Teeth are found in almost all vertebrates, and they therefore provide a general paradigm for the study of epithelial organ development and evolution. Here, we review the developmental mechanisms ...underlying changes in tooth complexity and tooth renewal during evolution, focusing on recent studies of fish, reptiles and mammals. Mammals differ from other living vertebrates in that they have the most complex teeth with restricted capacity for tooth renewal. As we discuss, however, limited tooth replacement in mammals has been compensated for in some taxa by the evolution of continuously growing teeth, the development of which appears to reuse the regulatory pathways of tooth replacement.
Tooth wear is the result of three processes: abrasion (wear produced by interaction between teeth and other materials), attrition (wear through tooth-tooth contact) and erosion (dissolution of hard ...tissue by acidic substances). A further process (abfraction) might potentiate wear by abrasion and/or erosion. Knowledge of these tooth wear processes and their interactions is reviewed. Both clinical and experimental observations show that individual wear mechanisms rarely act alone but interact with each other. The most important interaction is the potentiation of abrasion by erosive damage to the dental hard tissues. This interaction seems to be the major factor in occlusal and cervical wear. The available evidence is insufficient to establish whether abfraction is an important contributor to tooth wear in vivo. Saliva can modulate erosive/abrasive tooth wear, especially through formation of pellicle, but cannot prevent it.
The incidence of impacted and transmigrant mandibular canines in the mandible is not as high as that in the maxilla; consequently, it is more difficult to find clinical guidelines derived from sound ...studies based on large patient samples.
The aim of this systematic review was to summarize currently available data pertaining to the incidence and aetiology of impacted and transmigrant mandibular canines and the success rates of different treatment strategies.
This review was registered with PROSPERO (CRD42014006175) and was conducted using PRISMA and CRD (Centre for Reviews and Dissemination, University of York) statement. A computerized search of studies published up to February 2016 was conducted using the following databases: PubMed, Cochrane Central Register of Controlled Clinical trials, ISI Web of Knowledge, and Scopus. To identify any relevant publications not included in this list, we manually searched the references lists of the selected articles. The Newcastle-Ottawa Scale quality assessment tool was utilized to classify the included articles.
In total, 630 articles were identified after the removal of duplicates. A total of 13 studies published between 2001 and 2015 met all the eligibility criteria and were included for the final analysis. The sample size in these studies ranged from 14 to 112873 teeth, while their methodological quality ranged from low to medium.
According to the findings from our review, the incidence of canine impaction in the mandible ranges from 0.92 to 5.1 per cent, while that of canine transmigration ranges from 0.1 to 0.31 per cent. Various etiologies may play a role, including odontomes (up to 20 per cent) and lateral incisor anomalies (16 per cent). Surgical extraction (89 per cent in some studies) and orthodontic traction (20-32 per cent) are the most commonly used treatment strategies, with the latter showing a failure rate of 17 per cent in two studies.
Introduction Proper diagnosis and management of eruption disturbances remains challenging but is critical to a functional occlusion. The objective of this study was to establish definitive criteria ...to differentiate and diagnose eruption disorders, specifically primary failure of eruption (PFE) and ankylosis. Methods Sixty-four affected persons were placed into 3 cohorts: PFE diagnosed through confirmed PTH1R mutation (n = 11), PFE diagnosed based on clinical criteria (n = 47), and ankylosis diagnosed based on clinical criteria (n = 6). These groups were assessed to identify clinical features that differentiate PFE and ankylosis. Results Ninety-three percent of the subjects in the genetic and clinical PFE cohorts combined (n = 58) and 100% in the genetic PFE cohort had at least 1 infraoccluded first permanent molar. Additionally, a novel functional PTH1R mutation, 1092delG, was identified and linked to PFE in the deciduous dentition. Conclusions An infraoccluded, supracrestal first molar is a hallmark of PFE, often involving both arches in the permanent or deciduous dentition, and with unilateral or bilateral affection, infraoccluded second premolar or second molar, and multiple affected adjacent teeth. Our results further suggest that PFE and ankylosis might be clinically indistinguishable without knowledge of prior trauma, treatment history, genetic information, or obliteration of the periodontal ligament space.
