Abstract:
BACKGROUND: Dental arch dimensions, including dental arch width, length, and form, are
important value for the diagnosis, treatment, planning, and treatment outcomes concerning
patients who are seeking orthodontic treatment in all age groups. Different ethnic groups and
populations display variable dental arch measurements and characteristics. It is well-known that
dental arch dimensions continue changing throughout growth and development, but during
adulthood, the changes decrease. Arch form is the position and relationship of teeth to each other
in all three dimensions; dental arches are roughly categorized as square, ovoid, and tapered. These
arch forms can also be expressed as narrow, average and wide.
OBJECTIVES:.assessment of arch width and form in normal occlusion among 15-30 years old
jimmaoromo population, 2018.
METHODS: A crossectional study design with convenient sampling was conducted from October 20
to November 10, 2018, The data was collected using interview guide structured questioners,
clinical examination, dental impression was taken by alginate impression material and poured to by
dental stone to form dental stone vernier caliper was used to measure parameters . The obtained
data was coded, compiled and entered into a computer, and analyzed with the SPSS software
package ( SPSS 22.0). mean, SD, T- test and chi square were used to analyze results
RESULT AND DISCUSSION:Ovoid arch form is the most frequent arch form in both arches 29 (58%)
for upper and 35(70%) lower. Square arch form is not found in female; male has higher in square
and ovoid . The mean of ICW, IMW,IPW, and CR is more in both arches and more in male than in
female . CD of female is more frequent than male in both arches and MR and MD shows no
deference among gender in their frequency . In all parameters except CR upper mean value is
greater than lower counter parameters.
Conclusion and recommendation: Ovoid is the most common arch form in jimmaoromo with
normal occlusion and the mean value of arch width;Canine depth is higher in male in both arches
and the mean value of female shows higher canine ratio.Ovoid arch form is more frequent among
female in mandible. The clinician should select the appropriate preformed arch wire form based on
the patient’s arch form and ovoid arch wires should be the shape of choice. Further large scale
studies are needed to compare dental arch form between angle classification of malocclusion and
different ethnic groups.