scholarly journals Influence of Orthodontic Treatment with Premolar Extraction on the Spatial Position of Maxillary Third Molars in Adult Patients: A Retrospective Cone-bean Computed Tomography Study

2020 ◽  
Author(s):  
Fangwei Pan ◽  
Zhentao Yang ◽  
Jian Wang ◽  
Jialing Liu ◽  
Chenghao Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Orthodontic Treatment ◽  
Spatial Position ◽  
Adult Patients ◽  
Third Molars ◽  
Position Change ◽  
Premolar Extraction ◽  
The Third ◽  
Anterior Nasal Spine ◽  
Before And After

Abstract Background: The aim of this study was to evaluate the changes in position, angulation, and rotation of maxillary third molars in adults after orthodontic treatment with premolar extraction using a space coordinate system based on Cone-bean computed tomography (CBCT) images. Methods: Forty-nine maxillary third molars from 27 patients (mean age, 20.78 years) were included in the study. CBCT images were obtained before and after orthodontic treatment with premolars extracted (mean treatment duration, 31.47 months). The changes in the position, angulation, and rotation of the third molars were evaluated with a space coordinates system using four landmarks: anterior nasal spine (ANS), posterior nasal spine (PNS), left and right orbitales. Results: After orthodontic treatment, the third molars moved forward (mean, 1.44 mm) (p < 0.001) and downward (mean, 2.87 mm) (p < 0.001) accompanied by outward rotation (mean, 5.38°) of the crown (p = 0.001), but the changes in angulation were insignificant.Conclusions: This was the first study to systematically investigate the spatial position change of maxillary third molars in adult patients who received orthodontic treatment with premolar extraction. During the process, maxillary third molars moved downward and forward accompanied by outward rotation of the crown.

scholarly journals Influence of Orthodontic Treatment with Premolar Extraction on the Spatial Position of Maxillary Third Molars in Adult Patients: A Retrospective Cohort Cone-bean Computed Tomography Study

2020 ◽  
Author(s):  
Fangwei Pan ◽  
Zhentao Yang ◽  
Jian Wang ◽  
Ruilie Cai ◽  
Jialing Liu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coordinate System ◽  
Orthodontic Treatment ◽  
Spatial Position ◽  
Adult Patients ◽  
Third Molars ◽  
Premolar Extraction ◽  
The Third ◽  
Anterior Nasal Spine ◽  
Space Coordinate

Abstract Background: Based on low-dose radiation Cone-bean computed tomography (CBCT) images, This study aims to establish a space coordinate system, which offers more precise and comparable evaluation on changes of maxillary third molars influenced by orthodontic treatment with premolar extraction in adults. The system suggests promising application prospect in future studies related to CBCT superimposition and evaluation for its feasibility and efficiency.Methods: Forty-nine maxillary third molars from 27 patients (mean age, 20.78 years) were included. CBCT images were obtained before and after orthodontic treatment with premolars extracted (mean treatment duration, 31.47 months). The changes in the position, angulation, and rotation of the third molars were evaluated with a space coordinate system using four landmarks: anterior nasal spine (ANS), posterior nasal spine (PNS), left and right orbitales.Results: After orthodontic treatment, the third molars moved forward (adjusted mean, 1.44 mm) (p < 0.001) and downward (adjusted mean, 2.87 mm) (p < 0.001) accompanied by outward rotation of the crowns (adjusted mean, 5.38°) (p = 0.001), while changes in angulation were insignificant.Conclusions: This was the first study to systematically investigate the spatial position change of maxillary third molars in adult patients who received orthodontic treatment with premolar extraction. During the process, maxillary third molars moved downward and forward accompanied by outward rotation of the crowns. Orthodontists should take tooth movement potential into consideration when making extraction plans.

scholarly journals Influence of Orthodontic Treatment with Premolar Extraction on the Spatial Position of Maxillary Third Molars in Adult Patients: A Retrospective Cohort Cone-bean Computed Tomography Study

