scholarly journals The base of the tongue regulates the main occluding area in the patients with mandibular prognathism

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yuko Yamada ◽  
Hiroyuki Kanzaki ◽  
Satoshi Wada ◽  
Makoto Kurokawa ◽  
Hideho Handa ◽  
...  
2019 ◽  
Vol 53 (4) ◽  
pp. 256-263
Author(s):  
Jayshree D. Daryanani ◽  
N. Vijay ◽  
K. Sadashiva Shetty ◽  
Riddhi Chawla

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.


1989 ◽  
Vol 16 (4) ◽  
pp. 677-685
Author(s):  
Michael G. Parker ◽  
James A. Lehman ◽  
David E. Martin

2000 ◽  
Vol 8 (6) ◽  
pp. 264-264
Author(s):  
R. Alex Hsi, ◽  
Mary Ellen Witt, ◽  
Annie Yakshaw, ◽  
Amy Delay, ◽  
Joni Landes,

2015 ◽  
Vol 44 (8) ◽  
pp. 971-976 ◽  
Author(s):  
A. Moroi ◽  
Y. Ishihara ◽  
M. Sotobori ◽  
R. Iguchi ◽  
A. Kosaka ◽  
...  

Author(s):  
Anjana Atteeri ◽  
Praveen Kumar Neela ◽  
Pavan Kumar Mamillapalli ◽  
Vasu M. Sesham ◽  
Sreekanth Keesara ◽  
...  

Abstract Background Mandibular prognathism (MP) is a craniofacial deformity resulting from the combined effects of environmental and genetic factors. Although various linkage and genome-wide association studies for mandibular prognathism have identified multiple strongly associated regions and genes, the causal genes and variants responsible for the deformity remained ambiguous. Aim This research work was aimed to study the association between polymorphism rs10850110 of the MYO1H gene and skeletal class-III malocclusion in our local population. Materials and Methods Thirty patients with skeletal class III due to mandibular prognathism in the study group and 30 patients with skeletal class I in the control group were selected for this study. These patients were from both sexes and above age 10 years. Based on the cephalometric values, patients were categorized into study and control groups. SNB (angle between sella, nasion and point B at nasion) greater than 82 degrees with an ANB (angle between point A, nasion and point B at nasion) of less than 0 degrees in the study group and ANB (angle between point A, nasion and point B at nasion) of 2 to 4 degrees in the control group were categorized. The polymorphism (rs10850110) of the MYO1H gene was genotyped using polymerase chain reaction and restriction fragment length polymorphism. Associations were tested with SNP exact test using SNPstats software. Results The single-nucleotide polymorphism rs10850110 showed a statistically significant association with mandibular prognathism. The G allele of marker rs10850110 (5′ of myosin1H - MYO1H) was overrepresented when compared with the “A” allele in mandibular prognathism cases (p < 0.0001), and this was very significant. Conclusion These results suggest that the rs10850110 polymorphism of the MYO1H gene is associated with an increased risk for mandibular prognathism.


2021 ◽  
Vol 11 (10) ◽  
pp. 4444
Author(s):  
Ji Ho Yang ◽  
Dong Sun Shin ◽  
Jeong-Hun Yoo ◽  
Hun Jun Lim ◽  
Jun Lee ◽  
...  

Mandibular prognathism causes functional and esthetic problems. Therefore, many studies have been conducted to understand its etiology. Following our previous study, which revealed that the major characteristic of the mandible with prognathism is the volume/length ratio of the mandibular body and condyle, we analyzed the volume and orientation of the masseter muscle, which inserts into the mandibular body, expecting that the difference in the size of the masseter muscle causes the difference in the mandibular size. This study compared the masseter muscle of the participants in the prognathic group to those in the normal group on the volume/length ratio and orientation. The masseter muscle ratios (volume/length); the angle between the superficial and deep head of the masseter muscle; and the three planes (the palatal, occlusal, and mandibular) were analyzed. A total of 30 participants constituted the normal group (male: 15, female: 15) and 30 patients, the prognathic group (male: 15, female: 15). The results showed that the volume/length ratio of the masseter of the normal group was greater than that of the prognathic group (p < 0.05). In addition, the orientation of both the superficial and deep head of the masseter of the participants in the normal group was more vertical with respect to the mandibular plane than that of the prognathic group (p < 0.05). We concluded that the mechanical disadvantage of the masseter muscle of the prognathic group is attributed to mandibular prognathism.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jingheng Shu ◽  
Quanyi Wang ◽  
Desmond Y.R. Chong ◽  
Zhan Liu

AbstractLoadings in temporomandibular joints (TMJs) are essential factors in dysfunction of TMJs, and are barely noticed in treatment of maxillofacial deformity. The only approach, which can access stresses in TMJs, could expend day’s even weeks to complete. The objective of the study was to compare the differences of the morphological and biomechanical characteristics of TMJs between asymptomatic subjects and patients with mandibular prognathism, and to preliminarily analyze the connection between the two kinds of characteristics. Morphological measurements and finite element analysis (FEA) corresponding to the central occlusion were carried out on the models of 13 mandibular prognathism patients and 10 asymptomatic subjects. The results indicated that the joint spaces of the patients were significantly lower than those of the asymptomatic subjects, while the stresses of patients were significantly greater than those of asymptomatic subjects, especially the stresses on discs. The results of Pearson correlation analysis showed that weak or no correlations were found between the von Mises stresses and the joint spaces of asymptomatic subjects, while moderate, even high correlations were found in the patients. Thus, it was shown to be a feasible way to use morphological parameters to predict the internal loads of TMJs.


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