Abstract:

Objective To investigate the chewing function of zero-degree occlusal dentures after restoration. Methods Twenty patients with complete dentures were divided into zero-degree occlusal dentures group and anatomic occlusal dentures group, with 10 patients in each group. Bilateral temporalis and masseter activities were examined by electromyography soon after denture placement and one month after denture placement, and the chewing efficiencies of these two dentures were compared. Results There was no significant difference in peak electromyographic values between zerodegree occlusal dentures group and anatomic occlusal dentures group soon after denture placement and one month after denture placement (P>0.05). The peak electromyographic value of tapping teeth movement one month after denture placement was significantly higher than that soon after denture placement in anatomic occlusal dentures group (P<0.05), while there was no significant difference in zero-degree occlusal dentures group (P>0.05). The resting phase of electromyographic activity one month after denture placement was significantly shorter than that soon after denture placement in zero-degree occlusal dentures group (P<0.05), and was significantly shorter than that one month after denture placement in anatomic occlusal dentures group (P<0.05). There was no significant difference in the chewing efficiencies one month after denture placement between two groups (P>0.05). Conclusion Zero-degree occlusal dentures can produce similar masticatory function as anatomic occlusal dentures and better adaptiveness for patients with unfavorable alveolar ridge.

Key words: zero-degree occlusal dentures, complete dentures, electromyograph, chewing efficiency