Tuesday, November 22, 2005

Genetic Algorithm and Dentistry

Hello!!!

I was surfing the Web and I found an interesting paper about Genetic Algorithm and Dentistry:

  • Reconstructing Occlusal Surfaces Of Teeth Using A Genetic Algorithm With Simulated Annealing Type Selection.


  • The authors are from Hosei University and The University of Aizu, both from Japan. I, honestly, thought the paper very nice. The principal idea is just the application of a Genetic Algorithm to solve a problem of Computer Aided Design(CAD) in Dentistry. Here we have the abstract:

    "In this paper, we present an application of numerical optimization for surface reconstruction (more precisely: reconstruction of missing parts of a real geometric object represented by volume data) by employing a specially designed genetic algorithm to solve a problem concerning computer-aided design in dentistry. Using a space mapping technique the surface of a given model tooth is fitted by a shape transformation to extrapolate (or reconstruct) the remaining surface of a patient's tooth with occurring damage such as a ?drill hole.? Thereby, the genetic algorithm minimizes the error of the approximation by optimizing a set of control points that determine the coefficients for spline functions, which in turn define a space transformation. The fitness function to be minimized by the genetic algorithm is the error between the transformed occlusal surface of the model tooth and the remaining occlusal surface of the damaged (drilled) tooth. The algorithm, that is used, is based upon a proposal by Mahfoud and Goldberg. It uses a simulated-annealing type selection scheme, which is applied sequentially (pair-wise, or one-by-one) to the members in the parent generation and their respective offspring generated by mutation-crossover. We outline a proof of convergence for this algorithm. The algorithm is parallel in regard to computing the fitness-values of creatures".

    I showed that paper and explained the key ideas to my friend that work as a Dentist in the Army and she stayed very impressed that computers could do things like that. After I told her that Evolutionary Computation could do much more for a wide range of fields, and cited an example that Evolutionary Computation could help in the production of prosthetic teeth through the optimization of its features: durability, the use of less material, the (sub-)optimal use of the teeth's pressure over the food and so on. She liked so much the Evolutionary Computation ideas.

    Até Mais!!

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