F. FarahBakhsh; Fariborz Amini
Abstract
Background and aim: Knowledge of arch width characteristics in different malocclusion types such as Class II/2 malocclusion have considerable implications in orthodontic diagnosis and treatment planning. The purpose of this study was to compare the transverse dimensions of the dental arches in an Iranian ...
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Background and aim: Knowledge of arch width characteristics in different malocclusion types such as Class II/2 malocclusion have considerable implications in orthodontic diagnosis and treatment planning. The purpose of this study was to compare the transverse dimensions of the dental arches in an Iranian plaster cast samples with Class II division 2 (II/2) malocclusion and class I malocclsion.Materials and methods: In this case-control study, maxillary and mandibular intercanine (IC) and intermolar (IM) arch widths measured and recorded from 26 subjects with Class II/2 malocclusion. The data were compared with 26 control subjects with class I malocclsion.Results: In the Class II/2 group, the IC widths and IM widths in both arches were less than those in the control sample. Howeverstatistically significant difference was found only in maxillary IM width (p=0.001).Conclusion: The findings indicated that although both maxillary and mandibular arches are narrower in Class II/2 patientsbut posterior segment of maxilla is the site which is mostly affected by the Class II/2 etiologic factors.
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.
Amirfarhang Miresmaeili; Mohammad Atai; K. Mansouri; Nasrin Farhadian
Abstract
Background and aim: Present in-vitro study was designed to evaluate the effect of nanosilver incorporation on antibacterial properties and Bracket Bond Strength (BBS) of orthodontic composite resin. Materials and methods: A light curing composite resin was mixed with metallic nanosilver to obtain ...
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Background and aim: Present in-vitro study was designed to evaluate the effect of nanosilver incorporation on antibacterial properties and Bracket Bond Strength (BBS) of orthodontic composite resin. Materials and methods: A light curing composite resin was mixed with metallic nanosilver to obtain final concentrations of 0%, 0.5%, 1% and 2.5% (wt/wt). Scanning electron microscopy (TESCAN, VEGA II, XMU, Czech Republic) was used to confirm the uniform distribution of nanoparticles in resin matrix. Thirty disk type specimens (4.0 × 1.0mm) were prepared for each group. Antibacterial activity was determined by evaluation of bacterial growth in suspension media versus growth in direct contact with specimens. BBS and bond failure interface (ARI) were evaluated and compared between the specimens. Bacterial activity of control group compared with the group with maximum antibacterial activity. Results: There were no significant differences in bacterial growth in any specimens in suspension media (P=0.623). The results of second method (direct contact) showed significant differences between all groups (P<0.001). Specimens with maximum antibacterial activity (containing 1% nanosilver) and control group had no significant difference in the BBS (P=0.455). ARI was completely identical in these two groups. Conclusions: Nanosilver containing composite could confer surface antibacterial activity without significant difference on BBS and ARI.
Ahmad Sodagar; Elham Sadat Emadian Razavi; Y. Yazdani
Abstract
Background and aims: Nasolabial angle is an important landmark that affects patient’s profile and also appearance of smile. This study has done to assess the relationship between skeletal and dental parameters and nasolabial angle for formulating the individual value of the angle for each patient.
Subjects ...
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Background and aims: Nasolabial angle is an important landmark that affects patient’s profile and also appearance of smile. This study has done to assess the relationship between skeletal and dental parameters and nasolabial angle for formulating the individual value of the angle for each patient.
Subjects and methods: Sixty healthy girls who were referred to orthodontic department of Tehran University of Medical Science were included in the study. Eight skeletal, three dental and three nasal soft tissue parameters (14 parameters) were measured on lateral cephalograms.Results: There were no significant relationships between nasolabial angle and parameters which were analyzed, but derivatives of this angle which named FNA (Posteroinferior angle between Frankfort horizontal plane and columella of the nose) and FLA (Posteroinferior angle between Frankfort horizontal plane and upper lip) showed significant relationship with the parameters. FNA had a positive correlation with U1-Pal, U1-FH, U1-SN, SNA and SNB angles, FLA had positive correlation with SNA, SNB, U1-SN, U1-FH, U1-Pal, and SGn-SN. By means of Multiple Regression analysis for FLA angle, SNB and U1-FH, and for FNA angle, U1-PAL had significant effects. Conclusion: Hard tissue parameters couldn’t affect nasolabial angle, but they had an influence on its derivatives.
Azita Tehranchi; Hossein Behnia; Sepideh Soheilifar
Abstract
Background and aim: Bilateral mandibular distraction osteogenesis (BMDO) has been suggested as a suitable method for correcting severe mandibular deficiencies. The purpose of this study was to evaluate the cephalometric changes of patients undergoing BMDO.Materials and methods: Seven patients were selected ...
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Background and aim: Bilateral mandibular distraction osteogenesis (BMDO) has been suggested as a suitable method for correcting severe mandibular deficiencies. The purpose of this study was to evaluate the cephalometric changes of patients undergoing BMDO.Materials and methods: Seven patients were selected for BMDO, all suffering from severe mandibular retrognathia as a result of previous trauma. Pre-treatment (T1), post-treatment (T2) and follow up (T3) cephalograms were obtained. The changes in skeletal and soft tissue parameters were assessed by paired t-test within two time intervals (T1-T2 and T2-T3). Results with a P value <0.05 were considered statistically significant. Results: In patients treated by extra-oral distractor, BMDO improved jaw relationships by increasing SNB (12.1˚) and mandibular length (22.5mm) and decreasing ANB (10.3˚) and Wits (17.2mm). Lower facial height increased significantly (4.5mm). Dental relationships were changed by increasing interincisal angle (24.8˚) and decreasing IMPA (23.2˚) and overjet (8.8mm). Reduction in the distance between upper and lower lip to E-line led to changes in the soft tissue profile. Airway space analysis revealed an increase in the nasopharyngeal space (Nph2) (4.7 mm), the oropharyngeal space (Oph2) (5.4mm) and the posterior airway space (PAS) (9mm). The available cases remained stable during the follow up period.
