A survey is presented of the complaints and findings in a group of 451 patients referred to a multidisciplinary clinic for the management of hypodontia. The most common complaints were missing teeth, spacing in the dental arches, and poor appearance. The majority of patients were referred by their dental practitioners, and more than half were over 12 years old when first seen. Delayed referral can have educational and social consequences. Changing attitudes to dental care and the maintenance of an intact dentition are resulting in hypodontia, particularly in its more severe forms, becoming of increasing concern to children and their parents. The management of this condition is best organised via multidisciplinary specialist clinics.

We examined the mechanisms responsible for myocardial ischemia-reperfusion (MI-R) injury in a well-characterized animal model of type II diabetes mellitus. Diabetic ( db/db) mice and their littermate nondiabetic controls were subjected to 30 min of left anterior descending coronary artery occlusion and 2 h of reperfusion. Diabetic and nondiabetic mice experienced similar-sized areas at risk per left ventricle: 50.4 ± 2.0 and 53.4 ± 4.1%, respectively. However, myocardial necrosis (percentage of area at risk) was significantly greater ( P < 0.001) in diabetic than in nondiabetic animals: 56.3 ± 2.8 and 27.2 ± 3.1%, respectively. Histological examination revealed significantly ( P < 0.05) more neutrophils (PMNs) in the diabetic than in the nondiabetic hearts. Coronary endothelial expression of P-selectin was determined using radiolabeled monoclonal antibodies (MAbs). MI-R elicited a more intense ( P < 0.05) upregulation of P-selectin in the ischemic zone of diabetic than of nondiabetic myocardium: 0.310 ± 0.034 and 0.161 ± 0.042 μg MAb/g tissue. Immunoneutralization of P-selectin (RB40.34) reduced PMN accumulation in the diabetic myocardium but failed to reduce the extent of myocardial necrosis. Conversely, administration of an MAb directed against CD18 (GAME46) reduced PMN infiltration and attenuated the infarct size in the diabetic hearts. These results suggest that the diabetic heart is more susceptible to ischemia-reperfusion injury than normal myocardium. Furthermore, the mechanism of this injury may not be critically dependent on P-selectin in diabetic hearts.

An ex vivo study was carried out to determine differences in the bond strengths achieved with brackets placed using a crystal growth technique compared with a conventional acid-etch technique. A solution of 37 per cent phosphoric acid was used for acid-etching and a commercially available polyacrylic acid gel, Crystal-lok for crystal growth. A heavily-filled composite resin was used for all samples to bond brackets to healthy premolar teeth extracted for orthodontic purposes. Polycrystalline ceramic and stainless steel brackets were used and tested to both tensile and shear failure using an Instron Universal Testing machine. The tensile and shear bond strengths were recorded in kgF. In view of difficulties experienced with previous authors using different units to describe their findings, the data were subsequently converted to a range of units in order to facilitate direct comparison. The crystal growth technique produced significantly lower bond strengths than the acid-etch technique for ceramic and stainless steel brackets, both in tensile and shear mode. The tensile bond strength for stainless steel brackets with crystal growth was 2.2 kg compared with 6.01 kg for acid-etch, whilst with ceramic brackets the tensile bond strengths were 3.9 kg for crystal growth and 5.55 kg for acid-etch. The mean shear bond strength for stainless steel brackets with crystal growth was 12.61 kg compared with 21.55 kg for acid-etch, whilst with ceramic brackets the shear bond strengths were 7.93 kg with crystal growth compared with 16.55 kg for acid-tech. These bond strengths were below those previously suggested as clinically acceptable.