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Head & Face Medicine Mar 2023Morphological analysis of permanent anterior dentition is essential for achieving an ideal treatment outcome and avoiding unnecessary failure. This study aimed to...
PURPOSE
Morphological analysis of permanent anterior dentition is essential for achieving an ideal treatment outcome and avoiding unnecessary failure. This study aimed to analyze the morphologies of anterior teeth in the Chinese population in depth.
METHODS
In this retrospective study, 4309 anterior teeth from 401 Chinese patients were investigated using cone-beam computed tomography (CBCT) from 2019-2021. We summarized the morphological characteristics of the anterior teeth in terms of the root length, cementoenamel junction curvature (CEJ-C), root furcation and canal variations.
RESULTS
We found that the root lengths of the maxillary anterior incisors were similar (13.3 mm), while the root lengths of the mandibular central (12.2 mm) and lateral incisors (13.4 mm) varied significantly (p < .0001). Both the maxillary (16.6 mm) and mandibular canines (15.5 mm) were found to have greater root lengths than the corresponding incisors (p < .0001). The CEJ-C was significantly greater around incisors (2.5 mm) than around the canines (2.0 mm) in the maxilla (p < .0001), while the curvature remained similar in mandibular anterior teeth (1.8 mm). Root furcation was observed in mandibular canines and lateral incisors. Moreover, all types of Vertucci's classification in anterior dentitions were observed, while two other new types were found. Among them, the maxilla was only observed to exhibit types I, II, III, and ST II, while the mandible was found to exhibit almost all types. However, Type I still accounts for the majority of dentitions.
CONCLUSIONS
Morphological analysis of permanent anterior dentition revealed diversity in the tooth length, CEJ-C, furcation proportion, and canal variations. In general, mandibular anterior teeth showed a more complex structure than maxillary teeth.
Topics: Humans; Dentition, Permanent; Dental Pulp Cavity; Retrospective Studies; East Asian People; Incisor; Malocclusion; Cone-Beam Computed Tomography; Tooth Root
PubMed: 36959644
DOI: 10.1186/s13005-023-00357-2 -
Journal of Orthodontics Mar 2016To test the applicability of the Tanaka and Johnston equation for prediction of the mesiodistal width of unerupted permanent teeth in a Sudanese population and to...
OBJECTIVE
To test the applicability of the Tanaka and Johnston equation for prediction of the mesiodistal width of unerupted permanent teeth in a Sudanese population and to develop a new prediction equation for this specific population if necessary.
DESIGN
A descriptive, cross-sectional study.
SETTINGS
School-based study.
SUBJECTS AND METHODS
Two hundred and fifty subjects (118 males and 132 females) age 13 - 19 years were randomly selected from two public secondary high schools in Khartoum State. Mesiodistal widths of the upper and lower permanent canines, first and second premolars (CPM) as well as the mandibular permanent incisors (MPI) were measured manually on the dental casts using a digital caliper. The predicted values of the mesiodistal widths were statistically compared with the respective actual sum of the canine and premolars of the same quadrant.
RESULTS
Moderate correlation coefficients were found between the sum of the mesiodistal width of the MPI and the sum of the CPM in males (0.618 for mandibular arch and 0.626 for maxillary arch) and females (0.726 for mandibular arch and 0.680 for maxillary arch). A low coefficient of determination was recorded (0.45 and 0.48) in both jaws for combined genders.
CONCLUSIONS
The Tanaka and Johnston equations overestimated the actual mesiodistal width of CPM in both arches for males and females. New prediction equations with more accurate regression parameters were proposed for the Sudanese population.
Topics: Adolescent; Bicuspid; Cross-Sectional Studies; Cuspid; Dentition, Mixed; Female; Humans; Incisor; Male; Odontometry; Tooth, Unerupted; Young Adult
PubMed: 26778242
DOI: 10.1179/1465313315Y.0000000021 -
Archives of Oral Biology Nov 2023This study assessed the validity of dimensions in posterior dentition for sex estimation in forensic contexts. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
This study assessed the validity of dimensions in posterior dentition for sex estimation in forensic contexts.
DESIGN
A systematic review was established following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). After assessing the risk of bias and methodological quality with the QUADAS-2 system, the data were subjected to statistical tests for a meta-analysis of diagnostic accuracy and I to verify the heterogeneity.