Conclusion: BMDO improved maxillomandibular discrepancy by lengthening mandibular body. Lower anterior facial height was increased significantly. Lip prominency relative to the nose and the chin was decreased and dental relationships were corrected by the treatment. DO procedure significantly improves the pharyngeal spaces.
Masoumeh Johari; Farzad Esmaeili; Arman Saeedi vahdat; S. Naghinejad Ahmadi
Abstract
Background and aim: The aim of the present study was to measure the thicknesses of bone and soft issues in the mid palatal area at certain points for the placement of orthodontic mini-implants using CBCT and evaluate their relationships with age and gender.Materials and methods: A total of 161 subjects ...
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Background and aim: The aim of the present study was to measure the thicknesses of bone and soft issues in the mid palatal area at certain points for the placement of orthodontic mini-implants using CBCT and evaluate their relationships with age and gender.Materials and methods: A total of 161 subjects were evaluated in the present study, consisting of males (31.9%) with a mean age of 41.46±13.88 years and females (60.9%) with a mean age of 38.47±11.66 years. In all the samples 20 points were evaluated. First, the incisive foramen was located. Then para-coronal cross-sections were prepared at 4-, 8-, 16- and 24-mm distances from the posterior wall of the incisive foramen; in addition, on each cross-section, the mid-sagittal and para-sagittal areas were determined at 3- and 6-mm intervals bilaterally (5 points on the whole). The soft tissue and bone thickness were measured at these points. Results: The soft tissue thicknesses were significantly different at all the 20 sample points between males and females (P<0.05). In other words, at all the points the soft tissue thicknesses were significantly greater in males compared to females. In some areas there was a positive relationship between age and soft tissue thickness (P<0.01), i.e. the soft tissuethickness increased with age. In addition, in the majority of points the overall bone thickness was significantly higher in males compared to that in females; however, in the majority of points, no positive relationship was found between age and bone thickness.. Conclusion: Age was not a determining factor for bone thickness, while where was a stronger relationship between soft tissue thickness and age. In addition, the most appropriate locations for the placement of orthodontic mini-implants were paramedian area at 3- and 6-mm distances from the suture, 4 mm posterior to the incisive foramen.
Ali Rafighi; Aydin Sohrabi; Saeid Foroughi Moghaddam; Seyed Hossein Moslemzadeh; Reza Nemati; Leila Roshangar
Abstract
Background and aim: The aim of this study was to find out influence of the orthodontic devices on the oral epithelial cells.Materials and methods: Cells of lower lip oral mucosa from 32 orthodontic patients were collected by exfoliative cytology in three times: Day 0 (just before appliance placement), ...
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Background and aim: The aim of this study was to find out influence of the orthodontic devices on the oral epithelial cells.Materials and methods: Cells of lower lip oral mucosa from 32 orthodontic patients were collected by exfoliative cytology in three times: Day 0 (just before appliance placement), and 14 and 60 days after appliance insertion. Nuclear (NA) and cytoplasmic (CA) areas, NA/CA ratio, cell morphology, and cellularity of smears were analyzed by using cytologic and cytomorphometric methods.Results: The NA of the cells adjacent to orthodontic devices diminished after appliance placement, and reached to its lower level in day 60 (p = 0.000). Investigated epithelial cells showed insignificant changes in CA. Type II inflammatory smears, according to Papanicolau, increased insignificantly after the treatment initiation. Superficial epithelial cells, were predominant cell type in day 14 and 60 (p= 0.002)..Conclusion: Orthodontic appliances cause reduction in NA and induce epithelial hyperkeratosis in lower lip mucosa.
Mohammad Hosseinikhah; Soghra Yassaie; Navid Rezaie
Abstract
Background and aim: This study is aimed at specifying the indices of soft tissues of the face in male subjects 18-25 years old with proportional faces in Yazd, and comparing it to the northern European race using photography and anthropometry.Materials and methods: 80 male individuals in age range of ...
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Background and aim: This study is aimed at specifying the indices of soft tissues of the face in male subjects 18-25 years old with proportional faces in Yazd, and comparing it to the northern European race using photography and anthropometry.Materials and methods: 80 male individuals in age range of 18-25 were selected from among university students of yazd who had normal occlusion and proportional faces with no background of Truma, mandible-face surgery, rhinoplasty or orthodontic treatment. Standard photography of “natural head position” (NHP) and half face position was shot on subjects. Then the facial anthropometric indices were measured directly using a caliper with long jaws. All the photographs were printed out in color, and facial angles were drawn and measured. Acquired data was analyzed using the statistical software of SPSS II.Results: This study shows that that face form in Iranian race is different from that of northern Europeans. The Ala-Ala, Zy'-Zy', Go'-Go' indices, nasofrontal angle, upper and lower lips’ vermilion, facial index, and mandible-face widthes were significantly different from the study on northern European race carried out by Farkas.Conclusion: Considering less cheek (malar) width and more facial index in our study compared to that of Farkas, Iranian samples were more inclined to the dolichofacial form of the face.
