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The Journal of the Michigan Dental... Jan 2012Loss of space in the primary dentition is considered one of the main causes of malocclusion in the permanent dentition. The purpose of this paper is to review ond... (Review)
Review
Loss of space in the primary dentition is considered one of the main causes of malocclusion in the permanent dentition. The purpose of this paper is to review ond summarize the indications and use of space maintainers in primary and mixed dentitions as preventive measures of future malocclusion. Two main types of space maintainers are used to maintain the space in primary ond mixed dentitions: fixed and removable appliances. Band and loop is the appliance of choice when a primary maxillary or mandibular first molar is prematurely lost. With the premature loss of a second primary molar, Nance or transpalatal (TPA) appliances can be used on the maxillary arch and the lower lingual holding arch (LLHA) for the mandibular arch.
Topics: Dentition, Mixed; Humans; Malocclusion; Orthodontic Appliance Design; Space Maintenance, Orthodontic; Tooth Loss; Tooth, Deciduous
PubMed: 22439522
DOI: No ID Found -
Journal of Morphology Aug 2016Teeth have long served as a model system to study basic questions about vertebrate organogenesis, morphogenesis, and evolution. In nonmammalian vertebrates, teeth...
Teeth have long served as a model system to study basic questions about vertebrate organogenesis, morphogenesis, and evolution. In nonmammalian vertebrates, teeth typically regenerate throughout adult life. Fish have evolved a tremendous diversity in dental patterning in both their oral and pharyngeal dentitions, offering numerous opportunities to study how morphology develops, regenerates, and evolves in different lineages. Threespine stickleback fish (Gasterosteus aculeatus) have emerged as a new system to study how morphology evolves, and provide a particularly powerful system to study the development and evolution of dental morphology. Here, we describe the oral and pharyngeal dentitions of stickleback fish, providing additional morphological, histological, and molecular evidence for homology of oral and pharyngeal teeth. Focusing on the ventral pharyngeal dentition in a dense developmental time course of lab-reared fish, we describe the temporal and spatial consensus sequence of early tooth formation. Early in development, this sequence is highly stereotypical and consists of seventeen primary teeth forming the early tooth field, followed by the first tooth replacement event. Comparing this detailed morphological and ontogenetic sequence to that described in other fish reveals that major changes to how dental morphology arises and regenerates have evolved across different fish lineages. J. Morphol. 277:1072-1083, 2016. © 2016 Wiley Periodicals, Inc.
Topics: Animals; Dentition; Gene Expression Regulation, Developmental; Jaw; Pharynx; Smegmamorpha; Time Factors; Tooth
PubMed: 27145214
DOI: 10.1002/jmor.20557 -
Journal of Endodontics Dec 2019Each year, millions of children are injured and live with the consequences of those injuries. Through infancy and childhood, orofacial trauma caused by falls or being...
Each year, millions of children are injured and live with the consequences of those injuries. Through infancy and childhood, orofacial trauma caused by falls or being struck by or against objects occurs in children. The long-term implications on the developing permanent teeth are little known, even when the oral region is the second most frequently injured body area in children under 6 years of age. During this period, the developing permanent teeth may be directly involved after trauma, causing mild to severe hypoplasia, displacement, damage to the tooth germ, or an extended range of morphofunctional disturbances. In some cases, the effects of oral and dental injuries caused by trauma appear later with the eruption of the permanent incisors when ectopic eruption, malalignments, and other developmental disturbances become visible. Therefore, long-term follow up of the patient in order to diagnose and treat associated complications becomes essential. Critical points for facing the consequences of orofacial trauma on the developing dentition are to recognize the impact of orofacial trauma in young children and the dentist's role in providing anticipatory guidance to parents and health care professionals, differentiate between mild and severe disturbances affecting the developing permanent teeth after oral injuries in early childhood, recognize the importance of follow-up controls, and recognize the importance of early referral to a pediatric dentist and orthodontist for diagnosis and treatment planning.
Topics: Child; Child, Preschool; Dentition; Dentition, Permanent; Humans; Incisor; Tooth Avulsion; Tooth, Deciduous
PubMed: 31623906
DOI: 10.1016/j.joen.2019.05.006 -
Histological and developmental insights into the herbivorous dentition of tapinocephalid therapsids.PloS One 2019Tapinocephalids were one of the earliest therapsid clades to evolve herbivory. In acquiring derived tooth-to-tooth occlusion by means of an exaggerated heel and talon...
