The effects of non-extraction orthodontic treatment on the vertical dimension: a comparison of a dolichofacial and a mesofacial group

Abstract

AbstractObjective:The decision regarding extraction or non-extraction orthodontic treatment for patients with different skeletal facial patterns is more commonly based on traditional concepts rather than scientific facts. The present study aimed to investigate whether dolichofacial patients responded differently compared with mesofacial patients to non-extraction orthodontic treatment with respect to vertical changes in facial height.Methods:Twenty-eight dolichofacial patients and 29 mesofacial patients who underwent non-extraction orthodontic treatment were selected. All patients commenced treatment prior to 15 years of age and had a mean age of 12.3 years for the dolichofacial group and 12.6 years for the mesofacial group. Serial lateral cephalometric radiographs were traced by hand on acetate paper and digitised using the Rocky Mountain Orthodontics JOE 32 programme. Statistical analysis examined the recorded changes in facial axis angle, facial angle, menton-to-ANS distance and facial convexity.Results:An increase in menton-to-ANS distance and facial angle and a decrease in facial convexity were observed in both groups to a similar extent. Interestingly, the facial axis of both groups remained constant throughout treatment and up to two years post-treatment. Both groups showed slightly increased facial axis angle beyond the original value at two years post-treatment. No statistically significant difference between the two groups was observed in the changes of any of the variables over time.Conclusion:The results countered the traditional concept that dolichofacial patients would have an increased facial height after being subjected to non-extraction orthodontic mechanics. It appeared that long-term vertical height of the face was more dependent on genetics rather than environmental influences.