What department does the condition of being a "thick tongue" belong to?

Patient's question:

Main symptoms: Inaccurate pronunciation
Onset time: Since childhood
Laboratory test results: Have not had any tests done

Doctor's answer:

Dysarthria is a type of speech disorder, medically known as unclear speech or inarticulate speech, commonly referred to as "slurred speech." It is caused by spasms in the language center of the nervous system due to facial nerve palsy. During speech, pronunciation, articulation, and enunciation become unclear, making it difficult for listeners to understand. It is usually treated by the department of oral and maxillofacial surgery.