Method:
Eleven patients without tooth wear participated. A 3D stereophotograph was taken in 5 different situations; resting position, teeth in occlusion, with a 1mm-, a 3mm- or a 5mm resin block between the molars. Cephalometric measurements were performed on the 3D stereophotographs using the software program Maxilim, version 2.0.1 (medicim NV Mechelen, Belgium). To point out any differences, 4 distances were analyzed;
1) Subnasale - Gnathion, 2) Subnasale - Stomion, 3) Stomion - Gnathion and 4) Masseter left – Masseter right. A pairwise students’ T-test was applied to detect significant differences (p < 0,05). For reproducibility, the Pearson’s correlation coefficient was used, ( r> 0.8).
Result:
Statistically significant changes in facial appearance of the lower facial height were detected in all measured positions, tooth in occlusion, 1mm-, 3mm-, and 5mm block (p < 0.05). For the main distance (Subnasale – Gnathion) the measured differences were 3,2mm; 5,4mm and 6,6mm (resp. 1mm,- 3mm,- and 5mm block).
The reproducibility is high for all values based on the high correlation coefficient (r > 0.8), except for distance 3, Stomion – Gnathion, 5mm block (r < 0.55).
Conclusion:
With novel 3D stereophotograph imaging technology, it is possible to detect changes in facial appearance after an increase of vertical dimension of occlusion. The increase of the lower facial height was visible with a minimum of 1 mm.