The relationship between facial bone wall defects and dimensional alterations of the ridge following flapless tooth extraction in the anterior maxilla

Purpose: To evaluate the relationship between defects of the facial socket wall at extraction and dimensional changes 8 weeks later in maxillary central and lateral incisor sockets.

Materials and methods: A total of 34 consecutive patients requiring single tooth implants in the anterior maxilla (27 central and 7 lateral incisors) were evaluated. Orofacial external ridge, bone dimensions and the location of the socket bone crest were measured at extraction and again 8.5 ± 2.91 weeks later. The status of the facial bone wall was recorded at the same time points.

Results: At extraction, 16 of 34 sites (47%) had intact facial bone. There were fenestration defects at 9 of 34 sites (26.5%) and dehiscence defects at 9 of 34 sites (26.5%). A significant reduction (P < 0.001) in the external orofacial ridge dimension occurred (mesial 1.4 ± 1.30 mm or 12.1%, facial 2.5 ± 1.46 mm or 22.2%, distal 1.1 ± 0.83 mm or 10.5%), with greatest change at dehiscence (3.3 ± 1.80 mm or 28.4%) and fenestration sites (2.8 ± 1.40 mm or 24.9%). A significant reduction in orofacial bone dimension occurred (mesial 0.8 ± 0.80 mm or 9.3%, P < 0.001; facial 1.2 ± 1.03 mm or 18.3%, P < 0.001; distal 0.4 ± 0.65 mm or 5.5%, P < 0.01). Vertical resorption of the bone crest was most marked at the mid-facial aspect (1.4 ± 1.94 mm, P < 0.001). Initial fenestration defect sites demonstrated the greatest vertical dimensional change (2.9 ± 2.67 mm; P = 0.008). Of 16 sites with initially intact facial bone, 9 sites (56.3%) developed dehiscence defects after 8 weeks. Of the 9 initial sites with fenestration defects, 5 (55.6%) turned into dehiscence defects. All 9 sites with initial dehiscence defects healed with persistence of the dehiscence.

Conclusions: Eight weeks after flapless extraction of maxillary central and lateral incisors, a reduction in the orofacial dimensions of the ridge was observed due to resorption of the facial bone of the socket. Tooth type (maxillary central incisor) and thin tissue phenotype significantly influenced the outcomes. The dimensional alterations were most pronounced at sites that initially had fenestration and dehiscence defects of the facial bone.