Correlation between Mandibular Radiomorphometric Parameters and Gonial Angle size in Iranian Adults

Background/Aim. It is considered that the shortage of space is the major cause of the third molar impaction. The aim of this study was to establish the frequency of insufficient lower third molar eruption space in Serbian population, to question the differences in this frequency in the subjects of different age, to determine the influence of the lower third molar space (retromolar space) size on third molar eruption, and to investigate a possible correlation between the size of gonial angle and the space/third molar width ratio. Methods. Digital orthopantomograms were taken from 93 patients divided into two groups: early adult (16-18 years of age) and adult (18-26) patients. Retromolar space, mesiodistal third molar crown width, gonial angle and eruption levels were measured. Results. The space/third molar width in early adult subjects was smaller (p < 0.0001) and insufficient space was significantly more frequent (p = 0.0003) than in adult patients. Considerably more third molars erupted in case of enough space in both age groups (p < 0.0001). There was no difference between the means of gonial angle size in relations to the available space. Conclusions. The retromolar space/third molar width ratio is more favorable in adult subjects. Gonial angle is not in correlation with the retromolar space/third molar width ratio.

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Accuracy and Reproducibility of Facial Measurements of Digital Photographs and Wrapped Cone Beam Computed Tomography (CBCT) Photographs

Diagnostics ◽

10.3390/diagnostics11050757 ◽

2021 ◽

Vol 11 (5) ◽

pp. 757

Author(s):

Maged Sultan Alhammadi ◽

Abeer Abdulkareem Al-mashraqi ◽

Rayid Hussain Alnami ◽

Nawaf Mohammad Ashqar ◽

Omar Hassan Alamir ◽

...

Keyword(s):

Computed Tomography ◽

Soft Tissue ◽

Cone Beam Computed Tomography ◽

High Reliability ◽

Three Dimensional ◽

Cone Beam ◽

Cross Sectional ◽

Facial Profile ◽

Digital Photographs ◽

Gonial Angle

The study sought to assess whether the soft tissue facial profile measurements of direct Cone Beam Computed Tomography (CBCT) and wrapped CBCT images of non-standardized facial photographs are accurate compared to the standardized digital photographs. In this cross-sectional study, 60 patients with an age range of 18–30 years, who were indicated for CBCT, were enrolled. Two facial photographs were taken per patient: standardized and random (non-standardized). The non-standardized ones were wrapped with the CBCT images. The most used soft tissue facial profile landmarks/parameters (linear and angular) were measured on direct soft tissue three-dimensional (3D) images and on the photographs wrapped over the 3D-CBCT images, and then compared to the standardized photographs. The reliability analysis was performed using concordance correlation coefficients (CCC) and depicted graphically using Bland–Altman plots. Most of the linear and angular measurements showed high reliability (0.91 to 0.998). Nevertheless, four soft tissue measurements were unreliable; namely, posterior gonial angle (0.085 and 0.11 for wrapped and direct CBCT soft tissue, respectively), mandibular plane angle (0.006 and 0.0016 for wrapped and direct CBCT soft tissue, respectively), posterior facial height (0.63 and 0.62 for wrapped and direct CBCT soft tissue, respectively) and total soft tissue facial convexity (0.52 for both wrapped and direct CBCT soft tissue, respectively). The soft tissue facial profile measurements from either the direct 3D-CBCT images or the wrapped CBCT images of non-standardized frontal photographs were accurate, and can be used to analyze most of the soft tissue facial profile measurements.

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Modelling growth curves of the normal infant’s mandible: 3D measurements using computed tomography

Clinical Oral Investigations ◽

10.1007/s00784-021-03937-1 ◽

2021 ◽

Author(s):

Jan Aart M. Schipper ◽

Manouk J. S. van Lieshout ◽

Stefan Böhringer ◽

Bonnie L. Padwa ◽

Simon G. F. Robben ◽

...

Keyword(s):

Computed Tomography ◽

Growth Models ◽

Normal Growth ◽

Growth Patterns ◽

Ct Scans ◽

Mandibular Ramus ◽

Linear Measurements ◽

Mandibular Growth ◽

Gonial Angle ◽

Mandibular Body

Abstract Objectives Data on normal mandibular development in the infant is lacking though essential to understand normal growth patterns and to discriminate abnormal growth. The aim of this study was to provide normal linear measurements of the mandible using computed tomography performed in infants from 0 to 2 years of age. Material and methods 3D voxel software was used to calculate mandibular body length, mandibular ramus length, bicondylar width, bigonial width and the gonial angle. Intra- and inter-rater reliability was assessed for these measurements. They were found to be sufficient for all distances; intra-class correlation coefficients were all above 0.9. Regression analysis for growth modelling was performed. Results In this multi-centre retrospective study, 109 CT scans were found eligible that were performed for various reasons (e.g. trauma, craniosynostosis, craniofacial abscesses). Craniosynostosis patients had larger mandibular measurements compared to non-craniosynostosis patients and were therefore excluded. Fifty-one CT scans were analysed. Conclusions Analysis showed that the mandible increases more in size vertically (the mandibular ramus) than horizontally (the mandibular body). Most of the mandibular growth occurs in the first 6 months. Clinical relevance These growth models provide insight into normal mandibular development in the first 2 years of life. This reference data facilitates discrimination between normal and abnormal mandibular growth.

