Eskimo Dentition c59 



The Dentition of the Western and Central Eskimos 



By Stephen G. Ritchie, B.A., D.M.D., L.D.S. 



Dalhousie Uniiersity 



In the collection of skulls and mandibles under examination all the dentures 

 were complete or nearly complete at death. Owing to the primitive methods 

 of burial, with a few notable exceptions, the specimens are now partially or wholly 

 edentulous. 



All the teeth present, regardless of condition, have been where possible,, 

 carefully measured in millimetres after the method advocated and used by the 

 late Dr. G. V. Black of Chicago, and the measurements checked and tabulated 

 in tables I and II. Average and greatest measurements will be found side by 

 side for comparative purposes with similar measurements made and compiled 

 by Dr. Black from a very large number of miscellaneous teeth collected by him. 



A critical study of the teeth and jaws of the Eskimo is instructive and 

 interesting. The dental arches are large and beautifully formed, approaching 

 closely to the normal ideal Caucasian type as presented by Selenka and Rose.O 

 The curve of the arch is in all cases semi-elliptical and numerous measurements 

 and calculations made indicate that it is almost mathematically accurate. In 

 measuring the maxillse, a point that has hitherto, as far as I am aware, escaped 

 notice was observed, namely — that the anterior palatine foramen is located 

 exactly at the focus of the ellipse. The arches are broad and short, the greatest 

 breadth or minor axis of the ellipse being in the neighbourhood of the first and 

 second molars, the third molars and tuberosities of the jaws lying on the inward 

 falling, backward curve with a proportional decrease in breadth in this region. 

 To one accustomed to the malocclusions of the civilized races the symmetry of 

 the dental arcade in these Eskimo jaws is striking. Only the slightest trace of 

 irregularity is in evidence in two cases — in one the canines, in the other a pre- 

 molar being sUghtly out of alignment. 



The occlusion in this race seems to be universally prosharmotic, i.e., the 

 teeth meet edge to edge. When this condition maintains, the cusps of the 

 premolar and molar teeth are usually short and the occlusal plane is flat or 

 faintly curved in the antero-posterior direction. Such an arrangement permits 

 of greatly extended forward and lateral excursions of the lower jaw as contrasted 

 with the restricted movements of Caucasian dentitions where a more or less 

 pronounced overbite of the upper teeth with a markedly curved occlusal plane, 

 and length of tooth cusp developed accordingly, is the rule with few exceptions. 

 But an edge to edge bite has far-reaching consequences; no matter in what 

 race it is found the wear of the teeth is pronounced. In the Eskimo it reaches 

 the extreme. Here, at middle age, the crowns of the incisors in many cases are 

 completely worn away; the cusps of the second and third molars have disappeared; 

 and, in the first molar and premolar region in the maxilla the entire lingual and 

 occlusal portions of the teeth from the buccal marginal ridge to the cervical border 

 of the lingual surface have been ground away, leaving oblique planes which meet 

 and occlude with their counterparts in the mandible where the buccal aspect of 

 the teeth has been removed almost to the same extent, leaving the sharp occlusal 

 margins of the lingual enamel plates intact and highly polished flat surfaces 

 bevelled almost to the buccal gum margin. (See Plates II, III, IV and VI, 

 Cat. No. XIV, F. 4. 



