Evaluation And Quantification Of 3- Dimensional Changes In The Arch Form– A Longitudinal Growth Study

BACKGROUND- Craniofacial growth is a multi-dimensional process influenced by genetic, environmental, and functional factors. Understanding the interrelationship between craniofacial structures and dental arch development is essential for orthodontic diagnosis, treatment planning, and long-term stability. This study evaluates three-dimensional changes in the dental arch form and their association with craniofacial morphology in growing children . OBJECTIVE: To quantify the incremental changes in arch width, arch length, arch perimeter, arch form, and palatal depth in children aged 8 to 14 years, with evaluations conducted at 18-month intervals. METHODS: A longitudinal study was conducted on 50 children (ages 8–14) with 5 sets of study models collected at 18-month intervals. Digital 3D scans were used to measure arch width, length, perimeter, palatal depth, and arch form, with statistical analysis performed using SPSS 17.0. RESULTS: Maxillary and mandibular intercanine and intermolar widths increased progressively from T0 to T4, indicating lateral expansion. Palatal depth exhibited a steady increase over time. Arch perimeter and length increased, reflecting anterior-posterior expansion. Arch form transitioned, with a decrease in ovoid arches and an increase in tapered and square forms. Growth changes were more pronounced between 8 and 9½ years, with gradual stabilization after 12½ years. CONCLUSION: Dental arch growth follows a predictable pattern, with significant increases in width, length, and perimeter during mixed dentition. The study confirms that genetic and environmental factors influence craniofacial development. These findings provide valuable insights for orthodontic treatment planning and growth prediction .