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Journal of Experimental Zoology. Part... Mar 2011Classically the oral dentition with teeth regulated into a successional iterative order was thought to have evolved from the superficial skin denticles migrating into... (Review)
Review
Classically the oral dentition with teeth regulated into a successional iterative order was thought to have evolved from the superficial skin denticles migrating into the mouth at the stage when jaws evolved. The canonical view is that the initiation of a pattern order for teeth at the mouth margin required development of a sub-epithelial, permanent dental lamina. This provided regulated tooth production in advance of functional need, as exemplified by the Chondrichthyes. It had been assumed that teeth in the Osteichthyes form in this way as in tetrapods. However, this has been shown not to be true for many osteichthyan fish where a dental lamina of this kind does not form, but teeth are regularly patterned and replaced. We question the evolutionary origin of pattern information for the dentition driven by new morphological data on spatial initiation of skin denticles in the catshark. We review recent gene expression data for spatio-temporal order of tooth initiation for Scyliorhinus canicula, selected teleosts in both oral and pharyngeal dentitions, and Neoceratodus forsteri. Although denticles in the chondrichthyan skin appear not to follow a strict pattern order in space and time, tooth replacement in a functional system occurs with precise timing and spatial order. We suggest that the patterning mechanism observed for the oral and pharyngeal dentition is unique to the vertebrate oro-pharynx and independent of the skin system. Therefore, co-option of a successional iterative pattern occurred in evolution not from the skin but from mechanisms existing in the oro-pharynx of now extinct agnathans.
Topics: Animals; Biological Evolution; Dentition; Fishes; Odontogenesis; Pharynx; Tooth
PubMed: 21328527
DOI: 10.1002/jez.b.21387 -
Gaceta Sanitaria 2007To examine the relationship between the presence of enamel defects, dental caries in primary teeth, and exposure to various fluoride technologies and the presence of... (Comparative Study)
Comparative Study
OBJECTIVE
To examine the relationship between the presence of enamel defects, dental caries in primary teeth, and exposure to various fluoride technologies and the presence of dental caries in permanent teeth in children with mixed dentition.
MATERIALS AND METHODS
A cross-sectional study was conducted in 713 children aged 6-9 years old in 4 elementary schools in Campeche, Mexico through the use of a questionnaire for the mothers and an oral examination in the children. The dependent variable was the prevalence of caries in permanent dentition.
RESULTS
The mean number of decay, missing or filling teeth in primary dentition (dmft) and in permanent dentition (DMFT) was 2.48 (2.82) (deft > 0 = 58.9%) and 0.40 (0.98) (DMFT > 0 = 18.2%), respectively. The significant caries index (SiC), which is calculated in deciduous dentition, was 5.85 for 6 year-olds. Multivariate logistic regression adjusted for variables related to fluoride exposure revealed that older age (OR = 2.99), a deft of > 0 (OR = 5.46), and lower maternal educational level (OR = 1.57) were significantly associated with a higher number of dental caries in permanent teeth. An interaction between sex and enamel defects was also found.
CONCLUSIONS
The number of dental caries in both primary and permanent dentitions was relatively smaller than that found in prior studies performed in Mexican populations. The results confirm that the presence of caries in primary dentition is strongly associated with caries in permanent dentition. No significant relationship was found between fluoride exposure and dental caries in permanent dentition.
Topics: Age Factors; Child; DMF Index; Dental Caries; Dental Enamel; Dentition, Permanent; Female; Fluoridation; Humans; Logistic Models; Male; Mexico; Multivariate Analysis; Prevalence; Sex Factors; Surveys and Questionnaires; Tooth, Deciduous
PubMed: 17565898
DOI: 10.1157/13106806 -
Oral Surgery, Oral Medicine, and Oral... Nov 1963
Topics: Congenital Abnormalities; Cuspid; Dentition; Radiography, Dental; Tooth
PubMed: 14082307
DOI: 10.1016/0030-4220(63)90408-0 -
ASDC Journal of Dentistry For Children 1969
Topics: Child, Preschool; Dentition; Humans; Radiography; Time Factors; Tooth Eruption; Tooth, Deciduous
PubMed: 4900330
DOI: No ID Found -
Nederlands Tijdschrift Voor... Oct 1991Every dentist has to know the dentitional development well enough to be able to assess regularly this complicated process with its many normal variations and (topical)...
Every dentist has to know the dentitional development well enough to be able to assess regularly this complicated process with its many normal variations and (topical) aberrations. If they become clinical problems, they require diagnosis, long-term supervision and interceptive and/or corrective treatment. In this article the advantages and disadvantages of panoramic radiology for the diagnosis of the dentitional development are described. A systematic method of interpretation of the panoramic X-rays is recommended.