RESULTS
The search resulted in 15 studies that underwent qualitative testing, all were selected for quantitative analysis. The papers included: the mesiodistal of the upper first molar, lower first molar, and upper second molar, and the buccolingual of the upper first molar and upper second molar. The results showed that sensitivity and specificity rates were lower with the mesiodistal diameter, with rates of 0.577 for the lower first molar, 0.674 for the upper first molar, and 0.698 for the upper second molar, while the rates were higher with the buccolingual diameter, with 0.724 for the upper first molar, and 0.743 for the upper second molar. The power to estimate sex is greater for males than for females. High heterogeneity was detected among the studies of almost all dimensions, except sensibility for the lower first molar and specificity for the upper second molar.
CONCLUSIONS
None of the dimensions reached an accuracy of ≥80%, however, so they are not a reliable method for sex estimation in forensic practice.
Topics: Male; Female; Humans; Dentition; Sex Characteristics; Molar; Dentition, Permanent; Tooth Crown
PubMed: 37611493
DOI: 10.1016/j.archoralbio.2023.105782 -
Anatomical Record (Hoboken, N.J. : 2007) Feb 2020Sharks of Late Paleozoic oceans evolved unique dentitions for catching and eating soft bodied prey. A diverse but poorly preserved clade, edestoids are noted for...
Sharks of Late Paleozoic oceans evolved unique dentitions for catching and eating soft bodied prey. A diverse but poorly preserved clade, edestoids are noted for developing biting teeth at the midline of their jaws. Helicoprion has a continuously growing root to accommodate >100 crowns that spiraled on top of one another to form a symphyseal whorl supported and laterally braced within the lower jaw. Reconstruction of jaw mechanics shows that individual serrated crowns grasped, sliced, and pulled prey items into the esophagus. A new description and interpretation of Edestus provides insight into the anatomy and functional morphology of another specialized edestoid. Edestus has opposing curved blades of teeth that are segmented and shed with growth of the animal. Set on a long jaw the lower blade closes with a posterior motion, effectively slicing prey across multiple opposing serrated crowns. Further examples of symphyseal whorls among Edestoidae are provided from previously undescribed North American examples of Toxoprion, Campyloprion, Agassizodus, and Sinohelicoprion. The symphyseal dentition in edestoids is associated with a rigid jaw suspension and may have arisen in response to an increase in pelagic cephalopod prey during the Late Paleozoic. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 303:363-376, 2020. © 2018 American Association for Anatomy.
Topics: Animals; Bite Force; Dentition; Feeding Behavior; Fossils; Jaw; Sharks; Tooth
PubMed: 30536888
DOI: 10.1002/ar.24046 -
GigaScience Mar 2022Reptiles exhibit a large heterogeneity in teeth morphology. The main variability comprises the different tooth shape, the type of tooth attachment to the underlying...
BACKGROUND
Reptiles exhibit a large heterogeneity in teeth morphology. The main variability comprises the different tooth shape, the type of tooth attachment to the underlying bone, or the ability to replace the teeth.
FINDINGS
Here, we provide full datasets of microtomography scans and 3D models of reptilian dentitions and skulls. We selected representative species for each of 9 reptilian families on the basis of their characteristic dental features. Because there are ≥4 different types of tooth-bone attachments, ranging from the mammalian-like thecodont attachment found in crocodilians to the simple acrodont implantation observed in some lizards, we aimed to evaluate species with different types of tooth-bone attachments. Moreover, another interesting feature varying in reptilian species is the complexity of tooth shape or the number of tooth generations, which can be associated with the type of tooth attachment to the jawbone. Therefore, selected model species also include animals with distinct tooth morphology along the jaw or different number of tooth generations. The development of tooth attachment and relationship of the tooth to the jaw can be further analysed in detail on a large collection of pre-hatching stages of chameleon. Next, we introduce different possibilities for how these datasets can be further used to study tooth-bone relationships or tooth morphology in 3D space. Moreover, these datasets can be valuable for additional morphological and morphometric analyses of reptilian skulls or their individually segmented skeletal elements.
CONCLUSIONS
Our collection of microcomputed tomography scans can bring new insight into dental or skeletal research. The broad selection of reptilian species, together with their unique dental features and high quality of these scans including complete series of developmental stages of our model species and provide large opportunities for their reuse. Scans can be further used for virtual reality, 3D printing, or in education.
