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International Dental Journal Oct 2023The early or delayed surgical removal of an asymptomatic lower third molar (M3) in orthodontic patients remains controversial. This study aimed to determine the changes...
OBJECTIVES
The early or delayed surgical removal of an asymptomatic lower third molar (M3) in orthodontic patients remains controversial. This study aimed to determine the changes in the impacted level of M3 such as angulation, vertical position, and eruption space, after orthodontic treatment in 3 groups, namely non-extraction (NE), first premolar (P1) extraction, and second premolar (P2) extraction.
METHODS
Relevant angles and distances related to 334 M3s from 180 orthodontic patients were assessed pre- and posttreatment. Angle between lower second molar (M2) and M3 (M3-M2) was used for evaluating M3 angulation. For M3 vertical position, distances from occlusal plane to the highest cuspid (Cus-OP) and fissure (Fis-OP) of M3 were used. Distances from the distal surface of M2 to anterior border (J-DM2) and centre (Xi-DM2) of the ramus were used for assessing M3 eruption space. Pre- and posttreatment values of the angle and distance in each group were compared using a paired-sample t test. Measurements of the 3 groups were compared using analysis of variance. Hence, multiple linear regression (MLR) analysis was used to determine significant factors that impacted changes in M3s' related measurements. Independent factors used for MLR analysis included sex, treatment starting age, pretreatment respective angle/distance, and premolar extraction (NE/P1/P2).
RESULTS
M3 angulation, vertical position, and eruption space at posttreatment were significantly different from those at pretreatment in all 3 groups. MLR analysis showed that P2 extraction significantly improved M3 vertical position (P < .05) and eruption space (P < .001). P1 extraction significantly decreased Cus-OP (P = .014) and eruption space (P < .001). Treatment starting age was significant factor that affected Cus-OP (P = .001) and M3 eruption space (P < .001).
CONCLUSIONS
After orthodontic treatment, M3 angulation, vertical position, and eruption space changed in favour of the impacted level. These changes in the 3 groups were clearer in order: NE, P1, and P2, respectively.
Topics: Humans; Molar, Third; Tooth Extraction; Molar; Dental Care; Tooth Eruption; Tooth, Impacted; Mandible
PubMed: 36868979
DOI: 10.1016/j.identj.2023.01.006 -
European Journal of Orthodontics Nov 2023During orthodontic therapy, bond failure of molar tubes may delay treatment. With the high failure rate of molar tubes, alternative bonding techniques were tested to... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
During orthodontic therapy, bond failure of molar tubes may delay treatment. With the high failure rate of molar tubes, alternative bonding techniques were tested to improve bond strength.
OBJECTIVES
To compare the failure rates of molar tubes bonded with conventional and alternative bonding techniques by adding a layer of compomer adhesive at the molar/tube interface.
TRIAL DESIGN
Single-centre, single-blinded, split-mouth, randomized clinical trial.
METHODS
Patients aged 12 years or older, who required fixed appliance orthodontic treatment without extraction and with no occlusal interference were eligible to participate. They were allocated randomly using a simple non-stratified split-mouth design with a 1:1 allocation ratio. Blinding was only possible for the patients and data analysts. Molar tubes bonded with the modified bonding technique had an additional layer of compomer at the occlusal molar/tube interface. The patients were followed-up for nine months. Outcome measures included the survival time of molar tubes and the number of molar tubes debonded. The bond failure of molar tubes was analyzed using Kaplan-Meier and Cox regression analysis (P < 0.05).
RESULTS
Thirty patients were recruited, randomized, and analyzed (mean age 20.33 years). The failure rate of molar tubes bonded with the modified bonding technique was 4.2 per cent and that of molar tubes bonded with the conventional bonding technique was 6.7 per cent. This difference was not statistically significant (P > 0.05). The dental arch and molar type were found to be as significant predictors for molar tube failure rate. No harm was detected during treatment.
LIMITATIONS
The effect of compomer to reduce enamel demineralization was not tested.
CONCLUSIONS AND IMPLICATIONS
The modified bonding technique did not significantly reduce the failure rate of molar tubes. The molar tubes bonded on the upper arch and second molars are more susceptible to debond.
REGISTRATION
The trial was registered with ClinicalTrials.gov on 21 May 2022 (Registration number: NCT05391386).
FUNDING
This research did not receive any funding.
Topics: Humans; Young Adult; Adult; Dental Bonding; Compomers; Dental Enamel; Molar; Orthodontic Appliances, Fixed; Orthodontic Brackets; Resin Cements
PubMed: 37467348
DOI: 10.1093/ejo/cjad029 -
Journal of Endodontics Dec 2023This study aimed to assess the fracture resistance of mandibular first molars after preparation with 3 different access cavity designs and 2 rotary systems using finite...
