Discover the most talked about and latest scientific content & concepts.

Concept: Deciduous teeth


Skulls (n = 1,205) of southern sea otters were examined macroscopically according to defined criteria. The museum specimens, acquired from strandings, varied in age from juvenile to adult, with an equal sex distribution. The results from all young adult and adult specimens were pooled according to tooth type. Ninety-two percent of teeth were available for examination, with 6.5% artifactually absent, 0.6% deemed absent due to acquired tooth loss and 0.03% deemed congenitally absent. All teeth were normal in morphology, except for three pairs of fused teeth, including two instances of fused maxillary first incisor teeth. Supernumerary teeth were associated with 97 normal teeth (most commonly maxillary canine teeth) in 68 specimens. At least one persistent deciduous tooth was present in six skulls, two of which were from adults. The majority (94.6%) of alveoli, either with or without teeth, were not associated with bony changes consistent with periodontitis; however, the majority (74.4%) of specimens did have at least one tooth associated with mild periodontitis. The mesial root of the mandibular third premolar tooth was the most common location at which periodontal hard tissue lesions were observed (56.6%). Ten sea otters had lesions consistent with focal enamel hypoplasia. Approximately half of the teeth (52.0%) were abraded; almost all adult specimens (98.1%) contained at least one abraded tooth, while fewer young adults were affected (76.4%). Tooth fractures were uncommon, affecting 1,343 teeth (4.5%). Periapical lesions were associated with 409 teeth (1.3%) in a total of 176 specimens, and these would likely have caused considerable morbidity while the animals were alive.

Concepts: Teeth, Tooth development, Incisor, Canine tooth, Maxillary lateral incisor, Premolar, Sea otter, Deciduous teeth


- Primary tooth impaction is a rare phenomenon when compared to permanent teeth impaction. The purpose of this report is to present a 5-year-old Chinese girl who exhibited impaction of tooth 51, its unusual consequence on the permanent successor tooth and its comprehensive management. Her parents revealed that at 6 months of age, the patient had fallen from her bed and struck her face on the floor; however, there were no teeth present in the oral cavity. The intraoral examinations identified a bony-like projection on the buccal aspect of the alveolus in the 51 region. Radiographic examination revealed that tooth 51 exhibited an unfavourable orientation, with the crown directed towards the palate. Therefore, the impacted tooth 51 was surgically removed, and two years later tooth 11 erupted into the oral cavity with an indentation on its incisal aspect, which resembled the crown of the primary teeth, thus giving the appearance of a tooth within a tooth or ‘dens in dente’. Subsequently, enameloplasty and composite resin build-up was performed on tooth 11 for aesthetic reasons. It is very unusual to have the clinical crowns of both primary and permanent teeth in such close proximity within the alveolar bone, and the present case is a good example to emphasize that trauma to the primary teeth is of considerable importance due to the close proximity of the primary teeth to permanent tooth germs.

Concepts: Teeth, Incisor, Maxillary central incisor, Canine tooth, Maxillary lateral incisor, Deciduous teeth, Permanent teeth


We aimed to consolidate all epidemiologic data about untreated caries and subsequently generate internally consistent prevalence and incidence estimates for all countries, 20 age groups, and both sexes for 1990 and 2010. The systematic search of the literature yielded 18,311 unique citations. After screening titles and abstracts, we excluded 10,461 citations as clearly irrelevant to this systematic review, leaving 1,682 for full-text review. Furthermore, 1,373 publications were excluded following the validity assessment. Overall, 192 studies of 1,502,260 children aged 1 to 14 y in 74 countries and 186 studies of 3,265,546 individuals aged 5 y or older in 67 countries were included in separate metaregressions for untreated caries in deciduous and permanent teeth, respectively, using modeling resources from the Global Burden of Disease 2010 study. In 2010, untreated caries in permanent teeth was the most prevalent condition worldwide, affecting 2.4 billion people, and untreated caries in deciduous teeth was the 10th-most prevalent condition, affecting 621 million children worldwide. The global age-standardized prevalence and incidence of untreated caries remained static between 1990 and 2010. There is evidence that the burden of untreated caries is shifting from children to adults, with 3 peaks in prevalence at ages 6, 25, and 70 y. Also, there were considerable variations in prevalence and incidence between regions and countries. Policy makers need to be aware of a predictable increasing burden of untreated caries due to population growth and longevity and a significant decrease in the prevalence of total tooth loss throughout the world from 1990 to 2010.