2020 ◽  
Author(s):  
Fangwei Pan ◽  
Zhentao Yang ◽  
Jian Wang ◽  
Ruilie Cai ◽  
Jialing Liu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coordinate System ◽  
Orthodontic Treatment ◽  
Spatial Position ◽  
Adult Patients ◽  
Third Molars ◽  
Premolar Extraction ◽  
The Third ◽  
Anterior Nasal Spine ◽  
Space Coordinate

Abstract Background: Based on low-dose radiation Cone-bean computed tomography (CBCT) images, ThisThe study aims of this study was to establish a space coordinate system, which offers more precise and comparable evaluation on changes of maxillary third molars influenced by orthodontic treatment with premolar extraction in adults. The system suggests promising application prospect in future studies related to CBCT superimposition and evaluation for its feasibility and efficiency.evaluate the changes in position, angulation, and rotation of maxillary third molars in adults after orthodontic treatment with premolar extraction using a space coordinate system based on Cone-bean computed tomography (CBCT) images. Methods: Forty-nine maxillary third molars from 27 patients (mean age, 20.78 years) were included in the study. CBCT images were obtained before and after orthodontic treatment with premolars extracted (mean treatment duration, 31.47 months). The changes in the position, angulation, and rotation of the third molars were evaluated with a space coordinates system using four landmarks: anterior nasal spine (ANS), posterior nasal spine (PNS), left and right orbitales. Results: After orthodontic treatment, the third molars moved forward (adjusted mean, 1.44 mm) (p < 0.001) and downward (adjusted mean, 2.87 mm) (p < 0.001) accompanied by outward rotation (mean, 5.38°) of the crowns (adjusted mean, 5.38°) (p = 0.001), whilebut the changes in angulation were insignificant.Conclusions: This was the first study to systematically investigate the spatial position change of maxillary third molars in adult patients who received orthodontic treatment with premolar extraction. During the process, maxillary third molars moved downward and forward accompanied by outward rotation of the crowns. Orthodontists should take tooth movement potential into consideration when making extraction plans.

scholarly journals Influence of orthodontic treatment with premolar extraction on the spatial position of maxillary third molars in adult patients: a retrospective cohort cone-bean computed tomography study

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Fangwei Pan ◽  
Zhentao Yang ◽  
Jian Wang ◽  
Ruilie Cai ◽  
Jialing Liu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coordinate System ◽  
Orthodontic Treatment ◽  
Spatial Position ◽  
Adult Patients ◽  
Third Molars ◽  
Premolar Extraction ◽  
The Third ◽  
Anterior Nasal Spine ◽  
Space Coordinate

Abstract Background Based on low-dose radiation Cone-bean computed tomography (CBCT) images, This study aims to establish a space coordinate system, which offers more precise and comparable evaluation on changes of maxillary third molars influenced by orthodontic treatment with premolar extraction in adults. The system suggests promising application prospect in future studies related to CBCT superimposition and evaluation for its feasibility and efficiency. Methods Forty-nine maxillary third molars from 27 patients (mean age, 20.78 years) were included. CBCT images were obtained before and after orthodontic treatment with premolars extracted (mean treatment duration, 31.47 months). The changes in the position, angulation, and rotation of the third molars were evaluated with a space coordinate system using four landmarks: anterior nasal spine (ANS), posterior nasal spine (PNS), left and right orbitales. Results After orthodontic treatment, the third molars moved forward (adjusted mean, 1.44 mm) (p < 0.001) and downward (adjusted mean, 2.87 mm) (p < 0.001) accompanied by outward rotation of the crowns (adjusted mean, 5.38°) (p = 0.001), while changes in angulation were insignificant. Conclusions This was the first study to systematically investigate the spatial position change of maxillary third molars in adult patients who received orthodontic treatment with premolar extraction. During the process, maxillary third molars moved downward and forward accompanied by outward rotation of the crowns. Orthodontists should take tooth movement potential into consideration when making extraction plans.

scholarly journals Mesioangular impacted lower third molars: angulation before and after orthodontic treatment with premolar extraction

