Occlusion Flashcards
Abfraction
Occlusal loading on surfaces causing tooth flexure (in the cervical area)
What are some clinical signs of trauma to the periodontum?
- Tooth fracture
- Increased tooth mobility
- Increased PDL space (radiographically)
- Tooth migration
- Pain on chewing
- Occlusal prematurities
- Fremitus
- Hypertrophy of muscles of mastication
- Temporomandibular joint dysfunction
- Wear facets
- Thermal sensitivity
- Root resorption
- Cemental tear
Is there a relationship between mobile teeth and success of
periodontal treatment?
Fleszar et al4 studied 82 patients for 8 years and found that pockets of
clinically mobile teeth do not respond as well to periodontal treatment as do
those of immobile teeth exhibiting the same initial disease severity.
Grant et al5 found significantly higher proportions of Campylobacter rectus
and Peptostreptococcus micros in pockets around mobile teeth compared
with those adjacent to nonmobile teeth. Elevated levels of Porphyromonas
gingivalis were also found around mobile teeth, but the difference was not
statistically significant. The authors concluded that tooth mobility and its
associated increase in subgingival levels of periodontopathogens may
present a periodontal risk.
McGuire and Nunn6 reported increased probing depth, initial furcation
involvement, initial mobility, initial percent bone loss, parafunctional habit with
no bite guard, and smoking were all related to the risk of tooth loss.
Fan and Caton1 found that reduction of tooth mobility may enhance the
effect of periodontal therapy.
What percentage of the population has canine protection?
Group function?
Goldstein8 found that 14% of study participants exhibited canine protection,
46% had group function, and 24% demonstrated a different disocclusion
pattern on each side.
What type of occlusion is ideal for patients with implants?
Sheridan et al9 found that:
…occlusal schemes for single implants or fixed partial denture supported by implants include a mutually protected occlusion with anterior guidance and evenly distributed contacts with wide freedom in centric relation.
Suggestions to reduce occlusal overload include reducing cantilevers, increasing the number of implants, increasing contact points, monitoring 129 Implants
for parafunctional habits, narrowing the occlusal table, decreasing cuspal inclines, and using progressive loading in patients with poor bone quality.
What can cause occlusal overload? What is the effect of
occlusal overload for implants?
Causes of occlusal overload:
* Large cantilevers
* Parafunctional habits/bruxism
* Steep cusp inclines
* Poor distribution of forces (limited contacts)
* Interferences
* Poor quality bone
Occlusal overload effects:
* Screw loosening
* Prosthesis failure
* Screw fracture
* Implant fixture fracture
* Implant failure
Sheridan et al9 found that:
Occlusal overload has been regarded as a major cause of biomechanical complications, including screw loosening, prosthesis failure, and the
fracture of screws, veneering material, or the implant. This is significant because these complications can be costly, time consuming, and some
complications, such as implant fixture fracture, can lead to implant failure. Kozlovsky et al reported that overloading the implant aggravated the plaque-induced bone resorption when peri-implant inflammation was present. Fu et al found occlusal overloading to be positively associated with peri-implant marginal bone loss.
Describe the classic animal studies in the United States and
Sweden.
The Americans’ and Swedes’ results were similar in the following ways1:
1. In animals without periodontitis, occlusal trauma resulted in increased mobility and loss of bone density without apparent loss of connective tissue attachment.
2. If trauma was removed from animals without periodontitis, the loss of bone density was largely reversible.
3. In the presence of periodontitis and occlusal trauma, there was greater loss of bone volume and increased mobility.
4. The studies found that without plaque-induced inflammation, occlusal trauma does not cause irreversible bone loss of connective tissue attachment.
Occlusal trauma alone did not appear to cause periodontitis, but
it may be a cofactor that can accelerate periodontal breakdown in the presence of periodontitis.
Occlusal Discrepancies
Ramfjord and Ash found that traumatic occlusion does not initiate or aggravate gingivitis or initiate pockets, but it can increase mobility and may accelerate bone loss and pocket formation, depending on the presence of
inflammation. Bruxism can perpetuate trauma. Splinting is not indicated in self-limiting trauma from occlusion but is indicated in conjunction with occlusal
adjustment when trauma from occlusion is progressive.
Can periodontal disease be affected by bruxism?
Hanamura et al27 found significantly greater alveolar bone loss, attachment loss, and tooth mobility in patients with moderate to severe periodontitis than
in patients with bruxism, while more tooth attrition was found in the bruxism patients. In most cases, periodontal disease and bruxism did not coexist in the same individual, and the authors concluded that in general there was no close association between the two conditions.
Is there greater gain of clinical periodontal attachment in patients
who received occlusal adjustment compared with those
who did not?
According to Burgett et al,29 there was a significant gain in attachment of 0.4 mm in patients who received occlusal adjustment. Pocket depth was not affected by occlusal adjustment, and the response to occlusal adjustment was not impacted by initial tooth mobility or periodontal disease severity.
How does orthodontics help a periodontal patient?
- Aligns the teeth and helps the patient with oral hygiene
- Can improve osseous defects (decrease need for resective surgery)
- Can force eruption to align the gingiva
- Can force eruption of a cracked tooth (at least 1:1 crown-to-root ratio)
- Closes open embrasures
- Improves adjacent tooth position before implant placement
