Impacted supernumerary teeth can cause malalignment of the maxillary central incisors or impaired formation. However, few studies have investigated the effects of impacted supernumerary teeth on the inclination of adjacent central incisors. We performed statistical analyses of those effects using conebeam computed tomography (CBCT). For this study, 34 teeth from 34 children diagnosed with impacted supernumerary maxillary anterior teeth during the 1 year 1 month period starting from October 2013 were examined. To determine the vertical position of the impacted supernumerary tooth, a straight line connecting the crest of the maxillary alveolar bone and highest point of the inferior border of the nasal cavity floor (hereinafter, inferior border of nasal cavity floor line) was drawn. Next,we divided the length of this line by 3, and termed the upper, middle, and lower ranges as Positions 1, 2, and 3, respectively. Finally, using the nasal cavity floor inferior border line as a reference, the angle between that and the tooth axis of the affected and intact-side central incisors was termed the affected side/intact side central incisor axis inclination angle. We observed a significant difference between the affected-side and intact-side central incisor axis angles for each position. On the other hand,for the inclination angles of the central incisor axis of the affected and intact sides, there was no significant difference observed between each position expressing the vertical positions of the impacted supernumerary teeth.

Winemaking annually yields several thousand tons of byproducts called pomace, which contains several beneficial ingredients, such as polyphenols and oleanolic acid (OA), though it is primarily used as compost. We found that OA inhibits the growth of Streptococcus mutans, which has been identified as a cavity-causing bacterium, as well as synthesis of insoluble glucan in vitro. In addition,our results demonstrated an anticaries effect of OA-containing pomace extracts in humans, as the group that received pomace extract showed a significant decrease in S. mutans growth in saliva (P ＜0.05). Our results suggest that OA-containing pomace extract is effective for prevention of dental caries in humans. We consider that pomace extract may be used to exert its anticaries effect by being added to various foods, such as candies, jellies, tablets, and chewing gum, as well as oral care items including toothpastes and mouthwashes.

Elementary schools in Japan are committed to early discovery of child abuse and required to cooperate with other institutions such as dental services to prevent such abuse. However, the extent to which dental practitioners cooperate with schools remains limited. In the present study, we investigated the use of school dental examination data for early discovery of child abuse.

1)We examined the records of a total of 3569 elementary school students who underwent dental health examinations, of whom 89 were found to have been abused (abuse group).

2)Approximately 90% of all children had 2 or less deciduous teeth with untreated cavities.

3)A total of 95% of the children in the non-abuse group and 93.26% of those in the abuse group had no untreated cavities in permanent teeth.

4)A plaque score of zero was noted in 87.64% of the abuse group and 84.94% of the non-abuse group.

5)As for gingival inflammation score, that was zero in 87.04% of children in the non-abuse group and 91.01% of those in the abuse group.

No differences were found between abused and non-abused children in terms of the condition of their oral cavity. Our findings suggest that data collected from school dental health examinations are not useful to screen for possible child abuse. An environment in which dental practitioners spend time not only observing the oral cavity, but also the behavior of children and attitudes of their guardians is needed for early discovery and prevention of child abuse.

We investigated dental treatments given to persons with disabilities at a pediatric medical center in Japan between April 1, 2015 and March 31, 2016. Factors noted were age at first visit and most re cent visit during the study, type of disability, intervals between office visits, and contents of the dental treatment provided. The main results obtained were as follows :

1.A total of 449 patients (males 271, females 178) who visited the medical center were enrolled.

2.The age range at first visit was 0-24 years. The most common age was 1 year old and children 0-5 years old accounted for 78.2% of the total. The mean age was 16.4±8.3 years (range 0-59 years).

3.A duration of ＜5 years from first visit to most recent visit was most frequent and accounted for 23.8% of the total. A duration of 10-15 years was seen in 20.9% and of 5-10 years in 19.8% of the examined cases.

4.The most common patient disabilities were cerebral palsy (28.1% of total), pervasive developmental disorder (20.9%), intellectual disability (10.9%), Down syndrome (9.8%), neurological disorders other than cerebral palsy and epilepsy (9.6%), and epilepsy (8.0%).

