Each condition is considered benign and of unknown cause except one. Which one is the exception?

Name: Each condition is considered benign and of unknown cause except one. Which one is the exception?
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Question

Quizplus · Accepted Answer

Amelogenesis imperfecta represents a group of inherited conditions affecting the enamel of teeth. Hairy tongue is a benign condition of unknown cause. Migratory glossitis is a benign condition of unknown cause. Fissured tongue is a benign condition of unknown cause.

Each Condition Is Considered Benign and of Unknown Cause Except