Mouth, esophagus (food pipe), stomach, and intestines (K00-K67; K90-K93).
- Pulpitis (inflammation of the pulp, i.e., the tissue inside the tooth) – differential diagnosis to apical periodontitis (synonyms: apical periodontitis, apical osteitis, or root tip inflammation; from Latin apex ‘tip’; is inflammation at the root tip of a tooth)