Pacific Coast Society of Orthodontists Bulletin Spring 2023 - 45

Clinical Practice
Pearl of the Pacific
Vanity or Efficient Vanity?
Dr. Robert Kelleher received his DDS degree from
the University of Southern California, after which he
received a certificate in orthodontics from Tufts University
School of Dental Medicine. He is a member
of the Edward H. Angle Society of Orthodontists, is
a diplomate of the American Board of Orthodontics,
and serves on the craniofacial anomalies panel at
the University of California, Davis Medical Center.
Dr. Robert Kelleher
Folsom, CA
From my experience, the greater the number of aligners
that go into an aligner series, the more likely the
case may lose tracking. Extended treatment time and
multiple refinements are often required. There are
three things I find especially difficult with aligners:
Dr. Paul Kasrovi
Berkeley, CA
PCSO Bulletin Contributor
1. When upper laterals, or any tooth, loses tracking,
it's like being delayed by repeated broken
brackets. Inefficient leveling can similarly waste
time; engagement of the anterior attachments
for extrusion can be hit or miss. Also, 60° of
rotation of a rogue tooth will require 60 months
of treatment, just to resolve the de-rotation.
2. I haven't proven this, but it might be true: when
teeth are very crowded, aligner plastic is effectively
more thickly " corrugated " to surround
radical rotations. The modulus of elasticity of
the aligner plastic is higher in early alignment,
becoming lower after initial alignment. Highly
corrugated plastic may best explain the " mud
phase " of aligners.
3. Inefficient opening of the vertical with aligners
is the price we pay for being able to close bites
with aligners more easily. Even with bite ramps,
posterior plastic tends to intrude posteriors.
Ironically, brackets are really efficient with leveling,
aligning, and opening the bite. Aligners are
better, in my hands, with mid-treatment and finishing
stages than they are with leveling. Initial
bracket de-rotation allows aligner plastic to skip
the corrugated phase; the modulus of elasticity
is less, a bit like using a 0.014 NiTi wire initially.
Because adults often tire of aligners, it may be
worth considering a hybrid approach: the best of
brackets with the best of aligners. Bonding brackets
for a few months to get relatively quick leveling and
alignment is a huge boost for aligners to take over
and shorten overall treatment time. I strive to get
the number of aligners down to eight to 12 maximum
per arch, per series. Rarely is more than one
refinement necessary. Deep-bite cases with aligners
can be much easier to treat after upper and lower
anteriors are ballpark leveled and aligned prior to
switching to aligners. Perfect alignment is not critical,
but decent leveling does help. One could argue
that aligner appointments are short, so why worry
about inefficiency? Well, repeated refinements and
obvious lags in leveling and aligning do not instill
patient confidence; patients can get impatient with
aligner hiccups, and our practice profits can suffer
with rescans, Clin Checks, making appointments,
tracking shipments, and explaining details.
Our office poses this question at the exam: do you
prefer to go 24 to 48 months with all aligners, or go
four to six months with brackets and finish in 12 to
15 total months? With premolar extraction cases,
a reverse approach can serve the patient best:
Figure 1. Pretreatment intraoral photographs
Spring 2023 PCSO Bulletin
45
Pacific Coast Society of Orthodontists Bulletin Spring 2023

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Spring 2023
