scholarly journals Analysis of MYO1H Gene Polymorphism in Skeletal Class-III Malocclusion Due to Mandibular Prognathism

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 (6) ◽  
pp. 2520
Author(s):  
Andrea Deregibus ◽  
Simone Parrini ◽  
Maria Chiara Domini ◽  
Jacopo Colombini ◽  
Tommaso Castroflorio

Many studies report that maxillofacial growth is influenced by genetic and environmental elements and that incorrect breathing, chewing, sucking, and swallowing are promoting factors of malocclusion. This study aims to evaluate the function and the influence of the tongue positions in patients with Angle class III malocclusion, maxillary hypoplasia, and posterior crossbite. One hundred patients, aged between 6 and 12 years old, were enrolled for the study. In the first group, patients with a diagnosis of class III malocclusion, affected by maxillary hypoplasia, skeletal class III, and posterior dental crossbite were recruited. In the control group, not treated patients with no malocclusion, skeletal class I, and without posterior dental crossbite were selected. Regarding atypical deglutition, no statistical differences were reported between the two groups, and 14% of patients reported ankyloglossia. Statistical differences were found in tongue rest position and during the execution of “hold and pull” and “chuck” exercises. Results obtained in this observational study showed that the clinician (orthodontist or general dentist) should analyze the presence/absence of atypical swallowing, the anatomical and functional aspects, and the tongue behavior in the rest position.


2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Siti Nazirah Yahya ◽  
Nurul Syafiqah Abdul Razak ◽  
Noraini Abu Bakar ◽  
Khairani Idah Mokhtar ◽  
Azrul Fazwan Kharuddin

Introduction: Evidence suggests that several genes; including MYO1H, play an important role in the etiology of Class III malocclusion. Single nucleotide polymorphism (SNP) in marker rs10850110 (locus 12q24.11) within MYO1H gene has been associated with the incidence of mandibular prognathism (MP). MYO is a class 1 myosin that is responsible for the synthesis of Matrilin-1; an important protein involved in the formation of cartilage's extracellular matrix, hence is implicated in the formation of mandibular condyle cartilage. This study aimed to detect the presence of MYO1H (rs10850110) SNP and to determine its genotype and allele distribution in MP patient in the local population. Materials and Methods: The sample comprises of 31 patients; 14 patients from class I malocclusion (control samples) and 17 patients from class III malocclusion (MP). Cephalometric measurements were performed prior to saliva samples collection. The DNA was amplified using the specific primers for the marker rs10850110 and the genotyping was done by sequencing. Chi-square test was used to determine the over-representation of marker allele (p<0.05). Results:  Presence of MYO1H SNP (rs10850110) was detected in local population analysed and the distribution of its genotype and allele could be observed. There were significant differences between allele (p=0.000) and genotype (p=0.000) frequency within control (Class I) and Class III malocclusion. Conclusion(s):  Our findings are in agreement with previous studies suggesting positive influence of MYO1H (rs10850110) SNP in the incidence of MP. Further studies should be developed in order to understand the exact role and mechanism of MYO1H in different classes of malocclusions.


2015 ◽  
Vol 86 (3) ◽  
pp. 421-430 ◽  
Author(s):  
Svetlana Tyan ◽  
Hong-Sik Park ◽  
Munkhshur Janchivdorj ◽  
Sun-Ho Han ◽  
Su-Jung Kim ◽  
...  

ABSTRACT Objective:  To evaluate the characteristic transverse dental compensations in patients with facial asymmetry and mandibular prognathism and to compare features of dental compensations between two types of mandibular asymmetry using 3-dimensional (3D) cone-beam computed tomography (CBCT). Materials and Methods:  Seventy-eight adult patients with skeletal Class I (control group; n  =  33; 19 men and 14 women) or skeletal Class III with facial asymmetry (experimental group; n  =  45; 23 men and 22 women) were included. The experimental group was subdivided into two groups according to the type of mandibular asymmetry: translation type (T-type; n  =  20) and roll type (R-type; n  =  19). CBCT images were acquired before orthodontic treatment and 3D analyses were performed. Results:  The transverse dental distance was significantly different between the two groups only at the palatal root apex of the maxillary first molar (P &lt; .05). In the experimental group, the first molar axes were compensated significantly on both arches except the maxillary nondeviated side. The vertical molar heights were different between the two groups only on the maxillary arch (P &lt; .001). The R-type showed greater mandibular ramal length difference and menton deviation than the T-type (P &lt; .001). In the R-type, transverse compensation of the maxillary first molars was more obvious than with the T-type, which resulted in canting in the maxillary occlusal plane. Conclusions:  Mandibular asymmetry with prognathism showed a characteristic transverse dental compensation pattern. The mandibular asymmetry type influenced the amount and direction of molar compensation on the maxillary arch.


