[Functional research methods in the diagnosis of traumatic over- and underloading of the teeth]

Rheography and step-type discriminant analysis were used to examine rheographic characteristics of periodontal hemodynamics in 80 patients with primary traumatic occlusion and periodontitis-complicated traumatic occlusion. Mathematical models of the conditions were created, that may be used in practical orthodontics for the differential diagnosis, prediction of the results, and purposeful treatment of patients with traumatic overexercise of the teeth. The share of correctly classified cases for the differential diagnosis with the use of mathematical methods turned to be high--88.3%. The reliability of periodontal hemodynamics parameters for the diagnosis of traumatic overexercise of the teeth is 99.9%.

[The effects of occluding dysfunction on marginal parodontopathies]

Occluding dysfunction (occluding dysharmony, occluding trauma) is an important etiologic factor of parodontal disease. It is an integrating element of the destructive process which characterizes the parodontal disease. Occluding dysfunction does not trigger gingivitis, or the development of parodontal pouches, but it does exert an influence on the progress and the importance of parodontal pouches determined by local irritation due to tartar and to bacterial plaques. Occluding dysfunction and the inflammation of parodontal tissues are different processes which occur in the course of the same disease namely of marginal parodonthitis. The inflammation develops in the gums and propagates in the parodontal sustaining tissues. Occluding dysfunction (also known as occluding dysharmony or occluding trauma) occurs in the parodontal sustaining tissues, and both determine tissue destruction. Occluding dysfunction and inflammation become codestructive factors which are interconnected, and are both capable to determine clinical and radiologic changes which are typical for diseased marginal parodontium. Due to the fact that individuals have variable parodontal reactions to local irritation factors, and considering the fact that inflammation and occluding dysfunction occur together but with variable degrees of severity, it is possible that they will not determine in all cases intraosseus pouches with angular lesions, or crater-like lesions. However, when we are confronted with such lesions it is very likely that the combined effects of inflammation and occluding dysfunction are at the origin.

Osteoradionecrosis related to mastication and parafunction

This article discusses mastication and parafunctional habits as possible etiologic factors in the development of osteoradionecrosis. From the three case reports presented it was noted that bone necrosis can occur after extended periods after radiation therapy, is seen most frequently in the mandible, and occurs most often at dosage levels exceeding 6500 rad. Recommendations after treatment to patients receiving 6500 rad or more should include caution regarding consistency of diet, use of existing prostheses, and the potential harmful effects of parafunctional habits.

[S E M study of vascular architecture of periodontal ligament under chronic marginal periodontitis]

The present study was carried out by fabrication of microcorrosive resin cast to investigate the vascular changes of periodontium of dogs' mandibular incisors with severe mobility and deep pocket formation concomitant with suppuration and alveolar bone loss. With aid of the dissolution of soft tissues by protease, alveolar bone remained left with resin cast of specimen, which then was referred for scanning electron microscopic examination. Results were as follows: 1. The vasculature of inner gingival epithelium which originally appeared as a flat, mesh-like network underwent a conformational change and turned out to be a vasculature with glomerulus-like loops due to chronic inflammation. 2. No remarkable change was ever identified in vasculature of periodontal ligament surrounding cervix of tooth. 3. Certain parts of vasculature of periodontal ligament disappeared, which combining with the occlusion indicated the occurrence of occlusal trauma. 4. Exposed alveolar bone surface where the periodontal vasculature disappeared showed an amorphous, flat surface. Quite contrast to this, the surface of alveolar bone on which the vasculature is located appeared undergoing a resorptive process. 5. Accordingly, the damage occurred in periodontium was not merely due to chronic inflammation but to the accompanying occlusal trauma which was supposed to be a predominant factor.

Association between craniomandibular disorders and occlusal interferences

No theoretical model explaining craniomandibular disorders has been generally accepted, despite the large number of studies on its etiology. This article suggests that one reason for the lack of a well-structured causal explanation could be associated with the study design most often used: cross-sectional studies of samples representative of a base population. Variation in the number of interferences was increased among the subjects by eliminating occlusal interferences annually in the treatment group (n = 53). The control group (n = 46) underwent placebo treatment. A double-blind design was used throughout the 3-year study. A cross-sectional analysis in the third year disclosed a significant association between the number of interferences and the signs of craniomandibular disorders. The results suggest that the absence of interference-free subjects in nonselected samples can be one explanation for the lack of association reported in most studies.

[Orthodontic treatment and periodontal problems. 1]

Because of the increasing frequency of orthodontic treatments of patients with periodontal problems, the authors evaluate effects deriving from orthodontic treatment on periodontal tissues and provide practical indications to manage such patients. Experimental and clinical studies on effects of trauma from occlusion on periodontal tissues in different clinical conditions are examined. The authors have also considered studies dealing with periodontal response to different orthodontic therapy items, with particular regard to gingival inflammation degree and likelihood of root resorption. From the results of such clinical and experimental studies, the authors have pointed out clinical indications to treat periodontal patients.

Multiple external root resorption

Presented is an unusual case of multiple external root resorption. Although the cause of this resorption was not determined, several possibilities are presented. Trauma from occlusion, periodontal and pulpal inflammation, and resorption of idiopathic origin are all discussed as possible causes.

The relative importance of plaque and occlusion in periodontal disease

A series of studies has investigated interactions between periodontal trauma and marginal periodontitis in relation to the initiation, progression and treatment of periodontal disease. Lesions of trauma in the periodontal ligament do not initiate the loss of connective tissue attachment characteristic of marginal periodontitis. Studies conducted in squirrel monkeys and beagle dogs in which jiggling forces were superimposed upon an established marginal periodontitis reported increased loss of alveolar bone, but the accelerated loss of attachment which occurred in the dog model did not occur in the monkey model. In order to clarify the relative importance of inflammation and tooth mobility in the treatment of advanced periodontal disease, periodontal responses were evaluated after removing combinations of traumatic and inflammatory components. Elimination of trauma in the presence of existing marginal inflammation did not reduce tooth mobility or increase bone volume. Osseous regeneration and decreased tooth mobility occurred after resolving both components; however, similar findings occurred after resolving inflammation in the presence of continued tooth mobility. After resolution of inflammation, remaining tooth mobility does not result in increased loss of connective tissue attachment. On a clinical level for periodontal disease treatment, the findings place decreased emphasis upon management of tooth mobility and increased emphasis upon resolution of marginal inflammation.

Posterior capsulitis of the temporomandibular joint

Posterior capsulitis, which is characterized by pain and inflammation localized above and behind the condyle of the mandible, usually develops as a result of premature contacts in dental occlusion. The pain at the affected side is related to the severe spasm of M. Pterygoideus Lateralis or the splinting action of the masticatory muscles. This condition can be readily treated by occlusal grinding of these premature contacts after a definite diagnosis. The amount of grinding on the teeth varies according to the localization of premature contacts and the pain at the joint. This study covers 123 patients diagnosed as having posterior capsulitis and the results are presented.