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Dental Press Journal of Orthodontics 2023This study was designed to analyze and compare the cusp and apex movements of the maxillary canines and first molars during canine retraction in the first step of...
OBJECTIVE
This study was designed to analyze and compare the cusp and apex movements of the maxillary canines and first molars during canine retraction in the first step of extraction space closure, and to evaluate if these teeth follow a curvilinear (acceleration and/or deceleration) movement rate.
MATERIAL AND METHODS
Twenty-five patients (23.3 ± 5.1 years of age) were enrolled. The retraction of the maxillary canines was accomplished using nickel-titanium closed coil springs (100gf) on 0.020-in stainless steel archwire. Oblique cephalograms were traced and superimposed on the anatomic best fit of the maxilla (before the retraction [T0], and after one month [T1], three [T3], five [T5] and seven [T7] months). Statistics was based in a normally distributed data. Multilevel procedures were used to derive polynomials for each of the measurements. Student's t-test and one-way repeated measures ANOVA were conducted. The level of significance of 5% was adopted.
RESULTS
Canine cusps and apexes did not follow a quadratic curve regarding horizontal movement (neither accelerate nor decelerate). Canine and molar cusps showed more horizontal movement than apexes (4.80 mm vs. 2.78 mm, and 2.64 mm vs. 2.17 mm, respectively).
CONCLUSIONS
Canine did not accelerate or decelerate overtime horizontally; the cusps and apexes of the canines and molars showed more horizontal movement and larger rate at the beginning of canine retraction, followed by significantly smaller and constant movement rate after the first month.
Topics: Humans; Multilevel Analysis; Cuspid; Molar; Capsaicin; Menthol
PubMed: 37729287
DOI: 10.1590/2177-6709.28.4.e232338.oar -
Anesthesia and Analgesia Jul 2024The trigeminal ganglion (TG) collects afferent sensory information from various tissues. Recent large-scale RNA sequencing of neurons of the TG and dorsal root ganglion... (Comparative Study)
Comparative Study
BACKGROUND
The trigeminal ganglion (TG) collects afferent sensory information from various tissues. Recent large-scale RNA sequencing of neurons of the TG and dorsal root ganglion has revealed a variety of functionally distinct neuronal subpopulations, but organ-specific information is lacking.
METHODS
To link transcriptomic and tissue-specific information, we labeled small-diameter neurons of 3 specific subpopulations of the TG by local application of lipophilic carbocyanine dyes to their innervation site in the dental pulp, cornea, and meninges (dura mater). We then collected mRNA-sequencing data from fluorescent neurons. Differentially expressed genes (DEGs) were analyzed and subjected to downstream gene set enrichment analysis (GSEA), and ion channel profiling was performed.
RESULTS
A total of 10,903 genes were mapped to the mouse genome (>500 reads). DEG analysis revealed 18 and 81 genes with differential expression (log 2 fold change > 2, Padj < .05) in primary afferent neurons innervating the dental pulp (dental primary afferent neurons [DPAN]) compared to those innervating the meninges (meningeal primary afferent neurons [MPAN]) and the cornea (corneal primary afferent neurons [CPAN]). We found 250 and 292 genes differentially expressed in MPAN as compared to DPAN and to CPAN, and 21 and 12 in CPAN as compared to DPAN and MPAN. Scn2b had the highest log 2 fold change when comparing DPAN versus MPAN and Mmp12 was the most prominent DEG when comparing DPAN versus CPAN and, CPAN versus MPAN. GSEA revealed genes of the immune and mitochondrial oxidative phosphorylation system for the DPAN versus MPAN comparison, cilium- and ribosome-related genes for the CPAN versus DPAN comparison, and respirasome, immune cell- and ribosome-related gene sets for the CPAN versus MPAN comparison. DEG analysis for ion channels revealed no significant differences between the neurons set except for the sodium voltage-gated channel beta subunit 2, Scn2b . However, in each tissue a few ion channels turned up with robust number of reads. In DPAN, these were Cacna1b , Trpv2 , Cnga4 , Hcn1 , and Hcn3 , in CPAN Trpa1 , Trpv1 , Cacna1a , and Kcnk13 and in MPAN Trpv2 and Scn11a .
