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


Background: The aim of this study was to find out the dental arch form for patients with Down's syndrome and to compare the mandibular dental arch parameters of those patients with the corresponding norms, and to gain a correlation between the maxillary and mandibular arches for the Down's syndrome patients from previous study.
Subjects and methods: A total sample of 50 patients with Down's syndrome was examined with an age ranged from14-18 years. The mandibular 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 maxillary and mandibular arches were constructed, and then dental arch measurements were carried out and evaluated.
Results: The mandibular arch parameters for the patients with Down's syndrome showed 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 maxillary and mandibular jaws. The wide arch form is the dominated arch form while the flat is the least to appear.
Conclusion: The growth pattern of dental arches in Down's syndrome patients is proportionally reduced when compared with those of norms, with a symmetrical configuration. Hence all arch forms are presented with different distribution.
Keyword: Down's syndrome, Dental arch parameter, Genetic influence. (J Bagh Coll Dentistry 2008; 20(1) 72-77)