Tapinocephalids were one of the earliest therapsid clades to evolve herbivory. In acquiring derived tooth-to-tooth occlusion by means of an exaggerated heel and talon crown morphology, members of this family have long been considered herbivorous, yet little work has been done to describe their dentition. Given the early occurrence of this clade and their acquisition of a dentition with several derived features, tapinocephalids serve as an important clade in understanding adaptations to herbivory as well as macroevolutionary patterns of dental trait acquisition. Here we describe the histology of tapinocephalid jaws and incisors to assess adaptations to herbivory. Our results yield new dental characters for tapinocephalids including a peculiar enamel structure and reduced enamel deposition on the occlusal surface. These traits are convergent with other specialized herbivorous dentitions like those found in ornithischian dinosaurs and ungulates. Furthermore, these results demonstrate that while acquiring some specializations, tapinocephalids also retained plesiomorphic traits like alternate, continuous replacement. We interpret these findings as an example of how different combinations of traits can facilitate a derived and specialized dentition and then discuss their implications in the acquisition of a mammal-like dentition.
Topics: Animals; Dental Enamel; Dentin; Dentition; Dinosaurs; Herbivory; Tooth Crown
PubMed: 31665173
DOI: 10.1371/journal.pone.0223860 -
European Journal of Orthodontics Apr 2000This study produced simple linear regression equations to be used for mixed dentition space analysis for males and females, and sexes pooled in a population living in... (Comparative Study)
Comparative Study
This study produced simple linear regression equations to be used for mixed dentition space analysis for males and females, and sexes pooled in a population living in northeastern Thailand. Measurements of teeth were made to within 0.01 mm on the dental casts of 215 boys and 215 girls (mean age 15.7 years). All dentitions were required to be free of any signs of dental pathology or anomalies. It was found that males had significantly larger teeth than females as represented by summations of mandibular incisor, canine, and premolar widths. ANOVA of regression indicated a close relationship between mandibular incisor summation and corresponding summations of canine and premolars. The low coefficients of determination (r2) of the regressions ranged between 0.29 and 0.42, and were higher for females than males, which might be attributable to the ethnic diversity of the sampled population. The regression equations produced predictions of mesio-distal width summations for maxillary and mandibular canine, and premolar arch segments that were slightly different from other reported Asian studies. Moyers' prediction tables at the 50th percentile were found to under-estimate tooth size summation compared with the present investigation. The predictions from simplified regression equations matched well with those of this study for sexes pooled, and for males and females separately.
Topics: Adolescent; Algorithms; Analysis of Variance; Cephalometry; Cuspid; Dental Arch; Dentition, Mixed; Ethnicity; Female; Forecasting; Humans; Incisor; Linear Models; Male; Mandible; Maxilla; Models, Dental; Molar; Odontometry; Reproducibility of Results; Sex Factors; Thailand; Tooth
PubMed: 10822885
DOI: 10.1093/ejo/22.2.127 -
Journal of Morphology Sep 2003The correlation of the origin of teeth with jaws in vertebrate history has recently been challenged with an alternative to the canonical view of teeth deriving from... (Comparative Study)
Comparative Study
The correlation of the origin of teeth with jaws in vertebrate history has recently been challenged with an alternative to the canonical view of teeth deriving from separate skin denticles. This alternative proposes that organized denticle whorls on the pharyngeal (gill) arches in the fossil jawless fish Loganellia are precursors to tooth families developing from a dental lamina along the jaw, such as those occurring in sharks, acanthodians, and bony fishes. This not only indicates that homologs of tooth families were present, but also illustrates that they possessed the relevant developmental controls, prior to the evolution of jaws. However, in the Placodermi, a phylogenetically basal group of jawed fishes, the state of pharyngeal denticles is poorly known, tooth whorls are absent, and the presence of teeth homologous to those in extant jawed fishes (Chondrichthyes + Osteichthyes) is controversial. Thus, placoderms would seem to provide little evidence for the early evolution of dentitions, or of denticle whorls, or tooth families, at the base of the clade of jawed fishes. However, organized denticles do occur at the rear of the placoderm gill chamber, but are associated with the postbranchial lamina of the anterior trunkshield, assumed to be part of the dermal cover. Significantly, these denticles have a different organization and morphology relative to the external dermal trunkshield tubercles. We propose that they represent a denticulate part of the visceral skeleton, under the influence of pharyngeal patterning controls comparable to those for pharyngeal denticles in other jawed vertebrates and Loganellia.
