Ultrasonographic characterization of lingual structures pertinent to oral, periodontal, and implant surgery

Objectives: Increased applications of ridge augmentation in the lingual posterior mandible call for an urgent need to study its anatomy. Therefore, our first aim was to validate ultrasound in measuring the mandibular lingual structures in human cadavers. Secondarily, to test its feasibility in imaging the lingual nerve in live humans. Materials and methods: Nine fresh un-embalmed fully/partially edentulous cadaver heads were utilized for aim 1. Three areas in the lingual mandible were imaged (mandibular premolar, molar, and retromolar). Immediately after, biopsies were harvested from each site. The thickness of the mucosa, mylohyoid muscle, and lingual nerve diameter was measured via ultrasound and statistically compared to histology. Similarly, the lingual nerve in live humans was also imaged. Results: None of the differences between the ultrasound and histology measurements reached statistical significance (p > .05). The mean mucosal thickness via ultrasound and histology was 1.45 ± 0.49 and 1.39 ± 0.50 mm, 5 mm lingual to the mylohyoid muscle attachment. At 10 mm beyond the attachment, the ultrasound and histologic values were 1.54 ± 0.48 and 1.37 ± 0.49, respectively. The mean muscle thickness measured via ultrasound and histology was 2.31 ± 0.56 and 2.25 ± 0.47 mm, at the 5 mm distance. At the 10 mm distance, the measurements were 2.46 ± 0.56 and 2.36 ± 0.5 mm, respectively. The mean ultrasonic lingual nerve diameter was 2.38 ± 0.44 mm, versus 2.43 ± 0.42 mm, with histology. The lingual nerve diameter on 19 live humans averaged to 2.01 ± 0.35 mm (1.4-3.1 mm). Conclusions: Within its limitations, ultrasound accurately measured mandibular lingual soft tissue structures on cadavers, and the lingual nerve on live humans.Delta Dental Foundation (PAF01878)Osteology Foundation (PAF06301)National Institute of Dental and Craniofacial Research (1R21DE027765)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/169151/1/Barootchi et al. 2020 Ultrasound.pdfDescription of Barootchi et al. 2020 Ultrasound.pdf : Full text of published articleSEL

Effect of different implant placement depths on crestal bone levels and soft tissue behavior: A 5â year randomized clinical trial

ObjectivesThis randomized clinical trial analyzed the longâ term (5â year) crestal bone changes and soft tissue dimensions surrounding implants with an internal tapered connection placed in the anterior mandibular region at different depths (equiâ and subcrestal).Materials and methodsEleven edentulous patients were randomly divided in a splitâ mouth design: 28 equicrestal implants (G1) and 27 subcrestal (1â 3 mm) implants (G2). Five implants were placed per patient. All implants were immediately loaded. Standardized intraoral radiographs were used to evaluate crestal bone (CB) changes. Patients were assessed immediately, 4, 8, and 60 months after implant placement. The correlation between vertical mucosal thickness (VMT) and soft tissue recession was analyzed. Subâ group analysis was also performed to evaluate the correlation between VMT and CB loss. Rankâ based ANOVA was used for comparison between groups (α = .05).ResultsFiftyâ five implants (G1 = 28 and G2 = 27) were assessed. Implant and prosthetic survival rate were 100%. Subcrestal positioning resulted in less CB loss (â 0.80 mm) when compared to equicrestal position (â 0.99 mm), although the difference was not statistically significant (p > .05). Significant CB loss was found within the G1 and G2 groups at two different measurement times (T4 and T60) (p  .05).ConclusionsThere was no statistically significant difference in CB changes between subcrestal and equicrestal implant positioning; however, subcrestal position resulted in higher bone levels. Neither mucosal recession nor vertical mucosa thickness was influenced by different implant placement depths.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154286/1/clr13569.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154286/2/clr13569_am.pd

Target protection as a key antibiotic resistance mechanism

Antibiotic resistance is mediated through several distinct mechanisms, most of which are relatively well understood and the clinical importance of which has long been recognized. Until very recently, neither of these statements was readily applicable to the class of resistance mechanism known as target protection, a phenomenon whereby a resistance protein physically associates with an antibiotic target to rescue it from antibiotic-mediated inhibition. In this Review, we summarize recent progress in understanding the nature and importance of target protection. In particular, we describe the molecular basis of the known target protection systems, emphasizing that target protection does not involve a single, uniform mechanism but is instead brought about in several mechanistically distinct ways