Surgical Management of Impacted Lower Second Molars: A Comprehensive Review.

Impacted lower second molars (ILM2) are rarely reported in the literature, but various studies have been done for its treatment. Apart from solely orthodontic approaches, different surgical management techniques were reported to have successful outcomes. Surgical intervention of ILM2 can help expose the tooth for further orthodontic purposes, simplifying complex treatment methods, and reducing treatment time. This review illustrates the comprehensive evaluation and updated methods of surgical uprighting, repositioning, and transplantation of ILM2 with future directions for better understanding and treatment planning in the clinical setting. The successful outcome of surgical intervention depends on case selection, root development of ILM2, careful surgical manipulation, and adherence to sound biological principles.

Non-oral, aerobic, Gram-negative bacilli in the oral cavity of Thai HIV-positive patients on Highly-active anti-retrovirus therapy medication.

In the present study, we identified and evaluated the antibiotic susceptibility of 96 independent, aerobic, Gram-negative bacillus isolates from 255 Thai HIV-positive adults who were on Highly-active anti-retrovirus therapy (HAART) medication. Another 46 isolates from HIV non-HAART individuals, vertically transmitted HIV-positive individuals, and non-HIV controls were included for comparison. A total of 103 strains were tested for antibiotic susceptibility using disc diffusion for screening and E-test for minimal inhibitory concentration determination, with special attention on extended-spectrum beta-lactamase (ESBL) isolates. Pseudomonas aeruginosa, Pseudomonas luteola, Burkholderia cepacia, Aeromonas hydrophila, Klebsiella, and Enterobacter species were the most common bacteria. All strains were resistant against penicillin, amoxicillin, clindamycin, and metronidazole. No ESBL isolates were found.

Alveolar bone in human immunodeficiency virus infection: is it changed by long-term antiretroviral therapy?

BACKGROUND: Previous studies have reported that human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) can lead to osteoporosis in HIV-infected individuals. However, their effects on alveolar bone are not well established. The objective of this study was to measure the alveolar bone mineral density (BMD) of HIV-infected patients, with and without antiretroviral therapy (ART), in comparison with that of HIV-free individuals, and to determine factors associated with the BMD of alveolar bone. METHODS: A cross-sectional study was performed in non-HIV-infected individuals and HIV-infected individuals, with and without ART. Medical status and clinical data were recorded. Periapical radiographs of maxillary and mandibular right premolars were analysed for changes of alveolar BMD based on HIV/ART status. Other factors associated with the changes of alveolar BMD were explored using a parametric multivariate analysis of covariance (MANCOVA). RESULTS: One-hundred and one HIV-infected individuals receiving ART (age range: 23-57 years; median age 39 years), 58 receiving no ART (age range: 20-59 years; median age 34 years) and 50 HIV-negative individuals (age range: 19-59 years; median age 36 years) were enrolled. Neither HIV status nor use of ART was significantly associated with the changes of alveolar BMD. CONCLUSION: Although osteoporosis has been reported in HIV-infected individuals treated with ART, alveolar BMD does not appear to be changed as a result of the infection, or use of ART.

Highly-active antiretroviral therapy and oral opportunistic microorganisms in HIV-positive individuals of Thailand.

AIM: Oral mucosal lesions and opportunistic microorganisms in HIV-positive Thais treated with highly-active antiretroviral therapy (HAART) for more than 5 years were investigated. METHODS: A total of 221 HIV-infected patients, comprising 148 HIV patients undergoing HAART for more than 5 years, 20 non-HAART HIV patients, 53 vertically-transmitted (VT) HAART HIV patients, and 30 HIV-negative controls, were examined for CD4+ counts, viral load, saliva secretion rate, and oral mucosal lesions. Samples from the tongue, gingival crevices, and mucosal lesions when present were cultured for the amounts of Candida, staphylococci, enterococci, and aerobic Gram-negative bacilli. RESULTS: HAART (including HIV-VT) maintained oral microbial homeostasis predominated by alpha-hemolytic streptococci similar to the non-HIV controls and with a low prevalence of mucosal lesions. The HAART group had a reduced saliva secretion rate. The frequency and load of opportunistic microorganisms in the HAART group were similar to the non-HAART group, which was significantly higher than the HIV-negative controls. Candida spp. was found significantly more frequently on the tongue in HIV-infected individuals with CD4+ counts <500 cells/mm(3). CONCLUSION: Although we did not find lower levels of mucosal lesions among HAART compared to non-HAART individuals, HAART therapy could prolong the time before opportunistic oral pathogens overwhelm the commensal members of oral microbiota.

