Occlusal Trauma
Definition:
To facilitate orientation and understanding of this topic , the following definitions applied to the review and discussion of the relationship between excessive occlusal forces and the priodontiw.
Occlusal trauma :- injury resulting in tissue changes within the attachment apparatus as a result of occlusal force (s).
Primary occlusal trauma :- injury resulting in tissue changes from excessive occclusal forces applied to a tooth or teeth with normal support. It occurs in the presence of:-
1- normal bone level
2- normal attachment level
3- excessive occlusal force (s).
Secondary occlusal trauma :- injury resulting in tissue changes from normal or excessive occlusal forces applied to a tooth or teeth with reduced support . it occurs in the presence of :-
1- bone loss.
2- attachment loss.
3- normal / excessive occlusal force(s).
Histological studies :-
The histological features of occlusal trauma have been studied extensively in animal and human autopsy materials.
Atterations of the periodontium that have been associated with occlusal trauma will vary with the magnitied and direction of applied force and location (pressure versus tension). Fig(1 and 2,3 and 4)
These changes many include widening / compression of the periodontal liqament , bone remeodeling (resorptio /repair) , hyalinization-necrosis , increased cellularity , vascular dilatation / permeability , thrombasis , root resaption and cemental tears. Collectived , these changes have been interpreted as an attempt by the periodontium to adapt and undergo repair in response to traumatoqenic occlusion .
Despite isolated reportse of apical miqration of junction epittdium accompanying excessive occulsal forces , studies generally have failed to disclose associated pocket formation while demonstration remarkable stability of the sharpey,s fibe and periodontal fibers cotonal to the alveolar bone.
In the absence of existing inflammation , it was noted that bony changes accompaniting occlusal trauma may be reversed by discontinuing offending occlusal force.
Clinical studies
Since occlusal trauma is a histologic lesion , clinical and radioqrophic indicators are necessary to assist in its dignosis .
Clinical indicators include :-
1- mobility ( progressive).
2- occlusal prematurities.
3- thermal sensitivity.
4- wear facets.
5-muscle tenderness.
6- fractured teeth.
7- migration of teeth.
Radioqraphic indicators :-
1- altered lamina dura.
2- widened periodonted ligament space
3-evidence of root resorption and or bon loss
Although increased tooth mobility is one of the most widely used indicater of oclusal trauma,it may result from bone loss independent of osslusal forces.
In a beagle dog study, jiggling occlusal forces in a healthy periodontion were associated with mobility,lass of marginal bone,& greater clinical plobing depths, but not with changes in the connective tissues attachment level.
The increased in plobing depth was attributed to enlargement &alteration of the supracrestal connective tissue compartment.
In studies investigating,teeth in patient with occlusal disharmonies(centric relation-centric occlusior,balancing,or protrusive gontacts) did not demonstrate any greater severity of periodontitis, when compared with teeth without such contact.
Effectes of non-function on the periodontium
In a study of non-functional teeth, periodontal chang include adecreased width of periodontal ligaments, increased thicriness of cementum, inflammation due to increased plague &calculus accumulation,& increased bone loss due to supraeruption.
These changes are consistent with those previously defined os preriodontal atrophy.
Figs. 15-5. If the crown of a tooth is exposed to excessive,
horizontally directed forces (arrow), pressure (P)
and tension (T) zones will develop within the marginal
and apical parts of the periodontium (a). The supraalveolar
connective tissue remains unaffected by
force application. Within the pressure and tension
zones tissue alterations take place which eventually allow
the tooth to tilt in the direction of the force. When
the tooth has escaped the trauma, complete regeneration
of the periodontal tissues takes place (b). There is
no apical downgrowth of the dentogingival epithelium
Pig. 15-7. Two mandibular premolars with normal periodontal tissues (a) are exposed to jiggling torces (e) as illustrated
by the two arrows. The combined tension and pressure zones (encircled areas) are characterized by signs of
acute inflammation including collagen resorption, bone resorption and cementum resorption. As a result of bone resorption
the periodontal ligament space gradually increases in size on both sides of the teeth as well as in the periapical
region. When the effect of the force applied has been compensated for by the increased width of the periodontal
ligament space (c), the ligament tissue shows no sign of inflammation. The supraalveolar connective tissue is
not affected by the jiggling forces and there is no apical downgrowth of the dentogingival epithelium. After occlusal
adjustment the width of the periodontal ligament becomes normalized (d) and the teeth are stabilized.