2008 ◽  
Vol 78 (6) ◽  
pp. 1141-1152 ◽  
Author(s):  
Manuela Mucedero ◽  
Antonella Coviello ◽  
Tiziano Baccetti ◽  
Lorenzo Franchi ◽  
Paola Cozza

Abstract Objective: To identify the stability factors of skeletal Class III malocclusion after double-jaw surgery by a systematic review of the literature. Materials and Methods: The survey covered the period from September 1959 to October 2007 and used the MeSH, Medical Subject Headings. The inclusion criteria were stability of bimaxillary surgery of the permanent dentition, adult patients with skeletal Class III malocclusion, a follow-up of at least 12 months, randomized and nonrandomized controlled clinical trials (RCCTs; CCTs), prospective and retrospective studies with and without concurrent untreated as well as normal controls, and clinical trials (CTs) comparing at least two treatment strategies without any untreated or normal control group. Results: The search strategy resulted in 1783 articles. After selection according to the inclusion/ exclusion criteria, 15 articles qualified for the final review analysis. Quality was low in two studies, medium in twelve, and medium/high in one article, which was represented by a RCT (randomized clinical trial). Most of the studies had sufficient sample size, method error analysis, and adequate statistical methods. Thus, the quality level of the studies was sufficient to draw evidence-based conclusions. Conclusions: Surgical correction of skeletal Class III malocclusion after combined maxillary and mandibular procedures appears to be stable for maxillary advancements up to 5 mm and for the correction of presurgical sagittal intermaxillary discrepancies smaller than 7 mm.


2013 ◽  
Vol 83 (4) ◽  
pp. 630-640 ◽  
Author(s):  
Shushu He ◽  
Jinhui Gao ◽  
Peter Wamalwa ◽  
Yunji Wang ◽  
Shujuan Zou ◽  
...  

ABSTRACT Objective: To evaluate the effect of the multiloop edgewise arch wire (MEAW) technique with maxillary mini-implants in the camouflage treatment of skeletal Class III malocclusion. Materials and Methods: Twenty patients were treated with the MEAW technique and modified Class III elastics from the maxillary mini-implants. Twenty-four patients were treated with MEAW and long Class III elastics from the upper second molars as control. Lateral cephalometric radiographs were obtained and analyzed before and after treatment, and 1 year after retention. Results: Satisfactory occlusion was established in both groups. Through principal component analysis, it could be concluded the anterior-posterior dental position, skeletal sagittal and vertical position, and upper molar vertical position changed within groups and between groups; vertical lower teeth position and Wits distance changed in the experimental group and between groups. In the experimental group, the lower incisors tipped lingually 2.7 mm and extruded 2.4 mm. The lingual inclination of the lower incisors increased 3.5°. The mandibular first molars tipped distally 9.1° and intruded 0.4 mm. Their cusps moved 3.4 mm distally. In the control group, the upper incisors proclined 3°, and the upper first molar extruded 2 mm. SN-MP increased 1.6° and S-Go/N-ME decreased 1. Conclusions: The MEAW technique combined with modified Class III elastics by maxillary mini-implants can effectively tip the mandibular molars distally without any extrusion and tip the lower incisors lingually with extrusion to camouflage skeletal Class III malocclusions. Clockwise rotation of the mandible and further proclination of upper incisors can be avoided. The MEAW technique and modified Class III elastics provided an appropriate treatment strategy especially for patients with high angle and open bite tendency.


