Odontogenic myxoma recurring after 11 years: case report and observations on this unusual neoplasm

Odontogenic myxoma is usually a benign neoplasm, although it has the ability to infiltrate surrounding tissues thus becoming locally invasive. Furthermore, it has a moderately high recurrence rate and can sometimes display a really aggressive behaviour. An unusual case of a 48-y-old woman in whom odontogenic myxoma recurred 11 years after excision of the primitive lesion is reported. Although rare, the possibility of malignant evolution led us to consider which was the most appropriate management of both the neoplasm and the recurrence. A careful assessment of the clinical, radiographical, tomographical, histological and, if necessary, immunohistochemical features of the lesion allows a distinction to be made between lesions that are only locally invasive and the rarer, more dangerous aggressive lesions. In the first case we suggest that, where possible, a conservative treatment should be preferred, followed by close monitoring of the lesion over time. Since odontogenic myxoma is limited to the facial bones, excision may be uselessly disfiguring, above all in young patients. More aggressive surgical treatment should be reserved for lesions for which there is a strong suspicion of malignant transformation.     

Placement and replacement of restorations in general dental practice in Iceland

Ninety-one Icelandic practicing dentists (51% response rate) provided information related to the reasons for placement and replacement of 8,395 restorations and 741 sealants in 5,997 patients. Information included the patient's gender and age, the clinician's gender and experience in years since graduation, the defined criteria for replacement of restorations, the estimated past use of material in five-year increments and the records of 100 consecutively placed restorations. The materials used include composite (52.7%), amalgam (29.2%), glass ionomer (9.5%), resin-modified glass ionomer (7.1%) and other materials (1.4%). Although material selection was independent of the clinician's gender, female patients received more composite and fewer amalgam restorations than their male counterparts. Reasons for placing restorations comprised replacement of failed restorations (47.2%), primary caries (45.3%) and non-carious defects (7.5%). Secondary caries was the main reason for replacement for all types of restorations. Chi square analysis related to the dependence between the reasons for replacement and clinician's experience showed that more experienced clinicians recorded a lower frequency of secondary caries than less experienced ones (p<0.0001), while the diagnoses of discoloration and fracture of restorations increased with the clinicians' experience (p<0.0001).     

Bone strain patterns of the zygomatic complex in response to simulated orthopedic forces

Craniofacial bone strain upon orthopedic loading has rarely been characterized, despite its fundamental importance in our understanding of the anabolic and catabolic effects of orthopedic forces. The present study tested the hypothesis that zygomatic bone strain is modulated upon loading by headgear, a device widely used in craniofacial orthopedics. Ramp forces from 0 to 50 Newtons were applied via headgear attached to the permanent maxillary first molars in four juvenile and five adult human skulls. The average peak bone strain of the juvenile temporal articular eminence was significantly higher than the adult articular eminence (p < 0.05). Contrasting bone strain patterns were identified in the zygomatic arch: tensile in its lateral surface but compressive in its medial surface. The peak bone strain of the temporal articular eminence and the zygomatic arch both depend upon loading direction. Thus, headgear-generated orthopedic forces evoke bending of the zygomatic arch and stresses of the temporal articular eminence in vitro, suggesting the need to verify whether bone strain induces in vivo bone modeling and remodeling.     

An endosseous, implant-retained obturator for the rehabilitation of a recurrent central giant cell granuloma: a clinical report

The prosthodontic rehabilitation of a patient with a recurrent maxillary CGCG has been described. The patient's immense defect originally was rehabilitated with a scapular microvascular free flap, endosseous dental implants, and an ISP that became obsolete by virtue of the resection of recurrent disease and the subsequent need for velopharyngeal obturation. The patient was provided with a surgical obturator at the time of the resection of the recurrent CGCG. The surgical obturator thereafter was modified into an interim obturator to provide velopharyngeal competence while the soft tissues around the palatal defect healed. Finally, the construction of a bar-retained definitive obturator markedly improved the patient's speech, mastication, and deglutition.     

