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Macrodontic maxillary second primary molar in an Eskimo skull A morphogenetic study
Author(s) -
JAKOBSEN JAN,
ALEXANDERSEN VERNER
Publication year - 1970
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.1970.tb02105.x
Subject(s) - supernumerary , skull , molar , mathematics , tooth crown , crown (dentistry) , ridge , anatomy , orthodontics , paleontology , geology , biology , medicine
— The anomalous maxillary second primary molar of an Eskimo skull is described. The skull was found at Nugarssuk (Upernavik District, West Greenland). The slightly worn left Dm 2 displayed the following three anomalies: (1) increased mesiodistal crown diameter, (2) increased size of the mesiolingual portion of the crown and (3) supernumerary mesiolingual root. The morphogenesis of the anomalous tooth is discussed. The mesiodistal crown diameters of the two Dm 2 belonging to the skull showed a difference of 1.35 mm. Assuming a bilateral size asymmetry with mean zero and standard deviation 0.14 (based on 19 pairs of Eskimo Dm 2 ), the difference observed falls outside the range of normal variation. It is concluded that the enlarged molar represents a “gemination”. The morphology of the anomalous Dm 2 is compatible with the view that the tooth originated as an enlarged tooth germ. During the initial phase of growth the increase in size is predominantly in mesiodistal direction. The proportional changes of the dental papilla led to accentuation of the mesiolingual portion of the crown with formation of a mesiolingual cusplet termed protoconule. During root formation a supernumerary root was formed in association with the enlarged mesiolingual portion of the crown.