Shark and ray (elasmobranch) dentitions are well known for their multiple generations of teeth, with isolated teeth being common in the fossil record. However, how the diverse dentitions ...characteristic of elasmobranchs form is still poorly understood. Data on the development and maintenance of the dental patterning in this major vertebrate group will allow comparisons to other morphologically diverse taxa, including the bony fishes, in order to identify shared pattern characters for the vertebrate dentition as a whole. Data is especially lacking from the Batoidea (skates and rays), hence our objective is to compile data on embryonic and adult batoid tooth development contributing to ordering of the dentition, from cleared and stained specimens and micro-CT scans, with 3D rendered models. We selected species (adult and embryonic) spanning phylogenetically significant batoid clades, such that our observations may raise questions about relationships within the batoids, particularly with respect to current molecular-based analyses. We include developmental data from embryos of recent model organisms Leucoraja erinacea and Raja clavata to evaluate the earliest establishment of the dentition. Characters of the batoid dentition investigated include alternate addition of teeth as offset successional tooth rows (versus single separate files), presence of a symphyseal initiator region (symphyseal tooth present, or absent, but with two parasymphyseal teeth) and a restriction to tooth addition along each jaw reducing the number of tooth families, relative to addition of successor teeth within each family. Our ultimate aim is to understand the shared characters of the batoids, and whether or not these dental characters are shared more broadly within elasmobranchs, by comparing these to dentitions in shark outgroups. These developmental morphological analyses will provide a solid basis to better understand dental evolution in these important vertebrate groups as well as the general plesiomorphic vertebrate dental condition.
Analysis of Factors Associated with Cracked Teeth Seo, Deog-Gyu, DDS, MS, PhD; Yi, Young-Ah, DDS, MS, PhD; Shin, Su-Jung, DDS, MS, PhD ...
Journal of endodontics,
03/2012, Letnik:
38, Številka:
3
Journal Article
Recenzirano
Abstract Introduction The purpose of this study was to analyze the characteristics, distribution, and associated factors of longitudinal fractured teeth according to the well-defined criteria of the ...American Association of Endodontists (AAE). Methods One hundred seven teeth with longitudinal fracture from 103 patients were diagnosed and analyzed. The patients’ signs, symptoms, age, and sex were noted as well as the tooth number, dental arch, filling materials, size/classification of restoration, crack direction, pulp vitality, whether the patient had undergone endodontic treatment, bite test results, percussion test results, wear facet, and periodontal pocket depth. Results Eighty-seven teeth were diagnosed with a cracked tooth (81.3%), 14 were diagnosed with vertical root fracture (VRF, 13.1%), 4 had a split tooth (3.7%), and 2 had a fractured cusp (1.9%); 82.2% showed a sensitive reaction on the bite test. Longitudinal tooth fractures were observed most frequently in patient in their 40s. The upper first molar (28.0%) was most frequently cracked, followed by the lower first molar (25.2%), the lower second molar (20.6%), and the upper second molar (16.8%). Most longitudinal tooth fractures (72.0%) occurred mainly in restored teeth, whereas only 28.0% were found in intact teeth. Compared with resin (4.7%) or porcelain (0.9%), the use of nonbonded inlay restoration materials such as gold (20.5%) or amalgam (18.7%) increased the occurrence of longitudinal tooth fractures. Out of 107 of longitudinal fractured teeth, 33 (30.8%) were treated endodontically and 74 (69.2%) were not. VRF was associated with endodontic treatment. Conclusions The bite test is most reliable for reproducing symptoms. The combined use of various examination methods is recommended for detecting cracks and minutely inspecting all directions of a tooth.
: Cleidocranial dysplasia (CCD) is a rare, autosomal dominant skeletal dysplasia with a prevalence of one per million births. The main causes of CCD are mutations in the core-binding factor alpha-1 ...(CBFA1) or runt-related transcription factor-2 (RUNX2), located at the 6p21 chromosomal region. RUNX2 plays important roles in osteoblast differentiation, chondrocyte proliferation and differentiation, and tooth formation. The disease is characterized by clavicular aplasia or hypoplasia, Wormian bones, delayed closure of cranial suture, brachycephalic head, maxillary deficiency, retention of primary teeth, inclusion of permanent teeth, and multiple supernumerary teeth.
: A 22-year-old girl suffering from cleidocranial dysplasia with short stature, narrow shoulders, craniofacial manifestations (short face, broad forehead, etc.) and dental anomalies (different lower dental elements under eruption, supernumerary and impacted multiple teeth, etc.) was examined at our service (Complex Operative Unit of Odontostomatology of Policlinico of Bari). RX Orthopantomography (OPG) and cone beam computed tomography (CBCT) were requested to better assess the position of the supernumerary teeth and their relationships with others and to evaluate the bone tissue.
