The Experts below are selected from a list of 5271 Experts worldwide ranked by ideXlab platform
M V Swain - One of the best experts on this subject based on the ideXlab platform.
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fractographic analysis of a split tooth presenting radiographically as a horizontal root fracture in an unrestored Mandibular Second Molar
Journal of Endodontics, 2017Co-Authors: Unni Krishnan, Alex J Moule, Shaji Michael, M V SwainAbstract:Abstract Introduction Spontaneously catastrophic fracture of intact unrestored Molar teeth is not common. Nevertheless, cracks do occur that progress apically, resulting in the complete splitting of the tooth and root. This report describes a catastrophic fracture that occurred in an unrestored Mandibular Second Molar resulting in a previously unreported combination of a longitudinal and horizontal root fracture, appearing radiographically as a single horizontal root fracture. Methods Tooth fragments were examined clinically, stereoscopically, and by scanning electron microscopy. Fractographic analysis was used to investigate the dynamics involved in fracture initiation, structural resistances encountered during progression of the fracture, and reasons for direction changes culminating in the unusual radiographic appearance. Result The uniqueness of this report is that it describes fractographic evidence of factors contributing to the initiation and progression of an in vivo crack. It shows fracture markings that are evidence of the energy dissipation mechanisms. The topographic location of these markings confirmed that cracks occur in vivo in stages with different rates of progression. Conclusion This analysis helps to explain why split teeth are uncommon and highlights some of the multitude of factors that have to coincide for a tooth to catastrophically fracture. The report describes the mechanism of fracture and should stimulate clinicians and researchers to investigate cracking of teeth by undertaking fractographic analysis of extracted cracked teeth.
Marina Parreira Ribeiro - One of the best experts on this subject based on the ideXlab platform.
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Distalization of impacted Mandibular Second Molar using miniplates for skeletal anchorage: Case report
Dental Press Journal of Orthodontics, 2011Co-Authors: Belini Freire-maia, Tarcísio Junqueira Pereira, Marina Parreira RibeiroAbstract:This study describes a case with an impacted right Mandibular Second Molar which was distalized using miniplates for skeletal anchorage. Uprighting impacted Mandibular Second Molars has been a great challenge for orthodontists and oral surgeons because of the scarcity of anchorage options. Skeletal anchorage was first used in clinical orthodontics in the middle of the 1980s. Since then, several devices have been developed for that purpose, such as mini-screws, tooth implants and, lately, miniplates, which have been tested and showed encouraging results. This topic is relevant for orthodontists and oral surgeons because the use of miniplates may significantly change the treatment of impacted Mandibular Molars.
Inês Morais Caldas - One of the best experts on this subject based on the ideXlab platform.
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Chronology of mineralization of the permanent Mandibular Second Molar teeth and forensic age estimation
Forensic Science Medicine and Pathology, 2017Co-Authors: Pedro Fins, Maria Lurdes Pereira, Américo Afonso, Daniel Pérez-mongiovi, Inês Morais CaldasAbstract:Forensic age estimation frequently relies upon the chronology of mineralization of the third Molar teeth. However, even when present, third Molar teeth cannot always be used for estimating age in people who are classified as minors. Seconds Molars develop earlier and in a more predictable way, and therefore are often more reliable for age estimation in this age group. This study aims to contribute to forensic age estimation using an age threshold of 14-years, studying the stages of development of permanent Mandibular Second Molar teeth mineralization. 367 orthopantograms of a Portuguese population group, aged between 3 and 19 years, were studied. The stages of mineralization of Mandibular permanent Second Molar teeth were studied following the classification stages proposed by Demirjian et al. Stage descriptive analysis was performed, and associations between age and stage were studied. A logistic regression to determine age over 14 years, using maturation stages and sex as a predictive variables, was made. A Second sample was used for testing the model. The significance level was set at 5%. The model correctly classified 92.0% of cases overall. The equation was tested in the Second sample, and the results showed that there were no statistical significant differences between the binary real age (i.e. age
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chronology of mineralization of the permanent Mandibular Second Molar teeth and forensic age estimation
