For a full mouth examination, how many IOPAs are required for a child aged 8-9 years?

**Core Concept**
The full mouth examination in children involves taking intraoral periapical radiographs (IOPAs) to assess the development and status of their teeth. The number of IOPAs required depends on the age and size of the child.

**Why the Correct Answer is Right**
For a child aged 8-9 years, a full mouth series typically consists of 18-20 IOPAs. This is because the child's mouth is large enough to accommodate the necessary number of films for a comprehensive examination, but still requires a reduced number of films compared to adults. The American Academy of Pediatric Dentistry (AAPD) recommends a full mouth series for children aged 6-7 years, but for children aged 8-9 years, a reduced series of 18-20 IOPAs is sufficient.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because a full mouth series typically consists of more than 10 IOPAs for a child of this age.
* **Option B:** This option is incorrect because it implies that a full mouth series is not necessary for a child aged 8-9 years, which is not true.
* **Option D:** This option is incorrect because it suggests that a full mouth series is not relevant for a child of this age, which is not accurate.

**Clinical Pearl / High-Yield Fact**
When taking IOPAs in children, it's essential to use a reduced size film or a digital sensor to minimize radiation exposure and ensure accurate images.

**Correct Answer: C. 18-20 IOPAs.**