Bacterial endotoxin: a role in chronic inflammatory periodontal disease?

A review of current information was undertaken examining suggested roles for bacterial endotoxin in periodontal disease. Evidence for the presence of endotoxin in plaque, gingival crevicular fluid and periodontally involved cementum is discussed. The biological effects of endotoxin are numerous, and its abilities to induce tissue inflammation, resorb rat foetal bone, activate the complement pathway, stimulate macrophages and activate immune responses are examined in relation to the suggestion that endotoxin is an important factor in the pathogenesis of periodontal disease.     

Inverted-L osteotomy for correction of mandibular prognathism after relapse.

As more orthognathic surgery is performed, more case of relapse can be expected. A case of re-operation of a recurrent prognathism has been reported. An alternative surgical approach was used because the planned operation could not be accomplished. However, the implications of the use of the technique are broader than the single example given in this report. The inverted-L technique, because of its similarity to the combined oblique osteotomy and coronoidectomy for correction of extreme prognathism, provides an alternative procedure that leaves a greater proportion of the masticatory musculature in its natural position. In addition, with the development of techniques and instrumentation for intraoral approaches to oblique osteotomy of the ramus, the feasibility of an intraoral inverted-L osteotomy becomes apparent and the approach merits further consideration.     

Improvements in bracket base design

Acid etch bonding of orthodontic attachments to the labial and lingual surfaces of teeth is generally adequate for clinical service. Failures do occur, and these are related to technique problems in acid etching or resin manipulation or to bracket base design. The widely used foil mesh base can present problems in retention because of design defects or corrosion. Improvement in mechanical retention of resin to the attachment base would result in significant improvements in bonding and fewer clinical failures. One of our approaches to improved retention is to fuse metallic or ceramic particles onto the bracket base so as to achieve a particulate or porous layer into which resin can penetrate. The results of bond-strength tests showed that a 100 percent increase in bond strength could be obtained with sintered porous metal-coated brackets. Further development is proceeding.     

Importance of high pKA acids in cariogenic potential of plaque

Through the use of computer simulation, it is shown that anions of high pKA acids (e.g., acetic, propionic, butyric), present in resting plaque fluid, act as effective buffers during the production of stronger acids (e.g., lactic) by oral micro-organisms. Using reported organic acid compositions for plaque, obtained from caries-resistant and caries-susceptible individuals, analyzed at various times following sucrose exposure, it is shown that the calculated pH values of the aqueous phase of plaque describe typical Stephan curves. Furthermore, it is shown that for higher acid anion contents in resting plaque, a higher degree of saturation of the aqueous plaque phase with respect to enamel is maintained during acid production, resulting in a lower demineralization potential of plaque. Enamel demineralization experiments conducted in vitro confirmed the significance of the results of the computer simulations, thus providing evidence for a correlation between the known metabolic activity of plaque (organic acid composition), physical chemistry of plaque, and caries susceptibility.     

An improved split-denture technique

A technique for the construction of split dentures with a cast framework to hold the denture segments together has been described. The advantages of this technique to the patient were noted. Patients are carefully instructed first on how to insert the sections and then on how to insert the casting after the individual segments of each arch are in place.     

Temporomandibular degenerative joint disease. Part II. Diagnostic procedure and comprehensive management.

The diagnostic procedure is given in the detail necessary to arrive at an accurate diagnosis of temporomandibular degenerative joint disease (TDJD). The differentiating clinical findings of degenerative joint disease (DJD) and rheumatoid arthritis of the temporomandibular joint (TMJ) are described. Principles and modalities of comprehensive management of TDJD are presented in the manner and sequence needed to allow practical clinical application. Methods of treatment are applied to the management of patients with acute and chronic TDJD. The surgical procedure for TDJD, intracapsular high condylectomy with a preauricular incision, is described in the detail required for individual application. Case reports are presented to illustrate the comprehensive management of TDJD.