Maxillary Arch Dimensions in an Iraqi Population Sample

Introduction: nowledge of standard dimensions which concerns the dental arch in human populating are very useful to clinicians in different fields of dentistry in orthodontics, prosthodontics and oral surgery and they are of great interest to anthropologists in studying the dental arch growth and development in relation to different environmental , genetic and physical factors for different population (1-5) . A survey of arch size may help the clinician in choosing correctly shaped stock impression trays for prosthodontic treatment. In addition to the selection stock trays, the size of artificial teeth and the overall form of the artificial dental arch at the wax trial stage are amenable to modification by the dental surgeon in orthodontic treatment (6). Each dental arch describes a graceful curve and the teeth in these arches are well arranged to be in K Objectives: To determine the maxillary arch dimensions in an Iraqi (Salah Aldin city) sample aged (17-27) years with CL I(class one) normal occlusion and show the sex difference in this sample and compare these values of this group (males and females) combined with other studies in middle eastern population sample( Saudi and Egyptian population sample). Materials and Methods: The observation concerning maxillary arch dimensions were taken from 80 study models (40males and 40 females) the measurement distances from canine to canine (C-C), molar to molar (M-M), molar to canine (M-C) and molar to incisor (M-I) according to Mack criteria . The measurements were made by means of vernier calipers with sharpened points to the nearest 0.05mm. Statistical analysis of the collected data was performed; the t .test was used when two groups were compared. level of significance was chosen (p<0.05,p<0.01 , p<0,001). Results: The greater mean values of inter cusp distances from canine to canine, molar to molar , molar to canine and molar to incisor were significantly higher in Iraqi males than Iraqi females , and this result is similar to result of sex difference in Saudi and Egyptian samples . While the comparison of the results of Iraqi and Saudi sample reveals no significant difference for Iraqi sample (both males and females )than for the Saudi sample (both males and females ) in all measurements except (C-C) distance which shows significant difference . While higher statistically significant differences in (C-C), (M-M) distances for Egyptian sample than Iraqi sample while (M-I) difference is greater in Iraqi sample than Egyptian sample. Conclusion: The Iraqi maxillary arch dimension was greater in males than in females.There is a similarity between the Iraqi and Saudi maxillary arch dimensions, except a very little difference in (C-C) distance. The Egyptian maxillary arch dimensions (African group)was greater than that of the Iraqi sample (Asian group ) except in (M-C) distance which has no difference ,while (M-I) distance the difference is greater in Iraqi sample than Egyptian sample.