Topics: Adolescent; Child; Child, Preschool; Humans; Malocclusion; Radiography, Panoramic; Tooth Eruption; Tooth, Deciduous
PubMed: 1820535
DOI: No ID Found -
British Journal of Orthodontics May 1988Longitudinal records, in the form of study casts, of 35 Class I cases were examined for factors associated with changes of sagittal molar relationship during childhood.... (Review)
Review
Longitudinal records, in the form of study casts, of 35 Class I cases were examined for factors associated with changes of sagittal molar relationship during childhood. These were studied at two phases: between the deciduous and mixed dentitions, and between the mixed and permanent dentitions. During the first of these periods, there was a small, but general move to a less post-normal occlusion, although some cases were found to show a slight reverse trend. In the second period, the permanent molar relationship became less post-normal, but this was reflected only weakly in that of the canines. Throughout development, asymmetry of occlusal relation became more marked with age, an unexplained bias towards less post-normal occlusion on the left side developing in the second phase. The amount of change in this period was related to variations of deciduous molar size, especially that of the upper second molar.
Topics: Adolescent; Cephalometry; Child; Child, Preschool; Dental Arch; Dental Occlusion; Dentition, Mixed; Female; Humans; Longitudinal Studies; Male; Molar; Odontometry; Tooth, Deciduous
PubMed: 3293659
DOI: 10.1179/bjo.15.2.99 -
International Journal of Paediatric... Sep 1994The spread of local anaesthetic solution administered with a pressure syringe has not been studied as extensively in young animals having primary or mixed dentitions as...
The spread of local anaesthetic solution administered with a pressure syringe has not been studied as extensively in young animals having primary or mixed dentitions as in adult animals. The purpose of this investigation was to study the distribution of local anaesthetic solution injected into the periodontal ligament of young dogs. India ink was added to carpules containing 2% lidocaine and 1:100,000 epinephrine, and the spread of solution was examined macroscopically and microscopically. Injections were made with a pressure syringe (Ligmaject) at 58 sites mesial and distal to primary teeth in five dogs aged 3-9 months. Three dogs were killed within 12 hours, the other two after 5 days. Spread of the ink was studied in non-decalcified slabs, in three-dimensional cleared specimens, and in histological sections. The solution usually reached the alveolar bone crest, seeped under the periosteum and alongside vascular channels into bone marrow, reaching natural cavities such as the crypts of tooth buds and the mandibular canal. The ink did not penetrate into the enamel organ or contact the permanent tooth buds. The solution appeared to spread along the path of least resistance, governed by the intricacies of anatomical structures and fascial planes. Therefore the risk of mechanical damage to permanent tooth germs appears to be minimal.
Topics: Anesthesia, Dental; Anesthesia, Local; Animals; Dogs; Epinephrine; Lidocaine; Periodontal Ligament; Periodontium; Tooth Germ; Tooth, Deciduous
PubMed: 7811670
DOI: 10.1111/j.1365-263x.1994.tb00125.x -
American Journal of Orthodontics and... Mar 2001The purpose of this study was to investigate secular changes that may have occurred in dental arch dimensions by comparing a sample of contemporary North American white... (Comparative Study)
Comparative Study
The purpose of this study was to investigate secular changes that may have occurred in dental arch dimensions by comparing a sample of contemporary North American white children (born between 1992 and 1995) in the primary dentition to those children found in an earlier study of North American white children (born between 1946 and 1948). The sample of contemporary children has been followed prospectively since birth and was assessed at 4(1/2) to 5 years of age. Data for the historic sample were obtained from 5-year-old children who were enrolled in the Iowa Growth Study. The 2 samples were similar in terms of geographic location, racial and ethnic backgrounds, and socioeconomic status. To further enhance the comparison and to match the 2 groups, the 2 samples were restricted to white children with a normal overjet (<4 mm) and normal anteroposterior molar relationship, no anterior open bite, and no crossbite. In addition, individuals were excluded if any permanent teeth were erupted. Measurements of maxillary and mandibular arch lengths and intercanine and intermolar arch widths were made, with measurements of overjet and overbite. The results indicated that maxillary and mandibular arch lengths in both sexes were significantly shorter in the contemporary sample; all arch widths were significantly smaller in contemporary boys, but not in girls. These findings suggest that average arch dimensions may be smaller in contemporary children than in past generations. Further research is needed to determine whether smaller arch dimensions are associated with more crowding in the primary, mixed, and permanent dentitions.
