Describing shape changes in the human mandible using elliptical Fourier functions.

Area of Science:

• Biomorphometrics
• Human Growth and Development
• Orthodontics

Background:

• Understanding mandibular growth is crucial for diagnosing and treating dentofacial abnormalities.
• Previous studies have utilized various methods to analyze craniofacial development.

Purpose of the Study:

• To quantitatively analyze changes in mandibular shape during growth using Elliptical Fourier functions (EFF).
• To identify specific areas of mandibular morphology that undergo significant changes during puberty.

Main Methods:

• Elliptical Fourier functions (EFF) were applied to the mandibular outlines of 24 subjects at ages 9, 11, 13, and 15.
• Area standardization and centroid superimposition were used for comparative shape analysis.
• Residual fit analysis confirmed the accuracy of the EFF model (mean residual fit 0.11 mm).

Main Results:

• No significant mandibular shape changes were detected between ages 9 and 11 years.
• Between ages 11 and 15 years, significant shape alterations were observed in the lower incisor, mental, mandibular body, and gonial angle regions.
• These observed changes in mandibular morphology align with the pubertal growth spurt.

Conclusions:

• Elliptical Fourier functions provide an accurate method for quantifying mandibular shape changes during adolescent growth.
• The pubertal growth spurt significantly influences specific regions of the mandible, including the lower incisor and gonial angle.
• These findings contribute to a better understanding of normal mandibular development and can inform orthodontic treatment planning.