We propose a smart mandibular advancement device (MAD) that can monitor cardiorespiratory parameters intraorally. The device comprises a flexible hybrid wireless monitoring platform integrated with a MAD. This monitoring platform is based on acquiring the intraoral photoplethysmography (PPG) signals. It is designed on a double-sided flexible polyimide substrate. Our experimental measurements show that the PPG signals captured intraorally are highly correlated with the conventional PPG signals received from the fingertip. Intraoral PPG signals have vital information as well as adequate quality to be utilized for estimation of multiple-physiological parameters, such as heart-rate (HR), respiration rate (RR), respiration pattern (RP) and blood oxygen saturation (SpO2). The estimated values of HR, RR, and SpO2 from the intraoral PPG signals recorded by our smart MAD show an accuracy of over 96% with reference to the conventional monitoring techniques.