scholarly journals Comparisons of Jaw Line and Face Line after Mandibular Setback: Intraoral Vertical Ramus versus Sagittal Split Ramus Osteotomies

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Chun-Ming Chen ◽  
Yu-Chuan Tseng ◽  
Edward Chengchuan Ko ◽  
Michael Yuan-Chien Chen ◽  
Kwei-Jing Chen ◽  
...  
Keyword(s):  
Null Hypothesis ◽  
Frontal Bone ◽  
Sagittal Split Ramus Osteotomy ◽  
Gonial Angle ◽  
Mandibular Setback ◽  
Mandibular Plane ◽  
Level 3 ◽  
Intraoral Vertical Ramus Osteotomy ◽  
Mandibular Setback Surgery ◽  
Lateral Profile

Background. This study investigates the differences in the lateral profile and frontal appearance after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) procedures for the correction of mandibular prognathism. Methods. Sixty patients (30 SSRO and 30 IVRO) underwent mandibular setback surgery. Serial cephalograms were obtained: (1) T1: approximately 1 month before surgery; (2) T2: at least 6 months after surgery for SSRO and at least 1 year after surgery for IVRO. The landmarks, linear distances, and related angles were measured. The t-test was applied to the intragroup and intergroup comparisons. The null hypothesis was that SSRO and IVRO made no difference in the facial appearance. Results. In the IVRO group, the ramus and gonial widths significantly decreased by 3.9 mm and 5.8 mm, respectively. SSRO significantly reduced the gonial angle by 2.6°, and IVRO increased it significantly by 5.3°. The postoperative increases at frontal bone levels 0 and 1 after IVRO were significantly larger than those after SSRO, but, at level 3, the increases after SSRO were larger than those after IVRO. In the frontal muscular and facial planes, SSRO and IVRO presented no difference. The frontal jaw angle and face angle were significantly larger with IVRO than with SSRO. Therefore, the null hypothesis was rejected. Conclusions. The ramus width and gonial width were significantly decreased in IVRO compared to SSRO. IVRO increased angles in the lateral profile (gonial angle and mandibular plane angle) and frontal appearance (jaw angle and face angle) more than SSRO did.

scholarly journals The Changes of Cheek Line (Lateral) and Face Line (Frontal) after Correction of Mandibular Prognathism

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yu-Chuan Tseng ◽  
Jung-Hsuan Cheng ◽  
Michael Yuan-Chien Chen ◽  
Kwei-Jing Chen ◽  
Chun-Ming Chen
Keyword(s):  
Null Hypothesis ◽  
Sagittal Split Ramus Osteotomy ◽  
Facial Profile ◽  
Mandibular Prognathism ◽  
Postoperative Change ◽  
Mandibular Setback ◽  
Mandibular Setback Surgery

Objective. The purpose of the present study was to investigate the improvements of facial profile and postoperative stability by single mandibular setback surgery. Materials and Methods. The study included twenty-seven patients who underwent mandibular prognathism correction by sagittal split ramus osteotomy (SSRO). Cephalometric radiograms (lateral and frontal) were collected and analyzed at three intervals: preoperatively (T1), immediately postoperatively (T2), and final follow-up postoperatively (T3). The lateral and frontal cephalometric parameters were measured. The immediate postoperative change (T21), postoperative stability (T32), and final surgical change (T31) were calculated and analyzed. The null hypothesis is that postoperative stability (T32) was not significantly correlated to amount of mandibular setback (T21). Results. The immediate postoperative change (T21) of menton (Me) was significantly backward 8.7 mm. In the final postoperative change (T31), average chin points anterior movements were approximately 0.32 mm. Investigating frontal appearance, inter ramus posterior (InterRp) and intergonion (InterGo) widths were significantly increased with 1.8 and 2.2 mm, respectively. Bilateral ramus angles were not significantly increased, about 1°. The horizontal Me (T32) had significant correlation (p=0.028) with amount of setback (T21). Therefore, null hypothesis is rejected. Conclusion. Postoperative relapse was significantly correlated to the amount of setback. The frontal transverse changes (InterRp and InterGo) were significantly increased.

scholarly journals Changes of Hyoid, Tongue and Pharyngeal Airway after Mandibular Setback Surgery by Intraoral Vertical Ramus Osteotomy

