Researchers have long been interested in the role of the corpus callosum in reading disorder, but existing studies have yielded inconsistent results. Some have found larger corpus callosa in those with reading disorder, others have found smaller corpus callosa, and some have found no differences in the corpus callosa of persons with and without reading disability. Some possible problems with past studies include failure to control for whole brain size, intelligence, gender, lateral dominance, and the presence of other syndromes such as Attention Deficit Hyperactivity Disorder. The current study is an examination of the corpus callosum in 68 readers nested in 24 families. Data were centered around the family mean so that the variance within families could be determined. Corpus callosum volumes were measured and controlled for whole brain volume, intelligence, and gender. A series of regressions were used to determine whether the volume of the corpus callosum significantly contributed to the variance in oral reading, phonological processing, and rapid naming. The midsagittal slice was segmented into fifths, and similar regressions were performed. A logistic regression was used to determine whether variation in corpus callosum volume could predict RD and no RD group membership. Finally, left and right volumes were compared and a correlation between corpus callosum volume and area at the midsagittal slice were conducted. Results suggest that better readers within families have larger corpus callosum areas in the midsagittal slice at the midbody. Better phonological processors within families had smaller corpus callosum volumes, but a problem with restricted range for phonological processing scores renders this finding unreliable. Rapid naming scores appear to be unrelated to the corpus callosum in this sample. Differences in the corpus callosum are not robust enough to predict diagnostic group and there appears to be no differences between left and right hemisphere volumes of the corpus callosum. Measurements of area at the midsagittal slice are highly correlated with the volumetric measurements suggesting that for subsequent studies, area at the midsagittal slice may be sufficient. / text

The purpose of this study was to assess the changes in size of periapical lesions 3-12 months following root canal treatment using CBCT. Patients who had non-surgical root canal therapy (NSRCT) or non-surgical retreatment (ReTx) from July 30,2014 to August 19, 2015 with a periapical lesion of endodontic origin and received NSRCT or ReTx and had a pre-treatment or intra-treatment CBCT were invited to participate. Volumetric and linear measurements of periapical lesions on initial and post- treatment CBCT images were performed. A total of 20 patients with 23 treated teeth with 30 separate periapical radiolucent lesions returned for follow up 91-390 days after the initiation of endodontic treatment. Lesions showed an overall reduction in volume (p=0.0096), maximum coronal diameter (p=0.0117), maximum sagittal diameter (p=0.0071), and maximum axial diameter (p=0.0006). Lesions show a significant reduction in size 3-12 months following non-surgical endodontic treatment using CBCT.

Introduction Optimal nutrition is vital in the management of infants born preterm. Dietary fat in infancy is fundamental for the provision of energy for growth and development. Essential fatty acids, specifically Long Chain Polyunsaturated Fatty Acids (LC-PUFAs) such as docosahexaenoic acid (DHA), have been under investigation by several international research groups in the past decade. Essential fatty acids are critical in neurodevelopment as DHA is found in high proportions in structural lipids of cell membranes, particularly in the central nervous system (CNS). The accumulation of essential fatty acids and particularly DHA in the brain and retina occurs most rapidly during the perinatal period, therefore preterm infants are of particular concern (Singer, 2001). Current scientific consensus is that the optimum growth rate for preterm infants is equal to the in utero growth rate throughout the last trimester, however, failure to achieve the optimum intrauterine growth rate is common in preterm infants (Olhager and Forsum, 2003). Preterm infants require large amounts of energy and nutrients with which many infants are not provided or are not able to absorb, due to immature gastrointestinal and metabolic systems and other medical complications (Olhager and Forsum, 2003). There are a number of unresolved issues regarding optimal growth rate and total energy requirements (ER) for preterm infants. Hypotheses/Objectives This study is a “side study” to a double blind randomised controlled trial (RCT) of DHA supplementation in preterm infants. The hypothesis of this “side study” is that increased DHA during the neonatal