  In the orthognathic surgery, dental splints are important and necessary to
help the surgeon reposition the maxilla or mandible. However, the traditional
methods of manual design of dental splints are difficult and time-consuming.
The research on computer-aided design software for dental splints is rarely
reported. Our purpose is to develop a novel special software named EasySplint
to design the dental splints conveniently and efficiently. The design can be
divided into two steps, which are the generation of initial splint base and the
Boolean operation between it and the maxilla-mandibular model. The initial
splint base is formed by ruled surfaces reconstructed using the manually picked
points. Then, a method to accomplish Boolean operation based on the distance
filed of two meshes is proposed. The interference elimination can be conducted
on the basis of marching cubes algorithm and Boolean operation. The accuracy of
the dental splint can be guaranteed since the original mesh is utilized to form
the result surface. Using EasySplint, the dental splints can be designed in
about 10 minutes and saved as a stereo lithography (STL) file for 3D printing
in clinical applications. Three phantom experiments were conducted and the
efficiency of our method was demonstrated.
