scholarly journals Optimization of Loading Condition for Maxillary Molar Intrusion with Midpalatal Miniscrews by Using Finite Element Analysis

2021 ◽  
Vol 11 (24) ◽  
pp. 11749
Author(s):  
Ornnicha Pooktuantong ◽  
Takeshi Ogasawara ◽  
Masayoshi Uezono ◽  
Pintu-on Chantarawaratit ◽  
Keiji Moriyama
Keyword(s):  
Finite Element ◽  
Open Bite ◽  
Unit Load ◽  
Anterior Open Bite ◽  
Element Analysis ◽  
Molar Intrusion ◽  
Apical Direction ◽  
Root Injury ◽  
Maxillary Molar ◽  
Transpalatal Arch

An anterior open bite is one of the most difficult malocclusions in orthodontic treatment. For such malocclusion, orthodontic miniscrew insertion into both buccal and palatal alveolar regions has been indicated for molar intrusion, but it involves a risk of tooth root injury. To solve the problem, a midpalatal miniscrew-attached extension arm (MMEA) is adopted. However, this method causes palatal tipping of the molar because intrusive loads were applied only from the palatal side. Currently, a transpalatal arch is added to avoi0d tipping movement, but it induces the patient’s discomfort. Hence, the objective of this study was to evaluate the loading conditions for maxillary molar intrusion without tipping movement, only by MMEA through finite element (FE) analysis. FE models of maxillary right first molar and surrounding tissues were created. Three hook positions of MMEA were set at 6.0 mm perpendicular intervals in the occluso-apical direction along the mucosal contour. An intrusive unit load was applied from the palatal side of the molar, and various counter loads were applied from the buccal side. An optimal counter load for molar intrusion without palatal tipping was observed in each hook position. In conclusion, an ideal maxillary molar intrusion can be achieved only by MMEA with an optimal counter load.

scholarly journals Prediction of mandibular movement and its center of rotation for nonsurgical correction of anterior open bite via maxillary molar intrusion

2018 ◽  
Vol 88 (5) ◽  
pp. 538-544 ◽  
Author(s):  
Kyunam Kim ◽  
Kwangchul Choy ◽  
Young-Chel Park ◽  
Seo Yeon Han ◽  
Heekyu Jung ◽  
...  
Keyword(s):  
Linear Regression Analysis ◽  
Open Bite ◽  
Reference Plane ◽  
Mandibular Movement ◽  
Anterior Open Bite ◽  
Counterclockwise Rotation ◽  
Molar Intrusion ◽  
Lateral Cephalograms ◽  
Maxillary Molar ◽  
The Relationship

ABSTRACT Objectives: To evaluate quantitatively the relationship between molar intrusion (change [Δ] maxillary first molar [U6]–palatal plane [PP]) and changes in vertical and sagittal cephalometric parameters and to determine the center of mandibular autorotation. Materials and Methods: Twenty-one patients diagnosed with anterior open bite and successfully treated with molar intrusion (overbite [OB] > 0 mm) were retrospectively enrolled. Lateral cephalograms taken before and after molar intrusion were used to measure changes in vertical and sagittal cephalometric parameters. The center of mandibular autorotation was calculated by measuring displacement of gonion (Go) and pogonion (Pog). Paired t-tests were used to compare variables, and linear regression analysis was used to examine the relationship between ΔU6-PP and other variables. Results: The mandible exhibited counterclockwise rotation after maxillary molar intrusion, which led to closure of anterior open bite. Strong linear relationships, in descending order, between ΔU6-PP and ΔOB, Δanterior facial height (AFH), Δvertical reference plane (Pog), and Δsella-nasion to Go-menton (SN-GoMe), were observed. When the maxillary molar was intruded 1 mm, OB increased by 2.6 mm, AFH decreased by 1.7 mm, Pog moved forward by 2.3 mm, and SN-GoMe decreased by 2°. The center of mandibular autorotation was located 7.4 mm behind and 16.9 mm below condylion after molar intrusion. Conclusions: The mandible exhibited counterclockwise rotation after maxillary molar intrusion; the center of mandibular autorotation was located behind and below condylion with individual variations.

