Development of The Three-dimensional Dental Developmental Stage Model

Objectives: There have been many studies on the vicissitudes of dentition in children. However most of these studies relied on the findings of panoramic or cephalometric images, which are projection views of three-dimensional structures. The computed tomography (CT) images provide much more information, but have a relative higher radiation exposure. In this study, we used the CT data of dry skulls to observe the vicissitudes of dentition from primary to permanent dentition. The aim of this study was to develop a three-dimensional (3D) dental developmental stage model to provide useful information for dental students and clinicians.

Methods: The objects were 13 dry skulls which were in various developmental stages. The estimated age of these dry skulls was from 3 to 12 years of age. After we captured the CT images (Spiral CT, Radix Prima (Hitachi Medical Co.)), we reconstructed the 3D images for each developmental stage model using image analysis software Amira 3.1 (Mercury Computer Systems / 3D Viz group). Furthermore, the 3D primary and permanent dentition models which precisely expressed anatomical configuration were created. The anatomical configuration was given to each tooth model based on CT data with FreeForm and PHANToM (DICO Co.). Finally, we created the animation of tooth transition from primary to permanent dentition.

Results: We created 3D dental developmental stage models from the raw CT data sets of dry skulls. The transparency and color of each object that constitutes these models could be changed at your discretion.

Dentists and dental students can learn morphological characteristic of teeth and the process of tooth transition visually. In addition, they can understand the relation between position of teeth and tooth germs in the upper and lower alveolar bones three-dimensionally with our models.

Conclusion: Our 3D dental developmental stage model will provide useful information for dental students and clinicians.