## Core Concept
The growth and development of the mandible (lower jawbone) in humans involve various processes and stages. After the initial growth periods, the mandible continues to grow and change shape, particularly in response to the demands of the developing dentition and facial structures. Understanding the sites and periods of mandibular growth is crucial for orthodontics, oral surgery, and facial reconstruction.

## Why the Correct Answer is Right
The correct answer, , indicates that after the age of six, the increase in the size of the mandible occurs at the condyle. The mandibular condyle is a major growth site for the mandible. It is responsible for the bone growth that contributes to the increase in the length and height of the mandible. This growth happens through the process of endochondral ossification, where cartilage in the condyle is gradually replaced by bone tissue, allowing the mandible to elongate and adapt to the changing facial and dental structures.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because, although the alveolar process does contribute to the growth and changes in the shape of the mandible, particularly in response to tooth eruption, it is not the primary site for mandibular growth after the age of six.
- **Option B:** This option is incorrect because, while the mandibular growth does involve changes along the entire bone, specifying "the entire mandible" is too broad and does not accurately identify the primary site of growth.
- **Option C:** This option might seem plausible but is incorrect because, after the age of six, the primary growth site shifts more significantly to the condyle rather than being evenly distributed or at another specific location.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the mandibular condyle is a major growth center for the lower jaw. Understanding that significant mandibular growth occurs at the condyle after the age of six is crucial for planning orthodontic treatments and surgical interventions. Clinicians must consider the growth potential of the mandible when treating patients, especially during childhood and adolescence.

## Correct Answer: D. condyle