CONCLUSIONS
Our study uncovers previously unknown differences in gene expression between sensory neuron subpopulations from the dental pulp, cornea, and dura mater and provides the basis for functional studies, including the investigation of ion channel function and their suitability as targets for tissue-specific analgesia.
Topics: Animals; Cornea; Meninges; Nociceptors; Mice; Trigeminal Ganglion; Transcriptome; Molar; Mice, Inbred C57BL; Male; Gene Expression Profiling; Dental Pulp
PubMed: 38236765
DOI: 10.1213/ANE.0000000000006816 -
Clinical Anatomy (New York, N.Y.) Sep 2023Lingual nerve (LN) injury during surgical procedures in the third molar region warrants a detailed study of its common pathway and important variations. Therefore, the... (Meta-Analysis)
Meta-Analysis Review
Lingual nerve (LN) injury during surgical procedures in the third molar region warrants a detailed study of its common pathway and important variations. Therefore, the objective of this study was to analyze and compile the multiple anatomical variations of the LN for use in oral and maxillofacial surgery. It is anticipated that the results of the present meta-analysis may help to minimize the possible complications when performing procedures associated with this anatomical entity. Major online databases such as PubMed, Web of Science, Scopus, Embase were used to gather all relevant studies regarding the LN anatomy. The results were established based on a total of 1665 LNs. The pooled prevalence of the LN being located below the lingual/ alveolar crest was found to be 77.87% (95% CI: 0.00%-100.00%). The LN was located above the lingual/ alveolar crest in 8.21% (95% CI: 4.63%-12.89%) of examined nerves. The most common shape of the LN was established to be round with a prevalence of 40.96% (95% CI: 23.96%-59.06%), followed by oval at 37.98% (95% CI: 23.98%-53.02%) and flat at 25.16% (95% CI: 12.85%-39.77%). In conclusion, we believe that this is the most accurate and up-to-date study regarding the anatomy of the LN. The LN was found to be located below the lingual/alveolar crest in 77.87% of the cases. Furthermore, the LN was found to enter the tongue under the submandibular duct in 68.39% of the cases. Knowledge about the anatomy of the LN is crucial for numerous oral and maxillofacial procedures such as during the extraction of the third molar.
Topics: Humans; Lingual Nerve; Lingual Nerve Injuries; Oral Surgical Procedures; Surgery, Oral; Molar, Third
PubMed: 36864652
DOI: 10.1002/ca.24033 -
Journal of Endodontics Sep 2023Cone-beam computed tomography (CBCT) allows three-dimensional evaluation and has high diagnostic accuracy of endodontic conditions. Considering that the most indicated...
INTRODUCTION
Cone-beam computed tomography (CBCT) allows three-dimensional evaluation and has high diagnostic accuracy of endodontic conditions. Considering that the most indicated protocol for endodontics should have smaller field-of-view and higher spatial resolution, a higher radiation dose may be associated. Thus, this study evaluated the accuracy of an optimized CBCT protocol for the detection of intraoperative endodontic complications.
METHODS
An image phantom was custom-made with a human mandible covered with Mix-D and forty mandibular first molars. The teeth were subdivided into 4 groups of endodontic complications which were simulated. All teeth were individually inserted into the left second molar socket of the phantom and CBCT images were acquired with OP 300 unit adjusted to a field-of-view of 6 × 4 cm, 90kVp, and 2 dose protocols: low and high. Furthermore, a titanium implant, a tooth with endodontic treatment, and a cobalt-chromium post were inserted into the empty sockets adjacent to the teeth of interest and additional images were acquired. Four endodontists evaluated the images and indicated the presence of endodontic complications on a 5-point scale. Sensitivity, specificity, and area under the receiver operating characteristic curve were obtained. The different groups were compared by ANOVA and Tukey tests (α = 0.05).
