The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Voi. XXXVII. Part B5. Beijing 2008 
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Figure3. Photogrammetric system for face 3D model 
reconstruction 
It includes two digital IEEE 1394 cameras, structured light 
projector and 5Mpix still digital camera for texturing face 3D 
model. Texture mapping is performed in automated mode 
basing on preliminary system calibration and exterior 
orientation. 
Resulting face 3D model has resolution of 1 mm which is quite 
enough for face measurements and visualisation (Figure 4.). 
But this resolution is low for teeth presentation and could not be 
used for teeth arch documenting. So another problem to solve is 
to create multi-resolution face 3D model including high 
resolution teeth arch 3D models. 
Figure 4. Textured face 3D model 
An original technique is developed for determining proper teeth 
arch 3D models position relatively to face 3D model. The 3D 
model for occlusion visualization and documenting includes a 
face 3D model and teeth arches 3D model. It is used for 
presenting the teeth appearance before and after treatment. 
3. SURFACE-BASED 3D MODEL POSITIONING 
The developed photogrammetric systems allow generating 3D 
models of teeth arches and of a patient face in automated mode. 
To support all tasks to be solved by a dentist a set of 3D models 
is required. It includes upper teeth arch 3D model, lower teeth 
arch 3D model, 3D models of some separate teeth, 3D models 
of separate prepared teeth and a 3D model of patient face. But 
each 3D model is obtained in its local coordinate system, so it is 
required to develop a technique for installing this set of models 
in proper position according a real case. Original techniques are 
developed for this problems solution (Knyaz, V., 2007). 
3.1 Teeth occlusion registration 
The first step is to install 3D models of upper and lower teeth 
arches in a given position according their location and 
orientation in a mouth. For this purpose plaster models are 
installed in given posture using a dental articulator or silicon 
mould for setup (Figure 5). Dental articulator is used for 
registering central (normal) occlusion. Silicon mould is made 
by dentist in a mouth, jaws being in given position according 
left or right side occlusion. 
Figure 5. Silicon moulds for plaster casts setup 
Then the silicon moulds are placed between plaster teeth arch 
models providing plaster models being in the same mutual 
position as real teeth arches in a mouth. In this position the 
front surface of upper and lower teeth rows is scanned. The 
scan of the teeth front surface is then used as a reference surface 
for jaw 3D models translating into attitude corresponding real 
jaws occlusion (Figure 6.). 
Figure 6.. The scan of the teeth front surface for teeth arch 3D 
models positioning