The clinical utility of genetic testing of tissues from pregnancy losses.

OBJECTIVE: To map the current testing being undertaken following pregnancy loss across the UK and to examine the clinical utility in terms of identifying a cause for the loss and in identifying couples at risk of an unbalanced liveborn child. DESIGN: Retrospective audit. SETTING: UK, for the year 2014. POPULATION: An audit of 6465 referrals for genetic testing of tissue samples following pregnancy loss. METHODS: Data were obtained by questionnaire from 15 UK regional genetics laboratories. MAIN OUTCOME MEASURES: Data were analysed with respect to gestational age, the presence of identified fetal anomalies, methodologies used, abnormality rates and the presence of a parental balanced rearrangement. RESULTS: Of 6465 referrals a genetic cause was identified in 22% of cases (before 12 weeks' gestation, in 47%; at 12-24 weeks, in 14%; after 24 weeks, in 6%). In 0.4% of cases a balanced parental rearrangement was identified where there was a risk of an affected liveborn child in a future pregnancy. Eighty percent of genetic imbalances identified were aneuploidy or triploidy and could be identified by quantitative fluorescence polymerase chain reaction alone. There was significant variation across the UK in acceptance criteria, testing strategies and thus level of resolution of testing. CONCLUSIONS: Genetic testing of tissues following pregnancy loss identifies a probable cause of fetal demise in 22% of cases, but it is of low clinical utility in identifying couples at risk of a future unbalanced liveborn child. A comprehensive multidisciplinary review is needed to develop proposals for an affordable and equitable service. TWEETABLE ABSTRACT: UK audit of genetic testing of fetal loss shows variation in access to and resolution of analysis.

Guided tissue regeneration using a bioabsorbable membrane in the treatment of human buccal recession. A re-entry study.

A surgical technique involving a bioabsorbable membrane was used to treat localized buccal recession defects of between 2 and 5 mm on 17 sites in 13 patients. A conventional flap for coronal repositioning was raised consisting of a trapezoid flap with de-epithelialization of papillae, and the root surface planed back to reduce its convexity. The polylactate membrane with internal spacer bars was placed over the root surface with its coronal edge as near to the cemento-enamel junction (CEJ) as possible. This was held in place by a bioabsorbable retaining suture around the root, and the flap was coronally repositioned to cover the membrane. The patients were prescribed tetracycline for 2 weeks postsurgically, the sutures removed after 4 weeks, and cleaning procedures in the area reinstated after 6 weeks. Measurements were made using a custom made stent, and subjected to a Wilcoxon signed ranked analysis. These were clinical recession, clinical attachment level, probing depth, width of attached gingiva and the level of the buccal alveolar crest. The healing was monitored for a minimum of 1 year, and a surgical re-entry procedure was performed on 11 sites. The new buccal alveolar crest position was measured. This procedure resulted in a clinical and statistically significant reduction in clinical recession of 2.4 +/- 0.2 mm, a gain in attachment level of 2.7 +/- 0.2 mm, a gain in root coverage of 76 +/- 6% (P < 0.002), and a regeneration of buccal bone in all cases, with an average of 2.0 +/- 0.1 mm (P < 0.0023). This study shows that the use of a bioabsorbable membrane will predictably and significantly increase root coverage and regenerate buccal bone when used to treat localized buccal recession defects.

The effect on healing of the application of citric acid during replaced flap surgery.

The aim of this double-blind controlled clinical trial was to assess the effect on healing following conditioning the root surface with citric acid during replaced flap surgery. Healing was assessed in 18 pairs of sites in 12 patients before surgery and after 3 months; healing was also assessed in 13 pairs of these sites in 10 of the patients after 9 months. During surgery, the root surface at 1 site from each pair was treated with citric acid pH 0.6 for 3 min and the contralateral site was exposed to sterile saline. Healing was assessed by measuring attachment levels, probing depths and recession; in addition, gingival crevicular fluid flow was measured, as was the degree of bleeding on probing. The mean gain of attachment (mm) in the acid and control groups were 1.0 and 1.2, respectively, at 3 months and 1.1 and 0.9 respectively, at 9 months. The results of this study indicate, both clinically and statistically, that the difference in healing between the acid and the non-acid sites is not significant. Thus no additional benefit is shown by using citric acid in conjunction with replaced flap surgery on anterior teeth.