Long-Distance Orthodontic Treatment with Adjunctive Light Therapy

Dr. Shaughnessy describes how he used PBM to accelerate the orthodontic treatment of two long-distance patients, reducing their number of office visits. Combined with the efficient use of nickel titanium archwires and prescription brackets, PBM produced a dramatic effect on the overall treatment experience.

The acceleration of tooth movement, with a concomitant reduction in the required number of appointments, is the Holy Grail of orthodontics. We need to keep a close eye on this technology; it is likely to have a far-ranging impact, not only on orthodontic treatment but on our practice-management model.

WRR

Long-Distance Orthodontic Treatment with Adjunctive Light Therapy

Various techniques have been proposed to accelerate tooth movement and shorten orthodontic treatment time. Most require surgical intervention, lessening their acceptance by patients and clinicians.^1-4 As an alternative, low-level light therapy (LLLT), also known as photobiomodulation (PBM), has recently been developed as a noninvasive method of accelerating orthodontic tooth movement.

LLLT delivers tissue-penetrating red or near-infrared light to the periodontium to promote connective- tissue and bone remodeling.^5,6 Cytochrome c oxidase, a component of the mitochondrial respiratory chain, is activated upon photon absorption, increasing adenosine triphosphate production. Nitric oxide bioavailability also increases, thus promoting microcirculation through angiogenesis at the irradiated sites. Reactive oxygen species produced in the mitochondria have also been identified as modulators of bone metabolism.⁷ Preliminary data indicate that LLLT is safe and effective in accelerating tooth movement.^8-10

Accelerated treatment is advantageous not only for patients who may be concerned about treatment duration, but also for those who are unable to attend frequent orthodontic appointments. When appointment intervals are extended, efficient tooth movement becomes even more critical in reducing treatment time. This article chronicles two long-distance patients treated with LLLT from OrthoPulse - a removable intraoral device that emits a continuous light of 850 nanometers by means of LEDs (Fig. 1) - in conjunction with comprehensive fixed-appliance therapy.

Case 1

A 14-year-old female living in Charleston, South Carolina, presented to an office in suburban Atlanta for orthodontic treatment. Clinical examination showed inadequate space for the upper and lower left canines, mild lower-incisor malalignment, and relative extrusion of the upper central incisors (Fig. 2).

Twelve weeks later, the archwires were changed to .016" × .016" nickel titanium in the maxillary arch and .016" nickel titanium in the mandibular arch, and a coiled spring was placed over the lower left canine button to gain space (Fig. 5).

After 42 weeks of treatment, an .016" × .016" stainless steel archwire was placed in the mandibular arch, with elastic chain added for space closure in the left quadrant (Fig. 8). Nine weeks later, because the overjet had increased slightly with the lower space closure, appropriate elastics were added for overjet correction (Fig. 9). Another five weeks later, the fixed appliances were removed and a fixed retainer was bonded in the mandibular arch, extending to the lower left first premolar to avoid relapse of the adjacent canine.

This patient was seen nine times during 13 months of treatment, including the day of bracket placement and the day of bracket removal and retainer placement. Extraoral evaluation showed the lower lip slightly ahead of the E-line (Fig. 10). Lip competence was maintained, even though both the anterior teeth and lips were mildly advanced. The other primary concern with nonextraction treatment was the minimal attached gingiva overlying the labially displaced lower left canine. The tissue in this area appeared to improve, as the tooth was moved lingually into a better position over the alveolar ridge. The panoramic x-ray also showed that the canine root was tipped distally by a significant amount to achieve root parallelism. Unfortunately, efforts to level the marginal ridges between the lower right first and second molars inadvertently produced excessive mesial root angulation of the second molar.

The teeth were well aligned in both arches, and the left canines were brought into good static and functional occlusion. The Class I molar and canine relationship was maintained, while the midline was corrected. The bite was opened in part by intruding the upper central incisors to harmonize the gingival margins of the maxillary anterior teeth. Anterior guidance in protrusive movement still resulted in disclusion of the posterior teeth.

Case 2

The 12-year-old younger sister of the patient shown in Case 1 also presented for orthodontic treatment, and likewise was treated long distance. She had a unilateral left Class II dentition, a maxillary right midline discrepancy, and mildly excessive overjet (Fig. 11).

A mild malalignment of the anterior teeth was accompanied by rotation of the upper and lower right second premolars. All four third molars were immature and present on the panoramic x-ray. Cephalometric analysis confirmed a mild skeletal Class II relationship and a normal vertical dimension. Frontal and profile facial esthetics were pleasing, and there were no periodontal concerns.

Extraction of a premolar in the maxillary left quadrant was proposed for efficient and predictable correction of the asymmetrical occlusion. This plan would also reduce the need for auxiliary appliances and patient compliance. Unilateral space closure would result in overjet reduction, Class II canine correction, and movement of the maxillary dental midline to the left. As in Case 1, the patient agreed to wear an OrthoPulse for five minutes per arch per day.

Ten weeks later, the maxillary archwire was changed to .016" × .022" nickel titanium and the mandibular archwire to .016" nickel titanium. Another seven weeks later, the mandibular archwire was increased to .016" × .016" nickel titanium.

After 28 weeks of treatment, .016" × .022" archwires were placed in both arches, stainless steel in the upper and nickel titanium in the lower (Fig. 14). 

This patient was seen 10 times during her ¹⁵ months of treatment, including the day of initial bracket placement and the day of bracket removal and retainer placement. After treatment, although the facial esthetic change was unremarkable, the maxillary dental midline coincided with the midfacial axis and the center of the philtrum in smiling (Fig. 16).

Unilateral maxillary space closure resulted in correction of the midline discrepancy, the left Class II canine occlusion, and the excessive overjet. While all the teeth were aligned, a small space persisted between the upper left canine and first premolar - ironically, not at the second-premolar extraction site. Despite the limited space, the teeth fit well and a good functional occlusion was established. The panoramic x-ray confirmed good root parallelism, even at the extraction site. Cephalometric evaluation indicated a mild increase in lower-incisor proclination, secondary to bite opening, and a resolution of the anterior crowding.