: Under eruption was probably caused by dental interferences with supernumerary teeth; hence, extractions of supernumerary upper canines and lower premolars were performed under general anaesthesia. Surgery outcome was excellent with good tissue healing and improvements in the therapeutic possibilities with future orthodontics.
The objective of this article is to give an update about radiological, clinical, and molecular features of CCD and to alert the health team about the importance of establishing an early diagnosis and an appropriate treatment in these patients to prevent impacted teeth complications and to offer them a better quality of life.
Dental follicles are involved in odontogenesis, periodontogenesis, and tooth eruption. Dental follicles are unique structures, considering that their remnants can persist within the jawbones after ...odontogenesis throughout life if the tooth does not erupt. Pathological changes may occur in these tissues as individuals age. The changes range from benign to life threatening. Thus, the assessment of age‐related changes in dental follicles associated with unerupted teeth is of paramount importance. In this review, we summarize the physiological roles and changes in dental follicles in odontogenesis, tooth eruption, and aging, in addition to the pathological changes associated with these structures. We encourage investigators to consider this peculiar tissue as a unique model and explore its potential to clarify its importance from the viewpoints of developmental biology, tissue physiology, and pathology.
Key Findings
Dental follicle has important roles in odontogenesis, periodontogenesis, and tooth eruption. When tooth eruption is impaired, remnants of dental follicle can permanently persist in the jaws.
Oral pathologists tend to refer to the tissue associated with unerupted teeth as “dental follicles”. This term should be interpreted with caution, considering that these are remnants of the dental follicle.
As individuals age, dental follicles associated with unerupted teeth undergo morphological and molecular changes. Notably, odontogenic cysts and tumors can originate from dental follicles associated with unerupted teeth.
Herein, we integrated information on dental follicles from development to aging, and pathological changes.
Abstract Objectives The aim of this study was to identify predictor factors associated with the whitening outcome and risk and intensity of bleaching-induced tooth sensitivity from pooled data of 11 ...clinical trials of dental bleaching performed by the same research group. Methods The individual patient data of several published and ongoing studies about dental bleaching was collected and retrospectively analyzed. At the patient-level, independent variables (bleaching techniques at-home and in-office protocols, sex, age and baseline tooth color in shade guide unit SGU) as well as dependent variables (color change in shade guide units (ΔSGU), color change in the CIEL* a * b * system (Δ E ), risk and intensity of TS in a visual analog scale) were collected. Multivariable linear regression and multivariable logistic regression models were carried out using backward elimination whenever the p -values were higher than 0.05. Results A significant relationship between baseline color and age on color change estimates was detected ( p < 0.001). Every increase of one SGU in the baseline color resulted in an increase of approximate 0.66 in the final ΔSGU and 2.48 for the Δ E . For every increase of one year in the participant’s age we observed a decrease of the whitening degree of 0.07 for the final ΔSGU and 0.69 for the Δ E . The bleaching technique was shown to be a significant predictor of ΔSGU ( p < 0.001) but not of Δ E . In regard to TS, baseline color and bleaching technique are significant predictors ( p < 0.001). The risk of TS for at-home bleaching was 51% (95% CI 41.4–60.6) and for the in-office 62.9% (95% CI 56.9–67.3). Conclusions Younger patients with darker teeth reach a higher degree of whitening. Patient with darker teeth and submitted to at-home bleaching presents lower risk and intensity of TS. Clinical significance The baseline color of the teeth and the patient’s age is directly related to the effectiveness of dental bleaching and TS.
Whole-organ regeneration has great potential for the replacement of dysfunctional organs through the reconstruction of a fully functional bioengineered organ using three-dimensional cell manipulation ...in vitro. Recently, many basic studies of whole-tooth replacement using three-dimensional cell manipulation have been conducted in a mouse model. Further evidence of the practical application to human medicine is required to demonstrate tooth restoration by reconstructing bioengineered tooth germ using a postnatal large-animal model. Herein, we demonstrate functional tooth restoration through the autologous transplantation of bioengineered tooth germ in a postnatal canine model. The bioengineered tooth, which was reconstructed using permanent tooth germ cells, erupted into the jawbone after autologous transplantation and achieved physiological function equivalent to that of a natural tooth. This study represents a substantial advancement in whole-organ replacement therapy through the transplantation of bioengineered organ germ as a practical model for future clinical regenerative medicine.
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