What is the likely cause of brownish calculus found on a child's incisors?

Brownish calculus on a child's incisors is most commonly associated with poor oral hygiene. When dental hygiene practices are inadequate, plaque—a sticky film of bacteria—accumulates on teeth. Over time, this plaque can harden into calculus (also known as tartar), which can appear brown due to the presence of various factors, including the foods and beverages consumed, as well as the oral environment itself.

The discoloration typically indicates that the calculus has been allowed to build up, usually due to insufficient brushing and flossing. Children, in particular, might not have the same level of commitment or ability to maintain oral hygiene as adults, making them more susceptible to the formation of calculus if they do not receive proper guidance and supervision.

Other potential causes like dietary factors, medications, or intrinsic stains can contribute to discoloration in teeth, but they are less likely to directly lead to brownish calculus. Dietary factors can affect staining but generally do not cause calculus buildup on their own. Similarly, some medications can change the color of teeth but do not cause calculus formation. Intrinsic stains usually refer to discoloration within the tooth structure itself and are not related to the accumulation of external deposits like calculus.