RUNX2 Nonsense Mutation Associated with Cleidocranial Dysplasia with Unusual Dental Features.

Purpose: The purpose of this case report is to describe a RUNX2 nonsense mutation associated with cleidocranial dysplasia (CCD) with unusual dental features. The patient was a 12-year-old Brazilian girl who sought dental care due to over-retention of primary teeth and absence of erupted permanent teeth. Clinical and radiographic examinations revealed multiple impacted permanent teeth, a prominent cingulum of the permanent impacted maxillary incisors and enamel defects (hypoplasia and hypomineralization) in addition to skeletal abnormalities. No supernumerary teeth were present. The diagnostic hypothesis of CCD was raised and the patient was refer- red to the genetic medical service, where the diagnosis was cofirmed. After RUNX2 genetic screening, including polymerase chain reaction and sequencing of both DNA strands, a heterozygous nonsense mutation was identified in exon 2 (c.193 C>T [Q65X]). This article reports unusual dental features in a patient with CCD.

The effect of immediate controlled forces on periodontal healing of teeth replanted after short dry time in dogs.

BACKGROUND/AIM: The extra-alveolar dry period and storage medium in which a tooth is kept prior to replantation remain critical factors affecting the survival and repair potential of the periodontal ligament in avulsed teeth. When replantation is not immediate, replacement root resorption (RRR) is the most common complication. The aim of this histological study was to evaluate the effect of immediate controlled-orthodontic forces in periodontal healing of replanted teeth in a canine model. MATERIAL AND METHODS: Sixty maxillary and mandibular premolar roots were endodontically treated in vivo and subsequently hemisected and extracted. Roots were replanted after an extraoral dry time of 20 minutes and randomly assigned to two experimental groups: Group 1: root was stabilized with a flexible and passive bracket/stainless steel wire splint for 2 weeks; Group 2: root was stabilized with a flexible bracket/NiTi wire splint activated with orthodontic elastics for 2 weeks. After 4 months, the dogs were euthanized, and all specimens were processed for histology and microscopically evaluated. RESULTS: The mean percentage of RRR for Group 2 was 3.17 compared with 12.13 in Group 1. Eighty-three percent of specimens from Group 2 exhibited similar healing to the negative control group, compared to 60.5% of the specimens from Group 1. No statistical difference was found in periodontal healing between experimental groups. CONCLUSION: Immediate application of mild and controlled orthodontic forces was not detrimental to the periodontal healing of teeth replanted after 20 minutes extraoral dry time, although no significant improvement on periodontal healing was observed.

Mutans streptococci remained viable on toothbrush bristles, in vivo, for 44 h.

BACKGROUND: Toothbrushes harbor a high number of cariogenic microorganisms. AIM: To investigate the viability of mutans streptococci (MS) on toothbrushes bristles and the production of extracellular polysaccharide (ECP) related to drying time. DESIGN: Twenty children were submitted to brushing without dentifrice. Toothbrushes were kept at room temperature from 0 to 48 h and then submitted to microbiological processing. The number of MS colonies/biofilms was expressed according to scores: 0=no colonies were detected; 1=1 to 50; 2=51 to 100; 3=over 100. The amount of ECP was evaluated according to scores: 0=absence; 1=ECP recovering until 50% of the surface; 2=ECP recovering more than 50% of the surface. Data were analyzed by Wilcoxon test (α=5%). RESULTS: At the periods of 0 to 16 h, the toothbrushes had intense bacterial contamination (score 3). From the 18-h, there was a statistically significant decrease in the MS viability (P=0.0078), with predominance of score 1 on periods of 20 to 44 h. The most detected ECP amount was at 0- and 12-h period (P<0.05) with reduction until 32-h period. CONCLUSIONS: Mutans streptococci remained viable on toothbrushes bristles, in vivo, for 44 h.