An obturator in a cleft palate plate is primarily maintained by which of the following?

The primary mechanism by which an obturator in a cleft palate plate is maintained is through retention in the defect. The design of the obturator aims to fill the gap created by the cleft and create a stable and functional interface with the surrounding oral structures. This retention is essential for the obturator to effectively occlude the nasopharyngeal area, facilitating better speech and improving eating and swallowing.

Retention in the defect often involves conforming to the contours and walls of the cleft, which helps to secure the obturator in place. The specific adaptations made during the fabrication of the obturator contribute to its stability and functionality within the oral cavity, allowing it to remain in position even during normal movements like speaking and swallowing.

Other methods such as cohesion, atmospheric pressure, and patient support with the tongue can play supportive roles in stabilization or comfort but are secondary to the direct retention created by fitting the obturator to the cleft area itself. Thus, while these factors can contribute to the overall functioning of the obturator, they do not serve as the primary mechanism of retention.