Parents' oral health behaviour could influence their children's gingival health and dental caries directly and/or indirectly through its effect on children's oral health behaviour.

Transganglionic transport of horseradish peroxidase-wheat germ agglutinin conjugate (HRP-WGA) entrapped in hypoallergenic polyacrylamide gel was used to study the patterns of termination of primary afferents that innervate the lower and upper tooth pulps within the trigeminal sensory nuclear complex (TSNC). HRP injections were made into the inferior and superior alveolar nerves in order to compare the central projections of the whole nerve with those from tooth pulps. In addition, the relationship between the distribution of the trigeminothalamic tract cells and the projection sites of the tooth pulp afferents was investigated by injecting HRP into the posterior ventral thalamus. HRP-labeled tooth pulp afferent fibers innervating the lower and upper teeth projected to the subnucleus dorsalis (Vpd) of pars principalis, the rostrodorsomedial part (Vo.r) and nucleus dorsomedialis (Vo.dm) of pars oralis, the medial regions of pars interpolaris, and laminae I, II, and V of pars caudalis. Terminal fields of the lower tooth pulp afferents formed a rostrocaudally running, uninterrupted column from the midlevel of Vpd to the caudal tip of caudalis. In contrast, the column of termination of upper tooth pulp afferents was discontinuous at the Vpd/Vo.r transition, and ended at the more rostral level of the caudalis than that of the lower tooth pulp afferents. The representation of the lower and upper teeth in the TSNC was organized in a somatotopic fashion which varied from one subdivision to the next, although terminal zones of the inferior and superior alveolar nerves overlapped within the Vo.r, Vo.dm, and dorsomedial part of rostral pars interpolaris. The lower and upper teeth were represented in the Vpd, Vo.r, Vo.dm, medial region of pars interpolaris, and laminae I, II, and V, in a ventrodorsal or caudorostral, dorsoventral, lateromedial, dorsoventral, and mediolateral or dorsomedial-ventrolateral sequence, respectively. The smaller, more focal terminal areas of the teeth contrasted sharply with more extensive terminal fields of the alveolar nerves. The HRP injections within the thalamus indicated that neurons in Vpd, the caudal pars interpolaris, and laminae I/V of caudalis, which are subdivisions of TSNC that receive pulpal projections, sent their axons to the ipsilateral and contralateral posterior ventral thalamus.(ABSTRACT TRUNCATED AT 400 WORDS)

The purpose of this study was to investigate the relationship between gingival health and dental caries in elementary school children in Japan. The subjects were 474 children aged 7 to 12 years who attended dental checkups at an elementary school. The Oral Rating Index for Children, which consists of five categories (+2, +1, 0,-1,-2), was used to rate the findings of the gingival health e:xamination. The dental examination was performed using the WHO caries diagnostic criteria for DMFT. Children were divided into three groups: a healthier group (H-group) made up of those scoring +2 (excellent) or +1 (good), an equivocal group (E-group) made up of those scoring 0, and a gingival less-healthy group (L-group) made up of those scoring-2 (very poor) or-1 (poor). Overall percentages for the H-group, E-group and L-group were 48.3 %,21.5 % and 30.2 %, respectively. The number in the L-group increased with increasing age. The mean scores of the DT and DMFT in the H-group were significantly lower than those in the L-group (p < 0.01 and p < 0.05, respectively). The results suggest that oral hygiene instruction should be given to children in order to motivate self-care, not only to avoid dental caries but also to prevent gingivitis.

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