2010 ◽  
Vol 80 (2) ◽  
pp. 302-308 ◽  
Author(s):  
Soonshin Hwang ◽  
Chooryung Judi Chung ◽  
Yoon-Jeong Choi ◽  
Jong-Ki Huh ◽  
Kyung-Ho Kim
Keyword(s):  
Pharyngeal Airway ◽  
Mandibular Setback ◽  
Intraoral Vertical Ramus Osteotomy ◽  
Mandibular Setback Surgery ◽  
Vertical Ramus Osteotomy

MRI changes in the temporomandibular joint following mandibular setback surgery using sagittal split ramus osteotomy with rigid fixation

CRANIO® ◽  
2016 ◽  
Vol 35 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Namiaki Takahara ◽  
Yuji Kabasawa ◽  
Masaru Sato ◽  
Akemi Tetsumura ◽  
Tohru Kurabayashi ◽  
...  
Keyword(s):  
Temporomandibular Joint ◽  
Rigid Fixation ◽  
Sagittal Split Ramus Osteotomy ◽  
Mandibular Setback ◽  
Mandibular Setback Surgery ◽  
Mri Changes

scholarly journals Changes in Pharyngeal Airway After Mandibular Setback Surgery: A Retrospective Cephalometric Study

2019 ◽  
Vol 53 (4) ◽  
pp. 256-263
Author(s):  
Jayshree D. Daryanani ◽  
N. Vijay ◽  
K. Sadashiva Shetty ◽  
Riddhi Chawla
Keyword(s):  
Soft Palate ◽  
Sagittal Split Ramus Osteotomy ◽  
Mandibular Prognathism ◽  
Pharyngeal Airway ◽  
Mandibular Setback ◽  
Mandibular Setback Surgery ◽  
Cephalometric Study ◽  
Base Of The Tongue

Aim: To cephalometrically evaluate the alterations taking place in the pharyngeal airway space, hyoid bone, soft palate, and head posture after mandibular setback surgery (bilateral sagittal split osteotomy) for correction of mandibular prognathism, as well as to evaluate the immediate postsurgical and more than 6 months postsurgical adaptations of these structures. Setting and Design: A retrospective cephalometric study. Materials and Method: The study group consisted of 40 nongrowing patients (20 females and 20 males) with mandibular prognathism and ANB less than or equal to –2 degree for which mandibular setback surgery by bilateral sagittal split ramus osteotomy was performed along with fixed appliance therapy. There presurgical (T1), immediate postsurgical (T2), and more than 6 months postsurgical (T3) lateral cephalograms were analyzed. Statistical Analysis Used: Intragroup comparison was done by paired t-test. Results: Skeletal measurements after orthognathic surgery remained stable in the long term. It was evident that mandibular setback surgery narrowed the pharyngeal airway; however, these changes were not significant except at the base of the tongue. During the follow-up airway measurements at the base of the tongue, the intersection of tongue at the inferior border of mandible and the vallecula increased but they did not reach the presurgical values. Soft palate length increased significantly after surgery. Angulation of soft palate to nasal line also increased significantly following surgery but decreased during follow-up. Extension of the head occurred after surgery which was maintained even at long term. Conclusion: Careful analysis of airway should be performed, particularly in connection with large anteroposterior discrepancies and in those who have risk factors for development of obstructive sleep apnea. Such cases should be corrected by combined maxillary and mandibular osteotomies.

scholarly journals Clinical Comparative Study between Sagittal Split Ramus Osteotomy and Intraoral Vertical Ramus Osteotomy for Mandibular Setback

2010 ◽  
Vol 20 (3) ◽  
pp. 205-210 ◽  
Author(s):  
KENSUKE YAMAUCHI ◽  
TAKESHI KANEUJI ◽  
SHINNOSUKE NOGAMI ◽  
YOSHIHIRO YAMASHITA ◽  
TETSU TAKAHASHI ◽  
...  
Keyword(s):  
Comparative Study ◽  
Sagittal Split Ramus Osteotomy ◽  
Mandibular Setback ◽  
Intraoral Vertical Ramus Osteotomy ◽  
Vertical Ramus Osteotomy
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