The oral microbiome in human immunodeficiency virus (HIV)-positive individuals.

Human immunodeficiency virus (HIV) infection is associated with a range of oral conditions, and increased numbers of disease-associated microbial species have previously been found in HIV-positive subjects. The aim of this study was to use next-generation sequencing to compare the composition of the oral microbiome in HIV-positive and -negative individuals. Plaque and saliva were collected from 37 HIV-positive individuals and 37 HIV-negative individuals, and their bacterial composition determined by pyrosequencing of partial 16S rRNA genes. A total of 855,222 sequences were analysed. The number of species-level operational taxonomic units (OTUs) detected was significantly lower in the saliva of HIV-positive individuals (mean = 303.3) than in that of HIV-negative individuals (mean = 365.5) (P < 0.0003). Principal coordinates analysis (PCoA) based on community membership (Jaccard index) and structure (Yue and Clayton measure of dissimilarity) showed significant separation of plaque and saliva samples [analysis of molecular variance (AMOVA), P < 0.001]. PCoA plots did not show any clear separation based on HIV status. However, AMOVA indicated that there was a significant difference in the community membership of saliva between HIV-positive and -negative groups (P = 0.001). Linear discriminant analysis effect size revealed an OTU identified as Haemophilus parainfluenzae to be significantly associated with HIV-positive individuals, whilst Streptococcus mitis/HOT473 was most significantly associated with HIV-negative individuals. In conclusion, this study has confirmed that the microbial composition of saliva and plaque is different. The oral microbiomes of HIV-positive and -negative individuals were found to be similar overall, although there were minor but significant differences in the composition of the salivary microbiota of the two groups.

Phenotype, genotype, and antibiotic susceptibility of Swedish and Thai oral isolates of Staphylococcus aureus.

OBJECTIVE: The present study investigated phenotypes, virulence genotypes, and antibiotic susceptibility of oral Staphylococcus aureus strains in order to get more information on whether oral infections with this bacterium are associated with certain subtypes or related to an over-growth of the S. aureus variants normally found in the oral cavity of healthy carriers. MATERIALS AND METHODS: A total number of 157 S. aureus strains were investigated. Sixty-two strains were isolated from Swedish adults with oral infections, 25 strains were from saliva of healthy Swedish dental students, and 45 strains were from tongue scrapings of HIV-positive subjects in Thailand, and 25 Thai strains from non-HIV controls. The isolates were tested for coagulase, nitrate, arginine, and hemolysin, and for the presence of the virulence genes: hlg, clfA, can, sdrC, sdrD, sdrE, map/eap (adhesins) and sea, seb, sec, tst, eta, etb, pvl (toxins). MIC90 and MIC50 were determined by E-test against penicillin V, oxacillin, amoxicillin, clindamycin, vancomycin, fusidic acid, and cefoxitin. RESULTS: While the hemolytic phenotype was significantly (p<0.001) more common among the Thai strains compared to Swedish strains, the virulence genes were found in a similar frequency in the S. aureus strains isolated from all four subject groups. The Panton-Valentine leukocidin (PVL) genotype was found in 73-100% of the strains. More than 10% of the strains from Swedish oral infections and from Thai HIV-positives showed low antibiotic susceptibility, most commonly for clindamycin. Only three methicillin-resistant S. aureus (MRSA) strains were identified, two from oral infections and one from a Thai HIV patient. CONCLUSIONS: S. aureus is occasionally occurring in the oral cavity in both health and disease in Sweden and Thailand. It is therefore most likely that S. aureus in opportunistic oral infections originate from the oral microbiota. S. aureus should be considered in case of oral infections and complaints and the antibiotic susceptibility (including MRSA) should regularly be checked. The frequent presence of S. aureus, although in low numbers among students and staff, emphasizes the importance of standard infection control precautions and of using diagnostic test in the dental clinic.