INTRODUCTION
This study aimed to assess the fracture resistance of mandibular first molars after preparation with 3 different access cavity designs and 2 rotary systems using finite element analysis.
METHODS
Six 3-dimensionally printed mandibular first molars simulating natural teeth received traditional, conservative, and ultraconservative (truss) access cavity preparations. The root canals in each group were instrumented with either XP-Endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) or TruNatomy (Dentsply Sirona, Ballaigues, Switzerland) rotary files. The models were individually digitized, and micro-computed tomographic scans were transferred to Mimics software (Materialise NV, Leuven, Belgium) to create a geometric model of the tooth. The designed model was exported to 3-matic software (Materialise NV), and STL files were transferred to Geomagic Design X (3D Systems, Rock Hill, SC). Point cloud data were used for surfacing and transferred to ANSYS software (Ansys, Canonsburg, PA). A 200-N superficial force was applied vertically to the buccal cusps and central fossa, and the maximum and minimum equivalent von Mises stress values were calculated and reported.
RESULTS
The traditional and ultraconservative access cavity designs yielded the highest and the lowest von Mises stress values, respectively. In the ultraconservative cavity design, the stress values in pericervical dentin were lower in canal preparation with TruNatomy compared with XP-Endo Shaper. In the traditional and conservative cavity designs, stress was lower in the first 2 mm from the cementoenamel junction in the XP-Endo Shaper group and in the next 3 mm in the TruNatomy group.
CONCLUSIONS
Stress was lower in the ultraconservative and conservative cavity designs compared with the traditional design. Also, root canal preparation with TruNatomy yielded lower stress values in general compared with XP-Endo Shaper.
Topics: Dental Pulp Cavity; Finite Element Analysis; X-Ray Microtomography; Molar; Root Canal Preparation
PubMed: 37804945
DOI: 10.1016/j.joen.2023.09.014 -
BMC Oral Health Sep 2023This study aimed to assess the root canal morphology of primary molars using cone-beam computed tomography (CBCT).
BACKGROUND
This study aimed to assess the root canal morphology of primary molars using cone-beam computed tomography (CBCT).
METHODS
This cross-sectional study evaluated 60 maxillary and mandibular primary first and second molars on CBCT scans of patients retrieved from the archives of Hamadan School of Dentistry between 2018-2020. The teeth were evaluated regarding the number of roots and canals, canal type according to the Vertucci's classification, and root surface concavities. Data were analyzed descriptively and by independent t-test.
RESULTS
The most frequent number of canals and roots in the maxillary right and left first molars was 3 canals (60%) and 3 roots (80%). These values were 4 canals (80%) and 5 canals (50%) with 3 roots in the maxillary right and left second molars, respectively, 4 canals (100%) and 2 roots (50%), and 3 canals (60%) and 2 roots (50%) in mandibular right and left first molars, respectively, and 4 canals (92.3%) and 3 roots (61.5%) in mandibular right and left second molars. Vertucci's type IV was the most common canal type in mesial and distal canals, type I was the most common in mesiobuccal, mesiolingual, distobuccal, and distolingual, and types I and II were the most common in the palatal canal. The maximum and minimum concavities were noted in the buccal (26.7%) and mesial (8.3%) surfaces, respectively.
CONCLUSIONS
A wide variation exists in the number of roots and canals of maxillary and mandibular primary molars, which calls for further attention in treatment of such teeth.
Topics: Humans; Dental Pulp Cavity; Cross-Sectional Studies; Root Canal Therapy; Molar; Cone-Beam Computed Tomography
PubMed: 37749546
DOI: 10.1186/s12903-023-03414-z -
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... Jul 2023This study aimed to investigate the efficacy of molar distalization with or without anterior teeth retraction.
INTRODUCTION
This study aimed to investigate the efficacy of molar distalization with or without anterior teeth retraction.
METHODS
Forty-three patients who received maxillary molar distalization with clear aligners were retrospectively enrolled and further divided into 2 groups: a retraction group (with maxillary incisor retraction ≥2 mm in ClinCheck) and a nonretraction group (without anteroposterior movement or with the labial movement of the maxillary incisor in ClinCheck). Pretreatment and posttreatment models were collected and laser-scanned to obtain the virtual models. Three-dimensional digital assessments of molar movement, anterior retraction and arch width were analyzed in the reverse engineering software Rapidform 2006. To calculate the efficacy of tooth movement, the achieved tooth movement assessed on the virtual model was compared with the predicted tooth movement in ClinCheck.
