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Oral Radiology Oct 2023This study assessed the root proximity in molars and the furcation area (FA) in the first root separation point (RSP) using cone‑beam computed tomography (CBCT) and...
OBJECTIVES
This study assessed the root proximity in molars and the furcation area (FA) in the first root separation point (RSP) using cone‑beam computed tomography (CBCT) and evaluated the association between the furcation area of molars and periodontal status of the patients.
METHODS
A total of 264 molar teeth in 66 participants were included in the study. The control group consisted of 110 molar teeth of participants, and 154 molar teeth were included in periodontitis group, which consisted of only stage II and III periodontitis patients. FA, RSP, and root proximities were measured in axial slices, and bone resorption rates were measured in sagittal slices.
RESULTS
Both maxillary and mandibular molar groups had significantly less FA in periodontitis group than in controls (p < 0.005), and there were significant relationships between the degree of bone resorption in molars and FA and furcation grades (p < 0.001). According to regression analysis, the risk of periodontitis increased by 1.011 times as total FA decreased (p < 0.001), and periodontitis risk of maxillary molar was 1.693 times higher than mandibular molars but not found to be statistically significant (p = 0.152). When assessing the root proximity between molar teeth, maxillary molars showed significantly higher root proximity in CEJs than mandibular molars in both periodontitis and control groups (p < 0.05).
CONCLUSIONS
The results indicate that the association between FA and the degree of bone resorption and root proximity of maxillary molars might be considered as a risk indicator for bone resorption in molars and might play a role during disease progression.
Topics: Humans; Molar; Bone Resorption; Cone-Beam Computed Tomography; Periodontitis
PubMed: 37596499
DOI: 10.1007/s11282-023-00706-6 -
American Journal of Orthodontics and... Dec 2022This study aimed to investigate the dentoalveolar and skeletal changes achieved with a novel miniscrew-supported 3-dimensional maxillary bimetric distalizing arch...
Clinical effectiveness of buccally and palatally anchored maxillary molar distalization: The miniscrew-supported 3-dimensional maxillary bimetric distalizing arch vs the Beneslider.
INTRODUCTION
This study aimed to investigate the dentoalveolar and skeletal changes achieved with a novel miniscrew-supported 3-dimensional maxillary bimetric distalizing arch (3D-MBDA) and the Beneslider. In addition, the study aimed to compare these changes between each other and with an untreated control group.
METHODS
Sixty-five patients with bilateral Class II molar relationship and fully-erupted maxillary second molars were included in the study. Of these patients, 23 received the miniscrew-supported 3D-MBDA (group 1), 21 received the Beneslider (group 2), and 21 served as untreated control subjects (group 3). Lateral cephalometric films and dental casts, taken at the beginning and the end of maxillary molar distalization, were analyzed to study the differences between the groups.
RESULTS
The crown distalization of the first molars was similar between the treatment groups (group 1, 3.1 mm; group 2, 3.3 mm); however, root distalization was significantly more in group 1 (5 mm) when compared with group 2 (1.7 mm). The first molars tipped 6.2° in the mesial direction in group 1 and 8.2° in the distal direction in group 2. The mesiobuccal cusp tip of the first molars extruded for 1.2 mm and increased vertical dimensions in group 2, whereas it intruded for 1.7 mm in group 1. Meanwhile, aforementioned parameters presented insignificant changes throughout the observation period in the control group. Inter-first molar width increased significantly in group 2 (2.7 mm). Distalization time was similar between the groups (group 1, 14 months; group 2, 15 months). The distalization rate was higher in group 2 (0.27 mm/mo) than in group 1 (0.23 mm/mo) measured from the crowns; however, it was similar between the groups (group 1, 0.25 mm/mo; group 2, 0.19 mm/mo) when measured from the trifurcation point.
CONCLUSIONS
The miniscrew-supported 3D-MBDA was more effective in distalizing molar roots and maintaining vertical parameters and dental arch width while tipping the molars mesially. In contrast, the Beneslider distalized molar crowns faster, resulting in significant distal tipping.