Topics: Case-Control Studies; Cephalometry; Child, Preschool; Cohort Studies; Cuspid; Dental Arch; Female; Humans; Incisor; Iowa; Male; Mandible; Maxilla; Molar; Prospective Studies; Reproducibility of Results; Sex Factors; Tooth, Deciduous
PubMed: 11244414
DOI: 10.1067/mod.2001.112260 -
Brazilian Oral Research 2016The aim of the present study was to search for scientific evidence concerning the association between breastfeeding and bottle feeding and risk of malocclusion in mixed... (Review)
Review
The aim of the present study was to search for scientific evidence concerning the association between breastfeeding and bottle feeding and risk of malocclusion in mixed and permanent dentitions. An electronic search was performed in eight databases up to February 2015. Additionally, a gray literature search and hand searches of the reference lists of the selected studies were also carried out. There were no restrictions on language or on year of publication. The methodology of the included articles was evaluated using the Newcastle Ottawa scale. Out of the 817 identified citations, six studies fulfilled the eligibility criteria and were included in the systematic review. One study showed that children with mixed and permanent dentitions breastfed for more than 6 months presented greater mean protrusion of mandibular incisors and inclination of maxillary incisors compared with those breastfed for less than 6 months or those who were bottle-fed (p < 0.05). One study revealed that breastfeeding and bruxism were associated with Class II [OR = 3.14 (1.28 - 7.66)] and Class III [OR = 2.78 (1.21 - 6.36)] malocclusion in children with permanent dentition, while another study showed that an increase in breastfeeding duration was associated with a lower risk of malocclusion in children with both mixed and permanent dentitions (p < 0.001). Three studies did not report any significant association. Risk of bias was high in most selected articles. These findings do not support an association between breastfeeding and bottle feeding and the occurrence of malocclusion in mixed and permanent dentitions.
Topics: Adolescent; Bottle Feeding; Breast Feeding; Child; Child, Preschool; Dentition, Mixed; Dentition, Permanent; Female; Humans; Male; Malocclusion; Risk Assessment; Risk Factors
PubMed: 27050935
DOI: 10.1590/1807-3107BOR-2016.vol30.0022 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Jan 2024To compare and evaluate the difference in maxillary dentition position using an anatomical facebow and jaw movement analyzer. From March to May 2023, 15 medical...
To compare and evaluate the difference in maxillary dentition position using an anatomical facebow and jaw movement analyzer. From March to May 2023, 15 medical interns from Yantai Stomatological Hospital were recruited, including 9 males and 6 females, aged 20-25 years. Digital models and plaster models of maxillary dentition were obtained from the 15 medical interns. The anatomical facebow group (AFB) and jaw movement analyzer group (JMA) were used to transfer the position of the maxillary dentition to the virtual articulator. The virtual occlusal articulator module of exocad denture design software was used to measure the inclination angle of the occlusal plane of the two groups, the distance between the mesio-incisal angle of the left maxillary central incisor and the lateral center point of the lateral condylar sphere of the virtual occlusal articulator, the distance between the mesial buccal cusp of the maxillary first molar and the lateral center point of the lateral condyle sphere of the virtual articulator. The same marks (mesial incisor point of left maxillary central incisor and mesial buccal cusp point of both maxillary first molars) were measured in two groups of maxillary dentition, and the root-mean-square error between 3 points was calculated. The occlusal plane inclination angle in AFB group (9.11°±3.85°) was significantly larger than that in JMA group (4.94°±2.69°) (=10.45, <0.001). There were significant differences between AFB and JMA groups. The distances from the mesial cusp of the left first molar to the lateral center of the left condylar, from the mesial cusp of the left maxillary central incisor to the lateral center of the left condylar[(91.75±3.05), (129.09±4.60) mm]were significantly smaller than those in the JMA group[(95.68±5.45), (132.41±5.64) mm](=-4.48, =0.001; =-4.21, =0.001). In both groups of models, the distance of the mesial cusp of the left maxillary central incisor was (8.81±2.56) mm, and the distance between mesial buccal cusp of maxillary left first molar was (7.56±2.49) mm, the distance between mesial buccal cusp of maxillary right first molar was (7.13±2.77) mm; the root mean square error was (7.93± 2.94) mm. Compared with 0, the difference was statistically significant (=10.45, <0.001). There were differences between the two methods (anatomical facebow and the jaw movement analyzer) for transferring the maxillary dentition position to the three-dimensional space position of the virtual articulator.
Topics: Male; Female; Humans; Dentition; Dental Occlusion; Incisor; Molar; Dentition, Permanent; Maxilla
PubMed: 38172065
DOI: 10.3760/cma.j.cn112144-20230904-00137