In patients with shortened dental arches do removable dental prostheses improve masticatory performance?

Data sources PubMed, Medline, Cochrane Library, Embase and Science Direct.
Study selection: Studies published in English providing data on patients with shortened dental arch (SDA) and extreme SDA (ESDA) and masticatory performance with removable dental prostheses (RDP) were included.
Data extraction and synthesis Two reviewers independently selected studies and abstracted data, with disagreements being resolved by discussion.
Results Eight studies were included; four reported on comminution studies, three on mixing ability and one included both. In patients with ESDA comminution or mixing ability was 28-39% lower compared to patients with a complete dentition. In two studies, comminution outcomes when chewing with an RDP ranged from 2% to 32% reduction, indicating better chewing function (smaller X50) compared to comminution without the RDP. One study reported 28-83% lower mixing ability when chewing at the RDP side than chewing at the dentulous side. Generally, more artificial teeth (or longer occlusal platform) in experimental RDPs resulted in better comminution and better mixing ability (significant in four out of five studies), indicating a ‘dose-effect’ relationship. Two of the eight studies reported on biting force with higher maximum occlusal force for biting with natural teeth than for biting with artificial teeth in a distal-extension RDP.
Conclusions Within the limitations of this review it can be concluded that subjects with (E)SDA had a reduced masticatory performance in the order of 30-40%. Distal-extension RDPs compensated for this reduction only partially, namely in the order of 50%. RDP effects on chewing frequency were not conclusive.