what is the difference between functioning with PM occlusion vs 1st molar vs 2nd molar
Liang 2015 -
0-2 occl pairs have 40% less occl function
3-5 occl pairs have 30% less function
SDA of 3-5 OU has occlusal stability (Witter 1994)
how many occl pairs do you need to function
Witter and Kayser group
3-5 OU has shown to provide adequate function and occlusal stability overtime
if its asymmetric tooth loss then 6U is required
no sig difference between SDA and CDA for: function, TMD disorderes, tooth migration, periodontal support, and oral comfort.
number of OU will decrease as you get older, but is up to patient preference and ability to function
what is the affect of occlusal adjustment on outcomes of perio therapy
Burgett 1992 - more CAL gain in the occl adj group than non-adj group after SRP, but no change in PD between the groups
initial mobility or perio severity did not affect the response of CAL with OA
is occlusal trauma related to gingival recession
no, Harrel and Nunn 2004 found no difference
if occl adj is done but the perio is not eliminated, what happens
Lindhe dog study - improvement in mobility and PDL space, but no improvement in CAL levels compared to groups with continued OT
how much decrease in function do you have with 3-5 OU and 0-2OU compared to CDA
3-5OU has 30% reduction in fn
0-2OU has 40% reduction in fn
clinical signs of OT
- fremitus
- mobility
- occlusal discrepancies
- wear facets
- tooth migration
- fractured tooth
- thermal sensitivity
- pain on chewing
radiographic signs of OT
- widened PDL
- cemental tear
- root resorption
how do you tx bruxism
Okeson - hard acrylic splint (not soft, as this has shown to actually increase the muscle activity)
why do you want light forces vs heavy forces
Gryson - Light forces (less than capillary pressure [20 to 25 mm Hg]) causes temporary ischemia in the PDl without cell death allows for continuous tooth movement with concomitant bone resorption and formation . this allows for frontal resorption which is less damaging and more efficient compared to undermining resorption.
Should orthodontics be used to upright a molar?
Brown - decrease in PD by 3.5mm and less bone loss
Kessler - risk of bone loss and furcation exposure
Lundgren - no difference in risk of periodontal disease so uprighting does NOT decrease risk of periodontal disease
can ortho be done in patients with perio
Boyd - demonstrated in a non-perio group and a healthy but reduced perio group, no difference in CAL. teeth that were lost were associated with furcation involvement and PD>6mm. there is no detrimental effect of ortho tx on healthy and reduced periodontium
can the periodontium regeneration once teeth are move lingually back into alveolar housing
yes, Karring 1982 - teeth moved labially had dehiscence and once they were moved back lingually, they showed complete bone regeneration and the CT fibers inserted perpendicularly with no CAL
is malalignment a risk factor for periodontal disease
it is controversial whether alignment affects perio directly since OH is a confounding factor.
Study by Ainamo found that malalignment does not enhance perio breakdown but it makes OH more difficult.
thus, crowding itself doesnt necessariily lead to perio breakdown unless there is poor plaque control
what is the effect of OT on a healthy periodontium
-increases mobility
-widened PDL
-bone loss
BUT NO CAL LOSS
what is the effect of removing OT on a healthy perio
bone regeneration occurs
what is the effect of OT on active periodontitis
-bone loss
-CAL loss
the amount of bone loss is similar to if you just have perio without OT
but the Lindhe/Ericsson group found more apical migration of the JE when OT is superimposed on perio
so with active perio, OT may enhance the disease progression
if you treat the OT, is it reversible?
if you treat only the OT, you may have an improvement in the mobility and narrowing of the PDL space but you cannot regenerate the CAL. if you leave the perio, you will continue to see CAL