scholarly journals Correction of open bite with temporary anchorage device-supported intrusion

2019 ◽  
Vol 9 ◽  
pp. 246-251
Author(s):  
Joy Chang ◽  
Shivam Mehta ◽  
Po-Jung Chen ◽  
Madhur Upadhyay ◽  
Sumit Yadav
Keyword(s):  
Treatment Approach ◽  
Transverse Dimension ◽  
Open Bite ◽  
Anterior Open Bite ◽  
Posterior Teeth ◽  
Anterior Teeth ◽  
Molar Intrusion ◽  
Mandibular Plane ◽  
Temporary Anchorage Device ◽  
Transpalatal Arch

This case report describes the use of temporary anchorage device (TAD)-supported molar intrusion to correct anterior open bite and achieve overjet correction. A 13-year-old female presented with a Class II skeletal profile, with increased overjet and anterior open bite. She was treated with a combination of intrusion of the posterior teeth and extrusion of anterior teeth. The intrusion of maxillary posterior teeth was done with a palatal TAD and a transpalatal arch on the upper first molars to control the transverse dimension. The patient’s mandibular plane angle was maintained with this treatment approach.

scholarly journals Dentoskeletal changes following mini-implant molar intrusion in anterior open bite patients

2015 ◽  
Vol 85 (6) ◽  
pp. 941-948 ◽  
Author(s):  
Tyler R. Hart ◽  
Richard R. J. Cousley ◽  
Leonard S. Fishman ◽  
Ross H. Tallents
Keyword(s):  
Observation Time ◽  
Open Bite ◽  
Occlusal Plane ◽  
Plane Angle ◽  
Anterior Open Bite ◽  
Mini Implants ◽  
Molar Intrusion ◽  
Adolescent Patients ◽  
Maxillary Molar ◽  
Cephalometric Study

ABSTRACT Objective:  To evaluate skeletal and dental changes after intrusion of the maxillary molars in subjects with anterior open bite. Materials and Methods:  This retrospective cephalometric study evaluated skeletal and dental changes resulting from the use of maxillary orthodontic mini-implants in 31 consecutively treated patients. Radiographs were taken at the start and end of maxillary molar intrusion to evaluate the associated changes. Statistical analysis was performed using a one-sample t-test. Results:  The mean treatment observation time was 1.31 years (SD  =  2.03). The maxillary first molars (P  =  0.0026) and second molars (P  =  0.039) were intruded. However, the mandibular first molars (P  =  0.0004) and second molars (P  =  0.003) erupted in adolescent patients. Both the maxillary and mandibular first molars inclined distally (P  =  0.025 and P  =  0.044, respectively). The mandibular plane angle decreased (P  =  0.036), lower facial height decreased (P  =  0.002), and the occlusal plane angle increased (P  =  0.009). The overbite increased (P < .0001). The ANB angle decreased (P < .0001). Mandibular dental and skeletal changes were more apparent in adolescents, while adults tended toward maxillary changes. Conclusions:  Vertical traction from orthodontic mini-implants reduces the maxillary posterior dentoalveolar height, thereby assisting orthodontic closure of anterior open bite. However, simultaneous eruption or extrusion of the mandibular molars should be controlled. Adolescent patients tend to demonstrate more favorable effects of mandibular autorotation than do adults.

scholarly journals Upper Second Molar Distalization with Clear Aligners: A Finite Element Study

2020 ◽  
Vol 10 (21) ◽  
pp. 7739
Author(s):  
Gabriele Rossini ◽  
Matteo Schiaffino ◽  
Simone Parrini ◽  
Ambra Sedran ◽  
Andrea Deregibus ◽  
...  
Keyword(s):  
Finite Element ◽  
Periodontal Ligament ◽  
Element Analysis ◽  
Molar Distalization ◽  
Force System ◽  
Second Molar ◽  
Maxillary Molar ◽  
Clinical Environments ◽  
Upper Molar ◽  
Element Study