Genetic variation in the recognition of Porphyromonas gingivalis antigens in mice

T-cell cytokine profiles, anti-Porphyromonas gingivalis antibodies and Western blot analysis of antibody responses were examined in BALB/c, CBA/CaH, C57BL6 and DBA/2J mice immunized intraperitoneally with different doses of P. gingivalis outer membrane antigens. Splenic CD4 and CD8 cells were examined for intracytoplasmic interleukin (IL)-4, interferon (IFN)-gamma and IL-10 by FACS analysis and levels of anti-P. gingivalis antibodies in the serum samples determined by enzyme-linked immunosorbent assay. Western blot analysis was performed on the sera from mice immunized with 100 microg of P. gingivalis antigens. The four strains of mice demonstrated varying degrees of T-cell immunity, although the T-cell cytokine profiles exhibited by each strain were not affected by different immunizing doses. While BALB/c and DBA/2J mice exhibited responses that peaked at immunizing doses of 100-200 microg of P. gingivalis antigens, CBA/CaH and C57BL6 demonstrated weak T-cell responsiveness compared with control mice. Like the T-cell responses, serum antibody levels were not dose dependent. DBA/2J exhibited the lowest levels of anti-P. gingivalis antibodies followed by BALB/c with CBA/CaH and C57BL6 mice demonstrating the highest levels. Western blot analysis showed that there were differences in reactivity between the strains to a group of 13 antigens ranging in molecular weight from 15 to 43 kDa. Antibody responses to a number of these bands in BALB/c mice were of low density, whereas CBA/CaH and C57BL6 mice demonstrated high-density bands and DBA/2J mice showed medium to high responses. In conclusion, different immunizing doses of P. gingivalis outer membrane antigens had little effect on the T-cell cytokine responses and serum anti-P. gingivalis antibody levels. Western blot analysis, however, indicated that the four strains of mice exhibited different reactivity to some lower-molecular-weight antigens. Future studies are required to determine the significance of these differences, which may affect the outcome of P. gingivalis infection.     

Analysis of factors that may affect the enzymatic profile of gingival crevicular fluid: sampling technique, sequential sampling and mode of data presentation

To evaluate the possible effect of sampling technique and sequential sampling on gingival crevicular fluid (GCF) volume and myeloperoxidase (MPO) activity, 14 patients presenting at least two symmetrical maxillary sites with mild/moderate periodontitis were selected. Two sites in each individual were sequentially sampled using either the deep-intracrevicular or orifice technique. Spectrophotometrically determined MPO levels were presented either as total MPO activity or MPO concentration. Although the clinical periodontal status of the 20 sampling sites were similar, the deep-intracrevicular technique regularly provided larger GCF volumes. With both techniques, the last samples contained the highest GCF volume. During sequential orifice sampling, GCF volume was relatively more stable. In general, a depletion of MPO activity was observed with sequential sampling performed with either of the techniques. Depletion of MPO did not replenish to baseline levels at the end of the 10-min sequential sampling. Although MPO activity showed a general reduction during sequential orifice sampling with both modes of data presentation, total MPO activity and MPO concentration did not match with the deep-intracrevicular technique. Due to the potential of affecting GCF volume/composition, the selection of sampling technique seems to be a critical methodological decision in GCF-profile studies, primarily during sequential sampling. In GCF-profile studies, mode of data presentation should also be considered.     

