https://www.selleckchem.com/products/ten-010.html To the best of our knowledge, there is no case report or data published regarding COVID pneumonitis presenting initially as pneumothorax.There are 3 case reports published to-date (May 30, 2020) reporting secondary pneumothorax as complication in later stages of Acute respiratory distress syndrome (ARDS) secondary to COVID-19 in non-ventilated patients. We present a case of COVID-19 disease presenting as tension pneumothorax after a week of symptoms and developing a second pneumothorax on the contralateral side post mechanical ventilation.The purpose of the systematic review and meta-analysis was to analyze the existing evidence regarding the effect of crown-to-implant ratio (CIR) on the peri-implant crestal bone level change and implant survival. Randomized controlled clinical trials, prospective as well as retrospective studies with a minimum follow-up period of 12 months and 10 patients per group were included for this systematic review. Statistical analysis was performed to determine CIR effects on the peri-implant marginal bone level changes and implant survival. A total of 28 articles (14 prospective studies and 14 retrospective studies) from a database of 201 articles, with 2097 patients and 4350 implants, were included. A mean CIR ranging from 0.6 to 2.44 was presented by the study groups. A weighted mean implant loss of 0.19% per year and peri-implant marginal bone level change of 0.63 mm ± 0.55 over 46.8 ± 5.2 months was calculated from the included studies. The peri-implant marginal bone level change (p = 0.155) and the rate of implant loss (p = 0.245) showed a statistically insignificant difference between implant restorations of a high (>1.51) and low (1.51) or a low ( less then 1.51) CIR does not significantly affect the peri-implant marginal bone level change and implant survival rate. However, until further evidence becomes available, extrapolation to long term clinical success cannot be ascertained.