Topics: Humans; Molar; Treatment Outcome; Tooth Root; Vertical Dimension
PubMed: 36457217
DOI: 10.1016/j.ajodo.2022.09.009 -
Brazilian Dental Journal 2022This study aimed to analyze the root and root canal morphology of mandibular first and second molars using CBCT images. A total of 2,400 mandibular molars exams were...
This study aimed to analyze the root and root canal morphology of mandibular first and second molars using CBCT images. A total of 2,400 mandibular molars exams were selected from 600 patients aged between 18 and 75 years. The number of roots, number of root canals, and root canal configuration according to the Vertucci classification were verified. Overall, 94.92% of mandibular first molars and 90.17% of mandibular second molars had two separate roots. Among the biradicular molars, the first molars showed a greater incidence of type IV canals in the mesial root and type I in the distal root. In the second molars, the most common canal form was type IV in the mesial root and type I in the distal root. In the triradicular molars, the type IV and type I configurations were the most common in the mesial root of the first molar and second molar, respectively. In both triradicular molars, there was a prevalence of type I canal in the distal and DL roots. Statistical analysis was performed at a significance level of 0.05. The number of roots was correlated with gender (Spearman test), and the canal's configuration with gender and bilaterality (Wilcoxon test). The subpopulation studied has a high incidence of bilateral symmetry and mandibular molars with two roots with two distinct mesial canals and one distal canal. The bilateral configuration is possible to estimate the number of canals, especially in images that are difficult to visualize, such as atresic canals.
Topics: Adolescent; Adult; Aged; Humans; Middle Aged; Young Adult; Cone-Beam Computed Tomography; Dental Pulp Cavity; Mandible; Molar; Tooth Root
PubMed: 36287490
DOI: 10.1590/0103-6440202205105 -
American Journal of Orthodontics and... May 2020This study aimed to compare the 3-dimensional force system produced by transpalatal arch (TPA) mechanics with that produced by a continuous arch (CA) on the expansion of...
INTRODUCTION
This study aimed to compare the 3-dimensional force system produced by transpalatal arch (TPA) mechanics with that produced by a continuous arch (CA) on the expansion of maxillary first molars.
METHODS
A patient's model with 2 molars in 4-mm crossbite had orthodontic appliances bonded to all teeth. The first and the second molars were connected to two 3-dimensional load cells to compare the forces in the transverse and anteroposterior planes (Fx and Fy) and the rotational moments (Mz) produced in both molars by the expanded TPA and by 0.016-in nickel-titanium CA. The data were evaluated using 6 independent t tests, and the net moment at the molar's center of resistance was also calculated.
RESULTS
All forces and moments were different at both molars. At the first molar, CA produced Fx of 2.60 N, Fy of -0.08 N, Mz of -5.16 N·mm, and Net Mz of -5.68 N·mm, whereas the TPA produced Fx of 2.87 N, Fy of -0.60 N, Mz of -22.08 N·mm, and Net Mz of -25.09 N·mm. At the second molar, the TPA did not produce significant forces and moments, whereas the CA produced Fx of -1.00 N, Mz of 3.95 N·mm, Fy of -0.84 N, and Net Mz of -0.67 N·mm.
CONCLUSIONS
Based on our findings in a clinical set up with the specific horseshoe TPA and archwire tested, with the TPA used only on the first molars and the CA used from one second molar to the other, the mechanics produced different expansion forces at the first molar. The TPA produced a larger rotational side effect on the first molar, whereas the CA produced side effects on the second molar.
Topics: Dental Arch; Humans; Malocclusion; Molar; Orthodontic Appliance Design; Orthodontic Appliances; Tooth Movement Techniques
PubMed: 32354434
DOI: 10.1016/j.ajodo.2019.05.017 -
American Journal of Orthodontics and... Dec 2021The purpose of this study was to analyze the treatment effects after molar distalization using modified C-palatal plates with and without second molar eruption and to...
INTRODUCTION
The purpose of this study was to analyze the treatment effects after molar distalization using modified C-palatal plates with and without second molar eruption and to evaluate the three-dimensional position of the molars during long-term retention using cone-beam computed tomography.
