Skeletodental measurements in Iraqi patients sample with class II Division 1 malocclusion and different vertical discrepancies : a comparative cephalometric study

الملخص EN

Background : The vertical development in class II malocclusion has an important impact on orthodontic decisions including diagnosis, prognosis and treatment plan, this study is an attempt to explore effective characteristics of Class II Division 1 malocclusion with increased and decreased vertical measurements by comparing them with Class II Division 1 malocclusion associated with normal vertical height in Adult Iraqi patients.

Materials and method : Lateral cephalometric study was conducted on 75 Class II division 1 patients (diagnosed clinically and radiographically) aged 18-30 years, classified according to skeletal vertical relationship using SN-MP angle into three groups: High angle group (SN-MP > 36.5)ْ, low angle group (SN-MP < 28)ْ and control group (36.5ْ < SNMP > 28ْ ).

Cephalometric analysis of vertical problem was achieved by 13 angular and 9 linear variables using AutoCAD program 2008.

Results : The results revealed that angles : ANB, SNA, SNB, SN-MP, Basal plane, upper and lower occlusal plane and gonial angles and linear measurements: lower anterior, anterior, posterior facial height and the overbite, are all show a significant differences among the three groups, while Saddle angle, upper incisor –palatal plane, lower incisormandibular plane and inter incisal angle as well as the upper anterior, upper posterior facial height, overjet, maxillary and mandibular base length show a non significant differences among the three groups.

Conclusions : In Class II division 1 malocclusion, maxillary and mandibular anterior teeth are proclined regardless vertical discrepancy and normal overbite is independent of this problem which is mainly arise in the jaws area and the orthodontic treatment may effectively improve this deformity, also in high angle malocclusion, maxillary growth in downward direction is expected to exceed forward one, which rotate the mandible downward backward, aggravating horizontal and vertical discrepancy of jaws, while In low angle malocclusion, skeletal horizontal discrepancy is less than that of the high angle, possibly due to forward upward rotation of the mandible.