An epidemiologic survey of facial fractures and concomitant injuries

A 5-year review of facial fractures and concomitant injuries at a level 1 trauma center is presented. The anatomic location of the facial fractures, age and sex of the patients, cause of injury, and associated systems injuries are presented. The majority of facial fractures were found in males; the most prevalent age range was 16 to 30 years. Mandible fractures outranked zygomatic and maxillary fractures (6:2:1). Assaults and motor vehicle accidents were the most frequent causes of facial fractures, and lacerations followed by neurologic and orthopedic injury were the most frequently encountered concomitant injuries. Motor vehicle accidents were the most frequent cause of associated injury.     

Periodontal implications of orthodontic treatment in adults with reduced or normal periodontal tissues versus those of adolescents

This longitudinal study monitored periodontal status in 20 adults and 20 adolescents undergoing fixed orthodontic treatment. Ten adults had generalized periodontitis and received periodontal treatment, including periodontal surgery, before orthodontic treatment. They also received periodontal maintenance at 3-month intervals during orthodontic treatment. The other 10 adults had normal periodontal tissues. Neither these latter adults nor the adolescents received periodontal maintenance during orthodontic treatment. Periodontal status was determined (1) at six standard sites before fixed appliances were placed (baseline), (2) at 1, 3, 6, 9, 12, and 18 months after appliances had been placed, and (3) 1, 3, 6, and 12 months after appliances had been removed. At each of these visits, these sites were assessed for plaque index, gingival index, bleeding tendency, and pocket depth. Loss of attachment between baseline and 3 months after appliances were removed and tooth loss were also determined. Complete data were obtained for 15 adolescents and 14 adults. During orthodontic treatment the adolescent group showed significantly more (p less than 0.05) periodontal inflammation and supragingival plaque than the adults; after appliances were removed, this pattern was no longer statistically significant. For loss of attachment, there were no significant differences among adolescents, adults with normal periodontal tissues, or adults with reduced but healthy periodontal tissues who had undergone treatment for periodontal disease. For tooth loss, three nonstudy site teeth with pockets deeper than 6 mm and/or furcation involvements were lost because of periodontal abscesses in the adult group treated for periodontal disease.     

Arginolytic and ureolytic activities of pure cultures of human oral bacteria and their effects on the pH response of salivary sediment and dental plaque in vitro

Thirty-nine different microorganisms commonly found in supragingival plaque and salivary sediment were screened for their ability to raise the pH by producing base from arginine, lysylarginine and urea. Only Actinomyces naeslundii and Staphylococcus epidermidis showed significant pH-rise activity with all three compounds. Eleven bacteria demonstrated such activity with arginine and lysylarginine but not with urea. Only one, Actinomyces viscosus, produced a pH-rise with urea but not with the two arginine compounds. The remaining 26 bacteria showed little or no base-forming activity with any of the three test substrates. The ability of the different oral bacteria to produce base (especially from urea) was a less universal function than their ability to produce acid from fermentable carbohydrate. Substituting pure cultures of arginolytic or non-arginolytic bacteria for portions of the mixed bacterial populations of plaque or sediment in test incubations containing glucose and arginine altered their ability to produce pH-fall-pH-rise responses shaped like those of the Stephen curve in vivo. In general, addition of arginolytic bacteria made these in vitro pH responses less acidic, whereas addition of non-arginolytic bacteria made the responses more acidic. Because of the relatively high arginolytic activity of the plaque harvested in this study, the effect of adding non-arginolytic bacteria was more readily seen than the converse. Similar changes in levels of ureolytic microorganisms and incubation with glucose and urea had little effect on sediment or plaque being able to produce a pH-fall-pH-rise type of response. When increasing proportions of the mixed bacteria in salivary sediment were replaced with the highly cariogenic Lactobacillus casei or Streptococcus mutans, the pH minimum became slightly more acidic and then slightly more alkaline, whereas the pH-rise became progressively and significantly less. Thus arginolytic bacteria have a different and greater effect on shaping the pH response of plaque or sediment than ureolytic bacteria. A large change in the proportions of arginolytic or non-arginolytic microorganisms may be needed to make a plaque microflora potentially non-cariogenic or cariogenic, respectively.     

