Skeletal Facial Profile Research Articles

Role of the Growth Hormone Receptor (GHR) Gene in Skeletal Class II Malocclusion and Its Significant Influence on the Skeletal Facial Profile in Both the Sagittal and Vertical Dimensions: A Systematic Review.

This systematic review aims to determine the role of the growth hormone receptor (GHR) gene in skeletal malocclusion and its significant influence on the growth of the maxilla and the mandible in both sagittal and vertical dimensions. A search of the electronic databases of PubMed, Google Scholar, and Cochrane up to and including the year 2023 was made. In addition to this, a hand search of orthodontic and dentofacial orthopaedic journals was carried out. This search included randomized control trials. The Mesh terms used were "skeletal class II malocclusion", "mandibular retrognathism", "sagittal malocclusion", "genetic expression", "genetic factors", "genetic study", "genetic polymorphism", and "single nucleotide polymorphism". The inclusion criteria included studies such as clinical trials and orthopaedic appliances in the presurgical phase. The exclusion criteria for the study were studies not in the English language, case reports, case series, and studies with irrelevant data. It has been cited in various literature that polymorphic variations of the GHR gene could cause variations in mandibular morphogenesis affecting both the mandibular body length and ramal height. However, its effects are quite variable and are based on different population groups. Polymorphism of the GHR gene can be considered a reliable indicator predicting variations in affecting the growth of the mandible with greater significance in affecting the vertical ramal height compared to the body length of the mandible. Its effects on the maxillary skeletal base are rather limited comparatively.

Association of Polymorphism rs67920064 in ADAMTS9 Gene with Mandibular Retrognathism in a Chinese Population.

BackgroundMandibular retrognathism is a common oral and maxillofacial deformity that may cause a series of physical and psychological diseases. Many studies indicated that genetic factors play an important role in the occurrence of mandibular retrognathism. In this study, we assess the association between polymorphism rs67920064 in ADAMTS9 gene and mandibular retrognathism in a Chinese population.Material/MethodsSixty participants (20 to 45 y, mean age 32.79 y) were classified into Class I or mandibular retrognathism skeletal-facial profile groups in accordance with cephalometric parameters. Thirty patients with mandibular retrognathism were assigned to the subject group; the others were assigned to the control group. Cephalometric parameters including sella-nasion A point, SN point B, condylion-gnathion (Gn), and gonion-Gn were recorded. Saliva samples from these participants were collected and polymerase chain reaction-restriction fragment length polymorphism was used to distinguish different genotypes of the rs67920064 single nucleotide polymorphisms (SNPs).We evaluated the correlation between mandibular retrognathism and polymorphism rs67920064 in the ADAMTS9 gene.ResultsThe distribution of rs67920064 gene polymorphism in ADAMST9 gene conforms to Hardy-Weinberg equilibrium. The A point-nasion-B point angle of the participants with the GA genotype of the rs67920064 SNP showed significantly decreased values (P<0.05), but there was no difference in length of mandibular body. Beyond that, the chi-square test showed that the GA genotype of rs67920064 SNP was highly associated with mandibular retrognathism (P<0.05).ConclusionsOur research shows that there is an association between polymorphism rs67920064 in the ADAMTS9 gene and mandibular retrognathism in the Chinese population. Individuals with the GA phenotype are more likely to have mandibular retrognathism.

Skeletal changes in patients with mandibular prognathism after mandibular set back and bimaxillary surgery: A comparative cephalometric study

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.

Association between quality of life and severity of profile deviation in prospective orthognathic patients

to evaluate whether severity of skeletal facial profile deviation assessed by professionals associates with quality of life and psychosocial factors in patients with dentofacial deformities and prospective orthognathic treatment. The study consisted of 55 patients admitted to orthognathic treatment. Skeletal profile was assessed from lateral head films using cephalometric analysis. The following angles were used to assess the sagittal position of upper and lower jaw and profile: Sella-Nasion-A-point-angle, Sella-Nasion-B-point-angle, and A-point-Nasion-B-point-angle (ANB). For vertical assessment, gonial angle and the angle between Sella-Nasion and mandibular plane were used. Merrifield's Z-angle was used to assess soft-tissue profile. Severity of skeletal facial profile deviation was assessed with deviation in ANB angle. Orthognathic quality of life (OQoL) and psychosocial factors were defined with four questionnaires: Orthognathic Quality of Life Questionnaire, Symptom Checklist-90, Rosenberg Self-Esteem Scale, and a body image questionnaire. Increase in ANB deviation was associated with increased awareness of dentofacial deformity [Orthognathic Quality of Life Questionnaire subscale awareness of dentofacial deformity (OQLQ-AoDD), r = 0.319, P = 0.017). OQOL-AoDD was not found to be equal when ANB angle was divided into three different categories (χ 2 = 6.78, P = 0.034): G1. ANB = 0-4 degrees; G2. ANB <0 degrees; and G3. ANB >4 degrees. Furthermore, categories G1 and G2 differed significantly (U = 50.5, P = 0.017). Increase in ANB angle was also associated with a more positive body image (r = 0.342, P = .023). There were no significant correlations between other cephalometric variables, quality of life, and psychosocial factors. Skeletal facial profile seems to associate with some aspects of orthognathic quality of life. Professional cephalometric analysis of the severity of facial profile deviation correlates with patients' awareness of their own facial and dental appearance. Patients with more deviating skeletal profile are more aware of their dentofacial deformities compared to patients with normal values.