Forensic Science Medicine and Pathology, 2017Co-Authors: Pedro Fins, Américo Afonso, Inês Morais Caldas, Maria De Lurdes Pereira, Daniel PerezmongioviAbstract:Forensic age estimation frequently relies upon the chronology of mineralization of the third Molar teeth. However, even when present, third Molar teeth cannot always be used for estimating age in people who are classified as minors. Seconds Molars develop earlier and in a more predictable way, and therefore are often more reliable for age estimation in this age group. This study aims to contribute to forensic age estimation using an age threshold of 14-years, studying the stages of development of permanent Mandibular Second Molar teeth mineralization. 367 orthopantograms of a Portuguese population group, aged between 3 and 19 years, were studied. The stages of mineralization of Mandibular permanent Second Molar teeth were studied following the classification stages proposed by Demirjian et al. Stage descriptive analysis was performed, and associations between age and stage were studied. A logistic regression to determine age over 14 years, using maturation stages and sex as a predictive variables, was made. A Second sample was used for testing the model. The significance level was set at 5%. The model correctly classified 92.0% of cases overall. The equation was tested in the Second sample, and the results showed that there were no statistical significant differences between the binary real age (i.e. age < 14 and age ≥ 14 years) and the estimated age (p = 0.109). The developed model is useful for age estimation using 14-years as a threshold. However, stage maturation analyses showed that stage F, in males, and stages G and H, in both sexes, lead to an estimated age with significant statistical differences from chronological age.
Belini Freire-maia - One of the best experts on this subject based on the ideXlab platform.
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Distalization of impacted Mandibular Second Molar using miniplates for skeletal anchorage: Case report
Dental Press Journal of Orthodontics, 2011Co-Authors: Belini Freire-maia, Tarcísio Junqueira Pereira, Marina Parreira RibeiroAbstract:This study describes a case with an impacted right Mandibular Second Molar which was distalized using miniplates for skeletal anchorage. Uprighting impacted Mandibular Second Molars has been a great challenge for orthodontists and oral surgeons because of the scarcity of anchorage options. Skeletal anchorage was first used in clinical orthodontics in the middle of the 1980s. Since then, several devices have been developed for that purpose, such as mini-screws, tooth implants and, lately, miniplates, which have been tested and showed encouraging results. This topic is relevant for orthodontists and oral surgeons because the use of miniplates may significantly change the treatment of impacted Mandibular Molars.
Gallastorreira Mercedes - One of the best experts on this subject based on the ideXlab platform.
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a modified device for intraoral radiography to assess the distal osseous defects of Mandibular Second Molar after impacted third Molar surgery
Imaging Science in Dentistry, 2011Co-Authors: Fariainocencio Ana, Gallastorreira MercedesAbstract:Purpose : This article is to describe a modified device for intraoral radiography which was developed to obtain reproducible radiographic images for assessment of distal osseous defects of the Mandibular Second Molar (2 Mm) after impacted third Molar (3 Mm) surgery. Materials and Methods : A commercial available alignment system for posterior region was modified by adding a reference gauge pin (millimetric) and threading a hollow acrylic cylinder at the ring of the radiographic positioner to attach the X-ray collimator. The design included customized resin acrylic stent for the occlusal surface of the 2 Mm in maximum intercuspal position, individualizing the biteblock positioner. Periapical radiographs were taken before and after surgical extraction of 3 Mm, employing the radiographic technique of parallelism described by Kugelberg (1986) with this modified film holder and inserting the gauge pin on the deepest bone probing depth point. Results : This technique permitted to obtain standardized periapical radiographs with a moderate to high resolution, repeatability, and accuracy. There was no difference between the measurements on the pre- and post-operative radiographs. This technique allowed better maintenance of the same geometric position compared with conventional one. The insertion of the gauge pin provided the same reference point and localized the deepest osseous defect on the two-dimensional radiographs. Conclusion : This technique allowed better reproducibility in posterior radiographic records (distal surface of 2 Mm) and more accurate measurements of radiographic bone level by the use of a millimetric pin. (Imaging Sci Dent 2011; 41 : 115-21)