Face-bow registration and change of vertical dimension

Method: 33 subjects with complete dentures and absence of temporomandibular disorders (RDC/TMD) were included (Baseline = T0). After randomized allocation clinical remount technique of complete dentures was performed according to study groups: #1 in relation to mean settings, as given by the Bonwill-triangle and the Balkwill-angle or #2 arbitrary hinge axis with the aid of a face-bow registration. After occlusal adjustment until every posterior tooth had at least one occlusal contact point the prosthesis were incorporated. Operator as well as participants were blinded according to mounting method (mean setting vs. arbitrary hinge axis) of the models. Maintenance procedure was realized after 3(T1) and 84(T2) days and complied additionally with clinical need. Primary outcome was the change of OHRQoL measured with the Oral Health Impact Profile (OHIP-G49).

Result: Mean cumulative values of the OHIP-G49 were calculated for Group I (n=17; 62-98 years; f=8; m=9) at baseline T0=48, after 3 days T1=31 and after 84 days T2=29 and for group II (n=16; 44-93 years; f=13; m=3): T0=45, T1=42, T2=31. Mean summary score decreased for at least 6 scores: in Group I in 62.5% of the participants from point T0 to T1 and in 81.25% from T0 to T2; in Group II in 40.0% of the participants from T0 to T1 and in 64.3% from T0 to T2.

Conclusion: Oral health-related quality of life was improved in both interventional groups for the majority of participants after remount procedure in a clinical relevant dimension. Statistical Evaluation how far face-bow registration influenced the improvement of OHRQL as well as maintenance procedures is still in progress.