A Novel Protocol to Evaluate Hard and Soft Tissue Relationships in Three Dimensions without the Use of Additional Radiographic Studies.

Objective: The evaluation of hard and soft tissue relationships is an important part of the study of facial morphology, craniofacial development and orthodontic treatment and outcomes. Historically, this evaluation has occurred in two dimensions. The purpose of this study was to develop a protocol to study the relationships of hard and soft tissues in three dimensions without the use of additional radiation.

Materials and methods: Stereo photogrammetric images created by the 3dMDTM Face system and models digitized using the Motion View scanner were utilized. Using a previous lateral cephalometric image from the orthodontic records appointment, these hard tissue and soft tissue images were integrated.

Results: The integration of all data sets was accomplished with an average error rate of less than .05mm. A method was developed, thus allowing measurement of soft tissue thicknesses and changes over treatment time in relation to the underlying dentition.

Conclusions: Evaluation of hard and soft tissue relationship in three dimensions can be accomplished without the use of additional radiographic studies.