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PloS One 2024Tooth morphology is among the most well-studied indicators of ecology. For decades, researchers have examined the gross morphology and wear patterns of teeth as... (Review)
Review Meta-Analysis
Tooth morphology is among the most well-studied indicators of ecology. For decades, researchers have examined the gross morphology and wear patterns of teeth as indicators of diet, and recent advances in scanning and computer analysis have allowed the development of new and more quantitative measures of tooth morphology. One of the most popular of these new methods is orientation patch count (OPC). OPC, a measure of surface complexity, was originally developed to distinguish the more complex tooth crowns of herbivores from the less complex tooth crowns of faunivores. OPC and a similar method derived from it, orientation patch count rotated (OPCR), have become commonplace in analyses of both modern and fossil amniote dietary ecology. The widespread use of these techniques makes it possible to now re-assess the utility of OPC and OPCR. Here, we undertake a comprehensive review of OPC(R) and diet and perform a meta-analysis to determine the overall difference in complexity between herbivores and faunivores. We find that the relationship between faunivore and herbivore OPC or OPCR values differs substantially across studies, and although some support the initial assessment of greater complexity in herbivores, others do not. Our meta-analysis does not support an overall pattern of greater complexity in herbivores than faunivores across terrestrial amniotes. It appears that the relationship of OPC or OPCR to diet is taxon-specific and dependent on the type of faunivory of the group in question, with insectivores often having values similar to herbivores. We suggest extreme caution in comparing OPC and OPCR values across studies and offer suggestions for how OPCR can constructively be used in future research.
Topics: Humans; Tooth; Diet; Tooth Crown; Tooth Wear; Ecology
PubMed: 38306370
DOI: 10.1371/journal.pone.0292358 -
BMC Oral Health Mar 2022Whether to preserve a structurally compromised tooth or remove it is a dilemma often encountered by clinicians. The aim of this study was to assess the long-term success...
BACKGROUND
Whether to preserve a structurally compromised tooth or remove it is a dilemma often encountered by clinicians. The aim of this study was to assess the long-term success rate of fractured teeth preserved by modified crown lengthening surgery and restorations.
METHODS
Thirty-nine patients with a total of 45 fractured teeth who had received modified crown lengthening surgery were recruited and examined. Numbers of teeth lost were recorded, and the criteria for successful teeth were defined. Kaplan-Meier estimator was used to determine the success rate. Possible risk factors were compared between successful and unsuccessful groups by a Cox regression analysis to explore the potential predictors of failure with a significant level at α = 0.05.
RESULTS
The mean ± SD of success time without considering variants was 6.2 ± 0.6 years (95% CI 5.1-7.7). The mean survival rates ± SD at 1.0-, 2.0-, 3.0-, 5.0-, 7.0-, and 9.0-year intervals was 97.8 ± 2.2%, 92.2 ± 4.4%, 72.8 ± 7.9%, 68.2 ± 8.6%, 60.7 ± 10.5%, and 40.4 ± 13.6%, respectively. Failure cases in teeth with poor plaque control and step-shaped fracture margin were significantly more than those with good plaque control and knife-shaped fracture margin (HR = 7.237, p = 0.011; HR = 15.399, p = 0.006; respectively).
CONCLUSIONS
Fractured teeth treated with modified crown lengthening surgery are anticipated to have a high clinical success rate for 6.2 ± 0.6 years. Plaque control and fracture morphology appeared to be significantly associated with the success of the multidisciplinary treatment approach.
