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European Journal of Orthodontics May 2023To determine (a) the prevalence of spontaneous correction of posterior crossbites from the deciduous to the mixed dentition and (b) the development of new posterior...
AIM
To determine (a) the prevalence of spontaneous correction of posterior crossbites from the deciduous to the mixed dentition and (b) the development of new posterior crossbite cases during the eruption of the first permanent molars, in orthodontically untreated children.
MATERIALS AND METHODS
A cohort of pupils aged 4-12 years participated in annual dental screenings, from 2001 to 2019. Data were collected prospectively but examined retrospectively. Children were selected who had been initially screened in their deciduous dentition and on at least one consecutive year, presenting with a posterior crossbite in the deciduous or mixed dentition. Those with a posterior crossbite in the deciduous dentition were evaluated to see whether the crossbite persisted in the mixed dentition, and vice versa.
RESULTS
Of the 2571 children participating in the annual dental screenings, 1076 children were in the deciduous dentition at their first screening appointment, with 693 having attended at least two screening appointments. Of these 693 children, 70 had a posterior crossbite in the deciduous dentition (10.1%). The crossbite persisted in the mixed dentition in only 16 out of these 70 children. Twenty-six out of the 623 children who did not have a posterior crossbite in the deciduous dentition developed one in the mixed dentition.
LIMITATIONS
The retrospective data collection, multiple examiners carrying out the dental screenings, and the absence of data on para-functions and oral habits were some of the limitations of the present study.
CONCLUSIONS
In the present sample, 1 in 10 children have a posterior crossbite in the deciduous dentition, which is however autocorrected in about three-quarters of cases. On the other hand, 4% of children developed a new crossbite in the mixed dentition. It may thus be reasonable in cases with posterior crossbite in the deciduous dentition to wait for the first permanent molars to erupt before initiating treatment.
Topics: Child; Humans; Dentition, Mixed; Retrospective Studies; Tooth, Deciduous; Malocclusion; Molar
PubMed: 36203363
DOI: 10.1093/ejo/cjac061 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... May 2021For decades, the molecular and cellular mechanisms that govern tooth development have been extensively investigated. However, most of the studies are based on mice,... (Review)
Review
For decades, the molecular and cellular mechanisms that govern tooth development have been extensively investigated. However, most of the studies are based on mice, whose teeth are quite different from human teeth in morphological and developmental aspects. Mice are not the ideal model for understanding the development of permanent teeth as they have only one set of dentition. Thus, using of diphyodont mammals is a better model to study the deciduous and permanent tooth development and to understand the process of tooth replacement. Several diphyodont mammal models have been established including minipig, ferret, house shrew and rabbit. Studies based on the diphyodont mammals have characterized the morphological changes involved in tooth replacement and molecular mechanisms of tooth replacement. However, few developmental stages were studied on ferret due to the presence of seasonal estrus and the difficulty to obtain ferret embryos at the correct stage. The house shrew is limited as a model because their deciduous tooth germs become vestigial in the embryonic period. The main disadvantage of the rabbit is an incomplete dentition with the lack of canines. Compared to the above mentioned animal models, the miniature pig has proven to be a valuable animal model for diphyodont development due to its dentition similarities, including the morphology, number and size of teeth, to human's, and particularly its heterodont dentition consisting of incisors, canines, premolars and molars. The present article reviews the current knowledge on the development of the primary and successional teeth in minipig modle and briefly summarizes the studies based on other diphyodont mammal models.
Topics: Animals; Female; Ferrets; Mammals; Mice; Odontogenesis; Rabbits; Swine; Swine, Miniature; Tooth; Tooth, Deciduous
PubMed: 33904287
DOI: 10.3760/cma.j.cn112144-20200604-00314 -
PloS One 2024Morphological variation in modern human dentition is still an open field of study. The understanding of dental shape and metrics is relevant for the advancement of human...