Oral lichen planus in thai patients has a low prevalence of human papillomavirus.

Background. Oral lichen planus (OLP) is a common chronic inflammatory immune-mediated disease, with an etiopathogenesis associated with cell-mediated immunological dysfunction. Viral infection has been hypothesized as a predisposing factor in the pathogenesis of this disease. Viruses may alter host cell function by inducing the abnormal expression of cellular proteins leading to disease development. However, reports on the relationship between human papillomavirus (HPV) and OLP are inconclusive. Objective. To explore the association between HPV and OLP in Thai patients. Materials and Methods. DNA was extracted from thirty-seven fresh-frozen tissue biopsy specimens from OLP lesions, and polymerase chain reaction assay for the L1 and E1 genes covering 32 types of high- and low-risk HPV was performed. Results. HPV DNA was detected in one tissue biopsy from an atrophic-type OLP lesion. All control samples were negative. Genomic sequencing of the E1 gene PCR product demonstrated that the HPV-type 16 found in the lesion is closely related to the East Asian type. Conclusion. Our data indicate a low prevalence of HPV infection in OLP lesions in Thai patients.

Chitosan whiskers from shrimp shells incorporated into dimethacrylate-based dental resin sealant.

A resin-based sealant containing chitosan whiskers was developed for use as a pit and fissure sealer. Chitosan whiskers were synthesized and then characterized using Fourier transform infrared spectrometry and transmission electron microscopy. The whiskers were next incorporated into dimethacrylate monomer at various ratios by weight and subsequently analyzed for their antimicrobial and physical properties. The dimethacrylate-based sealant containing chitosan whiskers had a greater antimicrobial activity than control sealant and they were comparable with antimicrobial commercial resin sealants. The inclusion of the whiskers did not reduce the curing depth or degree of double bond conversion and the reduction in hardness was minimal. In conclusion, a resin-based sealant containing chitosan whiskers can be considered an effective antimicrobial pit and fissure sealant.

Infection of human gingival fibroblasts with Aggregatibacter actinomycetemcomitans: An in vitro study.

OBJECTIVE: Aggregatibacter actinomycetemcomitans is known to be a major cause of localized aggressive periodontitis. Previous research has suggested that A. actinomycetemcomitans can damage many types of host cells. There is evidence for the ability of this organism to invade endothelial and epithelial cells, but information pertaining to its potential for invading gingival fibroblasts is very limited. Internalization of bacteria is not only responsible for damaging host tissue but also a means to evade the host immune response. It was hypothesized that A. actinomycetemcomitans can invade and reside in human gingival fibroblasts (HGF). METHODS: Primary cultures of HGF were infected with A. actinomycetemcomitans at a ratio of 1:100. Bacterial internalization was determined by an antibiotic protection assay. Bacterial-fibroblast interaction was examined using phase-contrast, scanning and transmission electron microscopy. RESULTS: It was demonstrated that A. actinomycetemcomitans was internalized into HGF at an efficiency of 0.084%. Transmission electron microscopic study showed the presence of A. actinomycetemcomitans in the cytoplasm of HGF without the surrounding membrane. Scanning electron micrographs revealed the sloughing of HGF surfaces on which A. actinomycetemcomitans adhered. Rounded cells, attachment loss and damaged cells were also observed. CONCLUSIONS: It is concluded that the attachment and invasion of A. actinomycetemcomitans into human gingival fibroblasts play a role in periodontal tissue damage and may also be a means of immune evasion.

Antiretroviral Drug-Associated Oral Lichenoid Reaction in HIV Patient: A Case Report.

Antiretroviral therapy has changed the course of HIV disease and improved quality of life in HIV patients. Incidence of an oral lichenoid drug reaction induced by zidovudine is not common. Once it occurs, it affects a patient's well being, in particular their oral functions. Here we report the first case of a 34-year-old Thai man with painful erosive lesions involving the lip and buccal mucosa. Treatment with topical fluocinolone acetonide 0.1% alleviated the patient's oral pain, but it was not until the subsequent withdrawal of zidovudine that the patient showed improvement and resolution of the lesions. Long-term follow-up was useful in the management of this patient, and no recurrence of the lesion was found during 21-month follow-up in this patient.