Objectives: The purpose was to determine the influence of maxillary implant overdentures with and without palatal coverage on spirometric parameters.
Materials and methods: 14 healthy edentulous patients were participated in this study. All patients were received 4 implants in maxillary arch in canines premolars areas and 2 implants in mandibular canines areas. All patients were received 2 maxillary implant overdentures “with and without palatal coverage" and one mandibular implant overdenture. Locator attachments were used to anchor the overdentures. Spirometry test was performed in three different oral conditions: without prosthesis , with maxillary implant overdenture with palatal coverage, and with palateless implant overdenture. The test was done after 2 months of each overdenture delivery. Spirmetric parameters as, Vital capacity (VC), Peak expiratory flow (PEF), Forced expiratory volume in 1 sec. (FEV1), FEV1/FVC (Forced vital capacity), and Maximum expiratory flow between 25% and 75% (MEF25-75) were evaluated.

Results: There was statistically significant reduction in VC, FEV1/FVC, and MEF25-75 for without prosthesis compared to maxillary implant overdenture with or without palatal coverage (p <0.05). Also, there was statistically significant increase in VC, FEV1/FVC, and MEF25-75 for palateless implant overdenture compared to maxillary implant overdenture with palatal coverage (p <0.05). While there were no significant differences between the different oral conditions in FEV1, and PEF (p >0.05).

Conclusion: Covering the palate by dental prosthesis had an adverse effect on respiratory function as using the palateless implant overdenture showed improvement in respiratory performance in comparison to maxillary implant overdenture with palatal coverage.