Topics: Crown Lengthening; Crowns; Humans; Tooth Crown; Tooth Fractures
PubMed: 35354462
DOI: 10.1186/s12903-022-02143-z -
Brazilian Oral Research Oct 2018Pulp canal obliteration (PCO) is a frequent finding associated with pulpal revascularization after luxation injuries of young permanent teeth. The underlying mechanisms... (Review)
Review
Pulp canal obliteration (PCO) is a frequent finding associated with pulpal revascularization after luxation injuries of young permanent teeth. The underlying mechanisms of PCO are still unclear, and no experimental scientific evidence is available, except the results of a single histopathological study. The lack of sound knowledge concerning this process gives rise to controversies, including the most suitable denomination. More than a mere semantic question, the denomination is an important issue, because it reflects the nature of this process, and directly impacts the treatment plan decision. The hypothesis that accelerated dentin deposition is related to the loss of neural control over odontoblastic secretory activity is well accepted, but demands further supportive studies. PCO is seen radiographically as a rapid narrowing of pulp canal space, whereas common clinical features are yellow crown discoloration and a lower or non-response to sensibility tests. Late development of pulp necrosis and periapical disease are rare complications after PCO, rendering prophylactic endodontic intervention useless. Indeed, yellowish or gray crown discoloration may pose a challenge to clinicians, and may demand endodontic intervention to help restore aesthetics. This literature review was conducted to discuss currently available information concerning PCO after traumatic dental injuries (TDI), and was gathered according to three topics: I) physiopathology of PCO after TDI; II) frequency and predictors of pulpal healing induced by PCO; and III) clinical findings related to PCO. Review articles, original studies and case reports were included aiming to support clinical decisions during the follow-up of teeth with PCO, and highlight future research strategies.
Topics: Dental Pulp Cavity; Dental Pulp Diseases; Dentition, Permanent; Humans; Radiography, Dental; Tooth Avulsion; Tooth Crown; Tooth Discoloration; Tooth Fractures
PubMed: 30365616
DOI: 10.1590/1807-3107bor-2018.vol32.0075 -
Journal of Bone and Mineral Research :... Mar 2017The synchronization of cell proliferation and cytodifferentiation between dental epithelial and mesenchymal cells is required for the morphogenesis of teeth with the...
The synchronization of cell proliferation and cytodifferentiation between dental epithelial and mesenchymal cells is required for the morphogenesis of teeth with the correct functional shapes and optimum sizes. Epiprofin (Epfn), a transcription factor belonging to the Sp family, regulates dental epithelial cell proliferation and is essential for ameloblast and odontoblast differentiation. Epfn deficiency results in the lack of enamel and ironically the formation of extra teeth. We investigated the mechanism underlying the functions of Epfn in tooth development through the creation of transgenic mice expressing Epfn under the control of an epithelial cell-specific K5 promoter (K5-Epfn). We found that these K5-Epfn mice developed abnormally shaped incisors and molars and formed fewer molars in the mandible. Remarkably, ameloblasts differentiated ectopically and enamel was formed on the lingual side of the K5-Epfn incisors. By contrast, ameloblasts and enamel were found only on the labial side in wild-type mice, as Follistatin (Fst) expressed in the lingual side inhibits BMP4 signaling necessary for ameloblast differentiation. We showed that Epfn transfection into the dental epithelial cell line SF2 abrogated the inhibitory activity of Fst and promoted ameloblast differentiation of SF2 cells. We found that Epfn induced FGF9 in dental epithelial cells and this dental epithelial cell-derived FGF9 promoted dental mesenchymal cell proliferation via the FGF receptor 1c (FGFR1c). Taken together, these results suggest that Epfn preserves the balance between cell proliferation and cytodifferentiation in dental epithelial and mesenchymal cells during normal tooth development and morphogenesis. © 2016 American Society for Bone and Mineral Research.
Topics: Ameloblasts; Amelogenesis; Animals; Animals, Newborn; Biomarkers; Cell Differentiation; Dental Enamel; Dental Papilla; Epithelium; Fibroblast Growth Factor 9; Hedgehog Proteins; Incisor; Kruppel-Like Transcription Factors; Mesoderm; Mice, Inbred ICR; Mice, Transgenic; Models, Biological; Molar; Odontogenesis; Tooth Crown
PubMed: 27787957
DOI: 10.1002/jbmr.3024 -
European Journal of Orthodontics Aug 2017Torque of the maxillary incisors is essential in esthetics and proper occlusion, while torque expression is influenced by many factors. The aim of this finite element...
INTRODUCTION
Torque of the maxillary incisors is essential in esthetics and proper occlusion, while torque expression is influenced by many factors. The aim of this finite element study was to assess the relative effect of tooth morphology, bracket prescription, and bracket positioning on tooth displacement and developed stresses/strains after torque application.
