Can intravenous conscious sedation with midazolam be effective at facilitating surgical dentistry in adolescent orthodontic patients? A service evaluation.

Background Surgical dentistry during orthodontic care often occurs in adolescence and may involve surgical removal or exposure of teeth. The invasive nature of treatment, combined with dental anxiety, means care can often be provided under general anaesthesia (GA). Best-practice guidelines however endorse conscious sedation as an alternative, where appropriate. Although a limited number of studies have shown safe and effective use of intravenous conscious sedation (IVCS) with midazolam in this cohort, robust evidence to support routine use is lacking. Aim To assess whether IVCS with midazolam can effectively facilitate surgical dentistry in adolescent orthodontic patients in primary care.Method A retrospective service evaluation was undertaken reviewing clinical records of adolescents (aged 12-15 years) undergoing surgical exposure and/or surgical removal of teeth under IVCS with midazolam.Results A total of 174 adolescents (mean age 14.2 years) attended for treatment between 2009 and 2015. Of these adolescents, 98.9% (N = 172) allowed cannulation, with all surgical dentistry completed during a single visit. Midazolam dose ranged from 2-7 mg with 79.1% of patients having good or excellent cooperation and three minor adverse events occurring.Conclusion This service evaluation shows IVCS with midazolam can effectively facilitate surgical orthodontics in carefully selected adolescents. There is however a distinct need to further explore potential for this technique to provide a viable alternative to GA.

Tissue engineering of autologous aorta using a new biodegradable polymer.

BACKGROUND: Ovine pulmonary valve leaflets and pulmonary arteries have been tissue-engineered (TE) from autologous cells and biodegradable polyglycolic acid (PGA)-polyglactin copolymers. Use of this cell-polymer construct in the systemic circulation resulted in aneurysm formation. This study evaluates a TE vascular graft in the systemic circulation which is based on a new copolymer of PGA and polyhydroxyalkanoate (PHA). METHODS: Ovine carotid arteries were harvested, expanded in vitro, and seeded onto 7-mm diameter PHA-PGA tubular scaffolds. The autologous cell-polymer vascular constructs were used to replace 3-4 cm abdominal aortic segments in lambs (group TE, n = 7). In a control group (n = 4), aortic segments were replaced with acellular polymer tubes. Vascular patency was evaluated with echography. All control animals were sacrificed when the grafts became occluded. Animals in TE group were sacrificed at 10 days (n = 1), 3 (n = 3), and 5 months (n = 3). Explanted TE conduits were evaluated for collagen content, deoxyribonucleic acid (DNA) content, structural and ultrastructural examination, mechanical strength, and matrix metalloproteinase (MMP) activity. RESULTS: The 4 control conduits became occluded at 1, 2, 55, and 101 days. All TE grafts remained patent, and no aneurysms developed by the time of sacrifice. There was one mild stenosis at the anastomotic site after 5 months postoperatively. The percent collagen and DNA contents approached the native aorta over time (% collagen = 25.7%+/-3.4 [3 months] vs 99.6%+/-11.7 [5 months], p < 0.05; and % DNA = 30.8%+/-6.0 [3 months] vs 150.5%+/-16.9 [5 months], p < 0.05). Histology demonstrated elastic fibers in the medial layer and endothelial specific von Willebrand factor on the luminal surface. The mechanical strain-stress curve of the TE aorta approached that of the native vessel. A 66 kDa MMP-2 was found in the TE and native aorta but not in control group. CONCLUSIONS: Autologous aortic grafts with biological characteristics resembling the native aorta can be created using TE approach. This may allow the development of "live" vascular grafts.