Transient myeloproliferative disorder in children with Down syndrome: clarity to this enigmatic disorder

Children with trisomy 21 have a unique predisposition to develop a megakaryoblastic proliferative disease of varying severity during their first 3 months of life. This disorder exists in no other children or adults without the presence of trisomy 21 and only occurs in the fetal or neonatal period of life. Its spontaneous resolution in most cases further delineates it from otherwise indistinguishable neonatal leukaemias. The identification that GATA1 mutations are the leukaemogenic source along with three recently reported prospective clinical trials now provide a clearer understanding of this haematopoietic disorder. These recent advances in this enigmatic disorder, now known as Transient Myeloproliferative Disorder, are reviewed here in order to bring clarity to the breadth of organ involvement, the range of severity, the risk factors for mortality, the therapeutic options for severe manifestations, the natural course of spontaneous resolution regardless of therapy, and the elucidation of the subsequent risk for myeloid leukaemia.     

Complications of radiofrequency ablation of varicose veins

Radiofrequency ablation (RFA) has become a valued weapon in the phlebologist's armoury. It offers ease of use and reproducibility with good outcomes. However, as with all interventions, complications arise. In this review we examine the complications inherent with RFA and their relative risk, with their avoidance measures if available. Overall, we find that RFA offers a very safe procedure with rare severe complications.     

Shear bond strength evaluation of bonded molar tubes on fluorotic molars

Objective:To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis.Materials and Methods:This in vitro study included 140 first molars classified according to Dean''s index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope.Results:The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups.Conclusions:Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.     

Anatomy of sodium hypochlorite accidents involving facial ecchymosis—A review

Objectives

Root canal treatment forms an essential part of general dental practice. Sodium hypochlorite (NaOCl) is the most commonly used irrigant in endodontics due to its ability to dissolve organic soft tissues in the root canal system and its action as a potent antimicrobial agent. Although NaOCl accidents created by extrusion of the irrigant through root apices are relatively rare and are seldom life-threatening, they do create substantial morbidity when they occur.

Methods

To date, NaOCl accidents have only been published as isolated case reports. Although previous studies have attempted to summarise the symptoms involved in these case reports, there was no endeavour to analyse the distribution of soft tissue distribution in those reports. In this review, the anatomy of a classical NaOCl accident that involves facial swelling and ecchymosis is discussed.

Results

By summarising the facial manifestations presented in previous case reports, a novel hypothesis that involves intravenous infusion of extruded NaOCl into the facial vein via non-collapsible venous sinusoids within the cancellous bone is presented.

Conclusions

Understanding the mechanism involved in precipitating a classic NaOCl accident will enable the profession to make the best decision regarding the choice of irrigant delivery techniques in root canal débridement, and for manufacturers to design and improve their irrigation systems to achieve maximum safety and efficient cleanliness of the root canal system.