A Comparative study between facial growth pattern and dental arch width and form in regional population –an in vitro study

Abstract

It is generally accepted among orthodontists that a relationship exists between vertical facial morphology and the cant of mandibular plane. A subject with a high SN – MP angle (SN- Sella to Nasion and MP-mandibular plane)^.tends to have a longer face and one with a low SN – MP angle (flat MP) often has a shorter face. Materials and methods- This study includes lateral cephalograms and study models of untreated 75 males and 75 females (between age group 18-30 years) from regional population. Cephalometric analysis- SN-MP angle, study model analysis- inter molar, inter premolar, and inter canine width. Arch form-Ovoid, tapered and square arch forms were made with 0.016 ss wire with the help of  template for maxillary and mandibular arches of males and females. Result-samples with SN-MP angle <27⁰ shows wider arches and the samples with SN-MP angle>37⁰ showed narrow arch in male and female. Inter canine & inter molar width is more in males than females. & the preformed arch form was wider than the inter canine, inter first and second premolars & inter molar width. Conclusion- SN-MP angle is inversely proportional to the arch width. Hyperdivergent facial types tend to have narrow arch forms, Hypodivergent facial types tend to have wider arch forms in male and females. Males have wider arch width than females, this suggests to utilize customized arch wires for different facial growth patterns, pre- treatment arch form and width.