下顎

1. Origins, structure, and basic meaning

• Structure: 下顎, read かがく, combines lower 下 with jaw 顎 as the anatomical name of the lower jaw.
• Basic usage: It is the anatomical term for the lower jaw, as in 下顎の骨, and is read かがく.

2. Common pitfalls and similar expressions

• Tone and register
  • It is more technical than everyday 下あご and contrasts in position with the upper jaw 上顎.