Topics: Animals; Dentition; Humans; Lizards; Mammals; Skull; Tooth; X-Ray Microtomography
PubMed: 35254425
DOI: 10.1093/gigascience/giac016 -
European Archives of Paediatric... Dec 2021Dental trauma is a highly prevalent problem worldwide. The aim of this study was to describe characteristics of trauma to anterior primary teeth and its sequelae for...
BACKGROUND/AIM
Dental trauma is a highly prevalent problem worldwide. The aim of this study was to describe characteristics of trauma to anterior primary teeth and its sequelae for primary and successor teeth over a 10-year period of assistance at the paediatric dental traumatology clinic in the State University of Rio de Janeiro, Brazil.
MATERIALS AND METHODS
The data were obtained from the dental records of children assisted from 2006 to 2016. Inclusion criteria were trauma to anterior primary teeth; aged <1 to 9 years at the time of trauma; and at least one follow-up appointment. The data concerning traumatized teeth, child's age, soft tissue injuries, types of traumatic dental injuries and sequelae in both dentitions were collected.
RESULTS
Of the 1230 dental records, 483 (39.3%) were eligible, consisting of 815 teeth. The mean age at the time of trauma was 37.4 months (239 males and 244 females). The most important characteristics were: tooth 51 was most affected; falls, at home, on a ceramic floor, were the main cause; gingival laceration, enamel fracture and intrusive luxation were the most frequent types of trauma; premature tooth loss of primary teeth and enamel discoloration in their successor were the most frequent sequelae; and injuries in the periodontal tissue were demonstrated as the highest risk for sequelae in successors (OR, 3.798; p< 0.001).
CONCLUSIONS
Most traumatic injuries occur in young children, in their home environment. Consequences for the primary teeth were more frequent compared to the permanent successor tooth. Traumatized primary teeth involving periodontal tissue have more chances to result in sequelae to their successor teeth.
Topics: Brazil; Child; Child, Preschool; Dentition, Permanent; Female; Humans; Male; Retrospective Studies; Tooth Avulsion; Tooth Injuries; Tooth, Deciduous
PubMed: 34313973
DOI: 10.1007/s40368-021-00652-z -
Romanian Journal of Morphology and... 2023Dental transposition is an anomaly of eruption which is usually seen in the maxilla and rarely in the mandible. The mandibular lateral incisor's transposition with the...
Dental transposition is an anomaly of eruption which is usually seen in the maxilla and rarely in the mandible. The mandibular lateral incisor's transposition with the permanent canine has a prevalence of less than 0.03%. The following case presents an even rarer situation, of a right lateral mandibular incisor that erupted in the place of the first premolar, in transposition with the temporary canine. In the first phase, a series of extractions have been performed, to ensure the necessary free space for moving the lateral incisor closer to its appropriate place, and after that a fixed orthodontic appliance was used. The biomechanics for intra-arch tooth movement was ingenious enough to ensure a perfect alignment of all permanent teeth and a functional Class I canine and molar final occlusion. Early intervention and successful move of the permanent canine in its correct position ensured the functionality of the mandibular movements and a good long-term prognosis.
Topics: Humans; Incisor; Dentition, Mixed; Bicuspid; Cuspid; Dentition, Permanent; Maxilla; Mandible
PubMed: 37867361
DOI: 10.47162/RJME.64.3.15 -
Acta Odontologica Scandinavica Nov 2021The aim of this study was to evaluate the effect of periodontal inflammation on the approximal plaque pH after a sucrose rinse.
OBJECTIVES
The aim of this study was to evaluate the effect of periodontal inflammation on the approximal plaque pH after a sucrose rinse.
MATERIALS AND METHODS
Thirty-two periodontitis patients (aged 38-72 years; 9M/23F) were included. All patients were in need of periodontal surgery. Two non-adjacent interdental spaces, one healthy (no bleeding on probing [BoP] and probing pocket depth [PPD] < 4 mm) and one periodontally diseased (BoP and PPD ≥5 mm) were selected. Before and after surgery, the approximal plaque pH was measured before and after 2, 5 and 10 min after a 1-min rinse with sucrose solution.