Concepts: Epidemiology, Disease, Incidence, Teeth, Prevalence, Deciduous teeth


Scientific evidence of susceptibility to dental caries in the population with Down Syndrome (DS) is limited and conflicting, making it difficult to establish firm conclusions. The aim of this systematic review and meta-analysis was to obtain scientific evidence of the possible association between dental caries and individuals with DS, compared to individuals without DS (control). An electronic search of five databases was performed, with no language or publication date restrictions. The studies were selected by two independent reviewers (Kappa = 0.83). The systematic review included 13 studies, while eight studies were included in the meta-analysis. The studies are presumably all at risk of bias given their observational character. Two of these evaluated the presence or absence of caries in permanent and deciduous teeth, and six evaluated the mean DMFT index in permanent teeth. Combined odds ratios (OR), standard difference, standard error and a 95% confidence interval (CI) were obtained. The vast majority of the studies found that individuals from control groups had more carious lesions or caries experience than those with DS. The results were statistically significant in seven studies (p<0.05). Meta-analysis of two studies revealed that individuals with DS had a lower dental caries than those in the control group (OR = 0.36; 95% CI = 0.22-0.57). In six studies, individuals with DS had a significantly lower mean DMFT index than individuals from the control group (Sd = -0.18; SE = 0.09; 95% CI = -0.35--0.02). The quality of the studies varied and in general had a high risk of bias. Scientific evidence suggests that individuals with DS have fewer dental caries than individuals without DS.

Concepts: Scientific control, Scientific method, Statistics, Normal distribution, Teeth, Tooth development, Dental caries, Deciduous teeth


Traumatic brain injury (TBI) is one of the major causes of mortality and disability for all ages worldwide. Mesenchymal stem cells (MSCs)-originated exosomes have provided therapeutic effects. However, as an indispensable component of MSCs, whether odontogenic stem cell-generated exosomes could benefit TBI is still unclear. Thus we aimed to explore the potential of stem cells from human exfoliated deciduous teeth-originated exosomes (SHED-Ex) for the management of TBI.

Concepts: Cell, Stem cell, Mesenchymal stem cell, Bone marrow, Stem cells, Traumatic brain injury, Major, Deciduous teeth


The difficulties in reaching a good level of oral hygiene in young babies can be partly overcome with the use of baby oral wipes, which have been shown to effectively remove plaque from deciduous teeth. The presence of fluoride and calcium in these wipes could also prevent further demineralisation of the teeth, as well as promote remineralisation. The aim of this study is, therefore, was to analyze the preventive effect of OW containing F and CaGP on cariogenic demineralization in vitro.

Concepts: Infant, Milk, In vitro, Teeth, Tooth development, Bathing, Fluoride therapy, Deciduous teeth


Orthodontic treatment of a complex case that involves retained deciduous mandibular second molars with missing permanent successors is challenging. Usually, congenitally missing teeth are manifested with other dental anomalies that further complicate orthodontic treatment, such as retained deciduous teeth, impactions, transpositions and peg-shaped lateral incisors. Even though the long term prognosis of the retained deciduous tooth is not fully predictable, if the teeth are in good condition, the patient and clinician may incline towards a decision to preserve the deciduous teeth as long as possible. This case report demonstrates that deciduous teeth, in this case the mandibular second molars and maxillary canine, can be incorporated into final occlusion with clinically stable long-term results.

Concepts: Teeth, Canine tooth, Maxillary lateral incisor, Premolar, Deciduous teeth


Cherubism is an autosomal-dominant benign bone disorder, characterized by fibro-osseous lesions in the mandible and maxilla commonly caused by mutations in the SH3-binding protein 2-gene. The purpose of the authors' study was to analyze craniofacial and dental features of children diagnosed with cherubism, describe their treatment, and assess their dental age compared with norms for Finnish children. Six children were diagnosed, followed up and treated due to dental and skeletal disorders caused by cherubsim. The patients were followed up for an average of 91.5 months with emphasis on the skeletal changes and development of dentition. The treatment consisted of minor orthodontic treatment, dental extractions, and exposures. One patient underwent cosmetic mandibular surgery. All patients had lesions in the lower jaw and 5 of 6 patients had lesions in the maxilla as well. The patients were characterized by varying swelling of the jaws, premature loss of deciduous teeth in the affected area and widely spaced, displaced, un-erupted, or absent permanent teeth. The dental age was delayed at younger age but near to normal or even a little ahead at older age. Even though cherubism affects the jaws, jaw positions, and malocclusion, no common dentofacial proportions associated with the disease could be confirmed by cephalometric analysis. The surgical interventions did not provoke adverse reactions or local growth of the lesions.

Concepts: Bone, Mandible, Teeth, Tooth development, Orthodontics, Temporomandibular joint, Jaw, Deciduous teeth


A 6-week-old Thoroughbred filly was presented for evaluation of an expansile mass overlying the right nasal passage and causing respiratory stertor. On skull radiographs, there was a loculated, soft tissue-opaque mass identified dorsal to the right upper premolars and effacing the right nasal cavity. Computed tomography (CT) revealed a locally extensive mass with relatively benign characteristics located centrally on the tooth root apices of the deciduous second premolar (506). The mass extended axially into the right nasal cavity, occluding the meatuses and causing displacement of the nasal septum to the left.

Concepts: Left-wing politics, Nose, Nasal cavity, Canine tooth, Premolar, Deciduous teeth, Maxillary first premolar, Nasopalatine nerve


The aim of the present study was to assess the knowledge and practice of, and attitudes toward, pulp therapy in deciduous dentition among pediatric dentists.

Concepts: Present, Time, Teeth, Tooth development, Deciduous teeth, Deciduous