Cephalometry
Diptesh Guha; Dolly Patel; Surina Sinha
Abstract
Aim: To validate Pi angle with other sagittal discrepancy indicators like Beta angle, Yen angle and W angle in skeletal Class I, II and III patients, to correlate the Pi angle with the size and position of the mandible, and to evaluate the reliability of Dolphin imaging software.
Methods: One hundred ...
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Aim: To validate Pi angle with other sagittal discrepancy indicators like Beta angle, Yen angle and W angle in skeletal Class I, II and III patients, to correlate the Pi angle with the size and position of the mandible, and to evaluate the reliability of Dolphin imaging software.
Methods: One hundred fifty subjects were nominated based on the inclusion criteria and their lateral cephalograms were traced based on their ANB angle, they were placed into skeletal Class I, II and III groups. A-P discrepancy indicators and parameters of the size and position of the mandible were traced manually and digitally.
Results: Pi angle had 85% and 100% accuracy in identifying skeletal Class II and III groups, respectively. Parameters of the morphology of the mandible were found to have statistically significant correlation with Pi angle e.g., mandibular base length (-0.265), SNB (-0.408), articular angle (0.277), facial angle (-0.800), and Y axis (0.728), etc. When data was compared between manual and digital tracing, there was no difference in the mean values of Pi angle (P=0.87), Beta angle (P=0.73), and Yen angle (P=0.64) between the two techniques, suggesting good accuracy of Dolphin imaging software.Conclusion: The Pi angle could accurately differentiate the sample into skeletal Class I, II and III groups. A statistically significant correlation was determined between Pi angle and most of the parameters of the size and position of the mandible. It was found that the imaging software Dolphin 3D is dependable to the analysis of cephalometric variables, which are not available in the software.
Cephalometry
Azita Tehranchi; Setrareh Sohrabi; Farnaz younessian; Fatemeh Zahedipour
Abstract
Aim: Following maxillary impaction, the mandible rotates around a center. Inaccurate determination of mandibular rotation can have profound effects on orthognathic surgical treatment planning and final surgical outcome. The present study determined the relationship between the cephalometric characteristics ...
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Aim: Following maxillary impaction, the mandible rotates around a center. Inaccurate determination of mandibular rotation can have profound effects on orthognathic surgical treatment planning and final surgical outcome. The present study determined the relationship between the cephalometric characteristics of candidates for maxillary impaction surgery using sagittal and vertical locations of the center of rotation of the mandible.Methods: In a descriptive and cross-sectional trial, 36 candidates for LeFort I maxillary impaction surgery were selected. Two lateral cephalograms were obtained in open and closed mouth positions. The center of rotation of the mandible was determined by the Reuleaux technique. Cephalometric measurements of the patients with the determined center of mandibular rotation locations (regions 1 and 4 of the coordinate axis) were done and the results were subjected to the student t-test.Results: The center of mandibular rotation was located in region 1 of the coordinate axis in 17 (50%) and in 17 (50%) in the 4th region of the coordinate axis. Statistically significant differences existed regarding the MP-SN (p<0.006), CO-GO (p<0.006), and CO-GN (p<0.04) at two regions of 1 and 4 for the center of rotation of the mandible in the coordinate axis.Conclusion: With the decreased length of the ramus and increased inclination of the plane, the center of rotation of the mandible tended to be situated at region 1 of the coordinate axis, and together with the increased length of the ramus and decreased plane inclination, the center of mandibular rotation tended to be located at region 4 of the coordinate axis.
Katayoon Khaleghi; Azin Nourian; Pooya Ghorbankhan; Arash Farzan
Abstract
Background: Following the morphological features of different races and ethnic groups, knowledge of standard dentofacial patterns of each ethnic group is essential. Therefore, this study aimed to explain cephalometric standards for the Zanjanian population according to Downs' analysis and compare them ...
