Missing upper incisors: a retrospective study of orthodontic space closure versus implant

Background: The aim of this retrospective study was to compare the esthetic, periodontal, and functional outcomes of orthodontic space closure versus implant substitution in patients with missing maxillary incisors 5 years after completion of treatment. Methods: The study group consisted of ten patients treated with orthodontic space closure (six males, four females, mean age 19 ± 2.1 years at the completion of treatment) and ten patients treated with implant insertion (five males, five females, mean age 20 ± 1.4 years at the time of implant insertion). Tooth mobility, plaque index, probing depth, infraocclusion, open gingival embrasure (black triangle), and temporomandibular joint function were recorded at the 5.6 years follow-up. Self-perceived dental esthetic appearance was also evaluated through a visual analog scale (VAS) questionnaire. T-test was used to evaluate the data. Results: All patients were equally satisfied with the appearance of their teeth 5.6 ± 0.4 years after the completion of treatment. No statistically significant differences were found in relation to the VAS scores of the subjects (P < 0.857). No significant differences were found in tooth mobility, plaque index (P < 0.632), and the prevalence of signs and symptoms of temporomandibular disorders. However, significant infraocclusion was noticed in all implant patients (P < 0.001). Probing depth was also significantly higher in implant patients (P < 0.001). Conclusions: Orthodontic space closure and implant of missing maxillary incisors produced similar, well-accepted esthetic results. None of the treatments impaired temporomandibular joint function. Nevertheless, infraocclusion was evident in implant patients. Space closure patients also showed better periodontal health in comparison with implant patients

In vitro re-hardening of artificial enamel caries lesions using enamel matrix proteins or self-assembling peptides

ABSTRACT Objectives To assess the re-hardening potential of enamel matrix derivatives (EMD) and self-assembling peptides in vitro, hypothesizing that these materials may increase the mineralization of artificial carious lesions and improve hardness profiles. Material and Methods Forty-eight enamel samples were prepared from extracted bovine lower central incisors. After embedding and polishing, nail varnish was applied, leaving a defined test area. One third of this area was covered with a flowable composite (non-demineralized control). The remaining area was demineralized in an acidic buffer solution for 18 d to simulate a carious lesion. Half the demineralized area was then covered with composite (demineralized control), while the last third was left open for three test and one control treatments: (A) Application of enamel-matrix proteins (EMD - lyophilized protein fractions dissolved in acetic acid, Straumann), (B) self-assembling peptides (SAP, Curodont), or (C) amine fluoride solution (Am-F, GABA) for 5 min each. Untreated samples (D) served as control. After treatment, samples were immersed in artificial saliva for four weeks (remineralization phase) and microhardness (Knoop) depth profiles (25-300 µm) were obtained at sections. Two-way ANOVA was calculated to determine differences between the areas (re-hardening or softening). Results Decalcification resulted in significant softening of the subsurface enamel in all groups (A-D). A significant re-hardening up to 125 µm was observed in the EMD and SAP groups. Conclusions This study showed that EMD and SAP were able to improve the hardness profiles when applied to deep demineralized artificial lesions. However, further research is needed to verify and improve this observed effect

Large Scale Gene Expression Profiles of Regenerating Inner Ear Sensory Epithelia

Loss of inner ear sensory hair cells (HC) is a leading cause of human hearing loss and balance disorders. Unlike mammals, many lower vertebrates can regenerate these cells. We used cross-species microarrays to examine this process in the avian inner ear. Specifically, changes in expression of over 1700 transcription factor (TF) genes were investigated in hair cells of auditory and vestibular organs following treatment with two different damaging agents and regeneration in vitro. Multiple components of seven distinct known signaling pathways were clearly identifiable: TGFβ, PAX, NOTCH, WNT, NFKappaB, INSULIN/IGF1 and AP1. Numerous components of apoptotic and cell cycle control pathways were differentially expressed, including p27KIP and TFs that regulate its expression. A comparison of expression trends across tissues and treatments revealed identical patterns of expression that occurred at identical times during regenerative proliferation. Network analysis of the patterns of gene expression in this large dataset also revealed the additional presence of many components (and possible network interactions) of estrogen receptor signaling, circadian rhythm genes and parts of the polycomb complex (among others). Equal numbers of differentially expressed genes were identified that have not yet been placed into any known pathway. Specific time points and tissues also exhibited interesting differences: For example, 45 zinc finger genes were specifically up-regulated at later stages of cochlear regeneration. These results are the first of their kind and should provide the starting point for more detailed investigations of the role of these many pathways in HC recovery, and for a description of their possible interactions

Adult Consequences of Late Adolescent Alcohol Consumption: A Systematic Review of Cohort Studies

In a systematic review of cohort studies of adolescent drinking and later outcomes, Jim McCambridge and colleagues show that although studies suggest links to worse adult physical and mental health and social consequences, existing evidence is of poor quality