METHODS
The study sample comprised 74 third molars in 42 patients. Twenty-seven adolescent patients (mean age, 12.6 years) having 48 maxillary third molars were divided into 2 groups according to the eruption of their second molars: 15 patients with second molar eruption (group 1) and 12 patients without second molar eruption (group 2). Pretreatment, posttreatment, and long-term data (mean, 5.2 years) from cone-beam computed tomography were scanned and compared with control groups.
RESULTS
There was less tipping movement of the first and second molars (0.94° and 3.22°) and distal tipping movement of the third molars (8.91°) in group 1 than in group 2 (4.36°, 7.39°, and 3.08°, respectively), but the treatment time was shorter and the positional change of the third molars was insignificant in group 2. In the long-term, the second molars fully erupted after distalization in group 2, and there was no difference in the third molar position between group 1, group 2, and the control group, except for the vertical position of the third molars in group 1.
CONCLUSIONS
In the long-term, the second molars fully erupted after distalization, and the third molars were in a favorable position. Therefore, these findings suggest that clinicians do not need to extract developing third molars before distalization in adolescents.
Topics: Adolescent; Cephalometry; Child; Humans; Malocclusion, Angle Class II; Maxilla; Molar; Tooth Movement Techniques
PubMed: 34756786
DOI: 10.1016/j.ajodo.2020.06.052 -
The Angle Orthodontist Jan 2022To assess the changes in alveolar bone of the mandibular second molars following molar protraction and investigate the factors associated with the alveolar bone changes.
OBJECTIVES
To assess the changes in alveolar bone of the mandibular second molars following molar protraction and investigate the factors associated with the alveolar bone changes.
MATERIALS AND METHODS
Cone-beam computed tomography of 29 patients (mean age 22.0 ± 4.2 years) who had missing mandibular premolars or first molars and underwent molar protraction were reviewed. Alveolar bone level was measured as the distance from the cementoenamel junction at six points, buccal, lingual, mesiobuccal (MB), mesiolingual (ML), distobuccal (DB), and distolingual (DL), of the second molars at pretreatment (T0) and after molar protraction (T1). Factors associated with alveolar bone changes at the distal and mesial of the second molars were assessed.
RESULTS
Mean alveolar bone changes ranged from -1.2 mm (bone apposition) to 0.8 mm (bone resorption). The presence of a third molar impaction at T0 (P < .001), third molar angulation at T0 (P < .001), and Nolla's stage of third molar at T0 (P = .005) were significantly associated with alveolar bone level changes distal to the second molars. Treatment duration (P = .028) was significantly associated with alveolar bone level changes mesial to the second molar.
CONCLUSIONS
Patients with impacted third molars, third molars at an earlier stage of development, and mesially angulated third molars at pretreatment may have less alveolar bone resorption distal to the second molars following protraction. Patients with increased treatment time may have reduced alveolar bone resorption mesial to the second molars.
Topics: Adolescent; Adult; Bicuspid; Cone-Beam Computed Tomography; Humans; Mandible; Molar; Molar, Third; Tooth, Impacted; Young Adult
PubMed: 34587241
DOI: 10.2319/022321-147.1 -
Odontology Jan 2022The shaping outcomes after instrumentation with rotary and reciprocating glide path and shaping systems were evaluated through micro-computed tomography (Micro-CT)....
