Non-Recurrent Laryngeal Nerve and Concurrent Vascular Variants: A Review.

OBJECTIVE: The purpose of this paper is to review the current data on the coexistence of non-recurrent laryngeal nerve (RLN) and vascular variations. METHODS: A systematic literature search was conducted on MEDLINE for case reports, original articles and reviews regarding the presence of non-RLN and coexisting vascular variants. RESULTS: From the literature search, 104 cases of non-RLN with confirmed vascular variants were reported. More specifically, 97.7% (n=101) of cases involved a right and 2.3% (n=3) a left non-RLN. The most common concurrent vascular variant reported with a right non-RLN was an aberrant right subclavian artery (97%; n=98). One case report (0.9%) of an intrathyroidal right common carotid artery was noted and 2 cases (1.9%) were associated with normal vascular anatomy. Furthermore, all 3 cases of a left non-RLN were associated with a right aortic arch, while 2 of them were also accompanied with situs inversus. CONCLUSIONS: The presence of vascular variations of the great vessels must prompt the surgeon to search for a non-RLN. Intraoperative neuromonitoring increases the detection rate of non-RLN. Further research is required to determine anatomic landmarks for the perioperative identification of a non-RLN, allowing its protection from potential injury.

Behavior of CAL72 osteoblast-like cells cultured on zirconia ceramics with different surface topographies.

OBJECTIVES: Because of its inherent strength, biocompatibility, and tooth-like color, zirconia ceramics have the potential to become an alternative to titanium as dental implant material. This study aimed at investigating the osteoblastic response to yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) with different surface topographies. METHODS: CAL72 osteoblast-like cells were cultured on machined (TZP-m), airborne particle abraded (TZP-s), and airborne particle abraded and acid-etched Y-TZP (TZP-sa) surfaces. Polystyrene and airborne particle abraded with large grit and acid-etched (SLA) titanium served as a reference control. The surface topography was examined by scanning electron microscopy (SEM) and profilometry. At culture days 3, 6, and 12, cell proliferation, at day 12 cell morphology, and cell-covered surface area were determined. RESULTS: The surface roughness of Y-TZP was increased by airborne particle abrasion and additionally by acid etching. No statistically significant differences were found between average roughness (R(a)) and maximum peak-to-valley height (R(p-v)) values of airborne particle abraded and acid-etched Y-TZP and SLA titanium. Whereas the cell proliferation assay revealed statistically significant greater values at day 3 for surface-treated Y-TZP and polystyrene cultures as compared with machined Y-TZP, no differences between the Y-TZP groups, SLA titanium, and polystyrene were observed at culture days 6 and 12. CONCLUSIONS: Cell morphology and cell-covered surface area were not affected by the type of substrate. The results suggest that roughened Y-TZP is an appropriate substrate for the proliferation and spreading of osteoblastic cells.