RESULTS
In most conditions, irrespective of the presence of metallic materials, the values of accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve did not differ significantly (P > .05) between the dose protocols.
CONCLUSIONS
Optimized CBCT protocols should be considered for the detection of intraoperative endodontic Diagnostic complications.
Topics: Humans; Endodontics; Endodontists; ROC Curve; Cone-Beam Computed Tomography; Molar
PubMed: 37451335
DOI: 10.1016/j.joen.2023.07.006 -
BMC Oral Health Nov 2023The aim of orthodontic treatment, apart from esthetic and functional corrections, is uniform force distribution. Hence Occlusal analysis using a T scan gives scope for a... (Observational Study)
Observational Study
BACKGROUND
The aim of orthodontic treatment, apart from esthetic and functional corrections, is uniform force distribution. Hence Occlusal analysis using a T scan gives scope for a precisely targeted treatment plan. The T-scan evaluation of occlusal force, time, and location of contacts from initial occlusal contact to maximum intercuspation enables the orthodontist to sequentially balance the occlusal forces on the right and left sides through specific treatment plan options.
OBJECTIVE
The current study aimed to determine the force distribution in the different individuals by using a T-Scan as well as the net discrepancies of forces generated at a maximum intercuspation position in the first molar region between the left and right sides of the mouth.
METHODS
This is a descriptive-correlational study that was carried out in Ras Al Khaimah College of Dental Sciences clinics and Ajman University clinics from January 2020 to September 2022 by using the convenience sampling technique. The T-scan III Novus was employed in this investigation to record multi-bite scans for several patients. T-scan was utilised to examine various malocclusions.
RESULTS
The present study consisted of 158 participants. Analysis of Variance (ANOVA) showed that there is a statistically significant difference in the percentage of force between the three types of malocclusions (I, II, and III) on the right molar side (B-16 and B-46) (p < 0.05). Moreover, the overall discrepancy showed a statistically significant difference in the three types of malocclusion classifications (p < 0.05). On the other hand, there was no statistically significant difference in the percentage of force between B-26 and B-36 (p > 0.05). Post hoc analysis showed a statistically significant difference in the percentage of force between malocclusion classes I and III on the right molar, with a mean difference of 4.11190 (p < 0.05). Similarly, there was a statistically significant difference in B-46 between Malocclusion Classes I and II, 4.01806 (p < 0.05). Additionally, post hoc analysis showed a statistically significant difference between malocclusion classes I and III, with a mean difference of -4.79841 (p < 0.05) on the right molar.
CONCLUSION
The T-Scan is a useful tool for assessing occlusal discrepancies and can be helpful during treatment planning and follow-up, especially for orthognathic surgery patients. A T-scan could be used in orthodontic therapy in a simple and efficient way. Also, it turned out to be a useful tool for diagnosing problems and gave us new information about how therapies work. In this study, T-Scan showed that it can measure occlusal forces in timing in an objective, accurate, and repeated manner. The current study found that T-Scan was better able to report the difference in the percentage of force on the right molar side than on the left side.
Topics: Humans; Bite Force; Dental Occlusion; Cross-Sectional Studies; Malocclusion; Molar
PubMed: 37986159
DOI: 10.1186/s12903-023-03544-4 -
PloS One 2023The aim of this study is to evaluate if single nucleotide polymorphisms (SNPs) in WNT6 and WNT10A are associated with the risk of dental pulp calcification in...
