Transition dynamics in experimental gingivitis in humans

This study was conducted in order to investigate the dynamics of the gingival inflammatory status during periods of plaque accumulation and thorough oral hygiene. After a period of prophylaxis, 42 volunteers were asked to abstain from all oral hygiene measures for 2 weeks, whereafter oral hygiene was reinstituted. In the absence of oral hygiene, plaque was found at virtually all sites after 7 days and the number of sites with gingivitis increased simultaneously. A reduction in gingival inflammation occurred subsequent to plaque removal. During phases of both plaque accumulation and thorough oral hygiene, sites were found to convert from non-inflamed to inflamed status concurrently, as in the reverse direction. No association between plaque and gingivitis was revealed. The gingival status of a single site was a poor predictor of its status on the subsequent occasion. The proportion of inflamed sites converting to non-inflamed status was greater than the proportion of non-inflamed sites converting to inflamed status at any time. The estimated incidence rate remained fairly constant during both the plaque accumulation phase and the oral hygiene phase, whereas the estimated recovery rate was considerable lower during the plaque accumulation phase compared to oral hygiene phase. The clinical appearance is the outcome of the dynamics between these rates. The steady-state prevalences derived from the estimated "incidence" and "recovery" rates were quite similar to the actual findings after 14 d of plaque accumulation and the subsequent 10 d of thorough oral hygiene.     

Condylar displacement and temporomandibular joint dysfunction following bilateral sagittal split osteotomy and rigid fixation

In this study changes in intercondylar width (ICW) and intercondylar angle (ICA) that occurred with rigid fixation after bilateral sagittal split osteotomy and mandibular advancement are documented and correlated with temporomandibular (TM) symptoms, magnitude of advancement, and mandibular shape. Even though individual changes occurred, there was no significant difference between the mean preoperative and postoperative ICA and ICW measurements. There was also no significant difference between the preoperative and postoperative incidence of TM pain or clicking. No correlation was found between the magnitude of advancement and the percent change in ICA or ICW, and the mandibular shape did not correlate to changes in ICW. This study suggests that screw osteosynthesis does not significantly change ICA or ICW. The fact that no significant increase in TM symptoms occurred indicates that the changes in condylar position that did occur were within the range of clinical adaptability of the patients.     

Heterotopic brain tissue in the oral cavity

A most rare phenomenon of heterotopic brain in the soft palate, containing elements of choroid plexus, is presented. The principal theories regarding the pathogenesis of this malformation are presented and discussed. Its most frequent sites, the treatment to be followed, and the nomenclature to be employed in this type of lesion are also analyzed.     

Fracture resistance of endodontically prepared teeth using various restorative materials

This study compares the fracture resistance of endodontically treated premolars with modified types of cavity preparations and restoration with either amalgam or composite resin. The greatest influence on fracture resistance was the remaining tooth structure. The effect of adequate wall support on tooth strength was compared with intact unprepared teeth.     

Microleakage: the effect of storage and cycling duration

This investigation revealed that the limited storage time or cycling durations used had no significant impact on the microleakage patterns of a resin-bonded composite in Class V preparations. Short-term cycling appears as effective in demonstrating marginal leakage as protracted cycling regimens. These findings may be helpful in interpreting and comparing various microleakage studies.     

A microbiological study of pre- and postoperative apicectomy sites

There is little information on the microbiology of periapical lesions, and no data on the residual microbial flora in the periapex, if any, after apicectomy procedures. Hence, 64 patients treated by apicectomy procedures were prospectively studied to assess the bacterial flora in the periapex and to evaluate the residual bacteria in postoperative apicectomy sites. Of the 64 lesions studied, 14 (22%) were sterile and 50 (78%) yielded bacteria preoperatively. Bacteria could be recovered from 28 (56%) of the latter lesions after apicectomy and curettage. A total of 105 bacterial strains was isolated from 50 lesions, yielding a range of 1–4 (mean 2.1) species per sample. The isolates comprised 84 (80%) facultative anaerobes and 21 (20%) strict anaerobes. A polymicrobial growth was obtained from 39 lesions whilst 11 lesions yielded pure cultures. On detailed microbiological analyses of 29 lesions, 40% of the isolates were identified as alpha-haemolytic streptococci, half of which were Streptococcus sanguis; anaerobic streptococci were the predominant anaerobes. None of the organisms or group(s) of organisms emerged as recalcitrant colonisers which were difficult to dislodge after surgical debridement. These data indicate that the majority of periapical lesions harbour a variety of flora which cannot be eradicated despite thorough apicectomy procedures.     

Herpetic gingivostomatitis and teething difficulty in infants.

This investigation was conducted to determine whether primary herpetic gingivostomatitis may be responsible for those signs and symptoms commonly attributed to teething in infants. Twenty infants presenting with a parental diagnosis which indicated teething difficulty were included in this study (Group A). Twenty infants who were in no distress served as controls (Group B). Oral swab samples were obtained from each infant and then processed to ascertain the presence of herpes simplex virus (HSV). Each infant's temperature and oral status also were recorded. Nine subjects in Group A (45%) were positive for HSV. Of these nine, seven had elevated temperatures (less than 100 degrees F) and all had signs of oral infection of varying severity. Of the 11 subjects in Group A who were negative for HSV, five had elevated temperatures, but none showed evidence of oral infection. Subjects in Group B were all negative for HSV, elevated temperature, and signs of oral infection. Results of this study suggest that oral HSV infection should be included in the differential diagnosis of infants presenting with a parental diagnosis of teething difficulty.