1. A method of constructing a virtual three-dimensional model of an object, comprising the steps of: scanning said object; creating a three-dimensional virtual model of said object from said scanning step with the aid of a computer, said three-dimensional virtual model having a first portion thereof corresponding to scanning of a known structure forming a part of said object, said known structure of predetermined three-dimensional configuration, wherein said first portion is a less than an ideal three-dimensional representation of said known structure; retrieving a three-dimension virtual object from a memory, said three-dimensional virtual object corresponding to said known structure; registering said three-dimensional virtual object to said first portion of said three-dimensional virtual model to form a three-dimensional surface; and forming said virtual three-dimensional model of said object, said three-dimensional model including said three-dimensional surface.