The lingual angle of incisors

Area of Science:

• Anthropology
• Dentistry
• Human Genetics

Background:

• The lingual surface of incisors possesses a unique morphologic trait, the lingual angle, defined by the angle between the lingual fossa floor and the dental tubercle.
• This previously unregistered trait's potential for accurate measurement and its relationship with genetic and developmental factors warranted investigation.

Purpose of the Study:

• To investigate the lingual angle of incisors, a novel morphological trait on the lingual surface of human incisors.
• To analyze the distribution, variability, and correlations of this trait in a Norwegian population.
• To explore potential genetic influences and the role of the dental tubercle in determining the lingual angle.

Main Methods:

• Morphological analysis of the lingual angle of incisors in a Norwegian cohort.
• Statistical analysis including frequency distributions, skewness, kurtosis, and correlation assessments.
• Examination of bilateral asymmetry and sex-based differences.

Main Results:

• Mean lingual angles were recorded for maxillary and mandibular central (I1) and lateral (I2) incisors.
• No significant bilateral asymmetry or sex differences were observed.
• High correlations were found between homologous incisors, with lower correlations between central and lateral incisors, and across jaws, suggesting specific genetic determination.

Conclusions:

• The lingual angle of incisors is a measurable trait potentially influenced by genetic factors, as indicated by population-level similarities and correlation patterns.
• The dental tubercle appears to be a significant determinant of the lingual angle, providing insights into the incisor's lingual surface profile.
• This trait offers a new avenue for studying human dental morphology and its underlying genetic architecture.