TY - JOUR
T1 - Morphological variation of the maxillary lateral incisor
AU - Kondo, Shintaro
AU - Townsend, Grant
AU - Matsuno, Masanobu
N1 - Publisher Copyright:
© 2014 Japanese Association for Dental Science.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - The maxillary lateral incisor is a variable tooth morphologically. This tooth frequently shows reduction in size, and also various alterations in shape, for example, peg-shaped, cone-shaped, barrel-shaped and canine-shaped. The lateral incisor variant can be analyzed by family studies and using twin models, and these approaches have shown that genetic, epigenetic and environmental factors can all contribute to variation in the trait. Discordance of the phenotype in monozygotic twin pairs could be explained by the following two hypotheses: (1) the embryological environment of monochorionic twin pairs who share the same placenta and chorionic membrane during the prenatal period may differ, (2) phenotypic variation may be caused by epigenetic influences. Possible developmental factors are discussed in this review. Recent studies suggest that Msx1, Pax9 and Axin2 genes predispose to lateral incisor agenesis. Tooth reduction and agenesis seem to represent inter-related complex multifactorial traits, influenced by a combination of gene expression and function, environmental interaction and developing timing. Thus, accumulation of large data banks of morphological data is needed to support and clarify ongoing molecular genetic studies of dental development.
AB - The maxillary lateral incisor is a variable tooth morphologically. This tooth frequently shows reduction in size, and also various alterations in shape, for example, peg-shaped, cone-shaped, barrel-shaped and canine-shaped. The lateral incisor variant can be analyzed by family studies and using twin models, and these approaches have shown that genetic, epigenetic and environmental factors can all contribute to variation in the trait. Discordance of the phenotype in monozygotic twin pairs could be explained by the following two hypotheses: (1) the embryological environment of monochorionic twin pairs who share the same placenta and chorionic membrane during the prenatal period may differ, (2) phenotypic variation may be caused by epigenetic influences. Possible developmental factors are discussed in this review. Recent studies suggest that Msx1, Pax9 and Axin2 genes predispose to lateral incisor agenesis. Tooth reduction and agenesis seem to represent inter-related complex multifactorial traits, influenced by a combination of gene expression and function, environmental interaction and developing timing. Thus, accumulation of large data banks of morphological data is needed to support and clarify ongoing molecular genetic studies of dental development.
KW - Compensatory interactions
KW - Environmental factors
KW - Epigenetics
KW - Genetic factors
KW - Inhibitory cascade
KW - Twin model
UR - http://www.scopus.com/inward/record.url?scp=84908499766&partnerID=8YFLogxK
U2 - 10.1016/j.jdsr.2014.06.002
DO - 10.1016/j.jdsr.2014.06.002
M3 - Review article
AN - SCOPUS:84908499766
SN - 1882-7616
VL - 50
SP - 100
EP - 107
JO - Japanese Dental Science Review
JF - Japanese Dental Science Review
IS - 4
ER -