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Background: Following the morphological features of different races and ethnic groups, knowledge of standard dentofacial patterns of each ethnic group is essential. Therefore, this study aimed to explain cephalometric standards for the Zanjanian population according to Downs' analysis and compare them to Caucasian individuals.Methods: Seventy lateral cephalometries of Zanjanian adults (17 - 29 years old) who had been referred to a private orthodontic office in Zanjan, Iran with class I molar and canine relationship and normal overjet and overbite as well as minimum crowding/spacing/rotations were scanned and traced with the Novatech scanner and Dolphin software version 10. Next, statistical analyses were performed in order to compare the Zanjanian population to Caucasians. Results: We found a significant difference between males and females in terms of interincisal angle, incisor-occlusal angle, incisor-mandibular plane angle, upper incisor proclination, facial angle, and angle of convexity.Discussion: The analysis of six statistically significant parameters indicates that the upper and lower incisors in women of Zanjan were proclined and protruded compared with those of Caucasian subjects. Due to the statistical analysis on facial angle and angle of convexity, women also show more maxillary prognathism and skeletal class II pattern. Generally, a comparison of Zanjanian population cephalometrics based on Downs' analysis showed an increase in maxillary prognathism, maxillary and mandibular incisal protrusion and posterior rotation of the mandible.Conclusions: In conclusion, the Zanjanian population tends to have more dental and skeletal class II patterns than the Caucasians. In addition, gender comparison indicates lower and upper-incisors protrusion in women of Zanjan.
Shekoufeh Mohammadi; Ladan Eslamian; Reza Motamedian
Volume 15, Issue 2 , September 2020, , Pages 1-7
Abstract
Context: The nose and lips area play an important role in facial appearance and nasolabial angle (NLA) can be considered as a determinant factor for attractiveness. The perception of beauty and attractiveness is vastly influenced by media and thus, can change with trends over time. The aim of this study ...
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Context: The nose and lips area play an important role in facial appearance and nasolabial angle (NLA) can be considered as a determinant factor for attractiveness. The perception of beauty and attractiveness is vastly influenced by media and thus, can change with trends over time. The aim of this study was to conduct a systematic review of literature on NLA in faces perceived as attractive over time and in different ethnic groups.
Evidence acquisition: This study was performed following Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guideline. We conducted an electronic search using PubMed, Scopus, and Embase databases with the employment of MeSH and free text terms "beauty"[MeSH], "esthetics"[MeSH], "soft tissue", "nasolabial angle", "attractive" and "cephalometric analysis". The inclusion criteria were studies that indicated facial attractiveness by a panel of at least 10 judges, evaluated the soft tissue profile characteristics, and reported the preferred NLA.
Results: The search results revealed 271 related articles, of which 21 studies investigated NLA as a conducive factor in profile attractiveness and were included in the review. The range of preferred NLA was 86° to 107° for men and 84° to 123.12° for women.
Conclusions: The most pleasing lip position and subsequently NLA is influenced by variables including the observer and subject’s gender, and their ethnic background as well as time. Over all, NLA in faces perceived as attractive is more obtuse in women than men. Compared to white norms, NLA is more acute among Chinese and African-Americans, while amongst Iranian women, it is not distinctly far from north American Caucasians. Over the course of time, preferred NLA has significantly changed in women but has been unwavering in men.
Samaneh Sadeghi; Zohreh Hedayati
Abstract
Background: Reverse chin cap appliance consists of a removable plate that is attached to a vertical projection hooks via elastics. This appliance is preferred for treatment of combination of maxillary retrognathia and mandibular prognathism malocclusion.
Objectives: The aim of this study was to assess ...
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Background: Reverse chin cap appliance consists of a removable plate that is attached to a vertical projection hooks via elastics. This appliance is preferred for treatment of combination of maxillary retrognathia and mandibular prognathism malocclusion.
Objectives: The aim of this study was to assess the effects of the reverse chin cap appliance to hard and soft tissues.
Methods: In this retrospective study 16 consecutive Class III patients (6 females, 10 males) with mean age of 9.3 ± 2 (Mean ± SD) years, who were treated with reverse chin cap appliance were selected. Pre- and post- treatment lateral cephalograms were analyzed. The overall changes were compared with growth changes in 20 control samples of Class I (10 females and 10 males) with Cl I occlusion and average age of 9.9 ± 3 (Mean ± SD) years. Independent Samples t-test was used to compare mean differences between the two of them. Differences were considered significant at P < 0.05. Results: At the end of treatment in treatment group, SNB angle decreased 3.7º and ANB angle increased by 2.9º both (P = 0.005). Mandibular length decreased 0.18 mm (P = 0.009). Lower incisors retroclined 10.03º (P = 0.001). Linear distance of the upper lip and lower lip to the E-line significantly decreased 2.3 mm (P = 0.04) 1.1 mm (P = 0.05) respectively. Nasolabial angle decreased significantly 4.1º (P = 0.005).
Conclusions: Reverse chin cap appliance therapy has a skeletal and dental effects. This treatment is effective in correction of the Cl III malocclusion by retroclination of the lower incisors, and retardation of mandibular growth. At the end of treatment, soft tissue profile
Javad Chalipa; Mehrnoush Momeni Roochi; Mahsa Mortazavi; Elahe Soltanmohamadi Borujeni; Sarvin Sarmadi; Maryam Khodabakhshi; Mohammad Hashem Hosseini
Abstract
Background: Severe skeletal class III malocclusions usually need a combined treatment of orthodontics and orthognathic surgery. Knowing about changes occurred following such treatments lead to improve facial esthetics and better treatment results.