2020 ◽  
Vol 77 (4) ◽  
pp. 395-404
Author(s):  
Vladimir Sinobad ◽  
Ljiljana Strajnic ◽  
Tamara Sinobad

Bacground/Aim. Recently, maxillary and bimaxillary surgery gained the primacy in the surgical correction of class III deformities. The aim of this investigation was to compare the changes in the skeletal relationships in patients with mandibular prognathism after bimaxillary surgery. Methods. The study included 70 subjects divided into three groups. Twenty class III patients of the experimental group 1 underwent bilateral sagittal ramus osteotomy and twenty patients of the experimental group 2 were subjected to bimaxillary surgery. The control group consisted of 30 subjects with skeletal class I and physiological occlusion. Cephalometric research was conducted on 110 lateral cephalometric radiographs made in subjects of the experimental groups 1 and 2 before and after surgery and in subjects of the control group. Using the computer program ?Dr. Ceph?, 30 linear and angular skeletal variables were analyzed on each radiograph. Results. Bimaxillary osteotomies changed most of variables that characterize the mandibular prognathism. The changes in the sagittal plane included the significant increase of sella-nasion to the A point (SNA) angle (by 4? on the average) and the A point to B point (ANB) angle (6?), and significant reduction in angles sellanasion to the B point (SNB) (3?), gonial angle (ArGoMe) (8?), gonial angle inferior (NGoMe) (6.2?), and Bj?rks sum (7?). The vertical relationships were normalized by significant reduction in overall anterior face height N-Me (by 5 mm on the average), the lower anterior face height ANS-Me (4 mm), significant increase in the total posterior face height S-Go (2.5?3 mm), lower posterior face height PNS-Go (4 mm), and significant reduction of the basal and mandibular plane angles. Conclusion. Compared to the isolated mandibular operations, bimaxillary surgery changes more efficiently the sagittal and vertical skeletal relations in patients with class III deformities and harmonizes more successfully the entire skeletal facial profile.


2017 ◽  
Vol 18 (5) ◽  
pp. 410-414
Author(s):  
Mohamed I Hashem ◽  
Zeeshan H Ahmad ◽  
Sukumaran Anil ◽  
Khalid J Alanazi

ABSTRACT Introduction Chin cup (CC) therapy has been used as the traditional appliance for treating class III malocclusion during mixed dentition period. The aim of this study was to investigate the effect of CC on the improvement of skeletal and dentoalveolar skeletal changes in class III patients during mixed dentition stage. Materials and methods A total of 30 patients (7–9 years old) with skeletal class III malocclusion were selected based on clinical and cephalometric examination. Out of 30 patients, 20 underwent CC therapy. All orthodontic records and measurements were taken before and after treatment. Similar records were collected from the control group. The lateral cephalometric films were traced before and after treatment and analyzed. Results There was a significant improvement in maxillary and the mandibular skeletal measurements after CC therapy. Improvement of ANB angle and an increase in Wits appraisal have been detected in the treated group according to intermaxillary skeletal variables. Conclusion The study concluded that the CC therapy is effective for correcting skeletal class III malocclusion along with positive changes in the dentoskeletal variables during the mixed dentition stage. How to cite this article Al-Khalifa HN, Hashem MI, Alanazi KJ, Anil S. Orthopedic Effect of Chin Cup during Mixed Dentition Stage. J Contemp Dent Pract 2017;18(5):410-414.


2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Noraini Abu Bakar ◽  
Khairani Idah Mokhtar ◽  
Azrul Fazwan Kharuddin

Introduction: PAX9 (Paired box 9) gene is one of the genes which play significant role during craniofacial development. Single nucleotide polymorphism (SNP) in PAX9 has been associated with Class II/Division 2 malocclusion (with or without hypodontia). However, the relationship between PAX9 SNP marker (rs8004560) with mandibular prognathism (MP) has not been analysed, at least in our local population. This study aimed to detect the presence of PAX9 (rs8004560) SNP in Class III malocclusion patients (with MP) in the local population. Materials and Methods: Genomic DNA were extracted from unstimulated saliva of 31 class I malocclusion (control samples) and 30 patients from Class III malocclusion (MP). Cephalometric measurements were performed prior to saliva samples collection. The DNA was amplified using the specific primers for the marker rs8004560 and the genotyping was done by sequencing. Chi-square test was used to determine the overrepresentation of marker allele (p<0.05). Results:  Presence of PAX9 SNP (rs8004560) was detected in local population analysed and the distribution of its genotype and allele could be observed. There were significant differences between allele (p=0.000) and genotype (p=0.000) frequency within control (Class I) and Class III malocclusion. Conclusion(s): The most common allele of a marker flanking PAX9 (rs8004560) was over-represented in the mandibular prognathism (MP) subjects indicating the genetic association of PAX9 (rs8004560) SNP in the incidence of MP. Further studies involving larger number of samples should be developed in order to understand the exact role and mechanism of PAX9 in different classes of malocclusions.


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