Topics: Animals; Branchial Region; Dermis; Fishes; Fossils; Phylogeny; Tooth
PubMed: 12833371
DOI: 10.1002/jmor.10124 -
The Journal of Evidence-based Dental... Mar 2016Impact of lateral occlusion schemes: A systematic review. Abduo J, Tennant M. J Prosthet Dent 2015;114(2):193-204 SOURCE OF FUNDING: Not reported
ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION
Impact of lateral occlusion schemes: A systematic review. Abduo J, Tennant M. J Prosthet Dent 2015;114(2):193-204 SOURCE OF FUNDING: Not reported
TYPE OF STUDY/DESIGN
Systematic review.
Topics: Dental Occlusion; Dental Occlusion, Balanced; Dental Occlusion, Centric; Dentition; Dentition, Mixed; Dentition, Permanent; Tooth
PubMed: 27132554
DOI: 10.1016/j.jebdp.2016.01.029 -
Evolution & Development Mar 2017One major innovation of mammals is the tribosphenic molar, characterized by the evolution of a neomorphic upper cusp (=protocone) and a lower basin (=talonid) that...
One major innovation of mammals is the tribosphenic molar, characterized by the evolution of a neomorphic upper cusp (=protocone) and a lower basin (=talonid) that occlude and provide shearing and crushing functions. This type of molar is an evolutionarily flexible structure that enabled mammals to achieve complex dental adaptations. Among carnivorous mammals, hypercarnivory is a common trend that evolved several times among therians (marsupials, placentals, and stem relatives). Hypercarnivory involves an important simplification of the carnassial molar pattern from the ancestral tribosphenic molar pattern, with the modification of the triangular tooth crown, and the loss of several cusps and cuspids typical of the tribosphenic molar. These losses confer to the molars of the hypercarnivorous mammals a plesiomorphic/paedomorphic morphology that resembles more the earliest mammaliaforms than the earliest therians. Here, we demonstrate that the modification of the molar morphology is fully explained by a patterning cascade mode of cusp development. Contrary to what was previously proposed, our study concludes that the metaconid (mesiolingual cusp of lower molars, associated with a puncturing function) does not influence cusp development of the talonid (distal crushing heel of lower molars). Moreover, it provides a new example of how heterochronic changes were crucial to the evolution of mammal dentition. To overcome the difficulty of applying behavioral or ecological definitions of diets to fossil animals, we characterize hypercarnivorous dentitions on the basis of the molar morphology and more particularly on the loss or retention of crushing structures, each dentition resulting from adaptations to a distinct ecomorphotype. Despite repeated and convergent evolution of hypercarnivorous forms, hypercarnivory appears as a highly constrained specialization (i.e., "dead end") that is unlikely to evolve back to omnivorous dentition, especially when the crushing structures are lost.
Topics: Animals; Biological Evolution; Dentition; Diet; Mammals; Molar
PubMed: 28181377
DOI: 10.1111/ede.12219 -
The Journal of Clinical Pediatric... 2001The aim of this study was to investigate the relationship between occlusal factors (overjet, overbite, Angle's Classification of molars and cuspids, the relationship of... (Comparative Study)
Comparative Study
The aim of this study was to investigate the relationship between occlusal factors (overjet, overbite, Angle's Classification of molars and cuspids, the relationship of the primary molars, openbite, lateral openbite, scissorbite and crossbite) and bruxism in permanent and mixed dentition in Turkish children. For this reason 182 children with mixed dentition and 212 children with permanent dentition were included in this study. Occlusal conditions were examined clinically and bruxism was assessed by using interview and questionnaires. Z Test was used to compare the results. It was found that in both dentitions some occlusal factors related with bruxism (overjet > 6 mm, overbite > 5 mm, negative overjet, openbite in permanent dentition; overjet > 6 mm, overbite > 5 mm, scissorbite, anterior-posterior multiple teeth crossbite, Angle Class I occlusion in mixed dentition.
Topics: Adolescent; Bruxism; Child; Cuspid; Dentition, Mixed; Dentition, Permanent; Female; Humans; Incisor; Interviews as Topic; Male; Malocclusion; Molar; Statistics as Topic; Surveys and Questionnaires; Tooth, Deciduous; Turkey
PubMed: 12049076
DOI: 10.17796/jcpd.25.3.84m695q650622568 -
Journal of the American Dental... Nov 1953
Topics: Dental Pulp; Dentition, Mixed; Humans; Tooth
PubMed: 13108494
DOI: 10.14219/jada.archive.1953.0205