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Mandibular Dysmorphology in Unicoronal Synostosis and Plagiocephaly without Synostosis

The Cleft Palate-Craniofacial Journal ◽

10.1597/1545-1569_1996_033_0418_mdiusa_2.3.co_2 ◽

1996 ◽

Vol 33 (5) ◽

pp. 418-423 ◽

Cited By ~ 14

Author(s):

Alex A. Kane ◽

Lun-Jou, Lo ◽

Michael W. Vannier ◽

Jeffrey L. Marsh

Keyword(s):

Body Length ◽

Statistical Significance ◽

Coronoid Process ◽

Therapeutic Interventions ◽

Lateral Side ◽

Tertiary Referral Center ◽

Gonial Angle ◽

Affected Side ◽

Mandibular Body ◽

Ct Data

Patients with unicoronal synostosis (UCS) or plagiocephaly without synostosis (PWS) have distinctive skull dysmorphologies. Associated mandibular dymorphologies have been suspected but not quantified. This study was performed to test the hypothesis that discrete mandibular dysmorphology exists in both UCS and PWS. All patients at a tertiary referral center at a medical school-affiliated children's hospital with confirmed diagnosis of UCS or PWS with adequate pretreatment CT data were included in the study population, which population was comprised of 20 UCS, 23 PWS, and 8 normal infants. Each patient had a head CT scan using 2-mm slices. 3-D images were created using AnalyzeTM, a biomedical imaging program. The mandibles were isolated, and the coordinates of 8 landmarks were sampled from each mandible by a single investigator: a single volume value was measured, and 9 linear distances and 4 angles were calculated. Corresponding measurements from each hemimandible were expressed as ratios of ipsilateral/contra lateral side. In UCS, the affected side was defined as the side ipsilateral to the synostosis; in PWS, the affected side was defined as the side ipsilateral to the occipital flattening. The results from both groups were t tested for statistical significance. For UCS, statistically significant (p < .001) findings included: ipsilateral hemimandibular volume 5% smaller than contralateral; affected hemimandibular body length 1.9% shorter; affected gonial angle 2.6% more acute; affected coronoid process tilted anteriorly 2.5%; and distances from condylion and tip of the coronoid process to the chin landmarks 4% shorter on the affected side. For PWS, significant findings included: affected hemimandibular volume 3.8% larger; ramal height 3.5% shorter; mandibular body length 3% longer; and coronoid process tilted anteriorly by 2.3% on the affected side. In the UCS/PWS comparison, findings included: affected hemimandibular volume in UCS 8.7% less; affected gonial angle in UCS 3% more acute; affected mandibular corpus length in UCS 5% shorter; distances from the condylion and the tip of the coronoid process to the chin landmarks 4% shorter on the affected side in UCS. The hypothesized presence of diagnosis specific mandibular dysmorphology in UCS and PWS is confirmed. This analysis forms the baseline for study of the effects of unperturbed growth or therapeutic interventions upon the dentoskeletal dysmorphology of these anomalies.

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Orthognathic Surgery for Correction of Patients With Mandibular Excess: Don’t Forget to Assess the Gonial Angle

Journal of Oral and Maxillofacial Surgery ◽

10.1016/j.joms.2012.12.012 ◽

2013 ◽

Vol 71 (6) ◽

pp. 1063-1072 ◽

Cited By ~ 7

Author(s):

Marcello Guglielmi ◽

Keith M. Schneider ◽

Giorgio Iannetti ◽

Changyoung Feng ◽

Alan Y. Martinez

Keyword(s):

Orthognathic Surgery ◽

Gonial Angle

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The Value of Lateral Cephalometric Variables Measured by Cephalogram in Sex Determining among Iranians

Global Journal of Health Science ◽

10.5539/gjhs.v9n6p214 ◽

2016 ◽

Vol 9 (6) ◽

pp. 214

Author(s):

Naimeh Farhidnia ◽

Siamak Soltani ◽

Kamran Aghakhani ◽

Sasan Salehi ◽

Leila Khloosy ◽

...

