**Core Concept**
The crown completion of maxillary third molars is a critical aspect of dental anatomy, influenced by the complex interactions between genetic, hormonal, and environmental factors. The timing of crown completion is essential for understanding the development and eruption of third molars in the human dentition.

**Why the Correct Answer is Right**
The crown completion of maxillary third molars typically occurs between 12 to 16 years of age. This timing is influenced by the continuous growth and development of the jaw, particularly the maxilla and mandible, which accommodate the eruption of third molars. The mesial and distal roots of the maxillary third molar develop simultaneously, with the mesial root often completing its development before the distal root.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect as the crown completion of maxillary third molars does not typically occur before the age of 10.
**Option B:** This is incorrect as the crown completion of maxillary third molars does not typically occur after the age of 18.
**Option C:** This is incorrect as the crown completion of maxillary third molars does not typically occur between 8 to 10 years of age.

**Clinical Pearl / High-Yield Fact**
The timing of crown completion of maxillary third molars is an essential factor in the diagnosis and management of impactions, supernumerary teeth, and other developmental anomalies.

**Correct Answer: C. 12 to 16 years of age.**