RESULTS
The achieved efficacy rates of molar distalization for the maxillary first and second molars were 36.48% and 41.94%, respectively. There was a significant difference in molar distalization efficacy between the retraction group (31.50% at the first molar and 35.63% at the second molar) and the nonretraction group (48.14% at the first molar and 52.51% at the second molar). In the retraction group, the efficacy of incisor retraction was 56.10%. The efficacy of dental arch expansion was more than 100% at the first molar levels in the retraction group and at the second premolar and first molar levels in the nonretraction group.
CONCLUSIONS
There is a discrepancy between the outcome and the predicted maxillary molar distalization with clear aligners. The efficacy of molar distalization with clear aligners was significantly affected by anterior teeth retraction, and the arch width significantly increased at the premolar and molar levels.
Topics: Humans; Retrospective Studies; Malocclusion, Angle Class II; Molar; Tooth Movement Techniques; Maxilla; Orthodontic Appliances, Removable; Cephalometry
PubMed: 36872177
DOI: 10.1016/j.ajodo.2022.11.016 -
The Angle Orthodontist Sep 2023To evaluate the changes after maxillary molar distalization in Class II malocclusion using the miniscrew-anchored cantilever with an extension arm.
OBJECTIVES
To evaluate the changes after maxillary molar distalization in Class II malocclusion using the miniscrew-anchored cantilever with an extension arm.
MATERIALS AND METHODS
The sample included 20 patients (9 male, 11 female; mean age 13.21 ± 1.54 years) with Class II malocclusion, treated with the miniscrew-anchored cantilever. Lateral cephalograms and dental models obtained before (T1) and after molar distalization (T2) were evaluated using Dolphin software and 3D Slicer. Superimposition of digital dental models using regions of interest on the palate was performed to evaluate three-dimensional displacement of maxillary teeth. Intragroup change comparisons were performed using dependent t-test and Wilcoxon test (P < 0.05).
RESULTS
The maxillary first molars were distalized to overcorrected Class I. The mean distalization time was 0.43 ± 0.13 years. Cephalometric analysis demonstrated significant distal movement of the maxillary first premolar (-1.21 mm, 95% confidence interval [CI]: -0.45, -1.96) and maxillary first (-3.38 mm, 95% CI: -2.88, -3.87) and second molars (-2.12 mm, 95% CI: -1.53, -2.71). Distal movements increased progressively from the incisors to the molars. The first molar showed small intrusion (-0.72 mm, 95% CI: 0.49, -1.34). In the digital model analysis, the first and second molars showed a crown distal rotation of 19.31° ± 5.71° and 10.17° ± 3.84°, respectively. The increase in maxillary intermolar distance, evaluated at the mesiobuccal cusps, was 2.63 ± 1.56 mm.
CONCLUSIONS
The miniscrew-anchored cantilever was effective for maxillary molar distalization. Sagittal, lateral, and vertical movements were observed for all maxillary teeth. Distal movement was progressively greater from anterior to posterior teeth.
Topics: Male; Female; Humans; Tooth Movement Techniques; Malocclusion, Angle Class II; Maxilla; Molar; Cephalometry; Orthodontic Anchorage Procedures; Orthodontic Appliance Design
PubMed: 37079798
DOI: 10.2319/091222-640.1 -
Anatomical Science International Jul 2023This study purposed to develop statistical models to predict palatal (PRL), mesial (MRL), and distal (DRL) root canal length and pulp volume (PV) of the maxillary first...
This study purposed to develop statistical models to predict palatal (PRL), mesial (MRL), and distal (DRL) root canal length and pulp volume (PV) of the maxillary first permanent molar using stature, gender, mesiodistal (MD), and buccopalatal (BP) crown diameters and some facial morphometries. 57 individuals were included in the study. Cone beam computed tomography was used to measure root canal lengths and PV. The PV calculation was carried out using the software ITK-SNAP 3.4.0. PRL was positively correlated with BP, stature, middle facial height, interalar distance, and bicommissural distance (BCD) (p < 0.05). DRL was positively correlated with BP, MD, and stature (p < 0.05). MRL was positively correlated with BP, MD, stature, lower face height, bizygomatic distance, and BCD (p < 0.05). PV was negatively correlated with age and BCD (p < 0.05). Although all models have significant predictive power for the root lengths and PV, no model could explain variances greater than 30%. The highest and lowest predictive ability was obtained for PRL and DRL, respectively. While the most significant predictor was BP for PRL and DRL, it was the age for PV.