METHODS
A three-dimensional upper right central incisor with its periodontal ligament (PDL) and alveolus was modelled. The tooth varied in the crown-root angle (CRA) between 156°, 170°, and 184°. An 0.018-inch slot discovery® (Dentaurum, Ispringen, Germany) bracket with a rectangular 0.018 × 0.025-inch β-titanium wire was modelled. Bracket torque prescription varied between 0°, 12°, and 22°, with bracket placement at the centre of the middle, gingival or incisal third of the crown. A total of 27 models were generated and a buccal root torque of 30° was applied. Afterwards, crown and apex displacement, strains in the PDL, and stresses in the bracket were calculated and analysed statistically.
RESULTS
The palatal crown displacement was significantly affected by bracket positioning (up to 94 per cent), while the buccal apex displacement was significantly affected by bracket prescription (up to 42 per cent) and bracket positioning (up to 23 per cent). Strains in the PDL were affected mainly by CRA (up to 54 per cent), followed by bracket positioning (up to 45 per cent). Finally, bracket prescription considerably affected the stresses in the bracket (up to 144 per cent).
LIMITATIONS
These in silico results need to be validated in vivo before they can be clinically extrapolated.
CONCLUSION
Tooth anatomy and the characteristics of the orthodontic appliance should be considered during torque application.
Topics: Computer Simulation; Esthetics, Dental; Finite Element Analysis; Humans; Incisor; Orthodontic Appliance Design; Orthodontic Appliances; Orthodontic Brackets; Orthodontic Wires; Periodontal Ligament; Stress, Mechanical; Titanium; Tooth Crown; Tooth Movement Techniques; Tooth Root; Torque
PubMed: 27932407
DOI: 10.1093/ejo/cjw074 -
International Journal of Oral Science Dec 2013The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was... (Review)
Review
The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was conducted to identify studies on tooth wear against ceramic crowns in posterior region. The selected studies were analyzed in regard to type of crowns, natural antagonist, measuring protocol and outcome. From a yield of 1 000 titles, 43 articles were selected for full-text analysis; finally, no in vitro and only five in vivo studies met the inclusion criteria. As there is heterogeneity in design, used measuring method, ceramics and analysis-form, a meta-analysis was not possible. Results of these studies are very controversial which makes a scientifically valid comparison impossible. This review indicated that some all-ceramic crowns are as wear friendly as metal-ceramic crowns. Up to now, it has been impossible to associate tooth wear with any specific causal agent. The role of ceramic surface treatment that might be responsible for the changing in rate of tooth wear seems undetermined as yet through clinical trials. The literature reveals that studies on this topic are subject to a substantial amount of bias. Therefore, additional clinical studies, properly designed to diminish bias, are warranted.
Topics: Crowns; Dental Enamel; Dental Porcelain; Humans; Metal Ceramic Alloys; Surface Properties; Tooth Crown; Tooth Wear
PubMed: 24136675
DOI: 10.1038/ijos.2013.73 -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Oct 2017With the development of the oral clinical technology and materials, the concept of complex crown root fracture has become more scientific and developed. Epidemiological...
With the development of the oral clinical technology and materials, the concept of complex crown root fracture has become more scientific and developed. Epidemiological characteristics, causes and clinical features of this disease are generalized. Aesthetic, functional and minimally invasive coordination is reflected by expounding the diagnosis of complex crown-root fracture, recommendation of treatment and techniques, and characteristics of immature permanent teeth to systematize the treatment strategy, and to guide the clinical therapy of complex crown-root fracture.
Topics: Crowns; Esthetics, Dental; Humans; Incisor; Tooth Crown; Tooth Fractures; Tooth Root
PubMed: 29188637
DOI: 10.7518/hxkq.2017.05.002 -
International Journal of Environmental... Jul 2022The anatomical variability of primary molars promotes research to improve clinical restorative activity, forensic identification, and industrial development. The...
