Scleral exposure changes after Le Fort I maxillary advancement with vertical component in individuals with skeletal Class III malocclusion—A stereophotogrammetric image study

Author(s):  
Hanife Nuray Yılmaz ◽  
Yasemin Bahar Acar ◽  
Elvan Onem Ozbilen
2020 ◽  
Vol 9 (1) ◽  
pp. 262
Author(s):  
Hsin-Chih Lai ◽  
Rafael Denadai ◽  
Cheng-Ting Ho ◽  
Hsiu-Hsia Lin ◽  
Lun-Jou Lo

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.


2016 ◽  
Vol 6 ◽  
pp. 312-318
Author(s):  
Anadha Gujar ◽  
M. S. Rani ◽  
Sujala G. Durgekar

Class III malocclusions with a severe hyperdivergent growth pattern are very complex to plan and treat. This case report describes the treatment of an adult with a skeletal Class III malocclusion with a midface deficiency, severe bilateral posterior crossbite, and a severe hyperdivergent growth pattern by a combination of a bonded rapid maxillary expansion appliance and surgical procedure of Le Fort I osteotomy for maxillary advancement.


2020 ◽  
pp. 105566562096957
Author(s):  
Bahadır Sancar ◽  
Şuayip Burak Duman

Objective: This study aimed to evaluate the Le Fort I osteotomy line and pterygomaxillary junction via cone-beam computed tomography in individuals with cleft lip and palate (CLP). Design: Retrospective study. Patients and Methods: The study included individuals older than 16 years with CLP, who were scheduled for repositioning of the maxilla by Le Fort I osteotomy, and those with class III malocclusion with maxillary hypoplasia, who were scheduled for Le Fort I osteotomy. The measurements made in the area of the cleft of individuals with CLP were compared with both the side with no cleft and those with class III malocclusion with maxillary hypoplasia. A total of 11 measurements were made on the axial section parallel to the Frankfurt Horizontal plane, corresponding to the lower 1/5 of the distance between the infraorbital foramen and the anterior nasal spine. Results: There were significant differences both in the comparisons made between the individuals with CLP and those without CLP in terms of the canal-anterior alveolar crest (G) and sinus-anterior alveolar crest (L) measurements ( P < .05). The mean measurement values showed that the measurement results were higher in individuals with CLP in general. Conclusion: In conclusion, we believe that there might be difficulties both in osteotomy and down fracture stages during Le Fort I osteotomies performed in individuals with CLP.


Author(s):  
Ramin Foroughi ◽  
Oveis Khakbaz ◽  
Mehrdad Maneshi

Introduction Maxillary advancementis applied extensively for malocclusion class III correction.This procedure is done using one of the two methods, Conventional or High. Maxilla moves in both vertical and horizontal and only in the horizontal directions in Conventional and High method respectively, so expecting a difference in facialsoft tissue changes. In present study is a case series that describes this issue. Materials and Methods: The cases included 30 patients with class III malocclusion due to maxillary deficiency, whom underwent Le Fort I osteotomy for maxillary advancement in Shahid Beheshti Hospital in Babol, Iran during 1995 to 1995. According to surgical technique, the cases were placed in group 1 (Conventional) or group 2 (High). Maxillary advancement and changes in hard and soft tissue of the middle and lower facial regions where measured through tracing on the lateral cephalometry. Intra-group and inter-group statistical comparisons were done using SPSS20 software at significance level as 0.05. Result: The pre-surgical mean size of SNA, SNB, nasolabial and mentolabial angles was similar in two groups. In all patients, after surgery, SNA angle size was increased and SNB، nasolabial and Mentolabial angles size were decreased. The mean value of these change was similar in two groups. In group 2, the displacement of point A ‘(mean difference: 1.30 mm) and Labrale Superius (mean difference: 1.40 mm) were significantly more than group 1. The amount of displacement of SN (mean difference: 1.30 mm), Labrale Inferius (mean difference: 0.88 mm) and Pogonion (mean difference: 0.23 mm) points in group 2 was higher than that of group 1, but this difference was not statistically significant. Conclusion: It is needed strong evidence for decision about selecting High or Conventional approach maxillary advancement in terms of facial aesthetic aspects. So, further studies with larger sample sizes and cohort or quasi-experimental design is suggested


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