The aim of this study is to evaluate if single nucleotide polymorphisms (SNPs) in WNT6 and WNT10A are associated with the risk of dental pulp calcification in orthodontic patients. This cross-sectional study followed the "Strengthening the Reporting of Genetic Association Studies" (STREGA) guidelines. Panoramic radiographs (pre- and post-orthodontic treatment) and genomic DNA from 132 orthodontic patients were studied. Dental pulp calcification (pulp stones and/or pulp space narrowing) was recorded in upper and lower first molars. The SNPs in WNT6 and WNT10A (rs7349332, rs3806557, rs10177996, and rs6754599) were assessed through genotyping analysis using DNA extracted from buccal epithelial cells. The association between pulp calcification and SNPs were analyzed using allelic and genotypic distributions and haplotype frequencies (p<0.05). Prevalence of dental pulp calcification was 42.4% in the 490 studied molars. In the genotypic analysis, the SNPs in WNT10A showed a statistically significant value for molar calcification (p = 0.027 for rs1017799), upper molar calcification (p = 0.040 for rs1017799) (recessive model), and molar calcification (p = 0.046 for rs3806557) (recessive model). In the allelic distribution, the allele C of the SNP rs10177996 in WNT10A was associated with molar calcifications (p = 0.042) and with upper first molar calcification (p = 0.035). Nine combinations of haplotypes showed statistically significant value (p<0.05). The findings of this study indicates that SNPs in WNT10A and WNT6 are associated with dental pulp calcification in molars after orthodontic treatment and may be considered as biomarkers for dental pulp calcification.
Topics: Humans; Polymorphism, Single Nucleotide; Dental Pulp Calcification; Cross-Sectional Studies; Radiography, Panoramic; Molar; Dental Pulp; Wnt Proteins
PubMed: 37566620
DOI: 10.1371/journal.pone.0288782 -
Morphologie : Bulletin de L'Association... Sep 2023The ABFO study on third molar development is a benchmark in the scientific literature of dental age estimation. In its 30th anniversary, the study has been reproduced in...
The ABFO study on third molar development is a benchmark in the scientific literature of dental age estimation. In its 30th anniversary, the study has been reproduced in the present external validation. Standardized comparative outcomes were obtained and discussed across studies. The sample consisted of 1.087 panoramic radiographs of Brazilian females (n=542, 49.87%) and males (n=545, 50.13%) between 14 and 22.9 years. All available third molars were classified into developmental stages following Mincer's adaptation of Demirjian's system (8 sequential stages, from A to H). The mean chronological age of individuals within each stage was assessed. The probability of an individual being ≥ 18 years was calculated for each third molar, sex and stage. Maxillary and mandibular third molars showed a similar development with an agreement between stages of about 90%. In general, males developed 0.5 years (6 months) earlier than females. The probability of being an adult increased considerably when at least one third molar is in stage G. Maxillary third molars had higher coefficients of determination (right: 0.704; left: 0.702), showing that statistical models with these teeth could explain better the age estimation outcomes. The reproducibility of the ABFO study on third molar development led to reference tables and probability measures for the studied Brazilian population.
Topics: Male; Adult; Female; Humans; Brazil; Reproducibility of Results; Age Determination by Teeth; Forensic Dentistry; Molar, Third; Reproduction
PubMed: 37149420
DOI: 10.1016/j.morpho.2023.04.001 -
Journal of Dentistry Nov 2023The purpose of this in vitro study was to evaluate the internal adaptation, fracture resistance, and fracture pattern of the residual roots and crowns of molars restored...
OBJECTIVE
The purpose of this in vitro study was to evaluate the internal adaptation, fracture resistance, and fracture pattern of the residual roots and crowns of molars restored with computer-aided design/computer-aided manufacturing (CAD/CAM) glass fiber post-cores, and compare them with three other post-core restorations.
MATERIALS AND METHODS
We selected 32 extracted maxillary first molars and divided them into four groups according to the post-core system: traditional casting titanium (Ti) post-cores (TC group); Ti post-cores fabricated with selective laser melting (SLM group); CAD/CAM glass fiber post-cores of the split type (CCS group); and prefabricated glass fiber posts and composite resin cores (PF group). The internal adaptation was analyzed with microcomputed tomography. Teeth were restored with monolithic zirconia crowns and subjected to thermocycling and cyclic loading. A load was applied consistently along the long axis of the tooth until fracture to record the fracture resistance and pattern. For the statistical analysis, one- and two-way analyses of variance, Tukey's post hoc and chi-square tests were performed to compare the differences among the groups.
