The Influence of a Single Infrapositioned Anterior Ankylosed Tooth or Implant Supported Restoration In Smile Attractiveness.

OBJECTIVES: To investigate the influence of a single infrapositioned ankylosed tooth or implant supported restoration, in smile attractiveness.

MATERIAL AND METHODS: A series of 48 digital modified images, simulating a varying degree of infraposition(from 0.25 to 2.0 mm, with a step of 0.25 mm), was created for each one of the maxillary anterior tooth, by altering the full-portrait image of a smiling male adult, in medium and high smile lines. For the model with the high smile line, also a series of 24 digital modified images simulating infraposition of a single anterior tooth with a restored incisal edge was created. Smile attractiveness for each one of the images was evaluated from 160 participants (80 dentists and 80 laypersons), implementing a visual analog scale.

RESULTS: For the images with the high smile line, an infraposition ≥ 0.25mm in central incisor's region and ≥ 0.5mm in the region of the lateral incisor or the canine, had a negative effect on the perceived smile attractiveness both for the dentists and the laypersons. Regarding the medium smile line, an infraposition ≥ 0.5mm in central and lateral incisor's region, had a negative effect on the perceived smile attractiveness for both groups of observers. In the area of the canine, infraposition ≥ 0.5mm for the dentists and ≥ 0.75mm for the laypersons, had a negative impact on the smile attractiveness.

CONCLUSIONS: Even a minor infraposition of a single maxillary anterior ankylosed tooth or implant supported restoration, can reduce the perceived attractiveness of the face. Infraposition in canine's area can be better tolerated in a medium, compared to a high smile line. In patients with a high smile line prosthetic intervention in order to restore the incisal edge of an infrapositioned tooth, without to harmonize the gingival contour, can be beneficial for the lateral incisor, ineffective for the central incisor and unfavorable for the canine.