Topics: Humans; Tooth Root; Dental Pulp Cavity; Molar; Tooth; Cone-Beam Computed Tomography; Maxilla
PubMed: 37079264
DOI: 10.1007/s12565-023-00727-5 -
Oral Health & Preventive Dentistry Aug 2023The goal of this study was to assess the peri-implant condition, peri-implant bone loss (PBL), and complication rates of short dental implant-supported splinted crowns...
Clinical, Radiographic Peri-Implant Parameters and Patient Satisfaction with Splinted and Non-splinted Short Dental Implants in the Maxillary Premolar-Molar Region: A Long-Term Retrospective Clinical Study.
PURPOSE
The goal of this study was to assess the peri-implant condition, peri-implant bone loss (PBL), and complication rates of short dental implant-supported splinted crowns (SDI-SCs) and non-splinted crowns (SDI-NSCs) in the maxillary premolar-molar region.
MATERIALS AND METHODS
Patients who had short implants placed near their maxillary sinuses were evaluated. Both patient satisfaction and presence of any technical complication, e.g. porcelain wear and chipping, loss of retention and loosening of the abutment, fixture or screw, were noted. The peri-implant plaque index (PIPI), probing depth (PIPD), bleeding on probing (PIBP), and peri-implant bone loss (PBL) were evaluated. To assess the impact of prosthesis type and SDI placement on technical problems, a log-rank test was computed. p < 0.05 was considered statistically significant.
RESULTS
A total of 72 patients agreed to be followed-up, showing a mean follow-up time of 3.1 years. Ninty-five implants in total (55 SDI-SCs, and 40 SDI-NSCs) with moderately rough surfaces were evaluated. The average PBL score for implant and patients was 1.27 (0.02-3.97) and 1.25 (0.03-4.41), respectively. More technical complications were observed with single crowns than with splinted crowns. There were no statistically significant differences in the peri-implant parameters between SDI-SCs and SDI-NSCs (p > 0.05). PBL at molar sites was substantially higher than at premolar sites (p = 0.048). Sixty patients (83.3%) were satisfied with the appearance of the crowns, while 57 patients (79.1%) were satisfied with the crowns' performance.
CONCLUSION
The peri-implant conditions, bone levels, technical complication rates and patient satisfaction were comparable between the SDI-SCs and SDI-NSCs. However, implants placed in the molar sites had statistically significantly greater bone loss in comparison to those at the premolar sites.
Topics: Humans; Patient Satisfaction; Bicuspid; Retrospective Studies; Dental Implants; Molar
PubMed: 37724899
DOI: 10.3290/j.ohpd.b4347791 -
Journal of Dentistry Nov 2023To compare the success of silver diamine fluoride-modified atraumatic restorative technique (SMART) with that of the conventional drill and fill method in restoring... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To compare the success of silver diamine fluoride-modified atraumatic restorative technique (SMART) with that of the conventional drill and fill method in restoring carious lesions in primary molars.
METHOD
Children (4-8years old) reporting to a tertiary care hospital setting with asymptomatic cavitated dentinal carious lesions in primary molars were randomly allocated to two groups; SMART and Conventional; and subsequently restored with Glass Ionomer Cement (GIC). Follow-up evaluations were carried out by blinded independent evaluator at 6-months intervals to assess the status of restorations. Primary outcome was the success of restorations at 24 months and the secondary outcome was the child's behaviour and acceptance of the treatment at the time of interventions. Two sample Z-test of proportion, logistic regression analysis and Chi-square test were used to compare the outcomes in two groups.
RESULTS
A total of 226 children (SMART group, 112 and conventional, 114) were included with 280 and 282 GIC restorations placed by the SMART and the conventional method respectively. At 24-months, 459 (81.6 %) primary molars were available for evaluation. Success rates of restorations was 38.4 % and 45.8 % % in SMART and conventional groups respectively (p = 0.105). The rate of acceptability of treatment in the SMART and conventional group was 79 % and 56 % (p<0.001) respectively.
CONCLUSION
There was no significant difference in the success rates of GIC restorations by SMART and conventional technique in carious primary molars at 24 months. SMART was better accepted by children as compared to the conventional restorative technique.
CLINICAL SIGNIFICANCE
SMART can be an alternative option to treat the asymptomatic carious lesions in primary molars and is well accepted by children than the conventional drill and fill technique thus implying that it has a useful role in un-cooperative children.
Topics: Child; Humans; Dental Restoration, Permanent; Dental Atraumatic Restorative Treatment; Dental Restoration Failure; Tooth, Deciduous; Glass Ionomer Cements; Dental Caries; Molar
PubMed: 37704105
DOI: 10.1016/j.jdent.2023.104698