Abstract
In measuring basal crown and cusp areas of molars, one must determine a standard reference plane on which the projected measurements are made. In this paper, we present a new three-dimensionally based system which enables an objective determination of crown orientation. This is done by combining five laser scanned images of a molar taken occlusally and from four oblique angles to form a composite three-dimensional representation of the entire molar crown surface. Using this digitized data set, we derive a standard occlusal orientation that maximizes projected occlusal surface area. We can also choose other orientations for projection, such as those defined by the cervical line or cusp apices. Crown and cusp areas were measured in each of these orientations and compared for discrepancies on a mandibular first molar of Australopithecus afarensis. We found that orientations differ by more than 10 degrees, resulting in large discrepancies in cusp area values. It is concluded that, to enable reliable interpretation of cusp area data, whatever orientation methods used should be carefully chosen and rigidly followed.
| Original language | English |
|---|---|
| Pages (from-to) | 95-105 |
| Number of pages | 11 |
| Journal | Anthropological Science |
| Volume | 106 |
| Issue number | SUPPL. |
| Publication status | Published - 1998 |
| Externally published | Yes |
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Keywords
- Australopithecus afarensis
- Cusp area
- Orientation
- Three-dimensional metrics
ASJC Scopus subject areas
- Anthropology
Cite this
A refined method of measuring basal crown and Cusp areas by use of a three-dimensional digitizing system. / Suwa, Gen; Kono, Reiko.
In: Anthropological Science, Vol. 106, No. SUPPL., 1998, p. 95-105.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A refined method of measuring basal crown and Cusp areas by use of a three-dimensional digitizing system
AU - Suwa, Gen
AU - Kono, Reiko
PY - 1998
Y1 - 1998
N2 - In measuring basal crown and cusp areas of molars, one must determine a standard reference plane on which the projected measurements are made. In this paper, we present a new three-dimensionally based system which enables an objective determination of crown orientation. This is done by combining five laser scanned images of a molar taken occlusally and from four oblique angles to form a composite three-dimensional representation of the entire molar crown surface. Using this digitized data set, we derive a standard occlusal orientation that maximizes projected occlusal surface area. We can also choose other orientations for projection, such as those defined by the cervical line or cusp apices. Crown and cusp areas were measured in each of these orientations and compared for discrepancies on a mandibular first molar of Australopithecus afarensis. We found that orientations differ by more than 10 degrees, resulting in large discrepancies in cusp area values. It is concluded that, to enable reliable interpretation of cusp area data, whatever orientation methods used should be carefully chosen and rigidly followed.
AB - In measuring basal crown and cusp areas of molars, one must determine a standard reference plane on which the projected measurements are made. In this paper, we present a new three-dimensionally based system which enables an objective determination of crown orientation. This is done by combining five laser scanned images of a molar taken occlusally and from four oblique angles to form a composite three-dimensional representation of the entire molar crown surface. Using this digitized data set, we derive a standard occlusal orientation that maximizes projected occlusal surface area. We can also choose other orientations for projection, such as those defined by the cervical line or cusp apices. Crown and cusp areas were measured in each of these orientations and compared for discrepancies on a mandibular first molar of Australopithecus afarensis. We found that orientations differ by more than 10 degrees, resulting in large discrepancies in cusp area values. It is concluded that, to enable reliable interpretation of cusp area data, whatever orientation methods used should be carefully chosen and rigidly followed.
KW - Australopithecus afarensis
KW - Cusp area
KW - Orientation
KW - Three-dimensional metrics
UR - http://www.scopus.com/inward/record.url?scp=22644452107&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=22644452107&partnerID=8YFLogxK
M3 - Article
VL - 106
SP - 95
EP - 105
JO - Anthropological Science
JF - Anthropological Science
SN - 0918-7960
IS - SUPPL.
ER -