Palatal development of preterm and low birthweight infants compared to term infants – What do we know? Part 1: The palate of the term newborn

BACKGROUND: The evidence on prematurity as 'a priori' a risk for palatal disturbances that increase the need for orthodontic or orthognathic treatment is still weak. Further well-designed clinical studies are needed. The objective of this review is to provide a fundamental analysis of methodologies, confounding factors, and outcomes of studies on palatal development. One focus of this review is the analysis of studies on the palate of the term newborn, since knowing what is 'normal' is a precondition of being able to assess abnormalities. METHODS: A search profile based on Cochrane search strategies applied to 10 medical databases was used to identify existing studies. Articles, mainly those published before 1960, were identified from hand searches in textbooks, encyclopedias, reference lists and bibliographies. Sources in English, German, and French of more than a century were included. Data for term infants were recalculated if particular information about weight, length, or maturity was given. The extracted values, especially those from non-English paper sources, were provided unfiltered for comparison. RESULTS: The search strategy yielded 182 articles, of which 155 articles remained for final analysis. Morphology of the term newborn's palate was of great interest in the first half of the last century. Two general methodologies were used to assess palatal morphology: visual and metrical descriptions. Most of the studies on term infants suffer from lack of reliability tests. The groove system was recognized as the distinctive feature of the infant palate. The shape of the palate of the term infant may vary considerably, both visually and metrically. Gender, race, mode of delivery, and nasal deformities were identified as causes contributing to altered palatal morphology. Until today, anatomical features of the newborn's palate are subject to a non-uniform nomenclature. CONCLUSION: Today's knowledge of a newborn's 'normal' palatal morphology is based on non-standardized and limited methodologies for measuring a three-dimensional shape. This shortcoming increases bias and is the reason for contradictory research results, especially if pathologic conditions like syndromes or prematurity are involved. Adequate measurement techniques are needed and the 'normal palatal morphology' should be defined prior to new clinical studies on palatal development

Light absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM), in the St Lawrence Estuary (Case 2 waters)

The absorption coefficient and the fluorescence emission of chromophoric (coloured) dissolved organic matter (CDOM) were determined along a 1200 km transect in the Estuary and Gulf of St. Lawrence. Fluorescence spectra were spectrally corrected against a reference standard and normalized to the water Raman signal to provide results in Raman units. Because CDOM originates mainly from freshwater river runoff in the St. Lawrence system, its optical properties were found to be inversely correlated with salinity (r = -0.95) and sigma-t (r = -0.99). These strong linear relationships can be used as a tool for monitoring surface circulation and salinity in these coastal waters. The relationships between CDOM absorption and fluorescence were also characterized in the UV and visible regions. In the UV region, the observed relationship was found to be consistent with previously published results. In the visible region a relationship was found that was different from that in the UV. Our results therefore support the possibility of using fluorescence characteristics for extensive monitoring of CDOM in coastal waters strongly influenced by freshwater runoff. Such relationships may prove useful for remote sensing to correct chi a values and the large-scale modelling of primary production in coastal waters. Copyright (C) 1996 Elsevier Science Lt