Mandibular dental arch parameters in Down's syndrome patients with Class I occlusion. (A comparative study)

Abstract

This study is carried out to find the dental arch form for patients with Down's syndrome and to compare the lower dental arch parameters of those patients with the corresponding norms, and to gain a correlation between the upper and lower arches for the Down's syndrome patients from previous study. A total sample of 50 patients with Down's syndrome were examined with an age ranged 14-18 years, the lower dental arch parameters were compared with another group, control, on student of an intermediate school matching with the age and Angle's classification (Class I).Study models for the upper and lower arches were constructed, then dental arch measurements were carried out and evaluated. The results show that the lower arch parameters for the patients with Down's syndrome were significantly smaller mean values than the control group for both genders with the males had greater values in inter arch distance and length, with high correlation between the upper and lower jaws .The wide arch form is the dominated arch form while the flat is the least to appear. The conclusion of the study is that the growth pattern of dental arches in Down's syndrome patients proportionally reduced when compared with those of norms, with a symmetrical configuration. Hence all arch forms are presented with different distribution.