How tight is the relationship between the skeletal and soft-tissue facial profile: A geometric morphometric analysis of the facial outline

Correlations between facial bony structures and soft facial features are fundamental for facial approximation methods The purpose of this study was to assess the strength of the association between craniofacial shape and the shape of the soft-tissue profile and to determine the extent to which it might be possible to predict the latter from the former. Soft-tissue and skeletal facial profile curves were extracted from 86 lateral head cephalograms of a recent Central European population (52 males and 34 females, aged between 19 and 43 years), divided into five parts, segmented automatically and evaluated using geometric morphometrics. The magnitude of the hard–soft shape association was assessed by principal component analysis and subsequent multiple linear regression (Halazonetis, 2007), by partial least square analysis (PLS) (Rohlf and Corti, 2000) and the RV coefficient (Klingenberg, 2009). The greatest amount of association between the skeletal contour and overlying soft tissues was exhibited by the region of the forehead (predictive power: 95.1%, RV=0.91, correlation for PLS1 r=0,96), followed by the region of the nasal root (predictive power: 40.2%, RV=0.42, rPLS1=0.72) and the lower lip and chin (predictive power: 37.3%, RV=0.41, rPLS1=0.65). The smallest statistically significant covariation was displayed by the upper lip and the maxilla (predictive power: 9.6%, RV=0.14, rPLS1=0.43). The shape covariation between the nasal bridge and the tip and lateral border of the nasal aperture was found to be statistically insignificant (predictive power: 5.8%, RV=0.05, rPLS1=0.26). Shape covariation was visualized and described by thin-plate spine grids. These findings correspond with the observation that the shape of the nasal profile and the upper lip contour are difficult to reconstruct or predict reliably in facial approximations. It seems that the shape of soft tissues might not follow underlying structures as closely as expected.

Association analysis between rs6184 and rs6180 polymorphisms of growth hormone receptor gene regarding skeletal-facial profile in a Colombian population.

There is strong evidence that genetic factors may affect the craniofacial morphology. This study aimed to examine the association between the rs6184 and rs6180 polymorphic variants of the growth hormone receptor (GHR) gene and skeletal-facial profile in a Colombian population. Saliva samples from 306 individuals ranging in age from 15 to 53 (mean 24.33) years were collected. Cephalometric parameters were used to categorize the participants as Class I, Class II, or Class III skeletal-facial profile. The polymerase chain reaction-restriction fragment length polymorphism method was used to identify genotypes of the rs6184 and rs6180 single nucleotide polymorphisms (SNPs). The association of polymorphisms with the skeletal-facial profile was assessed separately and adjusted for confounding using a multivariate binary logistic regression model, alongside with analysis of linkage disequilibrium and haplotype associations. Although individuals carrying the CA genotype of the rs6184 SNP showed both significantly decreased values for ANB angle and increased measures concerning mandibular body length and mandibular length, no significant differences amongst genotype groups of rs6180 SNP were observed. Moreover, chi-square test and logistic regression analysis revealed that the CA genotype of rs6184 SNP and the A-A haplotype were highly associated with Class III skeletal-facial profile. Although these results do not support that rs6180 SNP could be identified as a predictor for skeletal-facial profile, they suggest that the allele A of rs6184 SNP alone or in combination with other SNPs in the GHR gene yields significant horizontal and longitudinal variations of the mandibular morphology and might be a strong/independent prognostic indicator for Class III skeletal-facial profile in the present population.

Cephalometric norms for the upper airway in a healthy North Indian population.

Objective:The aim was to obtain normative data for cephalometric measurements of the upper airway in the North Indian population.Design:Observational study. Setting: University department and teaching hospital out-patient clinic.Subjects and Methods:A total of 180 healthy patients were included out of which 90 were males (age range, 8-16 years), and 90 were females (age range, 8-16 years), with normal skeletal facial profile, no history of snoring, sleep apnea, upper airway disease, tonsillectomy or adenoidectomy, obesity, or pathology in the pharynx. Twenty cephalometric airway measurements, including size of the tongue, soft palate, nasopharynx, oropharynx, hypopharynx, and relative position of the hyoid bone and valleculae were obtained. Landmarks on cephalometric radiographs were digitized and measurements were made using a specially designed computer program. Error analysis of measurements was performed and comparison of measurements according to sex was made.Results:Significant sex dimorphism was seen for the majority of measurements, with the exception of minimal depth of the airway, oropharyngeal depth of the airway, and the soft palate angle with the hard palate.Conclusion:A minimum sagittal dimension of the upper airway was evident despite differences in measurements between sexes. Findings from this study should be a useful reference for the assessment of sleep apnea in the North Indian population.

