scholarly journals Masseter muscle adaptation following orthognathic surgery - Biomodelling analysis - A pilot study

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Fernando Duarte
Keyword(s):  
Orthognathic Surgery ◽  
Masseter Muscle ◽  
Fibre Orientation ◽  
Experimental Methodology ◽  
Muscle Adaptation ◽  
Imaging Protocol ◽  
Pilot Investigation ◽  
Magnetic Resonance Imaging Protocol ◽  
Le Fort I ◽  
Anterior Angle

Purpose: This pilot investigation was designed to apply several, newly developed and more sophisticated methods of measuring muscle structure, function and fibre orientation to a situation where adaptation of muscle is pivotal to the success of a therapeutic approach. Materials and Methods: Patients attending the combined orthodontic / orthognathic surgery clinic at the Clitrofa – Centro Médico, Dentário e Cirúrgico, in Trofa - Portugal were screen using Magnetic Resonance Imaging protocol. Ten patients scheduled for a bimaxillary osteotomy involving a combination of maxillary Le Fort I impaction procedure coupled with a sagittal split advancement of the mandible were select to form the study group. An Experimental design used to provide information in relation to masticatory muscle adaptation following orthognathic surgery. The study involved the contribution of two independent examiners that measured the changes in fibre orientation at the different jaw positions using AnatomicsTM software, at three different time moments. A combination of different parametric tests has been used to compare the different experimental variables. Results: Statistical differences have been identified between examiners measurements and between operations. There were no significant differences testing different times. Conclusions: The discrepancies between examiners probably arise from small variations in the experimental methodology used by them. The differences between operations reveal the masseter muscle adaptation following orthognathic surgery. The measurement of “P1 masseter muscle/ Zygomatic bone / process mastoid anterior angle” and “P2 masseter muscle / mandibular angle” can therefore be a valuable tool for controlling the reworking of masseter muscle upon orthognathic surgery.

W-Shaped Osteotomy to Avoid Paranasal Deformity After Standard Le Fort I in Orthognathic Surgery

2020 ◽  
pp. 229255032096965
Author(s):  
Mario Santagata ◽  
Nicola Sgaramella ◽  
Fabrizio Chirico ◽  
Salvatore D’Amato ◽  
Ivo Ferrieri ◽  
...  
Keyword(s):  
Orthognathic Surgery ◽  
Preliminary Report ◽  
Le Fort I Osteotomy ◽  
Maxillary Bone ◽  
Le Fort ◽  
First Time ◽  
Le Fort I ◽  
Pyriform Aperture

When occlusal alterations are not accompanied by paranasal deficiencies, mobilization of the maxilla via Le Fort I osteotomy should be made with a different design. In this preliminary report, a W-shaped osteotomy that doesn’t change the position of the maxillary bone surrounding the pyriform aperture was presented for the first time. Advantages and indications of this new procedure are discussed.

High-power diode laser in the circumvestibular incision for Le Fort I osteotomy in orthognathic surgery: a prospective case series study

2017 ◽  
Vol 33 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Filipe Jaeger ◽  
Gustavo Marques Chiavaioli ◽  
Guilherme Lacerda de Toledo ◽  
Belini Freire-Maia ◽  
Marcio Bruno Figueiredo Amaral ◽  
...  
Keyword(s):  
Orthognathic Surgery ◽  
Case Series ◽  
Le Fort I Osteotomy ◽  
Le Fort ◽  
Case Series Study ◽  
Prospective Case Series ◽  
Power Diode ◽  
Series Study ◽  
High Power Diode Laser ◽  
Le Fort I

scholarly journals Modified approach to the characterization of adrenal nodules using a standard abdominal magnetic resonance imaging protocol

2017 ◽  
Vol 50 (1) ◽  
pp. 19-25 ◽  
Author(s):  
António P. Matos ◽  
Richard C. Semelka ◽  
Vasco Herédia ◽  
Mamdoh AlObaidiy ◽  
Filipe Veloso Gomes ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Imaging Protocol ◽  
Intensity Index ◽  
Abdominal Magnetic Resonance Imaging ◽  
Phase Type ◽  
The Mean ◽  
Magnetic Resonance Imaging Protocol ◽  
Type 3

