ABSTRACT
Objective@#To measure the position of the mandibular nerve canal at the mandibular second molar by CBCT image data, analyze the theoretical implantation range of trans-alveolar implantation, and provide a theoretical solution to insufficiency of posterior mandibular bone volume in clinical practice. @*Methods@#Eighty patients with missing mandibular second molars whose vertical bone height of the edentulous area was less than 9 mm were selected for CBCT image measurement, and the distances from the mandibular nerve canal to the buccal cortex, lingual cortex, and alveolar crest were measured to simulate trans-inferior alveolar nerve implantation. The angular range of the buccolingual inclination of the implant was also measured.@*Results@#The distances from the mandibular nerve canal to the buccal cortex, lingual cortex and alveolar crest at the mandibular second molar were(6.913±1.222)mm, (2.859±0.891)mm and (7.991±0.783)mm, respectively. The distance from the mandibular nerve canal to the buccal cortex was significantly greater than that to the lingual cortex. And, 75% of the patients could be implanted by the inferior alveolar nerve. The minimum angle of buccolingual inclination of the simulated implant was 19.360°±7.086°, and the maximum angle was 39.462°±6.924°. @*Conclusion@#The mandibular nerve canal at the mandibular second molar is inclined toward the lingual side, which ensures sufficient buccal bone volume. Most patients with severe mandibular atrophy can still adopt implants of conventional length by trans-inferior alveolar nerve implantation to keep a safe distance from the nerve canal.
ABSTRACT
Background: Previous studies have confirmed that the presence of Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) increases the risks of various diseases including genital infections in women. Hence, the surveillance policies for the prevalence and antimicrobial susceptibility of UU and MH are important for both the prevention and the treatment of the diseases associated with genital mycoplasmas. Aim: The objective of this study is to investigate the characteristics of UU and MH prevalence and its antimicrobial susceptibility in Chinese women with genital infection. Methods: By using commercial mycoplasma strips, we investigated the incidence and antimicrobial resistance of UU and MH in 3306 Chinese women with genital infection between January 2005 and December 2009 in Changzhou China. Results: (1) The overall positive incidence of genital mycoplasmas was 62.16%. The most common pattern was UU monoinfection (46.52%), the UU-MH coinfection pattern ranked second (13.91%) and MH monoinfection was lowest (1.71%). According to annual analysis, MH infection revealed an increasing trend between 2005 and 2009. However, a significantly higher infection rate by genital mycoplasmas was found in young women (age range: 16-35 years). (2) Overall, MH susceptibility rates remained high only to doxycycline (DOX), minocycline (MIN) and josamycin (JOS), while UU had high susceptibility rates only to DOX, MIN and clarithromycin (CLA). The resistance rates of UU-MH-mixed isolates to most of drugs were significantly higher than those of UU- or MH-single isolates. Conclusions: High infection rates and severe drug resistances of genital mycoplasmas were found in Chinese women with genital infections. The laboratory screening and antimicrobial susceptibility testing for genital mycoplasmas is vital to treat the infection.