RESULTS
In periodontally diseased interdental spaces, a significant pH drop was seen 5 min after rinsing. In healthy spaces and after surgery, a significant pH drop was seen after 2 min. A multilevel regression analysis showed that greater probing pocket depths were significantly associated with pH change measured 5 min after rinsing ( < .05). Further on, the approximal pH drop after a sucrose rinse tended to be delayed in dentitions with ≥10% of PPD ≥5 mm ( = .052).
CONCLUSIONS
The results suggest that an ongoing periodontal inflammation could temporarily neutralize acidic metabolic products after a sugar challenge. This may further suggest that plaque pH measured after a sugar rinse might be used to identify an ongoing periodontal disease.
Topics: Dental Plaque; Dentition; Humans; Hydrogen-Ion Concentration; Periodontitis; Sugars
PubMed: 33956555
DOI: 10.1080/00016357.2021.1921258 -
Orthodontics & Craniofacial Research Nov 2019To clarify the mechanics of tooth movement in mesialization of the whole mandibular dentition when changing the force angulation.
OBJECTIVES
To clarify the mechanics of tooth movement in mesialization of the whole mandibular dentition when changing the force angulation.
SETTING
A finite element method was used to simulate long-term movements of the whole mandibular dentition.
MATERIAL AND METHODS
Tooth movement was simulated by accumulating the initial displacement, which was produced by elastic deformation of the periodontal ligament. Mesial forces of 3 N were applied to the second molar bracket at -30°, -15°, 0°, 15° and 30° to the occlusal plane.
RESULTS
The whole dentition and occlusal plane were rotated depending on the direction of the force with respect to the centre of resistance (CR). At a force angulation of -30°, the line of action of the force passed near the CR, and the whole dentition translated without rotation of the occlusal plane. The second molar tipped buccally due to a clearance gap between the archwire and bracket slot. When increasing a force angulation from -30°, the line of action of the force passed above the CR, and thereby, the occlusal plane rotated clockwise. This rotation of the whole dentition induced tipping of the individual teeth. Buccal tipping of the molar due to an elastic deformation of the archwire was prevented by using a lingually pre-bent archwire.
CONCLUSIONS
Careful selection of force angulation and biomechanics is essential to obtain proper tooth movement in total mesialization of the mandibular dentition.
Topics: Dentition; Finite Element Analysis; Molar; Tooth; Tooth Movement Techniques
PubMed: 31230415
DOI: 10.1111/ocr.12331 -
International Journal of Paediatric... Sep 1997The first aim of this study was to collect a large sample of radiographs from children with congenitally missing teeth (CMT) in the primary dentition and to analyse the... (Comparative Study)
Comparative Study
The first aim of this study was to collect a large sample of radiographs from children with congenitally missing teeth (CMT) in the primary dentition and to analyse the local relationship between agenesis of a primary tooth and the presence/absence of its permanent successor. The second aim was to compare, in the same sample, the pattern of agenesis in the primary dentition with the developmental pattern seen in the permanent dentition. 124 dentists from 72 municipalities contributed to the investigation of a total of 213 children. The dentists were asked to lend existing radiographic material from patients with agenesis in the primary dentition. The analysis of the local occurrence of agenesis showed that agenesis of a primary incisor was often but not always followed by agenesis of the succedaneous tooth. In the molar region, agenesis of a primary tooth was in all cases but one followed by agenesis of the succedaneous tooth. Comparison of the pattern of CMT in the primary dentition with the pattern of tooth presence/absence in the permanent dentition in a group of 33 patients, for whom complete radiographic material was available showed that agenesis always occurred in the permanent dentition and that the pattern of agenesis in the permanent dentition differed from that in the primary dentition. Incisors were most frequently missing in the primary dentition and premolars in the permanent dentition. The number of congenitally missing teeth was substantially larger in the permanent dentition that in the primary dentition. Also, permanent teeth that are very rarely congenitally missing were missing in this sample, characterized by the occurrence of agenesis in the primary dentition.
Topics: Adolescent; Anodontia; Chi-Square Distribution; Child; Child, Preschool; Denmark; Dentition, Permanent; Female; Humans; Incidence; Male; Radiography; Tooth, Deciduous; Urban Population
PubMed: 9482038
DOI: 10.1046/j.1365-263x.1997.00230.x