Maryam Poosit; Mohammad Basafa; Farzaneh Ahrari; Amin Reza Movahedian
Abstract
Aim: There is little information about the diagnostic ability of SNB and Facial angles in class II malocclusion. The aim of this study was to evaluate sensitivity and specificity of SNB and Facial angle in diagnosing anteroposterior position of mandible in patients with skeletal class II malocclusion.Material ...
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Aim: There is little information about the diagnostic ability of SNB and Facial angles in class II malocclusion. The aim of this study was to evaluate sensitivity and specificity of SNB and Facial angle in diagnosing anteroposterior position of mandible in patients with skeletal class II malocclusion.Material and Methods: Pretreatment cephalograms of 76 patients with skeletal class II malocclusion were assessed in this study. Sensitivity and specificity of SNB and Facial angles were determined using SPSS and ROC (Receiver Operative Characteristics) curves.Results: Sensitivity and specificity of Facial angle were 61 and 70 percent, respectively. The corresponding values for SNB angle were 40 and 86 percent. The highest sensitivity and specificity for SNB and Facial angles related to 75.5 and 79.5 degrees, respectively.Conclusion: The findings showed that in diagnosing mandibular anteroposterior position of class II patients, Facial angle is more sensitive and SNB angle is more specific. Moreover, it is suggested that in cephalometric analysis, patients with Facial and SNB angles less than 79.5 and 75.5 degree respectively, be assumed to have skeletal class II malocclusion.
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.