RESUMEN
OBJECTIVE: The aim of this study was to simulate reusing an opened package of bone substitute (BS) under typical clinical conditions, by analyzing bacterial growth in samples of resealed packages of alloplast and xenograft BS following different time periods up to a week. MATERIALS AND METHODS: The experiment was performed in 2 stages: dry stage and wet stage. In the dry stage, BS samples were exposed to air for 15 minutes and then were sealed again in their original package. After several "aging" periods [no aging (t0), 24 hours (t1), and 1 week (t7)], BS samples were plated onto brain heart infusion agar and were incubated at 37 °C for 24 hours under aerobic conditions. Bacterial colonies were enumerated and colony forming units per 1 mL was calculated. In the wet stage, the experiment was repeated but BSs were left to age in a brain heart infusion broth to simulate a more supporting humid environment to encourage bacterial growth. RESULTS: In the dry stage of the experiment, no bacterial growth was detected in both xenograft and alloplast samples (colony forming units/mL=0), in any of the time points (t0, t1, t7). In the wet stage, average bacterial growth was 0 for both groups in t0. In t1: 1.14 × 10 4 ±4.16 × 10 3 for the xenograft and 7.73 × 10 5 ± 9.99 × 10 5 for the alloplast. In t7: 1.64 × 10 9 ±1.82 × 10 8 in the xenograft compared with 8.86 × 10 8 ±4.00 × 10 8 for the alloplast. Analysis of variance with repeated measures showed a significant difference in comparison of the 2 BSs for each time group (t1 and t7) ( P <0.005). CONCLUSION: Under dry conditions, in a resealed package, there was no bacterial growth for up to 1 week for both BSs. Once the BSs are introduced to a humid environment, which supports bacterial growth, the xenograft BS allowed more rapid bacterial growth, compared with the alloplastic BS.
RESUMEN
PURPOSE: To know whether there is a correlation between maxillary advancement and the nasolabial angle change allows to preoperatively predict the precise affect a planned maxillary advancement will have over the nasolabial angle. The aim of this study was to determine the relationship between the maxillary advancement and the nasolabial angle. METHODS: The study is a retrospective analysis of 32 patients (12 males and 20 females, mean age 21â±â3.4âyears) who underwent a maxillary advancement. Lateral cephalometric radiographs were taken preoperatively and postoperatively. The lateral cephalograms were traced. Measurements were evaluated statistically using paired sample t-test and Pearson's correlation test. RESULTS: The mean maxillary advancement was 4.81â±â3.01âmm with a mean vertical change of -0.28â±â2.80âmm. The nasolabial angle decreased by a mean of 3.78â±â9.64° with statistical significance of Pâ=â0.03 using a paired sample t-test, however using Pearson's correlation test, no direct correlation between maxillary advancement and the nasolabial angle was found. Furthermore, the study contains a review of the literature from the last 25 years, which shows that in most studies there was no correlation and in some patients even opposite results. CONCLUSION: Maxillary advancement might influence the nasolabial angle; however, preoperatively predicting the influence a maxillary advancement will have over the nasolabial angle is difficult, and further studies need to be conducted.