Recurrence rate of odontogenic keratocyst treated by enucleation and peripheral ostectomy: Retrospective case series with up to 12 years of follow-up.

BACKGROUND: Odontogenic keratocysts have been reported with high recurrence rates in the literature so various treatment modalities from simple enucleation to resection have been performed to achieve the cure. The purpose of this retrospective study was to investigate the recurrence rate of odontogenic keratocysts (OKCs) treated by enucleation and peripheral ostectomy. MATERIAL AND METHODS: An electronic search of the database of the Hacettepe University, Faculty of Medicine, Department of Pathology, was undertaken to identify patients histologically diagnosed with OKCs treated at Department of Oral and Maxillofacial Surgery between 2001 and 2015. RESULTS: In total, 81 patients were studied. The mean age at the time of diagnosis was 42 years, and the male:female ratio was 1:0.7. OKCs were located primarily in the posterior mandibular region (41%). Twenty-seven patients were re-examined to determine the recurrence rate. The mean follow-up period was 5 years (range, 1-12 years). The recurrence rate was 14.8%. The relationship between location of the lesion and recurrence was not statistically significant (p = 0.559). There was also no statistically significant relation between the recurrence rate and treatment option of teeth involved in the lesion (p = 0.579). CONCLUSIONS: The authors conclude that treatment of OKCs by enucleation with peripheral ostectomy is associated with minimal morbidity and is preferred over other aggressive treatment modalities. Meticulous radiographic examination and careful surgical resection may decrease the recurrence rate of OKCs.

Alveolar ridge preservation with a free gingival graft in the anterior maxilla: volumetric evaluation in a randomized clinical trial.

The aim of this study was to evaluate and compare the dimensional changes in maxillary extraction sockets that have healed spontaneously and those treated with free gingival grafts. Ten subjects with at least two maxillary anterior teeth scheduled for extraction were selected for this study. Two maxillary teeth were allocated randomly to either the test group or the control group. In the test group, the extraction socket was covered with a free gingival graft harvested from the palate, while in the control group the sockets healed spontaneously. Cone beam computed tomography (CBCT) scans were taken on the day of extraction and at 3 months postoperative. Soft tissue healing of the extraction sockets was assessed visually by clinical inspection. Hard tissue measurements were obtained from the CBCT scans. After 3 months of healing, the control sockets had lost height in the buccal and lingual crestal bones (-1.03 and -0.56mm, respectively); however, the height in the buccal and lingual crestal bones was preserved at the test sites (+0.06 and +0.25mm, respectively). This difference between the two groups was statistically significant (P<0.05). In contrast, both the control and test groups lost width in the buccal and lingual crestal bones; the difference between the control and test groups was not statistically significant (P>0.05). The authors propose that covering the orifice of the extraction socket with a free gingival graft can result in preservation of the alveolar bone height.

Mechanisms of macrolide resistance in clinical pneumococcal isolates in a university hospital, Ankara, Turkey.

Macrolide resistance in Streptococcus pneumoniae is usually caused by the presence of the erm(B) or mef(A) resistance determinants. The aim of the present study was to identify the predominant macrolide resistance mechanisms among erythromycin-resistant S. pneumoniae isolated in a university hospital, Ankara, Turkey. A total of 669 S. pneumoniae strains were isolated from clinical specimens of patients admitted to the hospital between 1994--2002. The minimum inhibitory concentrations (MICs) of penicillin G, erythromycin A and clindamycin were determined by the agar dilution method according to NCCLS guidelines. Ninety-one (13.6%) isolates were resistant to erythromycin. Erythromycin-resistant isolates were examined for their macrolide resistance phenotypes by a triple disc diffusion assay. It assigned 57 (62.6%) of the 91 erythromycin-resistant pneumococci to cMLS(B) phenotype, 19 (20.9%) to iMLS(B) phenotype and 15 (16.5%) to M phenotype. All erythromycin-resistant isolates were analyzed by PCR for the presence of erm(B) and mef(A) determinants. The isolates were characterized for the underlying resistance genotype, with 83.5% having erm(B), 16.5% having the mef(A) genotypes. This study provides further evidence of the dissemination of macrolide-resistant mutants in pneumococci as the use of new, long-acting macrolides increases. This is the first article about MLS(B) resistance phenotypes and genotypes of S. pneumoniae from Turkey and it emphasizes the need for future epidemiological monitoring of macrolide-resistant pneumococci.

Stenotrophomonas maltophilia as a nosocomial pathogen.

The aim of this study was to investigate the molecular epidemiology of Stenotrophomonas maltophilia in a university hospital in Turkey. Thirty nine clinical isolates were collected from 37 patients and one from an environmental source between 1998 and 2001. Susceptibility to 11 antimicrobials was studied. The isolates were categorised into six groups: A through F. Trimethoprim sulfamethoxazole was the most active agent against the tested isolates. Genotypic analysis by pulsed-field gel electrophoresis (PFGE) of clinical isolates identified 21 different PFGE patterns. Three most common clusters were composed of 11, seven and four strains. Antimicrobial susceptibility identified multi-resistant phenotype in all S. maltophilia PFGE clones. All the remaining 18 isolates (45%) revealed unique PFGE patterns. Resistance was not lower in unique strains. The clones mainly with two unique macrorestriction profiles strongly suggests nosocomial transmission of these strains from either a common source and/or between patients.