Xeroradiography in the diagnosis of nonradiopaque sialoliths

Sialolithiasis may be the most common disease of the salivary glands in patients more than 20 years of age. Approximately 19% of sialoliths occur in the parotid gland. Of these, only up to 71% can be successfully diagnosed radiographically. The remaining 29% provide a diagnostic dilemma. Xeroradiography, because of its tissue-edge enhancement, can distinguish tissue margins of different density more dramatically than can conventional imaging and is an invaluable aid in the diagnosis of nonradiopaque sialoliths.     

An epidemiologic study of the oral health status of high school students in New Jersey

This study was performed in order to record the prevalence of tooth decay in high school students in New Jersey. During the Spring of 1986, 3,556 students, aged 13 to 18 years, in 8 public high schools in 7 communities, participated in the study. The subjects were examined by 3 trained examiners with mirror, explorer, air syringe and overhead auxiliary light. A lesion was recorded as dental caries if there was a perceptible break in the enamel surface. Questionable incipient areas were not recorded as carious lesions. Mean DMFT was found to be 4.17 +/- 3.7 and mean DMFS was 7.02 +/- 7.4. Hispanic subjects had more decay (DMFT 4.98, DMFS 9.03) than black subjects (DMFT 4.13, DMFS 6.94) and white subjects (DMFT 3.53, DMFS 5.43). Females had more decay (DMFT 4.51, DMFS 7.67) than males (DMFT 3.79, DMFS 6.33). Hispanic and black subjects also had more untreated decay (24 and 22 percent decayed of the DMFT) compared with only 11% untreated decay in white subjects. Socioeconomic level was inversely related to caries activity; however, geographic location of the school within the state (north versus south) was not a factor.     

Transmission illumination of teeth. A system for operative dentistry procedures

In an in vitro trial, transillumination provided good, comfortable vision of an operating area both during cavity preparation and the insertion of adhesive restorative materials. Secondly, transillumination provided better differentiation of hard tissues and their condition than incident illumination; this was particularly noticeable in deciding on the presence of caries at the dentino-enamel junction. The most suitable colour was in the green range of the spectrum and a variable intensity control was desirable. With refinement, this system could facilitate operative dentistry particularly for difficult situations.     

Image enhancement of the mandibular condyle through digital subtraction

The use of conventional radiography to visualize the mandibular condylar articulating surface is limited by the superimposition of surrounding bony elements, which can be termed structured noise. This study investigated the application of digital subtraction to reduce such noise. Two conventional radiographs were made of a temporomandibular joint: first a reference radiograph with the condyle seated in the glenoid fossa (simulating a patient with mouth closed), then a radiograph from the identical orientation but with the condyle translated slightly downward and forward (simulating mouth partially opened). The radiographs were digitized and, on a pixel-by-pixel basis, the intensity value of the second image was subtracted from the reference image to produce a third, subtracted image. The subtracted image provided a significantly improved visualization of the condyle's superior surface.     

The effects of megadoses of ascorbic acid on PMN chemotaxis and experimental gingivitis

A double-blind study was undertaken to determine the effects of megadose ascorbic acid supplementation on plasma ascorbate levels, polymorphonuclear neutrophil (PMN) chemotaxis and clinical and biochemical determinations of inflammatory progression in individuals with a mean daily ascorbate intake level of approximately twice the recommended daily allowances. Results indicate that although the group receiving ascorbate supplementation demonstrated a significant increase in plasma levels of the vitamin as compared to a placebo group, no significant differences with respect to PMN chemotaxis or responses to experimental gingivitis were found between the groups.