Keyword(s):

Cranial Base ◽

Personal Identification ◽

Effective Length ◽

Cross Sectional ◽

Male And Female ◽

Gonial Angle ◽

Anterior Nasal Spine ◽

Specificity And Sensitivity ◽

Lateral Cephalograms ◽

Cephalometric Measurements

PURPOSE: Sex determination is one of the most important aspects of the personal identification in forensic medicine. The present study thus aimed to assess the value of cephalogram in determining sex by applying eleven linear and an angular cephalometric variables measured on lateral cephalograms among Iranians.METHODS: In a cross-sectional study, 11 linear and 1 angular cephalometric measurements were studied. Those are: basion to anterior nasal spine, upper facial height, length of cranial base, total face height, frontal sinus height, mastoidale to sella-nasion plan, mastoidale to porion-orbital plan, mastoid height from cranial base, mastoid with at the level of cranial base, mandibular effective length (central condyle to prognation), occipitofrontal diameter, and gonial angle. Measurements were assessed in 150 individuals (75 males and 75 females) aged 25 to 54 years. After preparing lateral cephalograms, the cephalometric measurements were analyzed using PACS software. SPSS version 22.0 was used for analysis. P values of 0.05 or less were considered statistically significant.RESULTS: With the exception of gonial angle, comparison of lateral cephalometric indices between two sexs showed greater values in males than in females (p<0.001). In general, almost all of the cephalometric measurements were found reliable to distinguish between male and female sex skulls with a high sensitivity (100%) and specificity (97.3% to 1000%).CONCLUSION: The cephalometric measurements used in this study are able to differentiate with high specificity and sensitivity between male and female skull

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A New Orthodontic-Surgical Approach to Mandibular Retrognathia

Bioengineering ◽

10.3390/bioengineering8110180 ◽

2021 ◽

Vol 8 (11) ◽

pp. 180

Author(s):

Francisco Vale ◽

Joana Queiroga ◽

Flávia Pereira ◽

Madalena Ribeiro ◽

Filipa Marques ◽

...

Keyword(s):

Stainless Steel ◽

Orthognathic Surgery ◽

Growth Disorders ◽

Facial Skeleton ◽

Mandibular Bone ◽

Gonial Angle ◽

Lower Canine ◽

Bone Segment ◽

Free Solder ◽

Mandibular Retrognathia

(1) Background: Mandibular deficiency is one of the most common growth disorders of the facial skeleton. Recently, distraction osteogenesis has been suggested as the treatment of choice for overcoming the limitations of conventional orthognathic surgery; (2) Methods: A new custom-manufactured dental-anchored distractor was built and anchored in the first molar and lower canine. It consists of a stainless-steel disjunction screw, adapted and welded to the orthodontic bands through two 1.2 mm diameter connector bars with a universal silver-based and cadmium-free solder; (3) Results: The distractor described can be a useful tool to correct mandibular retrognathia and is better tolerated by patients, especially in severe cases; (4) Conclusions: The dental-anchored distractor increases the anterior mandibular bone segment without affecting the gonial angle or transverse angulation of the segments and avoids posterior mandibular rotation, overcoming the limitations of conventional surgical treatment.

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A 3D Reconstruction Framework of Buildings Using Single Off-Nadir Satellite Image

Remote Sensing ◽

10.3390/rs13214434 ◽

2021 ◽

Vol 13 (21) ◽

pp. 4434

Author(s):

Chunhui Zhao ◽

Chi Zhang ◽

Yiming Yan ◽

Nan Su

Keyword(s):

Remote Sensing ◽

3D Reconstruction ◽

Spatial Resolution ◽

Satellite Image ◽

Geometric Constraints ◽

Single Image ◽

Multiple Images ◽

Angle Size ◽

Reconstruction Methods ◽

Mesh Models

A novel framework for 3D reconstruction of buildings based on a single off-nadir satellite image is proposed in this paper. Compared with the traditional methods of reconstruction using multiple images in remote sensing, recovering 3D information that utilizes the single image can reduce the demands of reconstruction tasks from the perspective of input data. It solves the problem that multiple images suitable for traditional reconstruction methods cannot be acquired in some regions, where remote sensing resources are scarce. However, it is difficult to reconstruct a 3D model containing a complete shape and accurate scale from a single image. The geometric constraints are not sufficient as the view-angle, size of buildings, and spatial resolution of images are different among remote sensing images. To solve this problem, the reconstruction framework proposed consists of two convolutional neural networks: Scale-Occupancy-Network (Scale-ONet) and model scale optimization network (Optim-Net). Through reconstruction using the single off-nadir satellite image, Scale-Onet can generate water-tight mesh models with the exact shape and rough scale of buildings. Meanwhile, the Optim-Net can reduce the error of scale for these mesh models. Finally, the complete reconstructed scene is recovered by Model-Image matching. Profiting from well-designed networks, our framework has good robustness for different input images, with different view-angle, size of buildings, and spatial resolution. Experimental results show that an ideal reconstruction accuracy can be obtained both on the model shape and scale of buildings.

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