Does overbite reduction affect smile esthetics?

Abstract

Objectives: To compare the effects of two common methods of overbite reduction on smile esthetics.

Materials and methods: A prospective clinical trial was conducted with 32 patients in whom overbite reduction was achieved using a maxillary incisor intrusion arch (18 patients) or flat anterior bite plate (14 patients). Clinical and cephalometric records were compared pretreatment (T1), after overbite reduction (T2), and posttreatment (T3).

Results: Both treatment groups experienced a reduction in overbite and maxillary and mandibular incisor proclination during treatment (T1-T3). The center of resistance of the maxillary incisor and the incisal edge was significantly intruded in the intrusion arch group during overbite reduction (T1-T2). However, most of the intrusion of the center of resistance was lost by the end of treatment (T2-T3). Both treatment groups experienced a reduction in maxillary incisor display and flattening of the smile arc during overbite reduction.

Conclusions: Both overbite reduction methods caused a decrease in incisor display and flattening of the smile arc. Smiles were improved in some patients by the end of treatment. However, reduction in incisor display persisted. Clinicians should take precautions to prevent negative effects of overbite reduction.

Keywords: Esthetics; Intrusion arch; Lip to tooth; Overbite; Smile; Smile line.

Figures

Figure 1.

Means and 95% confidence intervals for lip-to-tooth relationship.

Figure 2.

Means and 95% confidence intervals for upper incisor edge to functional occlusal plane.

Figure 3.

Means and 95% confidence intervals for upper incisor center of resistance to functional occlusal plane.