Does Skeletal Facial Profile Influence Preoperative Motives and Postoperative Satisfaction? A Prospective Study of 66 Surgical-Orthodontic Patients

The aim of the present prospective study was to assess whether patients' pretreatment facial profile influenced their motives for wanting a change in their appearance. We also assessed whether their post-treatment facial profile influenced their overall satisfaction with surgical-orthodontic treatment, the perceived change in facial profile, and general appearance. Finally, we assessed whether their degree of satisfaction was influenced by the specific change in their facial profile. The gender differences in these variables were also analyzed. A total of 66 orthognathic surgery patients were examined. The skeletal facial profile was analyzed on the lateral head films. Using the sagittal relationship between the maxilla and mandible, all patients were classified into 1 of 9 facial profile types before and after treatment. The influence of the patients' appearance on their motives before treatment and their satisfaction after treatment were evaluated using questionnaires. The preoperative facial profile type had no influence on the strength of the appearance motives; however, men had stronger appearance motives than did women. Treatment was associated with a high degree of satisfaction with both the overall result of the treatment and the perceived change in profile and general appearance. Of those patients who obtained a relative prognathic mandibula after treatment, the men voiced more outspoken satisfaction with their general appearance than did the women. The overall treatment satisfaction was not related to any specific changes in the facial profile. Most of the patients expressed strong appearance motives before treatment and high degrees of satisfaction with the treatment afterward. The facial profile types had little influence on these parameters.

Changes in position and relationship between jaws in children treated with Delair’s mask

The aim of this study was to examine the efects of Delair`s mask on facial skeleton in patients with Class III antero-posterior jaw relationship. Two groups of children were evaluated. The first group of 34 children with Class III was treated with Delair`s mask. The second group of 46 children with Class III did not receive any orthodontic treatment and was presented as a control group. In the first group pretreatment and post treatment radiographic tracing was done while second tracing in the control group was done a year after diagnostic radiographic tracing. Analysis of the skeletal facial profile was done measuring SNA, SNB and ANB angles. Rotation of the maxillary base (NS/SpP), rotation of the mandibular base (NS/MP) and vertical relationship between jaws (SpP/MP) were also measured. The results were statisticaly analysed using T test, descriptive statistics and Wilcoxon`s test. The results of this study showed changes in facial skeleton in children treated with Delair`s mask compared to the control group. In the first group of children SNA and ANB angles were increased and the SNB angle was decreased.

Changes in position and relationship between jaws in children treated with Delair’s mask

The aim of this study was to examine the efects of Delair`s mask on facial skeleton in patients with Class III antero-posterior jaw relationship. Two groups of children were evaluated. The first group of 34 children with Class III was treated with Delair`s mask. The second group of 46 children with Class III did not receive any orthodontic treatment and was presented as a control group. In the first group pretreatment and post treatment radiographic tracing was done while second tracing in the control group was done a year after diagnostic radiographic tracing. Analysis of the skeletal facial profile was done measuring SNA, SNB and ANB angles. Rotation of the maxillary base (NS/SpP), rotation of the mandibular base (NS/MP) and vertical relationship between jaws (SpP/MP) were also measured. The results were statisticaly analysed using T test, descriptive statistics and Wilcoxon`s test. The results of this study showed changes in facial skeleton in children treated with Delair`s mask compared to the control group. In the first group of children SNA and ANB angles were increased and the SNB angle was decreased.

Growth changes in skeletal-facial profile and their significance in orthodontic diagnosis

Growth changes in skeletal facial profile were studied by analyzing serial cephalometric roentgenograms of forty persons who were grouped according to sex and occlusion. Four linear and four angular dimensions were measured. There were basic differences in the growth patterns of linear and angular dimensions. The linear dimensions showed puberal acceleration. In boys, greater forward growth was noticed in the lower face during the puberal period, making their faces more straight, square, and angular. The girls had rounded faces with slightly convex facial profiles. The group with normal occlusion was found to have a greater downward and forward growth pattern than the group with Class I malocclusion. The findings indicated that puberal growth changes in the face should be anticipated according to the sex of an individual. The faces of persons with malocclusion were more protrusive than those of persons with normal occlusion. The results of this study have a significant bearing on the clinical aspects of orthodontic practice. As has been observed, illustrated, and discussed in this article, no standard norm can be rigidly used to assess the growth pattern of an individual, as individual variation in skeletal growth is a normal occurrence.