Low-level laser therapy, piezocision, or their combination vs. conventional treatment for orthodontic tooth movement : Ahierarchical 6-arm split-mouth randomized clinical trial.

Abstract

The use non-invasive or minimally invasive methods to accelerate orthodontic tooth movements (OTM) is desirable. In this regard, low-level laser therapy (LLLT, photobiomodulation) and piezocision are suggested. However, because the efficacies of these methods remain controversial/inconclusive, we investigated and compared these two methods. Sixty-four quadrants in 32patients were randomized into three parallel intervention groups of22, 22, and20 (6parallel arms, n = 64 treatment/control sides). Bilateral first premolars were extracted and canine retraction commenced. In each group, one side of the mouth was randomly selected as control, while the other side underwent each of three interventions: LLLT (940 nm, 8J, 0.5 W, 16 s, 12sites), piezocision, and "LLLT + piezocision". At the 3rd, 6th, and 9th follow-up weeks, canine retraction and anchorage loss were measured. Data were analyzed statistically (α = 0.05). After 9weeks, LLLT, piezocision, and LLLT + piezocision improved canine retraction by 0.51, 1.14, and 1.93 mm, respectively. LLLT accelerated canine retraction (compared to control) by 1.6-, 1.4-, and 1.2-fold in the 3rd, 6th, and 9th week, respectively. These statistics were 2.1-, 1.7-, and 1.5-fold for piezocision and 2.7-, 2.1-, and 1.8-fold for LLLT + piezocision. Compared to controls, each intervention showed significant retraction acceleration (p < 0.05). The effect of LLLT + piezocision was greater than that of isolated piezocision (p < 0.05), which itself was greater than that for isolated LLLT (p < 0.05). All threemethods accelerated OTM, with the combination of LLLT + piezocision producing the strongest and LLLT producing the weakest acceleration.