Objectives: This study was done to determine cephalometric ...
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Background: Severe skeletal class III malocclusions usually need a combined treatment of orthodontics and orthognathic surgery. Knowing about changes occurred following such treatments lead to improve facial esthetics and better treatment results.
Objectives: This study was done to determine cephalometric changes of facial soft tissue after combined treatment in patients with skeletal class III problem.
Methods: 25 patients with skeletal class III discrepancy who needed a combined treatment, were selected. Changes in nasolabial angle , upper lip and lower lip to E-line distance, angle of convexity , lip-chin-throat angle and lower anterior facial height were measured before and 6 - 12 months after surgery. Changes in parameters were analyzed with Paired t-test. Results: Upper lip to E-line distance (P < 0.0001) and angle of convexity (P < 0.001) changed significantly following surgical procedures while changes of other parameters were not significant.
Conclusions: Clinical changes in the soft tissue following a combination of orthodontic treatment and orthognathic surgery in patients with skeletal class III discrepancy are significant while these changes mostly improves esthetics of patient’s facial profile.
Behnam Mirzakouchaki; Reza Faraji; Mahdi Rahbar; Hadi Shirvani
Abstract
Background: Lateral cephalometry is very important for the evaluation of growth, diagnosis, treatment planning and therapeutic evaluations. Considering the advantages of lateral cephalometric analyses with the automatic technique and given the existing problems, the present study was undertaken to use ...
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Background: Lateral cephalometry is very important for the evaluation of growth, diagnosis, treatment planning and therapeutic evaluations. Considering the advantages of lateral cephalometric analyses with the automatic technique and given the existing problems, the present study was undertaken to use a new automatic technique for determination of cephalometric landmarks.
Aim: The aim of the present study was to determine the specific anatomic area by SIFT algorithm for locating cephalometric points using an automatic technique.
Methods: In this study, 110 digital lateral cephalograms were randomly selected and pre-processing was carried out on the images. Three orthodontics used these cephalograms to manually select 11 cephalometric landmarks (point A, point B, PNS, ANS, Po, Or, N, Ar, Me, Gn and Pog) on a software program which had been designed to this end. The coordinates of the selected points were saved in the database for the corresponding process of the images. After completing the software program with these data, 30 new radiographs were submitted to the software program for anatomic determination of the points. SIFT algorithm was used in the software program for the anatomic identification of the landmarks. To make a comparison, these 30 cephalograms were manually analyzed by three orthodontists in order to evaluate the accuracy of the software program at various points. Paired t-teat was used to compare the manual and computerized techniques. Statistical significance was set at P < 0.05. Results: Based on the results, the differences between the manual and automatic methods in determining cephalometric landmarks were < 1 mm in 46% of cases, < 1.5 mm in 82% of cases and < 2 mm in 100% of cases. In addition, there were no significant difference between the two method except for points Or, Po and PNS (P > 0.05).
Conclusions: It was concluded that the designed algorithm had good performance for easy and relatively difficult points. In relation to very difficult points, too, it exhibited rather acceptable performance and located the points better than other algorithms.
Sanaz Soheilifar; Mohammad Ali Momeni
Abstract
Background: According to the close proximity of hyoid bone with dentofacial structures and its muscular attachments, a probable relationship between it and different types of skeletal patterns is suspected.
Objectives: The aim of this study is compare the position of hyoid bone in skeletal class I and ...
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Background: According to the close proximity of hyoid bone with dentofacial structures and its muscular attachments, a probable relationship between it and different types of skeletal patterns is suspected.
Objectives: The aim of this study is compare the position of hyoid bone in skeletal class I and class II patients.
Methods: In this study 50 cephalograms were divided into two groups, skeletal class I (1 ≤ ANB ≤ 4) and skeletal class II (ANB > 4), with 24 and 26 patients in each group, respectively. Horizontal and vertical position of hyoid bone were evaluated. SPSS software and student t-test were used to analyze the data. Results: According to the results of our study, there is no statistically significant difference between the hyoid bone position in skeletal class I and skeletal class II patients.
Conclusions: Since the hyoid bone position is similar in skeletal class I and class II patients, the skeletal pattern is not the only determinant of the position of hyoid bone.
