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Space Area (space + area)
Selected AbstractsAn association between mothers' speech clarity and infants' speech discrimination skillsDEVELOPMENTAL SCIENCE, Issue 3 2003Huei-Mei Liu The quality of speech directed towards infants may play an important role in infants' language development. However, few studies have examined the link between the two. We examined the correlation between maternal speech clarity and infant speech perception performance in two groups of Mandarin-speaking mother,infant pairs. Maternal speech clarity was assessed using the degree of expansion of the vowel space, a measure previously shown to reflect the intelligibility of words and sentences. Speech discrimination in the infants (6,8 and 10,12-month-olds) was measured using a head-turn task. The results show that mothers' vowel space area is significantly correlated with infants' speech discrimination performance. Socioeconomic data from both parents show that the result cannot be attributed to parental socioeconomic factors. This study is correlational and therefore a causal relationship cannot be firmly established. However, the results are consistent with the view that maternal speech clarity directly affects infants' early language learning. [source] Effects of distal radius malunion on distal radioulnar joint mechanics,an in vivo studyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2007Joseph J. Crisco Abstract Patients with a malunited distal radius often have painful and limited forearm rotation, and may progress to arthritis of the distal radioulnar joint (DRUJ). The purpose of this study was to determine if DRUJ congruency and mechanics were altered in patients with malunited distal radius fractures. In nine subjects with unilateral malunions, interbone distances and dorsal and palmar radioulnar ligament lengths were computed from tomographic images of both forearms in multiple forearm positions using markerless bone registration (MBR) techniques. The significance of the changes were assessed using a generalized linear model, which controlled for forearm rotation angle (,60° to 60°). In the malunited forearm, compared to the contralateral uninjured arm, we found that ulnar joint space area significantly decreased by approximately 25%, the centroid of this area moved an average of 1.3 mm proximally, and the dorsal radioulnar ligament elongated. Despite our previous findings of insignificant changes in the pattern of radioulnar kinematics in patients with malunited fractures, we found significant changes in DRUJ joint area and ligament lengthening. These findings suggest that alterations in joint mechanics and soft tissues may play an important role in the dysfunction associated with these injuries. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:547,555, 2007 [source] Effect of Auxiliary Grooves on Molar Crown Preparations Lacking Resistance Form: A Laboratory StudyJOURNAL OF PROSTHODONTICS, Issue 2 2008DClinDent, GradDipClinDent, Po-Ching Lu BDSc(Hons) Abstract Purpose: To investigate the effect of auxiliary grooves on resistance to dislodgment of crowns on compromised molar preparations lacking resistance form. Materials and Methods: Thirty human molar teeth were randomly assigned to three groups of ten, and prepared to a height-to-width ratio of 0.3 with a total convergence of 50°, and 1-mm shoulder margin. Base metal alloy copings were constructed with a 45° loading platform and cemented with zinc phosphate cement under a 50 N load. Initially, resistance testing was conducted using a Universal Testing Machine (Instron) at 1 mm/min for all 30 specimens. Following crown dislodgment, Group 1 copings were recemented and retested, Group 2 had one axial groove added, and Group 3 had two axial grooves added. New copings for Groups 2 and 3 were made, cemented, and again tested for resistance. Standardized radiographs were taken prior to initial cementation and scanned into digital images. The percentage of area occupied by the pulpal chamber above the acrylic mounting (PS), and the closest distance to pulp from the preparation surface (CD) were measured. Results: Recementation or the addition of one groove did not affect the dislodgment values (p > 0.05), but addition of two grooves caused a highly significant increase in resistance (p < 0.001). Regression analysis showed an inverse relationship between initial resistance values and pulpal space area. Lower resistance values were observed when the pulpal space area was large (p= 0.004). Conclusions: Crowns can be recemented without affecting resistance to dislodgment. Two grooves should be incorporated into compromised molar crown preparations to increase resistance form. Teeth with large pulps and therefore less coronal dentine have poorer resistance form, and therefore would benefit from placement of auxiliary grooves. [source] Effect of age on anterior chamber angle configuration in Asians determined by anterior segment optical coherence tomography; clinic-based studyACTA OPHTHALMOLOGICA, Issue 6 2010Mi Hyun Cheon Acta Ophthalmol. 2010: 88: e205,e210 Abstract. Purpose:, To evaluate the distribution of anterior chamber angle (ACA) parameters and to assess association of these parameters with age in Asian subjects. Methods:, Four hundred and thirty-nine consecutive Korean subjects aged from 30 to 89 were enrolled from a university clinic. All participants were scanned using anterior segment optical coherence tomography (AS-OCT, Visante, version 2.0). We measured ACA parameters such as anterior chamber depth (ACD), angle opening distance at 500 and 750 ,m (AOD500,750), angle recess area at 500 and 750 ,m (ARA500,750), trabecular iris space area at 500 and 750 ,m (TISA500,750), and determined age-related changes in these parameters with use of a linear mixed effect model that adjusted for gender, axial length, intraocular pressure, and keratometry data. Slopes of ACA parameters as a function of age were determined. For various AS-OCT parameters, the normalized slope was calculated by dividing the slope by the mean value. Results:, All analysed ACA parameters decreased with age in both nasal and temporal quadrants. Axial length and keratometry data were significant covariates for ACA changes. The slopes of ACD were ,0.02396 mm/year, AOD500, ARA500, and TISA500 measured at the temporal angle were ,0.00634 mm/year, ,0.0019 mm2/year, and ,0.00177 mm2/year, respectively. There was no age-dependent difference in central corneal thickness (p value; 0.4597) Based on the normalized slopes, the AOD showed the steepest slope at both temporal and nasal sectors. Conclusion:, All ACA parameters assessed by AS-OCT, which accounted for other ocular biometric parameters, showed significant negative slopes with increasing age. These results should be considered when assessing changes in the anterior chamber over time. [source] |