## **Core Concept**
Koplik spots are small, white spots that appear on the buccal mucosa during the early stages of measles (rubeola). They are a prodromal sign, appearing before the characteristic rash. These spots are pathognomonic for measles.

## **Why the Correct Answer is Right**
Koplik spots typically appear 1-2 days before the onset of the measles rash and are usually found on the buccal mucosa opposite the second molars. They are a result of the viral infection causing localized necrosis of the epithelial cells. The appearance of Koplik spots in relation to the second molars is a classic clinical finding.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because Koplik spots are not specifically associated with the first molars.
- **Option B:** This option is incorrect as there is no common association of Koplik spots with the canines in the context of measles.
- **Option D:** This option is incorrect because Koplik spots are not associated with the incisors.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that Koplik spots are an early diagnostic clue for measles. They appear as small, white or bluish spots on the buccal mucosa and are particularly noted opposite the second molars. Recognizing these spots can lead to early diagnosis and management of measles.

## **Correct Answer:** C. Second molars.