Measurement of tooth morphology has numerous applications in dental research. Image analysis in 2D has brought valuable advances over hand measurement. A reliable 3D methodology would increase the information available such as actual surface area, volume and contours of the teeth. Objectives: To develop a methodology for the 3D measurement of teeth and to validate this against the established 2D system. Methods: For each of twenty study models the permanent upper right lateral and upper left central incisors were cut out and imaged independently by two operators using 2D image analysis and a 3D laser scanning system. The mesio-distal (MD), bucco-lingual (BL) and inciso-gingival (IG) dimensions were recorded using the 2D system and the same projected variables were recorded using the 3D system for comparison. Repeat images and measurements were recorded one week later to assess reliability. 3D analysis was then used to calculate the reliability of the same variables but following the contours of the teeth (MDa, BLa and IGa) as well as the total 360° crown surface area (SA). Results:
|
|
(Upper right laterals) Variables |
||||||
|
|
MD |
BL |
IG |
MDa |
BLa |
IGa |
SA |
|
Correlation |
0.943 |
0.672 |
0.989 |
|
|
|
|
|
Inter-Reliability 2D |
0.779 |
0.818 |
0.919 |
|
|
|
|
|
Inter-Reliability 3D |
0.940 |
0.781 |
0.967 |
0.838 |
0.820 |
0.906 |
0.991 |
|
|
(Upper left centrals) Variables |
||||||
|
|
MD |
BL |
IG |
MDa |
BLa |
IGa |
SA |
|
Correlation |
0.931 |
0.530 |
0.947 |
|
|
|
|
|
Inter-Reliability 2D |
0.880 |
0.946 |
0.951 |
|
|
|
|
|
Inter-Reliability 3D |
0.918 |
0.561 |
0.975 |
0.759 |
0.704 |
0.967 |
0.988 |