Adherence to oral appliance treatment for obstructive sleep apnea in patients with continuous positive airway pressure failure.

Purpose: The primary aim of this study was to determine the continuation and success rates of oral appliance (OA) therapy for patients in whom continuous positive airway pressure (CPAP) therapy failed. The secondary aim was to identify predictive factors for the long-term use of OA in patients with CPAP failure.

Methods: A total of 81 patients who failed with CPAP use were included in this study.

Molecular structure and internal rotation of CF₃ group of methyl trifluoroacetate: gas electron diffraction, microwave spectroscopy, and quantum chemical calculation studies.

The molecular structure of methyl trifluoroacetate (CF3COOCH3) has been determined by gas electron diffraction (GED), microwave spectroscopy (MW), and quantum chemical calculations (QC). QC study provides the optimized geometries and force constants of the molecule. They were used to estimate the structural model for GED study and to calculate the vibrational corrections for GED and MW data.