Pacific Coast Society of Orthodontists Bulletin Winter 2017 - 52

Presentation Summary

Doctors

Orthodontics in 5-D: Optimizing
Treatment Efficiency and Outcomes
Dr. Bruce Hawley
PCSO Bulletin Regional Editor

Dr. Sunil Kapila
Professor and Eugene E. West
Endowed Chair of Orthodontics
at University of California
San Francisco

Presented by Dr. Sunil Kapila at the PCSO Annual
Session, Oct. 15, 2017
Because the long duration of orthodontic treatment is one of its major limitations, the question
of efficiency of treatment is especially relevant
at present. Patients request and even demand
shorter treatment times. We are quite familiar
with the first three dimensions, the three planes
of space by which we attempt to integrate skeletal, dental, intra-arch, and inter-arch elements.
The fourth dimension is time and is equated with
efficiency. The fifth dimension is the treatment
outcome. Our ultimate goal in controlling treatment in 3-D is to enhance the efficiency and outcome of orthodontic treatment.
Orthodontic Forces
With the application of an orthodontic force,
tooth movement initially consists of a small
physical displacement response. This is followed
over time by a delay phase, where there is minimal change, and then by a linear phase, where
the tooth moves in a gradual fashion. The whole
socket actually moves through osteoclastic
resorption on the pressure side and osteoblastic
bone deposition on the tension side. The concept
of expediting tooth movement is not new, having
been addressed as early as the 1890s. Appliancebased approaches look at light vs. heavy vs.
"optimal" forces and compare intermittent vs.
continuous forces. Light continuous forces
appear to be better than intermittent forces.
Presently, there is insufficient evidence to advocate for the use of self-ligating brackets as
opposed to conventional brackets with respect
to faster tooth movement, but the benefits of
reduced chair time and slightly less mandibular
incisor protrusion can be realized. The use of
custom wires has also been advocated for
enhanced treatment efficiency, but again,
conclusive evidence is lacking.

Surgical Interventions
Surgically facilitated orthodontic treatment
(SFOT) includes osteotomy-assisted orthodontics
(alveolar / PDL distraction osteogenesis, such as
for ankylosed teeth), corticotomy facilitated
orthodontics (e.g., accelerated osteogentic
orthodontics), and minimally invasive cortical
activation (such as microosteoperforation and
piezocision). SFOT injures the bone and/or modifies the reparative process, resulting in increased
bone turnover and increased tooth movement.
Although there is relative controversy regarding
the efficacy of most of these procedures in
enhancing tooth movement rates, the more
invasive procedures appear to have some effect.
Specifically, it has been shown that corticotomy
increases tooth movement for the first month or
two and then drops off. This short duration rate
effect and the invasiveness of SFOT are the major
limitations of these approaches.
Vibration
Orthodontic vibratory devices were originally
patented, as far back as 1931, for the purposes of
increasing bone density in the mouth and regenerating bone intraorally. Acceledent claims to
enhance tooth movement rates by increasing
bone turnover and by decreasing orthodontic
appliance friction through a slip / stick phenomenon. Three separate prospective randomized
clinical trials with Acceledent revealed (1) no
statistically significant increase in the rate of
tooth movement or time requirement for alignment and (2) no increase in alignment, but an
increased speed of canine retraction movement.
Imaging
What "tried and true" approaches are available?
First, we have traditional diagnosis and treatment planning. A second approach using 3-D
imaging is still a somewhat untapped possibility.
CBCT can give us transverse skeletal and dental
diagnoses not possible with the traditional 2-D

PCSO Bulletin  Winter 2017

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Winter 2017