5.There was a total of 17,033 consultations for all patients and 20,934 dental treatments were performed. The most common dental treatments given were fissure sealant (33.7% of total), scaling (29.8%), and cavity filling (33.7%).

6.There were significant differences in the ratios of dental treatments among those with different disabilities. However, the most common dental treatments performed regardless of disability were fis sure sealant, scaling, and cavity filling.

7.Among the various treatments, there were significant differences noted when the patients were divided by age.

When the mandibular first milk molar teeth are lost at an early stage, crown loops are often applied for space maintenance. However, depending on the shape of the tip of the crown loop, it has been reported to cut into the gingiva or detach from the tooth in some cases. In the present study, we simulated the influence of crown loops on tooth and crown loop movement using a finite element method for simulation with 3 different loop tip shapes (W-, I-, U-shape). The experimental methods were as follows. When force was applied to the second milk molar teeth in a mesial direction, another force was simultaneously applied in a lingual direction with the crown loop. The following results were obtained.

1.When a force in a mesial direction was applied to the crown loop, the second milk molar teeth inclined in a mesial direction. As a result, the tip of the crown loop was distracted towards the distal cervical gingiva. The amount of distraction was increased in the order of W-, I-, and U-shape.

2.When a force was applied to the crown loop in a lingual direction simultaneously with that in a mesial direction, the tip of the loop sank and moved in a lingual manner in the U-shape group. As a result, the tip of the loop became detached from the milk canine tooth.

3.With the same forces were applied as in section 2 above to the W-shaped loop, lingual movement was extremely limited and it was possible to prevent detachment from the milk canine tooth.

We determined the direction of lip closure force in children with normal occlusion and those with maxillary protrusion, and also compared tongue pressure between those groups. In addition, the prevalence of dental caries and lip closing habit was investigated using questionnaire findings. Among pediatric patients aged 8-11 years old who visited Kyushu Dental University Hospital, 15 with normal occlusion and 15 with maxillary protrusion were randomly selected as subjects for the present study. Measurements obtained using a multi-directional lip closing force measurement system showed no significant difference in regard to direction-specific lip closure force between the groups. On the other hand, the normal occlusion group had a significantly higher impulse value as compared to the maxillary protrusion group. As for tongue pressure, no significant difference was observed between the groups. Furthermore, there was no correlation found between tongue pressure and comprehensive lip closure force. Our investigation of dental caries prevalence also revealed no significant difference between children with normal occlusion and those with maxillary protrusion. Additionally, no correlation was found between comprehensive lip closure force and caries prevalence in our subjects with normal occlusion, whereas there was a negative correlation noted in those with maxillary protrusion. In our evaluation of lip closing habit investigated by questionnaire, children with maxillary protrusion were able to open their mouth more easily. Finally, there was no correlation observed between allergic predisposition and maxillary protrusion.

Trauma to the teeth is often encountered in pediatric dentistry clinical settings. However, there are few reports of treatment for dental trauma in children with disabilities or the long-term prognosis of such trauma. The authors encountered a child with Down syndrome for whom they replanted the avulsed right maxillary central incisor. The child also exhibited congenitally missing teeth, short roots, and other dental features specific to the syndrome. Although conditions were not conductive for stabilizing the replanted tooth, 3 weeks of stabilization using a wire and adhesive resin cement was performed in light of the adequate conditions. Four months after replantation, pulpal necrosis of the replanted tooth was noted, for which apexification was immediately performed. Seventeen months after replantation, the apex of the replanted tooth was confirmed to be sealed with hard tissue. The root canal was therefore filled with gutta percha points and the patient attended follow-up examinations every 3 to 4 months thereafter. Three years after replantation, percussion sounds produced by the affected tooth were sharp and clear, and its physiological mobility had disappeared. Tooth ankylosis was therefore deemed to have been achieved. No replacement resorption of the replanted tooth has been seen during the subsequent 10 years.