Fig. 15-10. A composite photomicrograph illustrating the interdental space between two pairs of teeth. The teeth
have been subjected to experimental, ligature-induced periodontitis and in (b) also to repetitive mechanical injury.
In (b), there is considerable loss of alveolar bone and an angular widening of the periodontal ligament space (arrows).
However, the apical downgrowth of the dentogingival epithelium in the two areas (a) and( b) is similar. E indicates
the apical level of the dentogingival epithelium. Courtesy of Dr. Meitner.
Fig. 15-11. Two mandibular premolars with supra- and subgingival plaque, advanced bone loss and periodontal
pockets of a suprabony character (a). Note the connective tissue infiltrate (shadowed areas) and the
noninflamed connective tissue between the alveolar bone and the apical portion of the infiltrate. If these teeth
are subjected to traumatizing forces of the jiggling type (b), pathologic and adaptive alterations occur within the
periodontal ligament space. These tissue alterations, which include bone resorption, result in a widened
periodontal ligament
space and increased tooth mobility but no further loss of connective tissue attachment (c). Occlusal adjustment results
in a reduction of the width of the periodontal ligament (d) and in less mobile teeth.
Fig. 15-12. Radiographic appearance of one test tooth (
T) and one control tooth (C) at the termination of an
experiment in which periodontitis was induced by ligature
placement and plaque accumulation and in which
trauma of the jiggling type was induced. Note angular
bone loss particularly around the mesial root of the
mandibular premolar (T) and the absence of such a defect
at the mandibular premolar (C). From Lindhe &
Svanberg (1974).
Fig. 15-13. Microphotographs from one control (C) and
one test (T) tooth after 240 days of experimental periodontal
tissue breakdown and 180 days of trauma
from occlusion of the jiggling type (T). The arrowheads
denote the apical position of the dentogingival epithelium.
The attachment loss is more pronounced in T
than in C. From Lindhe & Svanberg (1974).
Fig. 15-14. Illustration of a tooth where subgingival plaque has mediated the development of an infiltrated soft tis
sue (shadowed area) and an infrabony pocket (a). When trauma from occlusion of the jiggling type is inflicted (
arrows) on the crown of this tooth (b), the associated pathologic alterations occur within a zone of the
periodontium which is also occupied by the inflammatory cell infiltrate (shadowed area). In this situation the
increasing tooth mobility may also be associated with an enhanced loss of connective tissue attachment and
further downgrowth of dentogingival epithelium; compare arrows in (c) and (d). Occlusal adjustment will result in
a narrowing of the periodontal ligament, less tooth mobility, but no improvement of the attachment level (d) (
Lindhe & Ericsson 1982).
-how to diagnose trauma from occlusion?
Thisdepends on:
1-history:
a-teeth which are sensitive (not related to recession,caries,or broken fillings).
b-muscle pain
c-problems with TMJ (clicking,limitation in opening,or deviation).
2-examination:
a- attrition of teeth
There are 2 different types of bruxism(clenching,grinding).
b-decrease in vertical dimension.
The functional attrition is normally compensated by continuous deposition of cementus in the apical area which differs from bone in that it has no resorption.
c-some teeth with edges chipped.
d-broken restorations.
e-mobility of teeth(without periodontal disease or bone lesion).
f-changes in position of teeth
g-signs &symptoms of pulpal hyperemia or pulpitis without any obvious cause.
This could develop to pulpal necrosis then develope to periapical lesion.
3- x-ray;periapical x-ray
Widening in space of pdl
4- occlsal analysis
a-impression-cast-bite registration-mounted on fully adjustable articulater.the analyze occlusion and determine area of premature contact.
b-occlusion indicater
Treatment;
not every tfo require treatment just keep these patient under observation.
We should not change the pattern of occlusion unless we are sure that pattern is causing the proplem.
For example;sometimes the cause is the muscles[uncoordinated] so no matter how much we trim the teeth we wont solve the proplem.
1-interfering hopeless tooth-extraction.
2-new restoration of interfering teeth.
3-diminshed occlusal table require placement[bridge,partial denture….]
4-bite plane,night guard,now called[inter-occlusal appliance]
a-prevent teeth from fully interdigitating.
b-help in preventing or minimizing isomeric contraction of muscles.
c-abolish the effect of mechanoreceptors.
5-exercise for more harmonious occlusion.
6-portable electromyography contain warning system[feed back] measures the electric potential on the muscles.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .