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Orthodontics & Craniofacial Research Feb 2024When treating posterior crossbite, the primary goal is to achieve long-term crossbite correction. The majority of studies however focus on relapse of the increase in the... (Meta-Analysis)
Meta-Analysis Review
When treating posterior crossbite, the primary goal is to achieve long-term crossbite correction. The majority of studies however focus on relapse of the increase in the transverse dimension, but not relapse of the crossbite itself, which is an essential outcome. The aim of the present study was to determine long-term stability (2 years minimum post-treatment) of posterior crossbite correction, treated in mixed or early permanent dentitions of growing children. Following registration in PROSPERO (CRD42022348858), an electronic literature search including PubMed, Embase, Web of Science, the Cochrane Library, and a manual search were conducted up to January 2023, to identify longitudinal studies looking into the long-term stability of crossbite correction in growing children. Data extraction and risk of bias assessment were carried out, and subsequently, a random-effects meta-analyses models were used to calculate estimates for relapse of the crossbite and relapse at the transverse level. Twenty-two studies were included, of varying designs and quality, representing 1076 treated patients, with different expansion appliances and protocols. Meta-analysis results showed that 19.5% (95% CI: 15%; 25%) of patients present with relapse of posterior crossbite at long-term follow-up. At the transverse level, 19.3% of the total expansion (including overexpansion) relapsed (95% CI: 13%; 27%) regardless of whether there a was relapse of the crossbite itself. Data from existing studies, with a moderate level of evidence, indicate that the long-term stability of posterior crossbite correction in growing children is unfavourable in roughly 1 in 5 growing children, with crossbite relapse long-term. On average, 19% of the maxillary expansion performed (including overexpansion) relapses long-term, which may occur in cases with or without relapse of the crossbite.
Topics: Child; Humans; Dentition, Permanent; Malocclusion; Palatal Expansion Technique; Recurrence; Dentition, Mixed
PubMed: 38169092
DOI: 10.1111/ocr.12690 -
Anatomical Record (Hoboken, N.J. : 2007) Sep 2020Previous descriptive work on deciduous dentition of primates has focused disproportionately on great apes and humans. To address this bias in the literature, we studied... (Comparative Study)
Comparative Study
Previous descriptive work on deciduous dentition of primates has focused disproportionately on great apes and humans. To address this bias in the literature, we studied 131 subadult nonhominoid specimens (including 110 newborns) describing deciduous tooth morphology and assessing maximum hydroxyapatite density (MHD). All specimens were CT scanned at 70 kVp and reconstructed at 20.5-39 μm voxels. Grayscale intensity from scans was converted to hydroxyapatite (HA) density (mg HA/cm ) using a linear conversion of grayscale values to calibration standards of known HA density (R = .99). Using Amira software, mineralized dental tissues were captured by segmenting the tooth cusps first and then capturing the remainder of the teeth at descending thresholds of gray levels. We assessed the relationship of MHD of selected teeth to cranial length using Pearson correlation coefficients. In monkeys, anterior teeth are more mineralized than postcanine teeth. In tarsiers and most lemurs and lorises, postcanine teeth are the most highly mineralized. This suggests that monkeys have a more prolonged process of dental mineralization that begins with incisors and canines, while mineralization of postcanine teeth is delayed. This may in part be a result of relatively late weaning in most anthropoid primates. Results also reveal that in lemurs and lorises, MHD of the mandibular first permanent molar (M ) negatively correlates with cranial length. In contrast, the MHD of M positively correlates with cranial length in monkeys. This supports the hypothesis that natural selection acts independently on dental growth as opposed to mineralization and indicates clear phylogenetic differences among primates.
Topics: Anatomy, Comparative; Animals; Animals, Newborn; Calcification, Physiologic; Phylogeny; Primates; Tooth; Tooth, Deciduous
PubMed: 31802627
DOI: 10.1002/ar.24326 -
Scientific Reports Jul 2017Hairless dog breeds show a form of ectodermal dysplasia characterised by a lack of hair and abnormal tooth morphology. This has been attributed to a semi-dominant...
Hairless dog breeds show a form of ectodermal dysplasia characterised by a lack of hair and abnormal tooth morphology. This has been attributed to a semi-dominant 7-base-pair duplication in the first exon of the forkhead box I3 gene (FOXI3) shared by all three breeds. Here, we identified this FOXI3 variant in a historical museum sample of pedigreed hairless dog skulls by using ancient DNA extraction and present the associated dental phenotype. Unlike in the coated wild type dogs, the hairless dogs were characterised in both the mandibular and maxillary dentition by a loss of the permanent canines, premolars and to some extent incisors. In addition, the deciduous fourth premolars and permanent first and second molars consistently lacked the distal and lingual cusps; this resulted in only a single enlarged cusp in the basin-like heel (talonid in lower molars, talon in upper molars). This molar phenotype is also found among several living and fossil carnivorans and the extinct order Creodonta in which it is associated with hypercarnivory. We therefore suggest that FOXI3 may generally be involved in dental (cusp) development within and across mammalian lineages including the hominids which are known to exhibit marked variability in the presence of lingual cusps.
Topics: Animals; Bicuspid; Cuspid; Dentition, Permanent; Dogs; Exons; Female; Forkhead Transcription Factors; Fossils; Gene Expression; Hair; Incisor; Male; Mandible; Maxilla; Molar; Mutagenesis, Insertional; Phenotype; Tomography, X-Ray Computed; Tooth, Deciduous
PubMed: 28710361
DOI: 10.1038/s41598-017-05764-5 -
Scientific Reports Jan 2021The evolution of gigantism in extinct otodontid sharks was paralleled by a series of drastic modifications in their dentition including widening of the crowns, loss of...
The evolution of gigantism in extinct otodontid sharks was paralleled by a series of drastic modifications in their dentition including widening of the crowns, loss of lateral cusplets, and acquisition of serrated cutting edges. These traits have generally been interpreted as key functional features that enabled the transition from piscivory to more energetic diets based on marine mammals, ultimately leading to the evolution of titanic body sizes in the most recent forms (including the emblematic Otodus megalodon). To investigate this hypothesis, we evaluate the biomechanics of the anterior, lateral, and posterior teeth of five otodontid species under different loading conditions by using two-dimensional finite element analysis. Stress distribution patterns are remarkably similar among all models under puncture and draw (i.e., when subjected to vertical and lateral forces, respectively). Contrary to expectation, higher average stress values are detected under both loading scenarios in more recent species. Altogether, this suggests little correlation between tooth morphology and key aspects of biomechanical behaviour in otodontids, making it difficult to frame the morphological trend of their dentitions within an adaptive scenario. We propose that this pattern most likely emerged as a non-functional by-product of heterochronic processes driven by selection towards larger body sizes.
Topics: Animals; Biological Evolution; Biomechanical Phenomena; Body Size; Dentition; Finite Element Analysis; Fossils; Sharks; Tooth
PubMed: 33441828
DOI: 10.1038/s41598-020-80323-z -
Journal of Oral Science Jul 2022This study investigated the root and canal morphology of the permanent anterior dentition in a Black South African population.
PURPOSE
This study investigated the root and canal morphology of the permanent anterior dentition in a Black South African population.
METHODS
In total 2,343 permanent anterior teeth were evaluated using cone-beam computed tomography images and described according to the Vertucci and Ahmed et al. classifications. Demographic information, root number and internal canal morphology were recorded. Age and sex associations were made using Fisher's exact test (P < 0.05).
RESULTS
All anterior teeth were single-rooted (100%). The most frequent configuration in maxillary anteriors was a single canal (Vertucci Type I/MXA). In mandibular anteriors, single canal configurations (Type I/MDA) predominated, however 36.6% of mandibular central and 33.9% of lateral incisors displayed two canals. Older subjects (>40 years) demonstrated single canals more than younger subjects (P = 0.0004). Females displayed variations more compared to males (P = 0.002). The two classifications were found to be comparable for evaluation of permanent anterior teeth. Complex configurations were better described using the newer system.
CONCLUSION
The permanent anterior teeth of this population exhibited exclusively single roots and diverse internal characteristics. Clinicians should be aware of anatomical variations, particularly in mandibular incisors, as these may result in adverse endodontic outcomes if not taken into consideration by the treating practitioner.
Topics: Cone-Beam Computed Tomography; Dental Pulp Cavity; Dentition; Female; Humans; Male; South Africa; Tooth Root
PubMed: 35644562
DOI: 10.2334/josnusd.22-0027 -
Journal (Canadian Dental Association) 2014
Review
Topics: Alveolar Process; Child; Dental Occlusion, Traumatic; Dentition, Permanent; Diagnosis, Differential; Humans; Incisor; Tooth Injuries; Tooth Movement Techniques
PubMed: 25192445
DOI: No ID Found -
Indian Journal of Dental Research :... 2020One of the crucial challenges that any present-day general dentist confronts is the treatment determination between extracting a tooth and placement of a dental implant...
One of the crucial challenges that any present-day general dentist confronts is the treatment determination between extracting a tooth and placement of a dental implant or by conserving the natural tooth with an interdisciplinary approach. The rising concern amongst the patients towards preserving their dentition has driven the clinicians towards providing treatment options that are more appropriate and conservative and at the same time does not hamper its functional needs. This report highlights one such way of preserving the periodontally compromised natural tooth with just resecting the diseased part of it and also conserving the proprioceptive capacity of the tooth. One-year of regular follow up and maintenance paving way to a healthy periodontium and complete resolution of mobility concerning the affected tooth is described. This report also provides information on root resection in a mandibular molar as a viable and a definitive treatment modality, providing better access to the remaining tooth structure and thereby enabling successive prosthetic rehabilitation.
Topics: Furcation Defects; Humans; Mandible; Molar; Periodontium; Tooth Extraction; Tooth Root
PubMed: 33433527
DOI: 10.4103/ijdr.IJDR_91_18 -
Journal of Public Health Dentistry Sep 2018To compare common measures for dental caries in longitudinal caries research in support of a new measure, the Total Observed Caries Experience (TOCE). (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To compare common measures for dental caries in longitudinal caries research in support of a new measure, the Total Observed Caries Experience (TOCE).
METHODS
TOCE was calculated as the total number of decayed or filled teeth ever observed. TOCE was compared to dmft, DMFT, and the prevalence of untreated decay using data from a 4-year, cluster randomized community-based caries prevention program. Outcomes were analyzed using generalized estimating equations and assessed change over time and effects across treatment groups.
RESULTS
For TOCE and DMFT, the risk of caries over time increased. In contrast, risks decreased for dmft and the prevalence of untreated decay, driven largely by decayed primary teeth being exfoliated. Effects across treatment groups showed increased risk for some outcomes and attenuated risks in others; however, treatment effects for TOCE were more in line with expected results when compared with controls.
CONCLUSIONS
TOCE accounts for caries on primary and permanent dentition and is not subject to bias due to exfoliation. It can be used as a robust measure to evaluate community-based caries prevention programs.
Topics: DMF Index; Dental Caries; Dentition, Permanent; Humans; Prevalence; Tooth, Deciduous
PubMed: 30114726
DOI: 10.1111/jphd.12284 -
Journal of Dentistry Nov 2023To explore the variability of tooth wear progression at the surface-, tooth- and patient-level over a period of three years three years using in vivo 3D-measurements of...
Inter- and intra-variability in tooth wear progression at surface-, tooth- and patient-level over a period of three years: A cohort study: Inter- and intra-variation in tooth wear progression.
OBJECTIVE
To explore the variability of tooth wear progression at the surface-, tooth- and patient-level over a period of three years three years using in vivo 3D-measurements of full dentitions amongst patients with moderate to severe tooth wear and without demand for restorative rehabilitation.
METHODS
Fifty-five eligible patients with moderate to severe tooth wear had intra-oral scans taken using either the 3 M True Definition Intraoral Scanner or the 3 M Lava Chairside Oral Scanner. The maximum height loss (µm) per cusp/incisal/palatal surface at unrestored surfaces was measured using the 3D Wear Analysis (3DWA)-protocol with Geomagic Qualify, resulting in sixty-four measurements per dentition. Data was visualized using box plots. Correlation was calculated between tooth wear progression rates of different tooth types and surfaces.
RESULTS
Thirty patients with scans at intake and after three years were included (38 ± 8 years, 77% M, 23% F). Mean observation time was 3.1 ± 0.2 years. Surface measurements (N = 1,615) showed a high deviation and a high number of outliers at all surfaces, indicating large variability amongst the surfaces, tooth types and patients with tooth wear progression rates. Correlations between regions were very low: anterior-molar region -0.219, anterior-premolar region 0.116 and premolar-molar region 0.113. Correlations between the surfaces of molars were also low (between 0.190 and 0.565).
CONCLUSIONS
In a group of patients with moderate to severe tooth wear, large differences in wear progression were found within and amongst patients. Tooth wear progression is therefore highly individualized and can be very localized.
CLINICAL SIGNIFICANCE
This study confirms the necessity of individual management of patients with moderate to severe tooth wear. Effective monitoring of tooth wear is important when deciding the timing and need for restorative intervention.
CLINICAL TRIAL REGISTRATION NUMBER
NCT04790110.
Topics: Humans; Cohort Studies; Tooth Wear; Tooth Attrition; Molar; Bicuspid
PubMed: 37683799
DOI: 10.1016/j.jdent.2023.104693 -
Clinical and Experimental Dental... Feb 2022To evaluate the relationship between gingival phenotype and tooth location based on selected index teeth ("Ramfjord") and assess possible differences between women and...
OBJECTIVES
To evaluate the relationship between gingival phenotype and tooth location based on selected index teeth ("Ramfjord") and assess possible differences between women and men.
MATERIAL AND METHODS
Thirty-six women and 20 men voluntarily participated in this investigation with an average age of 23 years (min: 19; max: 37). Gingival phenotypes (GP) were assessed by transparency of a periodontal probe through the buccal gingival margin.
RESULTS
A comparable and similar GP on all index teeth was only found in seven out of the 56 subjects, that is, thin or thick only: Five participants (three male/two female) showed a uniform and constantly thick and two females a constantly thin GP. While the majority of molars (94.6%; p = 0.006) showed a thick GP, premolars (61.6%; p = 0.09) as well as incisors (70.5%; p = 0.046) were predominantly categorized as thin. In addition, significantly thicker GP was in general observed for maxillary teeth (p = 0.001) but without differences between genders (p = 0.722).
CONCLUSION
No constant GP can be expected within one dentition. The use of the "Ramfjord teeth" may serve as a quick overview and reliable method to screen GP distribution.
Topics: Adult; Female; Gingiva; Humans; Incisor; Male; Phenotype; Tooth Crown; White People; Young Adult
PubMed: 34766469
DOI: 10.1002/cre2.482