Severe root resorption associated with ectopically erupting teeth: a case report.

A 12-year-old Japanese boy had ectopic eruption of the permanent maxillary canines and permanent mandibular second molars accompanied by root resorption of the adjacent permanent teeth. The permanent maxillary lateral incisors were extracted, and fenestration traction treatment was performed for the ectopically erupting canines. They were moved to the occlusal position orthodontically using a lingual arch appliance and sectional arch wire. The mandibular second molars were moved distally with an appliance designed to minimize the load on the teeth. The treatment is discussed with consideration of the diagnosis and appliances.

Xylitol inhibition of acid production and growth of mutans Streptococci in the presence of various dietary sugars under strictly anaerobic conditions.

The aim of this study was to investigate the inhibitory effect of xylitol on the growth of and acid production by mutans streptococci in the presence of various dietary sugars, and the relationship between the inhibition and the accumulation of xylitol 5-phosphate (X5P) under strictly anaerobic conditions like those in the deep layers of dental plaque. Xylitol retarded the growth of mutans streptococci in the presence of glucose (G), galactose (Gal), maltose (M), lactose (L) or sucrose (S) as an energy source, though the inhibition of growth on fructose (Fr) was small. Xylitol inhibited acid production by washed cells of Streptococci mutans from G, Gal, M, L or S (12-83% inhibition). S. mutans accumulated X5P intracellularly through activity of the phosphoenolpyruvate-xylitol phosphotransferase system (PEP-xylitol PTS) when they fermented these sugars in the presence of xylitol. However, in the presence of Fr, no inhibition of acid production was observed. In addition, the amounts of X5P during the fermentation of Fr were smaller than those of other sugars in spite of the presence of PEP-xylitol PTS activity. These results suggest that along with the intracellular accumulation of X5P, xylitol decreases the growth and acid production of mutans streptococci in the presence of various dietary sugars except Fr.