2018 ◽  
Vol 1073 ◽  
pp. 022007 ◽  
Author(s):  
D F Hartono ◽  
B M Soegiharto ◽  
S Sumardi
Keyword(s):  
Orthodontic Treatment ◽  
Third Molars ◽  
Premolar Extraction ◽  
Before And After

scholarly journals Accuracy of cone-beam computed tomography in defining spatial relationships between third molar roots and inferior alveolar nerve

2016 ◽  
Vol 10 (04) ◽  
pp. 454-458 ◽  
Author(s):  
Roberto Pippi ◽  
Marcello Santoro ◽  
Ferdinando D'Ambrosio
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Root Morphology ◽  
Inferior Alveolar Nerve ◽  
Third Molar ◽  
Root Surface ◽  
Cone Beam ◽  
Spatial Relationships ◽  
Third Molars ◽  
The Third

ABSTRACT Objective: Cone-beam computed tomography (CBCT) has been proposed in surgical planning of lower third molar extraction. The aim of the present study was to assess the reliability of CBCT in defining third molar root morphology and its spatial relationships with the inferior alveolar nerve (IAN). Materials and Methods: Intraoperative and radiographic variables of 74 lower third molars were retrospectively analyzed. Intraoperative variables included IAN exposure, number of roots, root morphology of extracted third molars, and presence/absence of IAN impression on the root surface. Radiographic variables included presence/absence of the cortex separating IAN from the third molar roots on CBCT examination, number of roots and root morphology on both orthopantomography (OPG) and CBCT. The statistical association between variables was evaluated using the Fisher's exact test. Results: In all cases of intraoperative IAN exposure, the cortex appeared discontinuous on CBCT images. All cases, in which the cortical bone was continuous on CBCT images, showed no association with nerve exposure. In all cases in which nerve impression was identified on the root surface, the IAN cortex showed interruptions on CBCT images. No nerve impression was identified in any of the cases, in which the cortex appeared continuous on CBCT images. CBCT also highlighted accessory roots and apical anomalies/curvatures, not visible on the OPG. Conclusions: CBCT seems to provide reliable and accurate information about the third molar root morphology and its relationship with the IAN.

scholarly journals Geometric analysis of alveolar bone around the incisors after anterior retraction following premolar extraction

2019 ◽  
Vol 90 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Fan Zhang ◽  
Suk-Cheol Lee ◽  
Jun-Beom Lee ◽  
Kyung-Min Lee
Keyword(s):  
Orthodontic Treatment ◽  
Alveolar Bone ◽  
Shape Change ◽  
Geometric Analysis ◽  
Careful Consideration ◽  
Mandibular Incisor ◽  
Premolar Extraction ◽  
Significant Difference ◽  
Before And After ◽  
Mandibular Incisors

ABSTRACT Objective: To evaluate changes in shape and alterations in thickness and vertical marginal bone levels of the alveolar bone around the maxillary and mandibular incisors before and after orthodontic treatment with premolar extraction using geometric morphometric analysis. Materials and Methods: Thirty-six patients with Class I bialveolar protrusion who underwent orthodontic treatment with premolar extraction were included. Cone-beam computed tomographic scans were obtained from the patients before and after treatment. Five fixed landmarks and 70 semilandmarks were used to represent the morphology of the alveolar bone around the maxillary and mandibular incisors. The coordinates of the landmarks of the alveolar bones were generated by Procrustes fit. The labial and lingual alveolar bone thicknesses around the maxillary and mandibular incisors and vertical marginal bone level were assessed quantitatively. Results: There was a significant difference in shape change of the alveolar bone before and after treatment. The deformation grid of the thin plate spline showed that the thickness and vertical marginal bone decreased on the lingual side after treatment. Shape changes were greater for the lingual alveolar bone on the mandibular incisor than for the maxillary incisors. Conclusions: Orthodontic treatment with premolar extraction might cause loss of alveolar bone around the maxillary and mandibular incisors. Careful consideration is needed to avoid iatrogenic degeneration of periodontal support around the incisors, particularly in the lingual area.

