McGrigor-Campbell lines are imaginary lines traced across the face on an occipitomental (Waters) view skull radiograph to assess for fractures:
- first line is traced from one zygomaticofrontal suture to another, across the superior edge of the orbits
- second line traces the zygomatic arch, crosses the zygomatic bone, and traces across the inferior orbital margins to the contralateral zygomatic arch
- third line connects the condyle and coronoid process of the mandible and the maxillary antra on both sides
- fourth line crosses the mandibular ramus and the occlusal plane of the teeth
The face is inspected for any asymmetry along these lines and Dolan's lines.