What type of toothbrush head is described as being used by all three patients?

• A. Round head
• B. Oval head
• C. Square head
• D. Teardrop head

Answer: (A)

The main idea here is how toothbrush head shapes influence cleaning coverage and how a description in the case points to a specific shape. All three patients are described as using a round-headed toothbrush. A round (circular) head is designed so each tooth can be reached by bristles from multiple angles as you use gentle circular motions, helping to surround and clean around each tooth and along the gumline. This round geometry is a common feature in many popular brushes, making it a natural commonality across different patients in a case description.

Other shapes like oval, square, or teardrop are less likely to be described as a universal feature across three patients in the same way, because their contact patterns and contours don’t fit as neatly with the idea of “used by all three” in many standard descriptions. The round head best fits the description provided, aligning with how the patients’ brushing is portrayed.