Crown / root relations and root morphological characteristics of permanent maxillary central incisors in Class II, division 1 and 2 malocclusions.
R.A. Korda, D.K. Nikolidakis, M.D. Xagorakis, A.E. Athanasiou, M.A. Papadopoulos
Hellenic Orthodontic Review 2000;3:89-96.
AIM: To investigate in detail and through the use of new parameters the crown / root relations and the root morphological characteristics of permanent maxillary central incisors in Class II, divisions 1 and 2 malocclusions as well as the relationships of these teeth with the apical maxillary base.
DESIGN: Cross-sectional
SETTING: Department of Orthodontics, Aristotle University of Thessaloniki, 1998-1999.
MATERIALS AND METHODS: 43 lateral cephalometric radiographs from the records of the Department of Orthodontics, Aristotle University of Thessaloniki and the private practice of one of the authors. 16 of these belonged to subjects with Class II, division 2 malocclusion, whereas the other 27 to Class II, division 1 malocclusion. Mean age and standard deviation was 12.3 ± 2.6 years for Class II, division 1 and 15.0 ± 3.3 years for Class II, division 2.
MAIN OUTCOME MEASURES: Ten cephalometric points were identified on the radiographs. The most clearly seen incisor, right or left, was traced on the radiograph. Radiographs were digitized and cephalometric analysis was done by means of a personal computer and the cephalometric software Viewbox 2.5. Student’s t-test was applied to evaluate the possible differences between the two groups of patients by means of Statistica 5.0 software.
RESULTS: Class II, division 1 group presented increased values compared to Class II, division 2 group for the following variables: Pr-N-A angle (p<0.001), distance of Ans (p<0.05) and A (p<0.001) from the maxillary central incisor root axis, the angles formed by the root and tooth axes with the maxillary plane (p<0.001) and the angle formed by the root and crown axes (p<0.05).
CONCLUSIONS: The findings of this study suggest that there are differences in the morphological characteristics and the relationships of upper central incisors with the maxillary apical base between Class II, division 1 and 2 malocclusions for the sample and the cephalometric variables used in this study.Request for reprints:A.E. Athanasiou, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, GR-54006 Thessaloniki, Greece.
DESIGN: Cross-sectional
SETTING: Department of Orthodontics, Aristotle University of Thessaloniki, 1998-1999.
MATERIALS AND METHODS: 43 lateral cephalometric radiographs from the records of the Department of Orthodontics, Aristotle University of Thessaloniki and the private practice of one of the authors. 16 of these belonged to subjects with Class II, division 2 malocclusion, whereas the other 27 to Class II, division 1 malocclusion. Mean age and standard deviation was 12.3 ± 2.6 years for Class II, division 1 and 15.0 ± 3.3 years for Class II, division 2.
MAIN OUTCOME MEASURES: Ten cephalometric points were identified on the radiographs. The most clearly seen incisor, right or left, was traced on the radiograph. Radiographs were digitized and cephalometric analysis was done by means of a personal computer and the cephalometric software Viewbox 2.5. Student’s t-test was applied to evaluate the possible differences between the two groups of patients by means of Statistica 5.0 software.
RESULTS: Class II, division 1 group presented increased values compared to Class II, division 2 group for the following variables: Pr-N-A angle (p<0.001), distance of Ans (p<0.05) and A (p<0.001) from the maxillary central incisor root axis, the angles formed by the root and tooth axes with the maxillary plane (p<0.001) and the angle formed by the root and crown axes (p<0.05).
CONCLUSIONS: The findings of this study suggest that there are differences in the morphological characteristics and the relationships of upper central incisors with the maxillary apical base between Class II, division 1 and 2 malocclusions for the sample and the cephalometric variables used in this study.Request for reprints:A.E. Athanasiou, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, GR-54006 Thessaloniki, Greece.