Abstract Objective: To describe a modified approach to the evaluation of adrenal nodules using a standard abdominal magnetic resonance imaging protocol. Materials and Methods: Our sample comprised 149 subjects (collectively presenting with 132 adenomas and 40 nonadenomas). The adrenal signal intensity index was calculated. Lesions were grouped by pattern of enhancement (PE), according to the phase during which the wash-in peaked: arterial phase (type 1 PE); portal venous phase (type 2 PE); and interstitial phase (type 3 PE). The relative and absolute wash-out values were calculated. To test for mean differences between adenomas and nonadenomas, Student's t-tests were used. Receiver operating characteristic curve analysis was also performed. Results: The mean adrenal signal intensity index was significantly higher for the adenomas than for the nonadenomas (p < 0.0001). Chemical shift imaging showed a sensitivity and specificity of 94.4% and 100%, respectively, for differentiating adenomas from nonadenomas. Of the adenomas, 47.6%, 48.5%, and 3.9%, respectively, exhibited type 1, 2, and 3 PEs. For the mean wash-in proportions, significant differences were found among the enhancement patterns. The wash-out calculations revealed a trend toward better lesion differentiation for lesions exhibiting a type 1 PE, showing a sensitivity and specificity of 71.4% and 80.0%, respectively, when the absolute values were referenced, as well as for lesions exhibiting a type 2 PE, showing a sensitivity and specificity of 68.0% and 100%, respectively, when the relative values were referenced. The calculated probability of a lipid-poor lesion that exhibited a type 3 PE being a nonadenoma was > 99%. Conclusion: Subgrouping dynamic enhancement patterns yields high diagnostic accuracy in differentiating adenomas from nonadenomas.

Le Fort I osteotomy for non-orthognathic surgery indications: a review

Oral Surgery ◽  
2013 ◽  
pp. n/a-n/a
Author(s):  
L. Pingarron Martin ◽  
J. Arias-Gallo ◽  
M. Chamorro-Pons ◽  
G. Demaria-Martinez ◽  
J.L. Cebrian-Carretero
Keyword(s):  
Orthognathic Surgery ◽  
Le Fort I Osteotomy ◽  
Le Fort ◽  
Le Fort I

scholarly journals Effect of Le Fort I Maxillary Advancement and Clockwise Rotation on the Anteromedial Cheek Soft Tissue Change in Patients with Skeletal Class III Pattern and Midface Deficiency: A 3D Imaging-Based Prediction Study

2020 ◽  
Vol 9 (1) ◽  
pp. 262
Author(s):  
Hsin-Chih Lai ◽  
Rafael Denadai ◽  
Cheng-Ting Ho ◽  
Hsiu-Hsia Lin ◽  
Lun-Jou Lo
Keyword(s):  
Soft Tissue ◽  
Orthognathic Surgery ◽  
Class Iii ◽  
Le Fort ◽  
Skeletal Class ◽  
Tissue Change ◽  
Maxillary Advancement ◽  
Soft Tissue Change ◽  
Mass Position ◽  
Le Fort I

Patients with a skeletal Class III deformity may present with a concave contour of the anteromedial cheek region. Le Fort I maxillary advancement and rotational movements correct the problem but information on the impact on the anteromedial cheek soft tissue change has been insufficient to date. This three-dimensional (3D) imaging-assisted study assessed the effect of surgical maxillary advancement and clockwise rotational movements on the anteromedial cheek soft tissue change. Two-week preoperative and 6-month postoperative cone-beam computed tomography scans were obtained from 48 consecutive patients who received 3D-guided two-jaw orthognathic surgery for the correction of Class III malocclusion associated with a midface deficiency and concave facial profile. Postoperative 3D facial bone and soft tissue models were superimposed on the corresponding preoperative models. The region of interest at the anteromedial cheek area was defined. The 3D cheek volumetric change (mm3; postoperative minus preoperative models) and the preoperative surface area (mm2) were computed to estimate the average sagittal movement (mm). The 3D cheek mass position from orthognathic surgery-treated patients was compared with published 3D normative data. Surgical maxillary advancement (all p < 0.001) and maxillary rotation (all p < 0.006) had a significant effect on the 3D anteromedial cheek soft tissue change. In total, 78.9%, 78.8%, and 78.8% of the variation in the cheek soft tissue sagittal movement was explained by the variation in the maxillary advancement and rotation movements for the right, left, and total cheek regions, respectively. The multiple linear regression models defined ratio values (relationship) between the 3D cheek soft tissue sagittal movement and maxillary bone advancement and rotational movements of 0.627 and 0.070, respectively. Maxillary advancements of 3–4 mm and >4 mm resulted in a 3D cheek mass position (1.91 ± 0.53 mm and 2.36 ± 0.72 mm, respectively) similar (all p > 0.05) to the 3D norm value (2.15 ± 1.2 mm). This study showed that both Le Fort I maxillary advancement and rotational movements affect the anteromedial cheek soft tissue change, with the maxillary advancement movement presenting a larger effect on the cheek soft tissue movement than the maxillary rotational movement. These findings can be applied in future multidisciplinary-based decision-making processes for planning and executing orthognathic surgery.

Sign in / Sign up

Export Citation Format

Share Document