Zahra Dalili Kajan; Navid Karimi Nasab; Jalil Khademi; Faegheh Gholinia; Zeinab Taheri; Mona Hajighadimi
Abstract
Background: Proper defining of normal landmarks in lateral cephalograms is important for establishing proper orthodontic treatment plan.
Objectives: To evaluate the agreement of dental students to identify normal landmarks (NLs) in digital lateral cephalograms and cone beam computed tomography (CBCT) ...
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Background: Proper defining of normal landmarks in lateral cephalograms is important for establishing proper orthodontic treatment plan.
Objectives: To evaluate the agreement of dental students to identify normal landmarks (NLs) in digital lateral cephalograms and cone beam computed tomography (CBCT) images.
Patients and Methods: In this study, lateral cephalograms and CBCT images of 11 orthodontic patients were selected. Three fourth-year dental students were asked to identify 19 NLs after calibrating digital lateral cephalograms and 3D CBCT images. Then, the distances of each landmark from the superior and anterior edges of the images were measured for each observer.
Results: The observers’ errors fell within a range of -1.03 to 2.74 in two-dimensional cephalometry and a range of -0.88 to 2.31 in 3D CBCT, showing a 95% limit of agreement. According to the intraclass correlation coefficient (ICC) comparison made by our student observers, only 5% of interobserver assessment in CBCT and 20% in lateral cephalometry showed poor reliability. These same observers showed more agreement when identifying NLs on soft tissue as compared to hard tissue structures and also in detecting NLs located in the midsagittal region rather than on lateral sides in both modalities. Their differences in agreement in detecting midsagittal NLs rather than on lateral sides were statistically significant (P = 0.0001).
Conclusions: The training of cephalometric tracing in orthodontic course based on 3D skull models and imaginary methods was deemed successful in increasing the ability of dental students to determine the precise location of NLs, even on CBCT images.
Mohammad Karim Soltani; Amirfarhang Miresmaeili; Bahareh Javanshir; Mojgan AkbarZadeh
Abstract
background and aim: functional appliances with various designs have been introduced in the treatment of Class II malocclusions. The aim of this study was to evaluate dentoskeletal effects of a modified bionator (FA) and Twin Block (TB) functional appliance in treatment of skeletal Class II malocclusion.Method ...
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background and aim: functional appliances with various designs have been introduced in the treatment of Class II malocclusions. The aim of this study was to evaluate dentoskeletal effects of a modified bionator (FA) and Twin Block (TB) functional appliance in treatment of skeletal Class II malocclusion.Method and material: in this retrospective study 30 treated cl II patients with overjet greater than 4mm have been selected from each of two private offices .in each office either FA or TB were used. Pre-treatment and post-treatment lateral cephalograms were digitized and traced with Dolphin Imaging software. ANCOVA and paired T test were used for analysis with SPSS software (19).Results: FA group consisted of 17 girls and 13 boys(mean age: 9.53± 1.1), TB group consisted of 12 boys and 18 girls(mean age: 10.26 ±.944 ) .ANB angle and overjet were reduced significantly in both groups. (p=.000) Mandibular body length demonstrated a significant increase in both groups( 3.06±4.98mm with TB and 3.03±5.52mm with FA ). In Both appliances significant retrusion of upper lip occurred as a result of decrease in overjet (TB=002, FA=.000). No statistical significant difference were found between two appliances.Conclusions: Treatment with both appliances resulted in correction of Class II discrepancy, reduction of overjet, and retrusion of upper lip. No significant dento-skeletal differences were observed between the 2 appliances.
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.
Esfandiar Akhavan Niaki; Tahereh HosseinZadeh Nik; B. Abbasian; Sedigheh SheikhZadeh
Abstract
Background and aim: G-axis which is defined by the angle between line S-N and S-G would be of great use in evaluation of the mandibular growth relative to other craniofacial structures the aim of this study was to evaluate the correlation of G-axis with vertical parameters in adult patients of different ...
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Background and aim: G-axis which is defined by the angle between line S-N and S-G would be of great use in evaluation of the mandibular growth relative to other craniofacial structures the aim of this study was to evaluate the correlation of G-axis with vertical parameters in adult patients of different malocclusions.Materials and methods: Lateral cephalograms of 90 patients with different malocclusions, were traced for evaluation of some horizontal and vertical cephalometric facial parameters. The patients were classified into three groups of 30 on the basis of clinical examination, ANB angle and wits appraisal. Pearson correlation test were conducted to compare the correlation of G axis with vertical parameters in different malocclusions.Results: Y-axis length showed significant and positive correlation with G-axis length. G-axis length and lower facial height had positive significant correlation in three categories. No significant correlation was found between G-axis length and ANB angle or wits. Conclusion: Application of the Y-axis and G-vector simultaneously seem to be more useful in cephalometric evaluation of mandibular growth pattern than emphasis on one.
