Geometric morphometric shape assessment of juvenile mandibles

Authors

Tiffany Tran, A.A. Dugoni School of Dentistry, University of the PacificFollow
Vicki Lo, A.A. Dugoni School of Dentistry, University of the PacificFollow
Hee Soo Oh, A.A. Dugoni School of Dentistry, University of the PacificFollow
Gary D. Richards, A. A. Dugoni School of Dentistry, University of the PacificFollow

Lead Author Affiliation

DDS A.A. Dugoni School of Dentistry

Introduction/Context/Diagnosis

OBJECTIVES: We explore three-dimensional data to delineate idiosyncratic and progressive growth variation in 6.0-8.0 year old mandibles (n=45).

Methods/Treatment Plan

METHODS: Thirty-nine landmarks were digitized. Using Morphologika we assessed shape using Principle Components (PC) Analysis on Procrustes-aligned shape variables.

Results/Outcome

RESULTS: PC 1-4 explain 18.5, 12.0, 9.6, and 8.0% of the variance, respectively. PC1 becomes positive between 6.0-6.5 years, stabilizing after 7.0 years. This shows that the corpus-to-ramus angle becomes more obtuse between 6-7.0 years. Dimensions comprising PC1 stabilize but idiosyncratic variation increases between 7-8.0 years. PC2 shows little intergroup growth but a significant change in idiosyncratic variation related to corpus width. PC3 shows substantial lateral coronoid process growth and concomitant anterior chin progression related to idiosyncratic variation but little in the way of progressive age change.

Significance/Conclusions

CONCLUSIONS: Geometric morphometric methods allows visualization of the range of idiosyncratic variation in specific age groups but also the type and degree of shape change between minor increments of age.

This will was presented at the Annual Meeting of the California Dental Association, Anaheim, California May 17^th-19^th 2018.

Location

2nd floor clinic and reception waiting areas

Format

Poster