period would increase total energy expenditure (TEE) and improve neurodevelopmental outcome. Specifically, at term postconceptual age (PCA) it was hypothesised that preterm infants receiving higher intake of DHA would have higher TEE’s due to the acceleration in brain maturation. Also, it was hypothesised that preterm infants receiving high levels of DHA would have TEE’s equivalent to term born infants due to their same brain maturation status. Other hypothesised effects of DHA supplementation include an accelerated maturation of the visual cortical pathways, and accelerated white matter (WM) tract development aiding in brain maturation. The first objective of this study was to measure TEE and ER in very preterm infants when they reached an age of 31-33 weeks post conceptional age (PCA). The effects of DHA supplementation on TEE, at simulated in utero levels, in very preterm infants (born < 33 weeks PCA), when assessed at term equivalent (40 weeks PCA) were studied. Another objective was to compare WM brain tissue volume at term PCA between two preterm groups and then with the term born infants. Visual latency was also compared between the two preterm infant groups and then with the term born infants. Methods TEE was measured using the doubly labelled water (DLW) method which is based on the differential elimination of 2H (deuterium) and 18O from the body subsequent to a loading dose of these isotopes. TEE was measured at the preterm age between 31-33 weeks PCA and again at term PCA. TEE measurements are made at term PCA in a term born control group. Brain assessment was by Magnetic Resonance Imaging and (MRI) and Visual Evoked Potential (VEP). Magnetic resonance imaging quantitatively measured brain volumes and WM. Visual evoked potential would provide information on visual latency and amplitude. Results The cohort consisted of 38 infants. The TEE of the very preterm infant group was measured at 31-33 weeks PCA. The mean (±standard deviation) (SD) TEE was calculated at 80(±27) kcal/kg/d, and using data in the literature for foetal energy accretion of 28kcal/kg/d, the mean ER was calculated to be 108(±27) kcal/kg/d. At term PCA TEE was calculated for the preterm DHA supplemented group to be 56(±19) kcal/kg/d and for the non-DHA supplemented group 70(±39) kcal/kg/d. These measurements were not statistically different. Flash VEP conducted on preterm given different amounts of DHA tested at term PCA found no statistically different measurements. When combining these results and comparing them to measurements of term born infants at term PCA, the right eye measurements showed that preterm infants had statistically greater latencies than term infants. When combining the left and right eye measurements the latencies no statistical significance was found. Amplitude was also not statistically significant between the groups. MRI measures at term PCA were not statistically different DHA supplemented and the non-DHA supplemented preterm infant group. When the preterm infant cohort was combined and compared to the term born infant group, the results showed that preterm infants imaged at term PCA had reduced WM development in a number of frontal lobe projections, and anterior and posterior commissarial pathways of the corpus callosum and corona radiata. Discussion The TEE and ER measurements in this study represent the largest preterm infant cohort to date. The ER values reported here are of value in allowing the calculation of appropriate feeding and nutritional strategies for preterm infants. Although no differences in TEE between the DHA and non DHA supplemented groups were found this may have been due to the small sample size. With regard to the latency outcomes, it can be speculated that if measurements were conducted at a later PCA the correlations may have been stronger and significant. Several other factors may have also affected the results, including alertness of the infant at the time of testing, thickness of the cranium, and other health factors could not be controlled for. This study contains the youngest cohort to be compared via Flash VEP. The MRI data did not find significant differences in brain volume and WM between the DHA supplemented and the non-DHA supplemented groups. The infant CNS is rapidly developing and there are multiple environmental factors which may have affected outcomes. The data did however find differences in WM development between the preterm and term infants. The reduced WM development found in the preterm infants compared to term born infants may provide some explanation for the correlation between preterm birth and poorer cognitive and functional outcomes. Larger studies which extend beyond the first months of life are recommended in order to investigate the long-term relationships between DHA supplementation, TEE and brain maturation.