Short Answer
Bring it if possible. The fit, purpose, wear pattern, comfort, and symptom response can provide useful clues.
How to think about it
A splint is not automatically good or bad. It should be interpreted with symptoms, jaw movement, muscle tenderness, bite contact, and when symptoms improved or worsened.
Evidence and limits for this question
What this question checks
This page uses the question "What if I already have a splint or mouthguard?" to organize a symptom pattern before assuming a TMJ-related cause.
What to rule out first
Urgent, organ-specific, dental, ENT, neurologic, traumatic, infectious, or breathing-related warning signs should be considered before jaw-related interpretation.
What is reviewed in clinic
Consultation details, symptom timing, jaw movement, chewing muscle tension, bite changes, previous exam results, and recurrence patterns may be reviewed together.
What not to decide from this page
Do not use this page alone to choose a diagnosis, appliance, procedure, medication, or emergency response.
Safety note
Do not adjust, stop, or replace an appliance based only on web content. The next step depends on evaluation.