Among orthodontists and scientists, in the last years, upper molar distalization has been a debated topic in the orthodontic aligner field. However, despite that few clinical studies have been published, no insights on aligners’ biomechanics regarding this movement are available. The aim of this study was to assess, through finite element analysis, the force system resulting in the upper arch during second maxillary molar distalization with clear aligners and variable attachments settings. The average tooth distalization was found to be 0.029, with buccal flaring of the upper incisors in all attachment configurations. The mesial deformation of the aligner was registered to be 0.2 mm on average. Different pressure areas on the interface between aligners and upper molars were registered, with the mesial attachment surface to be directly involved when present. Periodontal ligament pressure was reported to range between 67 g/cm2 and 132 g/cm2. Configurations with rectangular attachments from second molar-to-canine and from first molar-to-canine present, in an in silico environment, almost equal efficiency in distalizing the upper second molar. However, attachments from the second molar to the canine are suggested to be adopted in clinical environments due to greater feasibility in everyday practice.

Mandibular Prognathism and Anterior Open Bite: Treatment by Orthodontic Molar Intrusion and Two-jaw Surgery

2006 ◽  
Vol 18 (4) ◽  
pp. 296-302
Author(s):  
Hiromi Yoshitake ◽  
Eri Oki ◽  
Kazuhiro Ichikawa ◽  
Takatoshi Itoh ◽  
Takami Itoh ◽  
...  
Keyword(s):  
Open Bite ◽  
Anterior Open Bite ◽  
Mandibular Prognathism ◽  
Molar Intrusion ◽  
Jaw Surgery

scholarly journals A prospective clinical trial of the effects produced by the extrusion arch in the treatment of anterior open bite

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Juliana de Brito Vasconcelos ◽  
Renata Rodrigues de Almeida-Pedrin ◽  
Thais Maria Freire Fernandes Poleti ◽  
Paula Oltramari ◽  
Ana Cláudia Ferreira de Castro Conti ◽  
...  
Keyword(s):  
Open Bite ◽  
Mixed Dentition ◽  
Anterior Open Bite ◽  
Significance Level ◽  
Lateral Cephalograms ◽  
Maxillary Molar ◽  
Facial Pattern ◽  
Dental Models ◽  
Maxillary Incisors ◽  
Maxillary Dentition

Abstract Aim To evaluate the maxillary dentition effects of the extrusion arch for anterior open bite (AOB) correction in mixed dentition patients. Materials and methods Fourteen subjects with an initial mean age of 9.17 ± 1.03 years presenting with dentoalveolar AOB (mean − 1.28 ± 1.46 mm) and normal facial pattern (FMA = 25.76°) were treated with an extrusion arch. The mean treatment period was 7.79 ± 2.58 months. Lateral cephalograms and dental models were taken before (T0) and after the correction of AOB (T1). Data were analyzed using paired t test to evaluate differences between T0 and T1. For all tests, a significance level of P < .05 was used. Results All patients achieved positive overbite at T1, with a mean increase of 3.07 mm. The maxillary incisors extruded 1.94 mm. Retroclination of the maxillary incisors (− 6.15°) and an increase in the interincisal angle (5.57°) were observed. There was a significant decrease in the distance between the incisal edge of the maxillary incisors and the molars (− 2.21 mm). There was significant mesial tipping of the maxillary molar (− 11.49°). Significant reductions of overjet (− 1.65 mm), arch perimeter (− 3.02 mm), and arch length (− 2.23 mm) were noted. The transverse maxillary intermolar distance did not change significantly. Conclusions The use of a maxillary extrusion arch was effective in the treatment of AOB. Overbite increased due to incisor extrusion, as well as retroinclination and overjet reduction. However, side effects, such as mesial molar tipping and decreases in arch perimeter and length might occur.

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