Author (year) | Study design | No. of patients | BTA dose | Time of intervention | Primary outcome measures | Result |
---|---|---|---|---|---|---|
Tollefson et al. (2006) [20] | Pilot study, study type not specified | 3 | 1–2 units/kg | 7 Days preoperatively | Lip tension was measured prior to and after BTA injection with a manometry catheter placed between the lip and the alveolus. | Manometry measurements were reported to be inconsistent (no data were provided). |
Galarraga (2009) [21] | Study type not specified | 5 | 10 units | Intraoperatively | Lip tension was measured before and 10 days after BTA injection using electromyography. | When performed at rest, there was a significant reduction in the upper lip electromyographic tracings compared to the pre-treatment readings (P<0.039). However, there was no significant difference during activity (P>0.214). |
Chang et al. (2014) [22] | Double-blinded, placebo-controlled, randomized clinical trial | 30 (BTA) vs. 30 (normal saline) | 1 unit/kg | Immediately after surgery | The scars were assessed at a 6-month follow-up visit using: | 30 Patients in the BTA-treated arm and 29 patients in the control arm attended the 6-month follow-up visit |
-VSS | -VSS score: 2.70±1.29 in the BTA-treated group vs. 2.76±1.44 in the control group, P>0.05 | |||||
-VAS | -VAS score: 8.43±0.56 in the BTA-treated group vs. 7.19±0.95 in the control group, P<0.001. The interobserver consistency of both the VSS and VAS scores was high (Cronbach α=0.98 and 0.890, respectively). | |||||
-Photographic measurements of scar widtha) | -Scar width (BTA-treated group versus control group): | |||||
At the first point: 0.33±0.11 vs. 0.45±0.11, P<0.001 | ||||||
At the second point: 0.33±0.13 vs. 0.47±0.13, P<0.001 | ||||||
Chang et al. (2014) [8] | Double-blinded, placebo-controlled, randomized clinical trial | 30 (BTA) vs. 30 (normal saline) | 15 units | Immediately after surgery | The scars were assessed at a 6-month follow-up visit using: | 30 Patients in the BTA-treated arm and 28 patients in the control arm completed the 6-month follow-up |
-VSS | -VSS score: 2.45±1.52 in the BTA-treated group vs. 3.50±1.88 in the control group, P=0.023 | |||||
-VAS | -VAS score: 7.47±0.64 in the BTA-treated group vs. 6.10±1.06 in the control group, P<0.001. The VSS and VAS had high interobserver consistency (Cronbach α=0.936 and 0.923, respectively). | |||||
-Photographicb) and ultrasonographic measurements of scar length | -The BTA-treated group had narrower scars at the first point (0.62±0.18 mm vs. 0.95±0.31 mm, P<0.001) and the second point (0.63±0.18 mm vs. 0.92±0.36 mm, P<0.001). | |||||
Scar width measured by ultrasound was also narrower in the treated group (0.72±0.25 mm vs. 1.03±0.42 mm, P=0.001). |
a) Measured at two defined points: “the first point was 1 mm above the white roll and the second point was 1 mm below the C-flap suture line” [22];
b) Measured at two defined points: “the first point was 1 mm above the white roll and the second point was 1 mm below the turning incision line, which is located close to the nasal sill” [8].