. Unpublished laboratory manual. Arizona State University, Tempe. Turner CG I1 (1985)The dental search for Native American origins. In R Kirk and E Szathmary (eds.): Out of Asia: Peopling the Americas and the Pacific. Canberra: The Journal of Pacific History, pp. 31-78. Turner CG I1 (1992a)The dental bridge between Australia and Asia: Following Macintosh into the East Asian hearth of humanity. Perspect. Hum. Biol. 2/Archaeol. Oceania 27:120-127. Turner CG I1 (199213) Microevolution of East Asian and European populations: A dental perspective. In T Akaszawa, KAoki, and T Kimura (eds.):The Evolution and Dispersal of Modern Humans in Asia. Tokyo: Hokusen-Sha Publishing Co., pp. 415-438. Turner CG 11, Nichol CR, and Scott GR (1991) Scoring procedures for key morphological traits of the permanent dentition: The Arizona State University dental anthropology system. In MA Kelley and CS Larsen (eds.): Advances in Dental Anthropology. New York: Wiley-Liss, pp. 13-32.
