A child diagnosed with Down syndrome exhibits mental retardation and moon-shaped facial features. Which of the following facial characteristics is commonly observed in such cases?

Explanation

Children with Down syndrome often present with maxillary hypoplasia, which means the upper jaw is underdeveloped. This contributes to their distinctive facial appearance, including the characteristic moon face. Other options such as maxillary prognathism or mandibular prognathism do not typically describe the facial features seen in Down syndrome.