The anatomical variability of primary molars promotes research to improve clinical restorative activity, forensic identification, and industrial development. The objective was to study the morphology of the pulp chamber and its three-dimensional relationship with the external morphology of the tooth. A total of 151 deciduous molars were collected and subjected to three-dimensional imaging analysis in order to determine dental crown (CV) and pulp chamber (PV) volumes, their ratio (VR), pulp chamber roof (PCR) and pulp chamber floor (PCF) area, the furcation length (FD), and morphological peculiarities. The data were compared using the Kruskal-Wallis test in SPSS 26 software. The statistical analysis determined statistically significant differences between the four groups of molars for all variables. Great anatomical variability was observed, especially in the maxillary first molar, the volumes were higher in the maxillary second molar and the highest risk of furcal perforation was seen in the mandibular first molar. Additionally, mandibular second molars with six pulp horns, and some different density images compatible with accessory canals and pulp stones were found. Based on the findings of this investigation, we confirm the great anatomical variability that exists between the maxillary and mandibular molars.
Topics: Dental Pulp Cavity; Molar; Tooth; Tooth Crown; Tooth Root
PubMed: 35954635
DOI: 10.3390/ijerph19159279 -
Swiss Dental Journal Jul 2018Coronectomy is the intentional partial removal of a tooth. Thereby the crown of the tooth is removed and the roots are left in place. Compared to the complete operative...
Coronectomy is the intentional partial removal of a tooth. Thereby the crown of the tooth is removed and the roots are left in place. Compared to the complete operative removal of a wisdom tooth, the incidence of inferior alveolar nerve injury (IANI) is lower. The aim of this study is a survey on the use and acceptance of wisdom tooth coronectomy in Switzerland. An anonymous questionnaire was sent to 266 dentists specialized in oral surgery or maxillofacial surgeons; 58.3% of the questionnaires were returned and could be assessed. The statistical analysis was performed using Fisher’s exact test. The technique was classified as «non-reliable» by 51.6% of the respondents. In cases manifesting a high risk of IANI, 40.6% offered the patient a coronectomy. In a tooth exhibiting a high risk of IANI, 69.0% could envisage to perform a coronectomy instead of a complete operative removal. The technique was not used by 54.8%. A significantly larger proportion of study participants who specialized in or after the year 2005 (p < 0.05) rated the technique as “reliable”. The same applied to respondents who specialized in Bern (p < 0.05) and those who already had used coronectomy (p < 0.001). In conclusion, our results show that the majority of maxillofacial and oral surgeons reject coronectomy. In view of recent studies, this attitude should be reconsidered.
Topics: Humans; Mandible; Molar, Third; Switzerland; Tooth Crown; Tooth Extraction; Tooth Root; Tooth, Impacted; Trigeminal Nerve Injuries
PubMed: 29882398
DOI: No ID Found -
Oral Surgery, Oral Medicine, Oral... Nov 2010This study evaluated the reliability of tooth-crown radiographic references to aid in orthodontic mini-implant insertion and showed an insertion technique based on these... (Comparative Study)
Comparative Study
OBJECTIVE
This study evaluated the reliability of tooth-crown radiographic references to aid in orthodontic mini-implant insertion and showed an insertion technique based on these references.
STUDY DESIGN
The sample consisted of 213 interradicular septa evaluated in 53 bitewing radiographs. The proximal contour of adjacent tooth crowns was used to define septum width and its midpoint was linked to the interdental contact point to determine septum midline (SML). The distances from SML to mesial and distal teeth were measured and compared to evaluate SML centralization degree in 2 different septum heights.
RESULTS
The mesial and distal distances were not statistically different in the midpoint of the septum height, but they were different at the apical septum height.
CONCLUSIONS
The tooth-crown radiographic references determine a high centralization degree of the SML on which an insertion site could be defined. The greater SML centralization degree was observed at the coronal septum area.
Topics: Alveolar Process; Cephalometry; Dental Devices, Home Care; Dental Implantation, Endosseous; Dental Implants; Gingiva; Humans; Odontometry; Orthodontic Anchorage Procedures; Orthodontic Wires; Periodontal Ligament; Radiography, Bitewing; Tooth Crown; Tooth Root
PubMed: 20869273
DOI: 10.1016/j.tripleo.2010.05.063