Related Experiment Video
Updated: Aug 7, 2026

10:50
A Finite Element Approach for Locating the Center of Resistance of Maxillary Teeth
Published on: April 8, 2020
9.6K
Morphological differences between the first and second maxillary premolar crowns: A three-dimensional surface
Julie Miyazaki1, Shintaro Kondo2, Toyohisa Tanijiri3
1Department of Orthodontics, School of Dentistry at Matsudo, Nihon University, Chiba, Japan.
Journal of Oral Biosciences
|January 27, 2024
Summary
Maxillary first premolars (P1) are larger than second premolars (P2), with P1 exhibiting a more developed buccal cusp. These dental morphology differences are explained by developmental models.
Area of Science:
- Anthropology
- Dentistry
- Morphology
Background:
- Understanding tooth morphology is crucial for evolutionary and developmental studies.
- Maxillary premolars exhibit variations that may reflect genetic and environmental influences.
Purpose of the Study:
- To analyze the three-dimensional (3D) structure of maxillary first (P1) and second (P2) premolar crowns.
- To identify morphological differences, especially in cuspal structures, between P1 and P2.
Main Methods:
- Utilized 3D surface homologous modeling on plaster casts from 27 Japanese male students.
- Applied principal component (PC) analysis to 4498 anatomical data points, including 9 landmarks.
Main Results:
- P1 was significantly larger than P2, with similar intercuspal distances.
- PC analysis explained 61.5% of variance up to the fourth PC.
- P1 showed a more developed buccal cusp compared to the lingual cusp, unlike P2.
Conclusions:
- Mesiodistal and buccolingual variations in premolar size and cusp relationships can be elucidated by developmental biology.
- Morphological differences between P1 and P2 are significant and linked to developmental processes.
Related Concept Videos
Newman Projections
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as conformers.
Three-Dimensional Analysis of Strain
Three-dimensional strain analysis is crucial for understanding how materials deform under stress, particularly in elastic, homogeneous materials. This method employs principal stress axes to simplify complex stress states into more understandable forms. Subjected to stress, a small cubic element within a material either expands or contracts along these axes, transforming into a rectangular parallelepiped. This transformation effectively illustrates the material's deformation. The principal...