Morphological variation in modern human dentition is still an open field of study. The understanding of dental shape and metrics is relevant for the advancement of human biology and evolution and is thus of interest in the fields of dental anthropology, as well as human anatomy and medicine. Of concern is also the variation of the inner aspects of the crown which can be investigated using the tools and methods of virtual anthropology. In this study, we explored inter- and intra-population morphometric variation of modern humans' upper third and fourth premolars (P3s and P4s, respectively) considering both the inner and outer aspects of the crown, and discrete traits. We worked by means of geometric morphometrics on 3D image data from a geographically balanced sample of human populations from five continents, to analyse the shape of the dentinal crown, and the crown outline in 78 P3s and 76 P4s from 85 individuals. For the study of dental traits, we referred to the Arizona State University Dental Anthropology System integrated with more recent classification systems. The 3D shape variation of upper premolar crowns varied between short and mesio-distally broad, and tall and mesio-distally narrow. The observed shape variation was independent from the geographical origin of the populations, and resulted in extensive overlap. We noted a high pairwise correlation (r1 = 0.83) between upper P3s and P4s. We did not find any significant geographic differences in the analysed non-metric traits. Our outcomes thus suggest that geographical provenance does not play a determinant role in the shaping of the dental crown, whose genesis is under strict genetic control.
Topics: Animals; Humans; Bicuspid; Anthropology, Physical; Hominidae; Anthropology; Tooth Crown
PubMed: 38593117
DOI: 10.1371/journal.pone.0301482 -
American Journal of Orthodontics and... May 2021The first molar has been reported to be the most caries prone tooth in the permanent dentition. Orthodontists are treating more adult patients who are more likely to...
The first molar has been reported to be the most caries prone tooth in the permanent dentition. Orthodontists are treating more adult patients who are more likely to have missing and severely decayed first molars. This article will show the various orthodontic and restorative options for first molars that are already extracted or have to be extracted. The following clinical situations will be addressed: molar uprighting and its advantages for the future restoration vs orthodontic space closure, strategic extraction of salvable first molars, impacted molars, and early extraction of compromised permanent first molars in young children.
Topics: Adult; Child; Child, Preschool; Dental Arch; Dentition, Permanent; Humans; Molar; Orthodontic Space Closure; Tooth Extraction; Tooth, Impacted
PubMed: 33495060
DOI: 10.1016/j.ajodo.2020.09.024 -
European Journal of Paediatric Dentistry 2021In the literature, no single therapeutic approach is preferred for treating dental pulp responses such as pulp canal obliteration (PCO). Some authors still recommend... (Review)
Review
AIM
In the literature, no single therapeutic approach is preferred for treating dental pulp responses such as pulp canal obliteration (PCO). Some authors still recommend preventive endodontic treatment, whereas others choose not to intervene, to avoid causing possible iatrogenic complications. This review was conducted to explore, in the current scientific literature, the degree of knowledge concerning the onset and development of PCO and pulp necrosis (PN) following dental trauma (i.e. extrusive luxation and lateral luxation) in children and young adults (6-20 years). The authors also evaluated whether and to what extent the stage of dental root development at the time of traumatic dental injury (TDI) influences these pulp responses, and whether PN can arise in teeth already affected by PCO. MATERIALS AND METHODS The literature search was carried out during the period October 2019 to January 2020, using the following databases: PubMed/MEDLINE, SCOPUS and Web of Science. Articles in English reporting on young patients with PCO or PN in permanent teeth affected by trauma were included. Theresearch, whose questions were summarised according to the PICO method, considered the following aspects: patient age, type of TDI, stage of root development, initial treatment, presence of calcification or necrosis, time to onset of the two outcomes (PCO and PN), and duration of follow-up. The articles found were evaluated by two reviewers; in the event of disagreement regarding the inclusion of an article, a third reviewer was called upon to decide.
RESULTS
The initial screening of the databases, using the selected search keywords, yielded a total of 343 articles. After exclusion of duplicates and articles not meeting the inclusion criteria, 11 articles remained. Of these, only four completely met the inclusion criteria. Closer analysis of these four publications revealed that they would not easily yield standardised sets of clinical data that might be homogenised in order to produce clear meta-analytical data. Hence the need to limit the data collected to the following seven items: number and type of injuries, type of initial intervention, duration of follow-up, main pulp responses, number and type of pulp responses.
