What defines a localized gingival enlargement?

A localized gingival enlargement is specifically characterized by the involvement of a single tooth or a group of teeth. This means that the enlargement is not widespread throughout the entire mouth, nor is it limited to just the papillae or interdental areas. Rather, it typically appears in specific areas where there may be localized factors contributing to the condition, such as plaque accumulation, dental restorations, or localized irritation.

The other options do not accurately define localized gingival enlargement. For instance, involvement of the entire oral cavity would characterize a generalized condition, not a localized one. Furthermore, while papillae can be affected as part of gingival enlargement, the term itself does not restrict the enlargement solely to the papillae. Lastly, while some individuals may experience discomfort, localized gingival enlargement is not always painful, as the degree of pain varies among individuals and might not be present at all. Therefore, the definition aligns accurately with option B, confirming it as the correct answer.