Mahtab Nouri; Sohrab Asefi
Abstract
Introduction: The role of nasal septum in development of the maxilla after birth remains to be a question. Study of monozygotic twins may elucidate the role of epigenetic factors in growth and development of craniofacial structures.
Case Presentation: Herein, we report a case of 16 year-old male monozygotic ...
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Introduction: The role of nasal septum in development of the maxilla after birth remains to be a question. Study of monozygotic twins may elucidate the role of epigenetic factors in growth and development of craniofacial structures.
Case Presentation: Herein, we report a case of 16 year-old male monozygotic twins with Angle class III malocclusion and high angle facial pattern. One of them (patient M.H) had a history of mid-face trauma at the age of 6. Radiographic and clinical examinations revealed significant nasal septum deviation and the patient demonstrated nasal airway obstruction on the right side. The effects of this traumatic injury and the consequences of septal deviation were evident both clinically and radiographically at the age of 16. Increased airway resistance caused by septal deviation significantly affected the arch form and the configuration of the nose. The overall facial growth pattern is predetermined genetically but vertical dimension of the face may be more influenced by the environmental factors.
Conclusions: Patients should be carefully monitored after trauma to the nose and face and any deviation in the facial structure should be treated promptly in order to prevent asymmetries.
Mahtab Nouri; Sara Alijani; Alireza Akbarzade
Abstract
Background and aim: Number of studies evaluating the changes in head position following mandibular setback surgery (MSS) is scarce. This study sought to assess the craniofacial morphology, head and neck posture following mandibular setback surgery.Materials and methods: This retrospective, longitudinal, ...
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Background and aim: Number of studies evaluating the changes in head position following mandibular setback surgery (MSS) is scarce. This study sought to assess the craniofacial morphology, head and neck posture following mandibular setback surgery.Materials and methods: This retrospective, longitudinal, semi-experimental study was performed on 35 patients with Class III malocclusion. Radiographs taken at baseline and one year after surgery were retrieved from the medical records of patients. Lateral cephalograms were scanned and landmarks were marked on the first (baseline) radiograph. The second radiograph was superimposed on the first radiograph, true vertical lines or a ruler were considered as parallel images and a line was drawn along the SN from the point S. After superimposition, cephalometric variables were measured using Orthosurger X software (Iran). The mean, standard deviation (SD) and range of changes in each group were calculated. The significance of differences caused by surgery was analyzed using paired t-test.Results: The total mandibular length, mandibular body length, ramus length, SNB, SN-Pog, A-N-Pog, the angle between the body and ramus and the mandibular plane inclination significantly decreased; while, ANB angle, overjet and overbite significantly increased. No significant change occurred in the head position or cervical vertebra following MSS.
Conclusions: Since changes in the positions of cervical hard tissue were not significant, decreased airway volume following MSS seems to be related to the soft tissue structures namely the tongue, the soft palate and the suprahyoid and cervical muscles.
Mahtab Nouri; Arash Farzan; Alireza AkbarZadeh Baghban
Abstract
Background and aim: The aim of present study was to compare the 4th degree polynomials’ drawings generated by the invented laser scanner and ones generated by a CMM. Materials and methods: This diagnostic experimental study was conducted on maxillary and mandibular orthodontic study casts ...
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Background and aim: The aim of present study was to compare the 4th degree polynomials’ drawings generated by the invented laser scanner and ones generated by a CMM. Materials and methods: This diagnostic experimental study was conducted on maxillary and mandibular orthodontic study casts of 18 adults with normal Class I occlusion. First, coordinates of the points on all casts were measured by a CMM. Then, three-dimensional coordinates (X, Y, Z) of the points on the same casts were measured by a 3-D laser scanner designed in Shahid Beheshti University, Tehran.The validity and reliability of each of the systems were assessed by means of Intraclass Correlation Coefficient (ICC) and the root mean square(RMS). Results: The mean RMS for CBPs obtained from CMM and the fitted polynomial for upper and lower dental models was 0.885. The mean RMS for these CBPs on the custom defined polynomial obtained from the laser scanner was 0.911. The mean correlation coefficient for CBPs obtained from CMM and the fitted polynomial for upper and lower dental models was 0.996. The mean correlation coefficient for these CBPs on the custom defined polynomial obtained from the laser scanner was 0.994.Conclusion: The invented laser scanner is nearly as accurate as a CMM in providing an arch form drawing by recording of CBPs on the teeth and use of a 4th degree polynomial fitted to them.
Mahtab Nouri; Amin Aminian; Majid Heidarpour; Alireza Akbarzadeh Bagheban; Reza Massudi
Abstract
Aims: Comparison of 3D laser scanning and 2D conventional scanning in analysis of arch dimensions.
Methods: Twenty setups of upper and lower casts were duplicated in 20 corresponding dental stone models. 3D laser scanner was constructed in Shahid Beheshti University, and then casts were scanned with ...
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Aims: Comparison of 3D laser scanning and 2D conventional scanning in analysis of arch dimensions.
Methods: Twenty setups of upper and lower casts were duplicated in 20 corresponding dental stone models. 3D laser scanner was constructed in Shahid Beheshti University, and then casts were scanned with this machine. 2D scanning was performed by conventional scanner. Intercanine and intermolar widths and canine and molar depth were calculated directly on casts by digital caliper and on both scans. The mean differences between these three methods were evaluated by repeated measure analysis of variance and between each pair by paired t-test.Results: The correlation between intercanine and intermolar widths of all three modalities were higher than 0.9, but for canine and molar depths the correlation was not so strong and for canine depth was the weakest (R=0.45).The differences between intercanine and intermolar widths of all three modalities for upper and lower casts were significant, but for canine (and molar) depths, only the difference between 3D and direct technique for the upper casts was significant (P < 0.05). The highest recorded differences for intercanine and intermolar widths and molar and canine depths were 0.67, 0.42, 0.59 and 0.71 mm respectively.Conclusions: Digital models are valid reliable clinical tools for arch dimension evaluations. In addition, the most reliable measurements are intercanine and intermolar widths.