CONCLUSIONS
PCO is a physiological pulp response associated with a traumatic event, usually a luxation injury. It is diagnosed on the basis of combined radiographic and clinical-anamnesticdata. Signs of PCO start to appear at around one year after the traumatic event, and its development reaches completion by about five years post-trauma. PN, on the other hand, is clearly apparent within the first year. Endodontic treatment, be it carried out as a preventive measure or following detection of PCO, is inappropriate and can cause serious iatrogenic damage. Treatment is indicated only in cases of definite PN.
Topics: Child; Dental Pulp Cavity; Dental Pulp Necrosis; Dentition, Permanent; Humans; Tooth Avulsion; Young Adult
PubMed: 33719484
DOI: 10.23804/ejpd.2021.22.01.10 -
Canadian Journal of Dental Hygiene :... Jun 2023Lobodontia is a rarely documented dental condition associated with pointed or conical cusps on premolars and canines, multitubercular occlusal surfaces on molar teeth,...
Lobodontia is a rarely documented dental condition associated with pointed or conical cusps on premolars and canines, multitubercular occlusal surfaces on molar teeth, and irregularly shaped incisors. Information on this uncommon condition continues to be scarce, with particularly little information available on the primary dentition. The purpose of this article is to describe 6 cases of lobodontia and discuss the variability in presentation and management. Previously unreported manifestations in the primary dentition are included. The cases described in the current study demonstrate the spectrum of clinical and radiographic features of the condition, and show that a varied, individualized approach to treatment is necessary.
Topics: Humans; Dentition, Permanent; Tooth Abnormalities; Molar; Bicuspid
PubMed: 37464991
DOI: No ID Found -
Head & Face Medicine Mar 2023To determine whether odontometric parameters using cone beam computed tomography (CBCT) would aid in sex estimation by assessing sexual dimorphism of odontometric... (Review)
Review
OBJECTIVE
To determine whether odontometric parameters using cone beam computed tomography (CBCT) would aid in sex estimation by assessing sexual dimorphism of odontometric parameters.
MATERIAL AND METHODS
The focused question was whether there is sexual dimorphism in linear and volumetric odontometric parameters when assessed using CBCT. The preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines were followed to conduct a systematic search until June 2022 in all major databases. Data were extracted regarding the population, size of the sample, age range, teeth analyzed, linear or volumetric measurements, accuracy, and conclusion. The quality of included studies was assessed using (Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.
RESULTS
Out of the 3761 studies identified, twenty-nine full-text articles were assessed for eligibility. Finally, twenty-three articles (4215 participants) that provided data on odontometrics using CBCT were included in this systematic review. The odontological sex estimation were assessed either linear measurements (n = 13) or volumetric measurements (n = 8) or both (n = 2). Canines were analysed in maximum number of reports (n = 14), followed by incisors (n = 11), molars(n = 10) and premolars(n = 6). Most of the reports (n = 18) confirmed the existence of sexual dimorphism in odontometric parameters when assessed using CBCT. No significant differences in odontometrics between the sexes were noted in some reports (n = 5). The accuracy of sex estimation was assessed in eight investigations, which ranged from 47.8 to 92.3%.
CONCLUSIONS
Odontometrics of human permanent dentition using CBCT exhibit a certain degree of sexual dimorphism. Both linear and volumetric measurements of teeth can aid sex estimation.
Topics: Humans; Sex Characteristics; Cone-Beam Computed Tomography; Databases, Factual; Incisor; Molar
PubMed: 36882815
DOI: 10.1186/s13005-023-00352-7 -
West African Journal of Medicine Mar 2022Tooth variation within populations is important for anthropologists and dentists. The objective was to compare crown dimensions among three Nigerian ethnic populations.
BACKGROUND
Tooth variation within populations is important for anthropologists and dentists. The objective was to compare crown dimensions among three Nigerian ethnic populations.
