Occlusal splint therapy, occlusal adjustment, The Dahl Concept

Question 1

Types of splint therapy (5)

Answer 1

Occlusal splint
Michigan splint (upper)
Tanner appliance (lower
Stabilisation splint
Interocclusal appliance

Question 2

What can splints be made out of and which is better? (3)

Answer 2

Hard or soft acrylic

Hard acrylic is much more effective

Question 3

What is an occlusal splint? (3)

Answer 3

Removable device made of acrylic resin, which fits between the maxillary and mandibular teeth

Question 4

Indications for splint therapy (5)

Answer 4

TMJ dysfunction and pain
Diagnosis of occlusal disharmony
Establish centric relation prior to extensive rehabilitation
Severe bruxism
Protection of extensive dental work

Question 5

Goals of splint therapy (4)

Answer 5

Isolate the contact relations of teeth from masticatory system
To allow condyles to seat as optimally as possible thus stabilising and improving the
function of the TMJs
To allow optimal function of the neuromuscular system
Protect teeth from attrition and adverse loading

Question 6

Effectiveness of splint therapy (4)

Answer 6

Effective in muscle pain reduction in 70-90%
Most effective for pain of muscular origin
Pain relief after a few days or weeks - though some require several months
Important to adjust splint periodically to centric relation, and eliminate
grooves due to bruxism

Question 7

Features of occlusal splints (4)

Answer 7

Uniform contact in centric relation
Canine guidance to separate posterior teeth in eccentric excursions
Anterior guidance to separate posterior teeth in protrusion
Full coverage
 I.e. The splint creates an artificial ‘ideal’ occlusion

Question 8

Clinical stages of splint construction (3)

Answer 8

Visit 1
– Upper and lower alginate impressions
– Jaw registration in centric relation
– Facebow
Visit 2
– Fit splint
Subsequent visits
– Review and adjust as necessary

Question 9

How does the technician make a splint? (7)

Answer 9

Casts mounted, and incisal pin opened to give 2-3mm space
Outline drawn on casts
Two thicknesses wax adapted to cast and then shaped
Check disclusion in lateral and protrusive excursions
Finished wax up, showing contacts and anterior guidance
Fit splint
Splint seated and checked for retention and even contact

Question 10

Advantages of soft splints (4)

Answer 10

– Sometimes tolerated better by patients
– Easily constructed
– Cheap
– Useful for protection from trauma

Question 11

Disadvantages of soft splints (3)

Answer 11

 Difficult to adjust.
 Can encourage patient to brux
 Research has shown that muscle pain either did not change, or, in 26% cases,
it increased (Harkins and
Marteney, 1988)

Question 12

Definition of occlusal adjustment

Answer 12

Adjusting the occlusion to remove unwanted/interfering contacts, especially prior to restorative treatment

Question 13

Examples of uses of occlusal adjustment (3)

Answer 13

– Eliminating fremitus in a periodontally involved/ drifted tooth
– Reducing a cusp from an overerupted tooth prior to restoring the opposing tooth
eg. ‘plunging’ palatal cusp of upper molar
– Reducing load on a compromised tooth eg non-working side interferences, RCP contact etc

Question 14

Carrying out occlusal adjustment - tips (4)

Answer 14

 Be very careful and do not remove excessive tooth tissue
 You must have an accurate record of the occlusion prior to treatment
 It is much better to do it before restorative work – otherwise it looks like an excuse!
 You must get informed consent

Question 15

Definition of occlusal equilibration (1)

Answer 15

Reorganising the occlusion to give an ‘ideal’ occlusion by selectively adjusting tooth tissue

Question 16

Uses of occlusal equilibration (1)

Answer 16

Can be useful as a last resort for patients with TMD symptoms who have tried all other less invasive treatment modalities
Restricted to postgrad practice!
No longer really advocated at all

Question 17

What is the Dahl concept? (2)

Answer 17

any procedure where restorations are placed in supra-occlusion with the intention for the dentition to adapt to the altered occlusal scheme, in order to achieve even occlusal contact in ICP
through over eruption/ intrusion.

Question 18

Indications for the Dahl concept (3)

Answer 18

– Highly applicable to anterior tooth wear cases due to the loss of vertical tooth height
– Teeth can be restored to normal contour by increasing the vertical dimension of selected teeth without necessarily requiring restoration of all teeth in both arches
– However, not an excuse to cement any restoration high where it was not previously planned!

Question 19

Planning a case using the Dahl concept (5)

Answer 19

 Impressions, facebow and occlusal records (RCP)
 Diagnostic wax-up on articulated casts
 Patient information and consent!
 (Consider using a hard splint at the increased vertical dimension to check
patient tolerance)
 Undertake restorative procedures using the wax-up as your guide

Question 20

Practical aspects of using the Dahl concept (4)

Answer 20

 Warn patients regarding functional problems
for a number of weeks
 Movement often occurs quickly with occlusal
contact being achieved in 6-8 weeks, however it can take months
 Keep a record of occlusal changes and review the patient regularly
 Even very large increases in VD can usually be tolerated

Question 21

Problems with the Dahl concept (2)

Answer 21

 Most patients adapt very quickly but some may not adapt, however this is VERY rare
 In a very small number of patients tooth movement does not occur and
therefore these patients may require restorative intervention for the posterior teeth, such as onlays or crowns