Tahereh Jalaly; Farzaneh Ahrari; Rasool Saheb Alam; Foroozandeh Amini
Abstract
Objective: In spite of the continuous interest of orthodontists in the effects of soft tissues on dental and skeletal structures, this influence is not well clear. The purpose of this investigation was to clarify the effect of open lip posture on selected dentoskeletal features of growing children.Materials ...
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Objective: In spite of the continuous interest of orthodontists in the effects of soft tissues on dental and skeletal structures, this influence is not well clear. The purpose of this investigation was to clarify the effect of open lip posture on selected dentoskeletal features of growing children.Materials and Methods: In this cross sectional study, 193 pupils (99 girls, 94 boys) with age range of 9 to 13 years were participated. All patients were examined by a trained investigator and those having incompetent lip seal were selected and their dentoskeletal features were compared with a control group consisting of 36 subjects with normal occlusion. The data were analyzed by independent sample t-tests.Results: Among the 193 students examined in this study, 19 cases (10%) were diagnosed as having lip incompetence. A more open lip posture was associated with an increase in overjet, lower incisor inclination and Palatal plane to Mandibular plane angle (p<0.05); while Interincisal angle was significantly decreased in this group compared to control subjects (p<0.05). The amount of overbite and upper incisor inclination were not statistically different between the two groups (p>0.05).Conclusion: The data from this study suggest that lip incompetence may have a significant environmental effect on dentofacial structures. Since lip seal assessment can be achieved simply by practitioners, parents or teachers, it is suggested that adults observe and provoke children to maintain appropriate lip posture.
Maryam Poosti; Tahereh Jalaly; Farzaneh Ahrari; Samareh Mortazavi
Abstract
Aim: There are significant differences in morphological features of various racial and ethnic groups. The purpose of the present study was to identify cephalometric norms of Tweed diagnostic facial triangle in North East adolescents of Iran and to evaluate the effect of sexual dimorphism on cephalometric ...
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Aim: There are significant differences in morphological features of various racial and ethnic groups. The purpose of the present study was to identify cephalometric norms of Tweed diagnostic facial triangle in North East adolescents of Iran and to evaluate the effect of sexual dimorphism on cephalometric criteria of this population.Materials and methods: The sample comprised lateral cephalograms taken in natural head position of 40 pupils with normal occlusion (20 girls, 20 boys). Tweed diagnostic triangle was traced on each cephalogram and its angles were measured to the nearest 0.5°. The data were analyzed by SPSS software using independent samples t-tests and liotelling's test .Results: The lower incisors were significantly more proclined and mandibular plane was significantly steeper in north eastern Iranians compared to Caucasians (p<0.00 ). The average FMIA angle was significantly smaller than 65° as proposed by Tweed (p<0.001). There was no statistical difference in mean values of the three angles between boys and girls (p>0.05).Conclusion: There are significant differences in cephalometric norms of Tweed triangle between Iranians and Caucasians, showing important implications in orthodontic treatment planning. With respect to the significant differences in cephalometric norms of Iranians and Caucasians, it seems necessary to use standards of each racial group for orthodontic diagnosis and treatment of malocclusions in that population.
Mostafa Shahabi; Farzin Heravi; Naser Firoozi
Abstract
Aim: Some cphalometric angles change during growth and in accordance with facial height and other 'facial landmarks which make it less reliable for orthodontic diagnosis. The purpose of this study was to find out relationship between Beta Angle and the anterior-posterior position of jaws.
Materials ...
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Aim: Some cphalometric angles change during growth and in accordance with facial height and other 'facial landmarks which make it less reliable for orthodontic diagnosis. The purpose of this study was to find out relationship between Beta Angle and the anterior-posterior position of jaws.
Materials and Method: Sixty lateral cephalograms of 16 boys and 44 girls with class I, H or HI malocclusions were evaluated in our study. we traced all of the cephalograms to measure Beta angle and compare these values between different types of malocclusions. Data were annalized by means of T-student statistical test.
Results: Beta angle was 28.5° - 37.5° for class 1, less than 28.5° for class II and more than 37.5° for class III. There was no correlation between t3 angle and facial height.
Conclusion: Beta angle is independent from facial height. Beta Angle has an acceptable specificity and sensitivity for determining the anterior posterior position of Jaws (IJO 2006; 1: 184-7).