RESULTS
The CCS, TC, and SLM groups exhibited similar internal adaptations across all sections (P < 0.05). The FP group showed good fit with the root canals in the apical and middle sections but a poor fit with those in the cervical section. The fracture resistance was higher in the CCS, TC, and SLM groups compared to the PF group (P < 0.05). The proportions of restorable fractures in the CCS and PF groups were 62.5% and 50%, respectively. Unrestorable fractures were more frequent in the TC and SLM groups at frequencies of 100% and 87.5%, respectively.
CONCLUSION
The internal adaptation and fracture resistance of the CCS group were similar to those of the TC and SLM groups, and the fracture pattern was mostly restorable, thus meeting the clinical requirements for molar post-core restorations.
CLINICAL SIGNIFICANCE
CCS can be used to restore residual roots and crowns of molars and exhibit high efficacy in terms of adaptability and mechanical properties. More studies are required to evaluate the effectiveness of CCS.
Topics: Humans; Post and Core Technique; X-Ray Microtomography; Tooth Fractures; Crowns; Composite Resins; Glass; Molar; Computer-Aided Design; Dental Stress Analysis; Materials Testing
PubMed: 37659715
DOI: 10.1016/j.jdent.2023.104685 -
L' Orthodontie Francaise Nov 2023Molar incisor hypomineralization (MIH) and hypomineralized second primary molars (HSPM) are qualitative and asymmetric enamel defects. MIH affect at least one permanent... (Review)
Review
INTRODUCTION
Molar incisor hypomineralization (MIH) and hypomineralized second primary molars (HSPM) are qualitative and asymmetric enamel defects. MIH affect at least one permanent first molar and can also be associated with permanent incisors. HSPM affect at least one primary second molar and possibly primary canines. Hypomineralized enamel is characteristic: the enamel prisms are disorganized, less distinct, the interprismatic space is more marked, the mineral density is decreased and the protein content is increased. Currently, etiologies remain unknown but the various studies tend towards a multifactorial model with several systemic, genetic and/or epigenetic factors, acting in a synergistic or additive way.
MATERIAL AND METHOD
The authors highlight the various factors involved in diagnosing MIH and HSPM. A review of the prevalence (French and worldwide) and etiologies of these pathologies is also provided, to enable practitioners to answer any questions parents may have.
CONCLUSION
The knowledge of these different elements on diagnosis, structure, prevalence and etiologies will allow the orthodontist to better collaborate with the dentist but also with the parents in order to ensure an adequate dental and orthodontic management.
Topics: Humans; Molar Hypomineralization; Epigenomics; Incisor; Knowledge; Molar
PubMed: 37930345
DOI: 10.1684/orthodfr.2023.138 -
Australian Endodontic Journal : the... Dec 2023A novel system to classify root and canal morphology was recently introduced (Ahmed et al. 2017). This systematic review aimed to answer the following research question:... (Review)
Review
A novel system to classify root and canal morphology was recently introduced (Ahmed et al. 2017). This systematic review aimed to answer the following research question: Does the Ahmed et al. system provide a more accurate and practical classification of root and canal anatomy compared to other classifications? A literature search was conducted in Google Scholar, Scopus and Wiley Online Library to identify the citation counts for the article entitled 'A new system for classifying root and root canal morphology; doi.org/10.1111/iej.12685'. After removal of duplicates and unrelated articles, 15 studies were included and analysed. All studies compared the Ahmed et al. system with the Vertucci classification. Results revealed that both systems were able to classify simple canal configurations in single-rooted anterior and premolar teeth, disto-buccal and palatal roots of maxillary molars. However, the Ahmed et al. system provided more accurate and comprehensive categorisations of single-rooted teeth with complex canal anatomy, multi-rooted maxillary and mandibular premolars and the mesio-buccal root of maxillary molars. Further evidence on the utility of the Ahmed et al. system is required using other diagnostic devices especially in molars.
Topics: Molar; Root Canal Therapy; Tooth Root
PubMed: 37688283
DOI: 10.1111/aej.12780