Second premolar extraction improves the angulation of developing third molars better than first premolar extraction among subjects undergoing comprehensive orthodontic treatment

2016 ◽  
Vol 4 (1) ◽  
pp. 46
Author(s):  
Cheshta Yadav ◽  
Ashok Kumar Utreja ◽  
Satinder Pal Singh ◽  
Ashok Kumar Jena
Keyword(s):  
Orthodontic Treatment ◽  
Third Molars ◽  
Premolar Extraction ◽  
Better Than

scholarly journals Analysis of the Morphological Characteristics of the Palatal Rugae for Three-Dimensional Superimposition of Digital Models in Korean Subjects

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Sung-Hwan Choi ◽  
Kyongmin Koh ◽  
Kee-Joon Lee ◽  
Chung-Ju Hwang ◽  
Jung-Yul Cha
Keyword(s):  
Orthodontic Treatment ◽  
Three Dimensional ◽  
Morphological Characteristics ◽  
Digital Model ◽  
Initial Visit ◽  
Reference Area ◽  
The Third ◽  
Palatal Rugae ◽  
Before And After ◽  
Left And Right

Objective. The aim of this study was to evaluate the morphological characteristics of the palatal rugae in Korean subjects to determine whether the palatal rugae can be used as an appropriate reference area for three-dimensional digital model superimpositions. Materials and Methods. In total, 343 patients (110 men, 233 women; mean age, 25.6±8.2 years) who had a digital model taken at their initial visit were included, and the numbers and types of right and left palatal rugae were investigated according to the primary, secondary, and fragmentary rugae. Finally, the differences in the positions of the third primary ruga were investigated according to the presence of additional rugae posterior to the third primary ruga. Results. The number of primary palatal rugae ranged from one to six, with 43.5% of the subjects having three primary rugae and 36.1% having four primary rugae; there were no significant differences between sexes. Except for the fragment rugae, the numbers of primary and secondary rugae were not significantly different between the left and right sides. The third primary ruga was located more significantly anteriorly when there was an additional ruga posterior to the third primary ruga (P < 0.001). Conclusions. The numbers of the palatal rugae vary greatly among individuals, and this affects the anteroposterior position of the third primary ruga. When the third primary ruga is located anteriorly, care should be taken when using it as a reference area for superimposition with a digital model before and after orthodontic treatment.

scholarly journals Cone beam computed tomography evaluation of distance from cementoenamel junction to alveolar crest before and after nonextraction orthodontic treatment

2015 ◽  
Vol 86 (4) ◽  
pp. 543-549 ◽  
Author(s):  
Luma O. Castro ◽  
Iury O. Castro ◽  
Ana Helena G. de Alencar ◽  
José Valladares-Neto ◽  
Carlos Estrela
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Orthodontic Treatment ◽  
Alveolar Bone ◽  
Software Tool ◽  
Wilcoxon Test ◽  
Cone Beam ◽  
Before And After ◽  
Level Of Significance ◽  
Study Database

ABSTRACT Objective:  To evaluate the distance between the cementoenamel junction and the alveolar bone crest before and after orthodontic treatment using cone beam computed tomography (CBCT). Materials and Methods:  The sample comprised 30 patients with Angle Class I malocclusion and mild to moderate crowding. The study database comprised dental CBCT scans obtained before and after orthodontic treatment. The distance between the cementoenamel junction to the bone crest of the buccal (n  =  720) and lingual (n  =  720) surfaces was measured in 24 teeth for each patient using a specific software tool (Xoran version 3.1.62). The Wilcoxon test was used for statistical analysis, and the level of significance was set at P &lt; .05. Results:  The distance between the cementoenamel junction and the bone crest increased in 822 (57%) of the 1440 surfaces after orthodontic treatment. The buccal surface of the lower central incisors had the greatest frequency of increased distance (75%), and the lingual surface of lateral incisors had the lowest (40%). The distance between the cementoenamel junction and the alveolar bone crest was greater than 2 mm (alveolar bone dehiscence) in 162 (11%) of the 1440 surfaces before orthodontic treatment and in 279 (19%) after treatment. Conclusions:  The distance from the cementoenamel junction to the bone crest changed after orthodontic treatment; the distance was greater than 2 mm in 11% of the surfaces before treatment and in 19% after treatment.

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