Age of child with 20 permanent teeth and 4 temporary teeth is: Kerala 08, 09; Punjab 10; UP 10
**Core Concept**
The age of a child can be estimated based on the number of permanent and temporary teeth present. This is a crucial skill in pediatric dentistry and forensic medicine.
**Why the Correct Answer is Right**
The correct answer is based on the fact that the eruption time of permanent teeth is relatively consistent in children. Typically, the first permanent teeth (incisors) erupt when the child is around 6 years old, followed by the eruption of first molars at around 10 years old. The presence of 20 permanent teeth, including 4 temporary teeth, suggests that the child is in the late mixed dentition stage. This corresponds to an age range of 9-11 years old. The exact age can be estimated by considering the number of permanent teeth erupted and the sequence of eruption.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is too young for a child with 20 permanent teeth, including 4 temporary teeth.
**Option B:** This option is incorrect because it is too old for a child with 20 permanent teeth, including 4 temporary teeth.
**Option C:** This option is incorrect because it is not consistent with the normal sequence of tooth eruption.
**Clinical Pearl / High-Yield Fact**
Remember that the eruption time of permanent teeth can vary, but the presence of 20 permanent teeth, including 4 temporary teeth, typically indicates an age range of 9-11 years old.
**Correct Answer:** C. 10 years