MATERIALS AND METHODS
An electronic caliper was used to measure mesiodistal and buccolingual tooth width of maxillary and mandibular permanent teeth except third molars from study casts of 132 Nigerian subjects with a mean age of 19.03 ± 4.27 years. The Hausa sample was 50 (37.9%) subjects (25 males and 25 females); the Yoruba population was 50 (37.9%) subjects (15 males and 35 females) and the Igbo sample was 32 (24.2%) subjects (16 males and 16 females). Single teeth and sums of groups of teeth were compared between males and females within and among the three populations using analysis of variance.
RESULTS
The findings indicated that (1) differences between antimeres are of small magnitude and of no statistical significance; (2) Significant gender differences in tooth dimension was observed with Yoruba and Hausa males having significantly larger teeth but a significant gender difference was only observed for mesiodistal width of the maxillary second molars in the Igbo population; (3) there is a greater similarity among Yoruba and Igbo subjects with differences from their Hausa counterparts with a magnitude considered statistically and clinically significant.
CONCLUSION
The crown dimensions of Hausa males and females were significantly smaller than their Yoruba and Igbo counterparts. There were similarities in crown dimensions between Yoruba males and females and their Igbo counterparts. Sexual dimorphism of crown size was observed in the three ethnic groups.
Topics: Adolescent; Adult; Dentition, Permanent; Ethnicity; Female; Humans; Male; Maxilla; Nigeria; Tooth; Tooth Crown; Young Adult
PubMed: 35381844
DOI: No ID Found -
British Dental Journal Mar 2023In the next part of this series on tooth wear management, we discuss the indications and clinical stages for the provision of removable prostheses for the treatment of...
In the next part of this series on tooth wear management, we discuss the indications and clinical stages for the provision of removable prostheses for the treatment of severely worn and depleted dentitions. The general design features of a complex prosthesis are described for reorganised occlusal schemes and maintenance guidelines are explained. In addition, the clinical stages for three different situations are described: removable-only approaches, and combined fixed and removable in the same arch and separate arches. The value of providing removable prostheses in worn dentitions allows the immediate rehabilitation of severely worn teeth taking a non-invasive and retrievable approach when the remaining dentition is of poor quality or structure and/or there are missing teeth.
Topics: Humans; Dentition; Prosthodontics; Dental Implants; Tooth Wear; Tooth Attrition; Denture, Partial, Removable
PubMed: 36964363
DOI: 10.1038/s41415-023-5583-5 -
Journal of Orofacial Orthopedics =... Oct 2022To assess the validity, reliability, reproducibility, and objectivity of measurements on stone casts of patients with mixed dentitions compared to measurements on...
PURPOSE
To assess the validity, reliability, reproducibility, and objectivity of measurements on stone casts of patients with mixed dentitions compared to measurements on three-dimensional (3D) digital models derived from surface scans of the stone casts.
METHODS
Pairs of stone casts of 30 young patients in their mixed dentition stage were included and processed into 3D digital models using an intraoral scanner (iTero Element 2; Align Technology, San Jose, CA, USA). Then an experienced and an inexperienced examiner independently performed measurements of five defined parameters, each in triplicate, both on the digital models with analysis software (OnyxCeph3™; Image Instruments, Chemnitz, Germany) and on the original casts with a vernier calliper. Paired t-tests were used for validity and interexaminer objectivity, Pearson correlation coefficients for intermethod reliability, and intraclass correlation coefficients (ICCs) for reproducibility testing.
RESULTS
Significant (p < 0.05) intermethod differences were identified for four parameters, but only the differences for overbite and intermolar distance exceeded the threshold of clinical relevance (≥ 0.5 mm). Intermethod reliability was high and method error invariably lower for the digital measurements and for the experienced examiner. Both examiners achieved ICCs > 0.907 with both methods. Interexaminer variation involved significant differences for all parameters but one (intermolar distance) on the stone casts and for three parameters on the digital models.
CONCLUSION
Measurements performed on digital models of mixed dentitions can yield clinically acceptable outcomes with OnyxCeph3™ software. Both the digital and the analogue measurements were highly reproducible and reliable. Objectivity of the measurements could not be confirmed, as operator experience did make a difference.
Topics: Dentition, Mixed; Humans; Imaging, Three-Dimensional; Models, Dental; Reproducibility of Results; Software
PubMed: 35238945
DOI: 10.1007/s00056-022-00376-9