Periodontal infection and preterm birth: results of a prospective study

BACKGROUND: Previous studies have suggested that chronic periodontal infection may be associated with preterm births. The authors conducted a prospective study to test for this association. METHODS: A total of 1,313 pregnant women were recruited from the Perinatal Emphasis Research Center at the University of Alabama at Birmingham. Complete periodontal, medical and behavioral assessments were made between 21 and 24 weeks gestation. After delivery, medical records were consulted to determine each infant's gestational age at birth. From these data, the authors calculated relationships between periodontal disease and preterm birth, while adjusting for smoking, parity (the state or fact of having born offspring), race and maternal age. Results were expressed as odds ratios and 95 percent confidence intervals, or CIs. RESULTS: Patients with severe or generalized periodontal disease had adjusted odds ratios (95 percent CI) of 4.45 (2.16-9.18) for preterm delivery (that is, before 37 weeks gestational age). The adjusted odds ratio increased with increasing prematurity to 5.28 (2.05-13.60) before 35 weeks' gestational age and to 7.07 (1.70-27.4) before 32 weeks' gestational age. CONCLUSIONS: The authors' data show an association between the presence of periodontitis at 21 to 24 weeks' gestation and subsequent preterm birth. Further studies are needed to determine whether periodontitis is the cause. CLINICAL IMPLICATIONS: While this large prospective study has shown a significant association between preterm birth and periodontitis at 21 to 24 weeks' gestation, neither it nor other studies to date were designed to determine whether treatment of periodontitis will reduce the risk of preterm birth. Pending an answer to this important question, it remains appropriate to advise expectant mothers about the importance of good oral health.     

Oral melanin pigmentation related to smoking in a Turkish population

OBJECTIVE: Besides genetic factors, tobacco smoking has been found to be the major cause of oral melanin pigmentation. The purpose of the present study was to evaluate the frequency of oral melanin pigmentation in a Turkish population and to present its correlation with clinical parameters relevant to periodontal status in current smokers, non-smokers, former smokers. METHOD: A sample of 496 patients was randomly selected. The subjects were interviewed regarding their smoking habits. They were clinically examined by a single examiner for the presence of oral melanin pigmentation in different oral mucosal regions. The same examiner recorded the clinical parameters including GI (gingival index), PI (plaque index), BOP (bleeding on probing), PD (probing depth) and GR (gingival recession). Examiner 2 completed a questionnaire concerning skin color and smoking habits. RESULTS: In the study group, 41% were current smokers, 46% nonsmokers and 13% former smokers. The frequencies of pigmented areas were significantly higher in current smokers than in those without any smoking habits. The clinical parameters revealed similar findings for all groups. Low GI and BOP values were observed for current smokers when compared with non-smokers and former smokers, respectively. GI values were significantly associated with the pigmentations in gingiva. CONCLUSIONS: The results of our study show that smokers in a Turkish population had significantly more pigmented oral surfaces than nonsmokers.     

Age as a determinant of severity of dental fluorosis in children residing in areas with 0.5 and 2.5 mg fluoride per liter in drinking water

The purpose of this study was to investigate the influence of age on the severity of dental fluorosis in children exposed to drinking water with either low or high fluoride concentrations. The children selected for this study were aged 10–14 years, with 28 permanent teeth and at least 1 tooth pair with fluorosis. The children were permanent residents of districts in western Uganda with either 0.5 mg (n=33) or 2.5 mg fluoride/l in drinking water (n=186). All vestibular tooth surfaces were examined for fluorosis using the modified Thylstrup and Fejerskov (TF) index. In the high fluoride community, the proportion of teeth per child with TF scores ≥4, and ≥5 was significantly higher among children aged 13–14 years compared to those aged 10–12 years. Children’s chronological age correlated positively and significantly with the median TF scores for all teeth, including early erupting (first molars and incisors) and late erupting teeth (canines, premolars and second molars). In linear regression analyses, the median TF score for all teeth, as well as for early erupting and late erupting teeth, increased significantly with age. On the other hand, in the low fluoride community there was no significant association between age and the severity of fluorosis. This study showed a significant increase in the severity of fluorosis with increasing age in a high fluoride community, whereas no change in severity with age was observed in a low fluoride community. Received: 3 February 2000 / Accepted: 15 March 2000