Clinical study of modified splitting osteotomy combined with guided bone regeneration applied in severe bone horizontal defect in anterior maxilla

Objective To evaluate the clinical effect of severe horizontal bone defect in anterior maxilla (the horizontal width ≥ 2 mm and ≤ 4 mm) with modified splitting osteotomy combined with guided bone regeneration guided bone regeneration (GBR) . Methods The data being collected is from February 2015 to March 2016 from selected 50 patients, whose horizontal bone widths were within the range of 2 mm and 4 mm, and the vertical bone heights were normal. Using simple randomized sampling, they were divided into the observation group (the number is 25) and the control group (the number is 25) . Observation group was treated with modified splitting osteotomy combined with GBR, while GBR was applied in the control group. Twenty-five implants were implanted in each group 6 months after operations, and superstructure was performed 4 to 6 months after implantation. Follow-up visit was carried on in half a year, when the clinical and imaging examinations were performed. SPSS 21.0 was used for statistical analysis. Results The follow-up rate was 100%. During the healing and follow-up periods, none of the implants fell off, and the survival rate was 100%. In observation group, the pink esthetic scores of restoration day was 6.96 ± 0.98, and that of 6 months after restoration was 8.28 ± 1.28. In control group, the PES of restoration day was 7.12 ± 1.13, and that of 6 months after restoration was 8.12 ± 1.30. There was no significant difference between the two groups at restoration day (t = -0.535, P = 0.595) . There was no significant difference between the two groups 6 months after restoration (t = 0.439, P = 0.663) . Horizontal width of observation group was (7.08 ± 0.40) mm, and that of control group was (5.81±0.53) mm. The horizontal width of observation group was larger than that of control group 6 months after operation (t = -9.461, P<0.001) . The mesial marginal bone loss of the observation group was (0.34 ± 0.02) mm, and that of control group was (0.45 ± 0.04) mm. The mesial marginal bone loss of the observation group was lower than that of the control group 6 months after loading (t = -12.86, P<0.001) . The distal marginal bone loss of the observation group was (0.35 ± 0.02) mm, and that of control group was (0.44 ± 0.04) mm. The distal marginal bone loss of the observation group was lower than that of the control group 6 months after loading (t = -10.44, P<0.001) . Conclusion The modified splitting osteotomy combining with guided bone regeneration can effectively solve the problem of severe bone defect in anterior maxilla and thus achieve good clinical results. Key words: Guided tissue regeneration; Dental implants; Osteotomy; Alveolar process; Bone defect