Which of the following would likely not be a factor when assessing the aesthetics of denture teeth?

When assessing the aesthetics of denture teeth, the arch form is typically not a primary factor. Aesthetics in this context primarily focuses on how the teeth look and fit within the overall facial appearance. Midline alignment, cuspal height, and facial contour directly influence the visual appeal and harmony of the denture with the patient's natural features.

Midline alignment is crucial as it ensures the central teeth align symmetrically with the center of the face, contributing to a balanced appearance. Cuspal height affects the functionality and visibility of the teeth when a patient smiles, directly impacting aesthetics. Facial contour is significant because it helps in the overall integration of the denture teeth with the patient's facial structure, enhancing the natural appearance.

On the other hand, arch form is more about the geometry and structure of the dental arch rather than the specific aesthetics of the teeth within that arch. While it is important for function and proper fit, it does not directly influence the visual aesthetics in the same way as the other factors. Therefore, it is likely to be considered less significant when specifically assessing the aesthetic appeal of denture teeth.