Molecular epidemiology of penicillin-resistant Streptococcus pneumoniae in a university hospital, Ankara, Turkey.

Penicillin-resistant Streptococcus pneumoniae isolates (n = 76) from clinical samples of patients admitted to Hacettepe University Hospital between January 1997 and December 2001 were included in the study. MICs of penicillin G, erythromycin A, clindamycin, cefaclor, cefotaxime, vancomycin, chloramphenicol, tetracycline, ciprofloxacin and rifampicin were determined by agar dilution. The isolates were serogrouped on the basis of the Neufeld Quellung reaction and were typed by BOX-PCR. Genetic polymorphism of the penicillin resistance genes pbp2b and pbp2x was investigated by restriction fragment length polymorphism (RFLP) analysis. Of the 76 isolates tested, 64 (84.2%) showed intermediate resistance to penicillin, while 12 (15.8%) were resistant to higher levels of penicillin (MIC > or = 2 mg/L). The resistance patterns of the isolates revealed six different resistance profiles. There were 22 different serotypes, with c. 55% of the isolates belonging to serotypes 23B, 19A, 19F, 14, 6 A and 9V. Five distinct patterns for pbp2b and 12 distinct patterns for pbp2x were obtained by RFLP analysis of penicillin-binding protein genes. The combination of these patterns allowed isolates to be classified into 22 fingerprint subgroups. BOX-PCR analysis showed that the isolates fell into 14 distinct BOX genotypes, with 33 subtypes. Serotype 9V isolates with pbp genotype 2-6 and BOX-PCR type 4, 4.1 or 4.2 were related to the pandemic clone Spain(9V)-3. No relatedness to other international clones was detected among the other study strains, but genetic relatedness was observed among some of the serotype 19A and 23B isolates. Overall, the results demonstrated that most of the penicillin-resistant pneumococcal isolates in Turkey, other than those belonging to serotypes 9V, 19A and 23B, were derived from several independent clones, possibly resulting from multiple importation of strains originating from outside the country. Differences in pbp patterns, serotypes and resistance profiles among isolates that showed similar BOX-PCR patterns supported the hypothesis that horizontal transfer of capsular genes, pbp genes and other genetic determinants between S. pneumoniae and viridans group streptococci may have occurred.

Epidemiology of chronic Pseudomonas aeruginosa infections in cystic fibrosis.

Chronic lung infection with Pseudomonas aeruginosa is primarily responsible for pulmonary deterioration of cystic fibrosis patients. The purpose of this study was to type the P. aeruginosa isolates collected sequentially from cystic fibrosis patients, chronically colonized with P. aeruginosa, by random amplified polymorphic DNA fingerprinting-PCR (RAPD-PCR). Sequential P. aeruginosa isolates (n: 130) that had been collected from 20 CF patients over at least 9 years were investigated. The isolates were analyzed by RAPD-PCR using two arbitrary primers. Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. RAPD-PCR typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some CF patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. However, some patients may be colonized with more than one genotype. The results also demonstrated that there might be a risk of cross-colonization between CF patients followed-up at the same center.

The value of routine antibiotic prophylaxis in mandibular third molar surgery: acute-phase protein levels as indicators of infection.

Postoperative infections in the oral region are usually caused by anaerobic bacteria. While some authors claim that routine antibiotic prophylaxis is necessary after third molar surgery, others do not recommend this practice. The major subject of controversy is what constitutes postoperative infection. Previous studies that have examined the benefit of routine antibiotic prophylaxis have used several clinical symptoms (pain, swelling, and trismus) as indicators of infection; however, these clinical symptoms may be vague and unreliable, and cannot be evaluated scientifically. As a result, their use has only sparked more debate in this area of research. The present study assessed the value of routine antibiotic prophylaxis in impacted mandibular third molar surgery using acute-phase protein levels as potential indicators of early and late postoperative infection. Specifically, serum levels of C-reactive protein and alpha-1 antitrypsin were measured preoperatively and postoperatively in patients who received either prophylactic antibiotics or placebos. The results revealed no statistically significant difference between treated and control patients in terms of incidence of postoperative infection.

Detection of Listeria monocytogenes in milk by the polymerase chain reaction.

A on the polymerase chain reaction (PCR) method based was developed for detection of Listeria monocytogenes in milk samples after enrichment culture. It consists of culturing samples in Listeria enrichment broth, followed by DNA extraction and detection of the organism using PCR. Dilutions of L. monocytogenes in milk were subjected to PCR amplification after enrichment culture. When determining the sensitivity of the method, it was found to be possible to detect 37 CFU (colony forming unit gl/ml) of the bacterium in milk. The method was assessed as a sensitive, specific, times-saving and practical way of detecting L. monocytogenes in milk samples.

The biological effects of implanted magnetic fields on the bone tissue of dogs.

Five titanium caps were implanted in the mandibles of five dogs. Three caps contained Sm-Co mini magnets and two caps were empty. The aim of this study was to determine if implanted magnetic fields had any biological effects on the bone tissue of dogs. At the end of 6 months, the animals were sacrificed and segments containing implants and segments from the side opposite the implants, for control, were removed. Sections were made from the specimens and no pathology was seen upon microscopic examination.