Table 4.
Multilevel model to explore factors associated with the 6-month gingival margin distance reduction (mm) at the surgical area and at the experimental site
| Term | Surgical Area | Experimental Site | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Estimate | SE | p-Value | 95% CI | Estimate | SE | p-value | 95% CI | ||
| Intercept | 3.73 | 0.89 | < 0.001 | 1.98; 5.47 | 4.30 | 1.07 | < 0.001 | 2.19; 6.40 | |
| Patient level | |||||||||
| Gender | –0.32 | 0.43 | 0.46 | –1.15; 0.52 | –0.57 | 0.49 | 0.25 | –1.54; 0.39 | |
| Age | 0.02 | 0.02 | 0.28 | –0.02; 0.06 | 0.06 | 0.02 | 0.01 | 0.02; 0.10 | |
| Smoke | 0.25 | 0.42 | 0.56 | –0.58;1.07 | 0.15 | 0.48 | 0.75 | –0.80; 1.09 | |
| Phenotype | |||||||||
| 1 | –0.55 | 0.39 | 0.15 | –1.32; 0.21 | –1.46 | 0.45 | < 0.001 | –2.34; 0.58 | |
| 2 | 0.19 | 0.43 | 0.65 | –0.65; 1.04 | 0.43 | 0.50 | 0.39 | –0.55; 1.40 | |
| Site level | |||||||||
| Treatment (0 = Apical) | –0.95 | 0.25 | < 0.001 | –1.44; -0.46 | –1.60 | 0.39 | < 0.001 | –2.35; − 0.83 | |
| GMD T0 | 0.80 | 0.09 | < 0.001 | 0.62; 0.97 | 0.60 | 0.08 | < 0.001 | 0.45; 0.75 | |
| Time level | |||||||||
| T1 | –1.39 | 0.16 | < 0.001 | –1.70; -1.08 | –2.00 | 0.20 | < 0.001 | –2.40; − 1.60 | |
| T3 | –1.76 | 0.16 | < 0.001 | –2.07; -1.45 | –2.44 | 0.20 | < 0.001 | –2.84; − 2.03 | |
| T6 | –2.01 | 0.16 | < 0.001 | –2.32; -1.70 | –2.62 | 0.20 | < 0.001 | –3.02; − 2.22 | |
| Interaction | |||||||||
| Treatment (1 = Crestal)*T1 | 0.65 | 0.22 | < 0.001 | 0.21; 1.09 | 1.19 | 0.29 | < 0.001 | 0.61; 1.76 | |
| Treatment (1 = Crestal)*T3 | 0.75 | 0.22 | < 0.001 | 0.31; 1.19 | 1.31 | 0.29 | < 0.001 | 0.74; 1.88 | |
| Treatment (1 = Crestal)*T6 | 0.71 | 0.22 | < 0.001 | 0.27; 1.15 | 1.38 | 0.29 | < 0.001 | 0.80; 1.94 | |
| Variances | |||||||||
| σ2n patient | 0.12 | 0.15 | 1.94− 11 | ||||||
| σ2u site | 0.29 | 0.13 | 0.71 | 0.19 | |||||
| σ2e time | 0.20 | 0.02 | |||||||
Theoretic model at the surgical area and at the experimental site: GMDijk = β0ijk + β1k Gender (0 = female) + β2k Age + β3k Smoke (0 = No) + β4k Phenotype (0 = thin) + β5jk Treatment (0 = Apical) + β6jk GMD T0 + β7ijk T1 (GMD 1 month respect to GMD at surgery) + β8ijk T3 (GMD 3 months respect to GMD at surgery) + β9ijk T6 (GMD 6 months respect to GMD at surgery) + β10ijk Treatment (0 = Apical)*T1 + β11ijk Treatment (0 = Apical)*T3 + β12ijk Treatment (0 = Apical)*T6.
σ2n, σ2u, and σ2e indicate the variances at the Patient, at the Site and at the Time level respectively. In the theoretic model formula, the subscript k refers to the Patient level. The subscript j refers to the Site level. The subscript i refers to the Time level. b0ijk is the “intercept”. SE standard error; Apical Flap apical to the bone crest; Crestal Flap at the level of the bone crest