Mandibular premolar transplantation to replace missing maxillary anterior teeth: A multidisciplinary approach.

One of the most challenging problems for orthodontists is that of multiple missing maxillary teeth in a growing patient. In many patients, a good treatment option is autotransplantation. This case report describes the multidisciplinary treatment of an 11-year-old girl with regional odontodysplasia affecting the maxillary right and left central incisors, and congenitally missing maxillary left lateral incisor and canine. Autotransplantation of the mandibular second premolars to the affected area was combined with orthodontic space closure, and the transplanted premolars were reshaped and restored with a resin composite to be in line with the left central and lateral incisors. After completion of the orthodontic treatment, gingivectomy was performed to obtain an even gingival contour and symmetrical gingival tissue. Space closure of the maxillary anterior teeth was achieved. Autotransplantation enabled the patient to retain her natural teeth rather than having a prosthesis or dental implant. The autotransplanted tooth allows for alveolar bone growth in synchrony with neighboring teeth and the formation of normal interdental papilla while adapting to functional stimuli and confers a high survival rate in the long term.

Clinical and histological evaluations of alveolar ridge augmentation using a novel bi-layered porous polyethylene barrier membrane.

Guided bone regeneration (GBR) is an effective alveolar ridge reconstruction technique used before or at implant placement. The combination of various barrier membranes and bone substitutes has been employed. This study aimed to perform a preliminarily evaluation of the safety and performance of a new nonabsorbable bi-layered porous polyethylene (PPE) membrane, in combination with a freeze-dried cortical bone allograft in posterior mandibular ridge augmentation. Fifteen adults who had combined posterior mandibular defects were included for ridge augmentation via GBR using PPE membrane and allograft before implant placement. The keratinized mucosa width (KW), ridge width (RW), ridge height (RH), distance from measurement matrix to bone (DMB), and horizontal alveolar width at 14.0 mm apical to the occlusal plane (HAW) were clinically measured at 15 intended implant sites before and after the augmentation. Fifteen biopsy specimens were harvested at the implant sites for histological analysis. All the subjects completed the whole study. The KW and RH showed minor gains by 0.2 ± 1.4 mm and 0.9 ± 2.3 mm respectively; however, no statistically significant differences were found between, before, and after the augmentation (P > 0.05). In contrast, the RW and HAW significantly increased by 4.8 ± 1.6 mm and 2.3 ± 1.7 mm, respectively, (P ≤ 0.001), while DMB significantly decreased by 1.0 ± 0.8 mm after treatment (P < 0.001). Histological analysis revealed that allograft underwent active bone remodeling. The PPE membrane was adequately safe and efficient to use with allograft in GBR for the reconstruction of combined ridge defects. Although some complications were observed, these were manageable and subsequently lead to successful implant placement for all the subjects. However, further randomized controlled trials are still needed to confirm these findings.

Prolonged Suppressive Effects of Periodontitis on Salivary TFF3 Production.

OBJECTIVE: As a follow-up to our previous study that demonstrated decreased salivary trefoil factor family 3 (TFF3) peptide levels in chronic periodontitis patients, this current study aimed to observe the effects of nonsurgical periodontal treatment on salivary TFF3 peptides in patients with periodontal diseases. MATERIALS AND METHODS: Eighty-seven volunteers that comprised of 30 individuals with healthy periodontium, 31 with gingivitis, and 26 with chronic periodontitis were considered for the study. Prior to periodontal treatment, a general periodontal examination was performed along with collection of saliva samples from each volunteer. Nonsurgical periodontal treatments were provided to patients with gingivitis and periodontitis. Two weeks post-treatment, saliva samples were recollected, and the periodontal status was re-evaluated. Salivary TFF3 concentrations were measured by enzyme-linked immunosorbent assay. STATISTICAL ANALYSIS: Mann-Whitney U test was used when the investigated data were not normally distributed. Chi-squared test was used when dealing with categorical data. Kruskal-Wallis test with post-hoc corrections was used to compare data among the three investigated groups. Two-tailed p < 0.05 was considered as statistically significant. RESULTS: Prior to the periodontal treatment, salivary TFF3 concentrations in patients with gingivitis and periodontitis were significantly lower than those with healthy periodontium. Two weeks post-treatment, increased levels of salivary TFF3 were observed in patients with gingivitis, whereas the concentrations decreased in patients with chronic periodontitis. CONCLUSION: This study demonstrated the effects of periodontal disease on the production of salivary TFF3 peptides. Interestingly, nonsurgical periodontal treatment also affected the recovery of salivary TFF3 peptides but varied in their outcomes between gingivitis and periodontitis patients.

Synergistic effects of LFchimera and antibiotic against planktonic and biofilm form of Aggregatibacter actinomycetemcomitans.

