Basic Concepts in Occlusion (4)

9. Bruxism and TMJ disorder

a.  pain often caused by stress-induced parafunctional habits (bruxism & clenching)

b. signs and symptoms

• dislocation: the condyle moves too far forward and get stuck
• pain from the joints on opening and chewing
• tender teeth, especially on percussion and grinding
• bi-lateral sore tongue and cheeks
• muscle tenderness, especially in the mornings
• clicking noise
• jaw locking
• difficulty in opening the mouth, i.e. trismus
• wear facets on occlusal surfaces

c.  treatment:

• pain relief (best with NSAID, e.g. Ibuprofen)
• rest, soft food, relaxation
• exercise
• hard bite guard (Occlusal Splint, Michigan Splint) or soft;
• mostly on the upper teeth

d. other painful joint conditions: accidental injury, arthritis (rheumatoid or osteo-arthritis)

10. Edentulous VS dentate

a.  edentulous àaim for balanced occlusion in the setup

b. dentate ­àfollow the existing or designed guidances

11. Practical tips for DSAs.

• use slightly over-sized trays, must cover all the teeth
• must have accurate study casts: properly washed impressions and keep them moist; cut off unsupported alginate heels; pour immediately; avoid bubbles (use vibration)
• make sure there are no blobs of plaster on the occlusal surfaces or over-extended edges at the back ends that stop the casts from accurate positioning
• set up the articulator correctly
• moisten the bottom of the grooved casts for better adhesion
• mount the casts on the articulator correctly, use minimum of thick low expansion plaster first, add more plaster to build up the mass after the initial stem has set.
• for better finish use wet finger before the final set, then use wet sandpaper afterwards
• mark the cast with patients’ names and date of production

Reference information: www.bjdental.com/

It is not intended as medical advice to any specific person. If you have any need for personal advice or have any questions regarding your health, please consult your Dentist for diagnosis and treatment.