Tooth Shape as a Psychomorphological Indicator of Personality: Clinical Observations

Background/Objectives: Harmony between tooth morphology and facial features is a key factor in aesthetic dentistry. The sufficient smile design requires the integration of functional, biological aspects, individual identity and personality traits. The present study investigated the relationship between the shape of teeth and personality characteristics. Methods: A cross-sectional observational study was conducted among 142 participants. Data were collected through a standardized questionnaire, including demographic indicators, assessment of the shape of the teeth and personality characteristics according to two models: type 1 (choleric, sanguine, melancholic, phlegmatic) and type 2 (extraversion, openness, conscientiousness, focus on others, neuroticism). Pearson’s χ² test and Cramer’s coefficient (V) were applied to analyze the dependencies. Results: A statistically significant relationship was found between tooth shape and personality type 1 (χ²(9)=61.96, p<0.001; V=0.38), with a medium to strong effect. The oval shape was associated mainly with melancholic temperament, the triangular shape with sanguine, the rectangular shape with choleric, and the square shape with melancholic and phlegmatic types. A significant relationship was also observed between tooth shape and personality type 2 (χ²(12)=41.82, p<0.001; V=0.31), with a medium effect, with the different morphological shapes showing specific distribution profiles according to personality traits. No statistically significant relationship was found between the two personality models (χ²(12)=18.10, p=0.113). Conclusions: The shape of the frontal teeth is associated with temperament-based and trait-oriented personality characteristics, with the relationship being stronger in the classical temperament typology. This supports the hypothesis that dental morphology may reflect biologically determined aspects of personality and be relevant to individualized aesthetic dental design.