Adjunctive use of antibiotics in periodontal treatment have limitations and disadvantages including bacterial resistance. Antimicrobial peptides (AMPs) are potential new agents that can combat bacterial infection. In this study, antimicrobial activity of different concentrations of conventional antibiotics minocycline (MH), doxycycline (DOX), and antimicrobial peptides LL-37, LL-31, Lactoferrin chimera (LFchimera) and Innate Defense Regulator Peptide 1018 (IDR-1018) against Aggregatibacter actinomycetemcomitans ATCC 43718 were determined using colony culturing assay. Subsequently, in vitro activity of the most effective drug and peptide combination was evaluated by checkerboard technique. Impact of the drug and peptide co-administration on biofilm at different stages, i.e., during adhesion and 1-day old biofilm was compared to each of the agents used alone. Results revealed that the killing effects of all AMPs range from 13-100%. In contrast, MH and DOX at 1 and 5 µM showed no killing activity and instead stimulated growth of bacteria. DOX has better killing activity than MH. LFchimera displayed the strongest killing amongst the peptides. Checkerboard technique revealed that combining DOX and LFchimera yielded synergism. Confocal laser scanning microscopy further showed that the combination of DOX and LFchimera caused significant reduction of bacterial adhesion and reduction of biomass, average biofilm thickness and substratum biofilm coverage of 1-day old biofilm compared to DOX and LFchimera alone. In conclusion, LFchimera alone and in combination with DOX exhibited strong antibacterial and anti-biofilm property against A. actinomycetemcomitans. The findings suggest that LFchimera should be considered for development as a new potential therapeutic agent that may be used as an adjunctive treatment for periodontitis.

Alanine aminopeptidase and dipeptidyl peptidase IV in saliva of chronic periodontitis patients.

BACKGROUND: Alanine aminopeptidase (ALAP) and dipeptidyl peptidase IV (DPPIV) are ectopeptidases that play a role in collagen degradation and are thought to be involved in the destruction of periodontal tissue. This study compared the activities of salivary ALAP and DPPIV in patients with periodontitis and periodontally healthy subjects. The correlations of enzyme activities with clinical variables and the presence of Porphyromonas gingivalis were also evaluated. METHODS: Whole saliva was collected from 30 periodontally healthy subjects, 30 localized chronic periodontitis (LCP) patients, and 30 generalized chronic periodontitis (GCP) patients to determine the activities of ALAP and DPPIV. The presence of P. gingivalis in subgingival plaque was detected by polymerase chain reaction. Periodontal clinical assessments included probing depth, clinical attachment level, and bleeding on probing. RESULTS: The activities of DPPIV in the LCP and GCP groups were not significantly different from one another, but both groups had significantly higher enzyme activities than the periodontally healthy group (P = 0.001). DPPIV activity was positively correlated with all clinical parameters and the prevalence of P. gingivalis. The ALAP activities were not significantly different among the three study groups. There was no significant correlation of ALAP activity with any of the clinical and bacterial parameters. CONCLUSION: DPPIV, but not ALAP, activity is associated with periodontitis and the presence of P. gingivalis.

Adult rat bones maintain distinct regionalized expression of markers associated with their development.

The incidence of limb bone fracture and subsequent morbidity and mortality due to excessive bone loss is increasing in the progressively ageing populations of both men and women. In contrast to bone loss in the weight-bearing limb, bone mass in the protective skull vault is maintained. One explanation for this could be anatomically diverse bone matrix characteristics generated by heterogeneous osteoblast populations. We have tested the hypothesis that adult bones demonstrate site-specific characteristics, and report differences at the organ, cell and transcriptome levels. Limb bones contain greater amounts of polysulphated glycosaminoglycan stained with Alcian Blue and have significantly higher osteocyte densities than skull bone. Site-specific patterns persist in cultured adult bone-derived cells both phenotypically (proliferation rate, response to estrogen and cell volumes), and at the level of specific gene expression (collagen triple helix repeat containing 1, reelin and ras-like and estrogen-regulated growth inhibitor). Based on genome-wide mRNA expression and cluster analysis, we demonstrate that bones and cultured adult bone-derived cells segregate according to site of derivation. We also find the differential expression of genes associated with embryological development (Skull: Zic, Dlx, Irx, Twist1 and Cart1; Limb: Hox, Shox2, and Tbx genes) in both adult bones and isolated adult bone-derived cells. Together, these site-specific differences support the view that, analogous to different muscle types (cardiac, smooth and skeletal), skull and limb bones represent separate classes of bone. We assign these differences, not to mode of primary ossification, but to the embryological cell lineage; the basis and implications of this division are discussed.