The shaping outcomes after instrumentation with rotary and reciprocating glide path and shaping systems were evaluated through micro-computed tomography (Micro-CT). Thirty extracted maxillary first molars were selected. Mesio-buccal canals were randomized into two groups (n = 15): rotary system ProGlider and ProTaper Next X1, X2 (PG-PTN) and reciprocating system WaveOne Gold Glider and WaveOne Gold Primary (WOGG-WOG). Specimens were micro-CT scanned before, after glide path and after shaping. Increase in canal volume and surface area, percentage of removed dentin from the inner curvature, centroid shift and canal geometry variation through ratio of diameter ratios (RDR) and ratio of cross-sectional areas (RA) were measured in the apical and coronal levels and at the point of maximum curvature. The number of pecking motions needed to reach the working length (WL) was recorded. One-way ANOVA and post hoc Turkey-Kramer tests were used (p < 0.05). Post-glide path analysis revealed that in the coronal third, RDR was more favorable to PG and centroid shift was lower for WOGG in the apical third. Post-shaping analysis showed a reduced removal of dentin and a more favorable RA for PTN at point of maximum curvature. The number of pecking motions up to WL resulted in different between groups both for glide path and shaping phases. Despite a higher dentin removal for reciprocating instruments at the point of maximum curvature, both systems seemed to produce well-centered glide path and shaping outcomes. Rotary and reciprocating systems seemed able to respect the original canal anatomy.
Topics: Dental Pulp Cavity; Equipment Design; Gold; Molar; Root Canal Preparation; X-Ray Microtomography
PubMed: 34173078
DOI: 10.1007/s10266-021-00631-2 -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Jun 2021With a case of mesial impaction of maxillary first and second molar, the mechanical analysis and clinical applications of a self-made helical spring for the uprighting...
With a case of mesial impaction of maxillary first and second molar, the mechanical analysis and clinical applications of a self-made helical spring for the uprighting treatment of mesial impacted molars was introduced.
Topics: Humans; Mandible; Maxilla; Molar; Molar, Third; Tooth Movement Techniques; Tooth, Impacted
PubMed: 34041888
DOI: 10.7518/hxkq.2021.03.018 -
Current Medical Imaging 2020To evaluate impacted mandibular third molar tooth region and obtain linear measurements using CBCT images and to assess the relationship between the impacted third molar...
OBJECTIVES
To evaluate impacted mandibular third molar tooth region and obtain linear measurements using CBCT images and to assess the relationship between the impacted third molar and the mandibular canal.
METHODS
CBCT scans of 351 patients (208 females, 143 males) were assessed. Age, gender, and impaction site were recorded for each patient. The relationship of third molars with the vertical axis of second molars, 2nd molar resorption and the relationship between third molar apices and the mandibular canal were assessed. In addition, the distance between ramus and second molar, mesiodistal width of the third molar, the angle between third molar and second molar, and width of the third molar capsule were measured. Binary Logistic Regression, Chi-Square Test, and General Linear Model were used for statistical analysis.
RESULTS
The highest percentage of impaction was found for mesioangular followed by transversal and vertical. The transversal impacted third molars revealed a significant association with adjacent second molar root resorption (p<0.001). There was a statistical significance between the second molar resorption and distance between ramus and second molar (p<0.001). The mesioangular impacted third molars revealed significant relation with the mandibular canal (p<0.05). The most frequent variation found was the dental canal followed by the retromolar canal. In general, higher measurement values were obtained for men when compared to women (p<0.05).
CONCLUSION
CBCT assessment of the third molar region provided useful information regarding impacted mandibular third molar surgery operations.
Topics: Cone-Beam Computed Tomography; Female; Humans; Male; Mandible; Molar; Molar, Third; Tooth, Impacted
PubMed: 33135608
DOI: 10.2174/1573405616666200103094611 -
Medicina (Kaunas, Lithuania) Mar 2021Endodontic microsurgery is a highly predictable treatment option in most cases when conventional endodontic treatment is not feasible. Nevertheless, mandibular molars... (Review)
Review
Endodontic microsurgery is a highly predictable treatment option in most cases when conventional endodontic treatment is not feasible. Nevertheless, mandibular molars are still considered by clinicians to be the most difficult type of teeth, with the lowest success rate. In recent years, endodontic microsurgery has been attempted more frequently with the emergence of modern cutting-edge technologies such as dental operating microscopes, various microsurgical instruments, and biocompatible materials, and the success rate is increasing. This review describes the current state of the art in endodontic microsurgical techniques and concepts for mandibular molars. Notably, this review highlights contemporary equipment, technology, and materials.
Topics: Humans; Microsurgery; Molar
PubMed: 33809673
DOI: 10.3390/medicina57030270