Ch 29 Periodontal Response to external forces
Last Modified: 2012-10-26
Marginal inflammation>bone loss>reduced periodontal ligament attachment area>change in leverage on remaining tissues>periodontium becomes vulnerable to injury>previously tolerated occlusal forces become traumatic
-Normal periodontium and reduced bone height=(secondary trauma from occlusion)
-Marginal periodontitis and reduced bone height=(secondary trauma from occlusion)
(see figure 29-3)
(figure 24-9 p472 ed10)
The ligament is widened at the expense of bone resulting in angular bone defects without periodontal pockets and
the tooth becomes loose
Damaged tissues are removed, new connective tissue, bone, cementum formed
forces remain traumatic only as long as damage produced exceeds reparative capacity of tissue
periodontium is remodeled -thickened periodontal ligament which is funnel shaped at the crest, angular defects in bone, no pocket formation, involved teeth become loose
-increased bone formation
What situations can cause it?
atrophy of fibers
osteoperosis of bone
reduction in bone height
hypofunction from open bite, lack of antagonistic tooth, unilateral chewing
presence of inflammation as result of plaque accumulation may affect it
in animals pulpal reactions noted unless force is minimal or occured over short periods-no pulpal reaction
It was bacterial plaque accuulation that initiated gingivitis and resulted in pp formation and affected marginal gingiva - trauma from occlusion occurs in supporting tissues and not in the gingiva
It is important to eliminate marginal inflammatory component in cases of trauma form occlusion because the presence of inflammation affects bone regeneration after the removal of the traumatizing contacts
therefore trauma from occlusion changes the architecture of the area around the inflamed site (though the trauma does not influence inflammation)
3-trauma induced areas are favorable for plaque and calculus may cause deeper lesions
4-supragigngival plaque becomes subgingival as tooth is tilted -favorable for infrabony pocket
5-loose teeth have a pumping effect on plaque metabolites increasing their diffusion
presence of inflammation==changes in shape of alveolar crest may be conducive to angular bone loss and existing pockets may become infrabony
2- Vertical rather than horizontal destruction of interdental areas
3-Radiolucency and condensation of alveolar bone
2-forces exerted on teeth (forces of occlusion, lips, cheeks, tongue)
thus path. migr. occurs under conditions that weaken the periodontal support,increase or modify forces exerted on teeth, or both
2-presence of full complement of teeth
3-physiologic tendency toward mesial migration
4-nature and location of contact point relationships
5-proximal, incisal, occlusal attrition
6-axial inclination of teeth
migration may continue after tooth no longer contacts its antagonist-tongue, food bolus, proliferating granulation tissue may provide the force
is also an early sign of "localized aggressive periodontitis"
excess tension= elongation of PDL fibers and apposition of alveolar bone, blood vessels are enlarged.
it is an important feature of the reparative process
also occurs when bone is destroyed by inflammation or osteolytic tumors
Words From Our Students
"StudyBlue is great for studying. I love the study guides, flashcards, and quizzes. So extremely helpful for all of my classes!"
Alice, Arizona State University
"I'm a student using StudyBlue, and I can 100% say that it helps me so much. Study materials for almost every subject in school are available in StudyBlue. It is so helpful for my education!"
Tim, University of Florida
"StudyBlue provides way more features than other studying apps, and thus allows me to learn very quickly! I actually feel much more comfortable taking my exams after I study with this app. It's amazing!"
Jennifer, Rutgers University
"I love flashcards but carrying around physical flashcards is cumbersome and simply outdated. StudyBlue is exactly what I was looking for!"