Maxillary canine anomalies and tooth agenesis

Area of Science:

• Dentistry
• Human Genetics
• Developmental Biology

Background:

• Tooth agenesis, the congenital absence of teeth, is a common dental anomaly.
• Maxillary canine-first premolar transposition (Mx.C.P1) and palatally displaced canines (PDC) are specific dental anomalies with potential links to agenesis.
• Understanding these associations can provide insights into dental development and genetic factors.

Purpose of the Study:

• To investigate the pattern of tooth agenesis in subjects with Mx.C.P1 and PDC.
• To compare the prevalence of tooth agenesis in these cohorts with existing literature.
• To explore potential genetic links, such as MSX1 or PAX9 genes, in the etiology of PDC.

Main Methods:

• Retrospective analysis of dental records from 26 subjects with Mx.C.P1 and 160 subjects with PDC.
• Statistical comparison of tooth agenesis prevalence (lateral incisor, lower second premolar, third molar) within the study groups and against reference values.
• Review of literature for comparative data and genetic association studies.

Main Results:

• A significant association was observed between Mx.C.P1 and agenesis of the lateral incisor (20% prevalence) and lower second premolar (24% prevalence).
• Third molar (M.3) agenesis showed a prevalence of 52.2% in the Mx.C.P1 group.
• Palatally displaced canines (PDC) exhibited weaker associations with lateral incisor (5%) and lower second premolar (5%) agenesis, with M.3 agenesis at 27.5%.

Conclusions:

• Mx.C.P1 is strongly associated with specific patterns of tooth agenesis, particularly lateral incisor and lower second premolar agenesis.
• PDC shows a less pronounced association with tooth agenesis, suggesting different underlying mechanisms.
• Current evidence does not strongly support the implication of MSX1 or PAX9 genes in the etiology of PDC.