A clinical study of anterior maxillary impacted supernumerary teeth based on the classification of horizontal and vertical positions

Objective

This study aimed to reveal the relationship between the surgical approach of extraction and the dimensional position of the anterior maxillary impacted supernumerary teeth (AMIST), impacted mesiodens according to the definition of the systematized classification of horizontal and vertical position.

Methods

This retrospective study included patients with AMIST who required computed tomography for extraction. The number of teeth, direction of impaction, age at the surgery, operative time, and surgical approach for AMIST were analyzed. AMIST was classified into two groups (H: horizontal position and V: vertical position); each group was divided into several subgroups (H1, 2, 3; V1, 2, 3, 4).

Results

In total, 223 AMIST were included. Based on the direction of impaction, 142 teeth were categorized as inverted, 69 normal, and 12 horizontal. With vertically higher positions, age at the operation and operative time were considerably increased in the H2 region (the area between the palatal side of the permanent central incisor and the incisive canal). The operative time was markedly increased in < 7 years old versus ≥ 10 years old and ≥ 7 years old and < 8 years old versus ≥ 10 years old in the H2 region. The palatal approach was the most common (214 teeth, 96.0 %), followed by the labial (8 teeth, 3.6 %) and nasal floor (1 tooth, 0.4 %) approaches.

Conclusions

Classifying of horizontal and vertical positions by computed tomography images is crucial in preoperative treatment planning since it helps surgeons decide on the surgical approach methods and evaluate surgical difficulty and invasion.