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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


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


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


The origin and dispersion of the first Americans have been extensively investigated from morphological and genetic perspectives, but few studies have focused on their health and lifestyle. The archaeological site of Lapa do Santo, central-eastern Brazil, has exceptionally preserved Early Holocene human skeletons, providing 19 individuals with 327 permanent and 122 deciduous teeth dated to 9,250 to 7,500 years BP. In this study, we test whether the inhabitants of Lapa do Santo had high prevalence of dental caries as previous studies of Lagoa Santa collection have indicated, using individual and tooth as units of analyses. The results show a high prevalence of dental caries in the permanent dentition (5.50%, n=327 teeth; 69.23%, n=13 individuals) compared to other samples of hunter-gatherers worldwide. In addition, dental caries in deciduous teeth start occurring as early as 3 to 4 years old, suggesting an early start to caries. Compared with other samples from Lagoa Santa, Lapa do Santo shows statistically similar prevalence of overall caries but different caries location pattern. We believe that a subsistence adaptation to a tropical environment rich in sources of carbohydrates, such as fruits, is the best explanation for the overall caries prevalence.

Concepts: Lactic acid, Teeth, Tooth development, Dental caries, Minas Gerais, Tooth fairy, Deciduous teeth, Permanent 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


Cultivation under hypoxia promotes different responses in the mesenchymal stem cells and it has been producing promising results for clinical applications. Pulp tissue from deciduous teeth is a source of stem cells which has a high proliferative potential but this is usually discarded. This study has evaluated the effects of hypoxia on proliferation, apoptosis, and the expression of the pluripotency-related genes of the stem cells from human exfoliated deciduous teeth (SHED).

Concepts: Gene, Cell, Developmental biology, Stem cell, Mesenchymal stem cell, Bone marrow, Stem cells, Deciduous teeth


A review of numerous case reports was made, in order to demonstrate the possibilities for treatment of dental disorders in patients with Cleidocranial dysplasia (CCD). In this paper, our own report, including a diagnosis of the effect on the auditory system, is presented. In addition to the triad of CCD symptoms that include hypoplastic or aplastic clavicles, impacted and supernumerary teeth, delayed closure of fontanelles and cranial sutures, impairment of the hearing system resulting in conductive hearing loss also occurs. Our own report is based on the case of a 12-year-old CCD patient, in whom Cone Beam Computed Tomography (CBCT) revealed the presence of 12 supernumerary teeth. Furthermore, a clinical examination pointed to the presence of retained deciduous teeth and a delayed eruption of permanent teeth. Orthodontic-surgical procedures were implemented, in accordance with the literature. During the course of the orthodontic treatment, a decrease in auditory sensitivity was observed, for which reason hearing tests were also performed. Conductive hearing loss was detected. As such, it is important to remember that in such cases, auditory check-ups need to be performed between the many surgical and orthodontic interventions, which usually last a few years.

Concepts: Medical imaging, Auditory system, Otology, Teeth, Hyperdontia, Deciduous teeth, Fontanelle, Cleidocranial dysostosis


Despite nearly a century of research, the treatment of cervical dentinal hypersensitivity (DH) remains challenging. This case report discusses the indications for different approaches to the treatment of DH in a single patient; the chosen alternatives took into account the different degrees of tooth wear and levels of pain at different sites. A 31-year-old woman reported DH in the maxillary right canine and first premolar and the maxillary left lateral incisor and canine in response to thermal, tactile, and osmotic stimuli. Clinical examination revealed that the teeth on the right side presented noncarious cervical lesions deeper than 1 mm, while the teeth on the left side presented only minimal wear. Therefore, the right canine and premolar were restored with composite resin to create a mechanical barrier against stimuli and reestablish form, function, and esthetics. Prior to restoration, the teeth on the right side were irradiated with a low-power laser (808 nm, 100 mW, 1.1 J/point, 10 seconds), which was applied in a single session at 2 locations on each tooth. In contrast, the left lateral incisor and canine were irradiated in 3 sessions with the low-power laser, which reduces pain levels and depolarizes nerve fibers by means of cell biomodulation, and received no restorations. A visual analog scale (0.0-10.0) was used to record the patient’s pain, and it was found that pain levels for the restored teeth decreased from 9.4 initially to 0.0 immediately after restoration, and pain levels for the irradiated teeth decreased from 5.4 initially to 2.0 after 3 sessions. After 6 months of clinical evaluation, both sets of teeth showed scores of 0.0 (no pain). Based on the results presented, it can be concluded that both treatments provided satisfactory outcomes when applied for the appropriate indication.

Concepts: Left-wing politics, Teeth, Right-wing politics, Incisor, Canine tooth, Premolar, French Revolution, Deciduous teeth


Any disturbance in the primary tooth can lead to an altered eruption pattern of the corresponding permanent tooth. This article presents a case of a carious permanent second premolar with an immature root that erupted prematurely following extraction of the infected primary second molar. The carious premolar was treated with a stepwise excavation, and a primary stainless steel crown was adapted to prevent microleakage and restoration failure. A follow-up evaluation at 4 years showed remarkable healing and complete root formation. To the authors' knowledge, this is the first case report in the literature that describes successful conservative management of a rootless premolar treated by pulp capping and restored with a primary stainless steel crown.

Concepts: Teeth, Deciduous teeth