March 30, 2011
This is an important question and the current wisdom is not to have implants placed until jaw and facial growth
are complete. Although it varies from person to person, growth of the
jaws in most cases is not complete until late teens. Of course, we are
faced with the dilemma of waiting for the optimal time to place dental
implants so that they will succeed on the one hand, and respecting the
psychological needs of a teenager missing front teeth on the other. Well,
you may say, that still doesn’t answer the question. The rest of the
answer has to do with the difference in the way in which teeth and
implants attach to bone in which they are embedded.
Teeth are attached to the bone through a membrane called the
periodontal ligament. The ligament is a living network which is
composed of tiny fibrils made of a protein called collagen. The fibrils
insert into the bone on one side and the tooth on the other. The most
fascinating thing about this very special structure is that it is
living and therefore capable of change. And it does, all the time.
Specialized cells continually remove collagen and bone and make it
anew; this does two things — it allows the teeth to react to stress, as
when forces are applied such as in eating and allows movement of the
teeth themselves through the magic of orthodontic treatment (braces).
In addition, as the face changes throughout life and the teeth
themselves wear, minute changes in the position of the teeth within the
bone are compensated for by changes in the periodontal ligament. This
“remodeling” process accommodates these changes.
An implant connection to the bone is quite different. Dental implants join biochemically to the bone by a process called osseointegration.
This fusion, almost like pillars in concrete,allows no movement at
all and stresses,even biting forces, are absorbed quite differently.
Consequently and most importantly, as the jaws continue to grow, the
upper jaw may move in an outward and downward direction. The teeth will
accommodate and move with jaw growth, but implants
will not. As the upper jaw moves, the implants (and the crowns attached
to them) remain stationary and so appear to intrude i.e. go back up
into the jaw. This also affects the position of the gum tissues which
also will not follow the growth of the jaws around the implants.
For these reasons, and since implants are a relatively permanent and best current solution to the problem of tooth replacement,
it is better to wait until growth of the jaws and face is complete.
Your orthodontist will be able to tell you when growth is complete by
examination and specialized radiographs (x-rays) which will provide a
good guideline. However, this is a very inexact science; it’s not
really possible to determine exactly when a person has finished
growing. Other factors can be indicative and helpful: Is your
daughter still changing shoe and clothes sizes? Is she comparable in
stature to her siblings and you, her parent(s)? These are good
intuitive signs, but in the end, we add the science to our experience
and make a judgment call.
There are many other good interim options for temporarily replacing
the teeth for a few years, both aesthetically and comfortably until
implants can be placed. For example, temporary “fixed-in” options like
bonded bridges can be attached to the adjacent teeth with little if any
irreversible change to them. You should consult your dentist about
Ultimately dentistry is an art form as well as science. This issue
has been studied in the scientific literature and also proven in
clinical practice. Sometimes, placing implants too early can be remedied
by changing the crowns which attach to them. Other times it may mean
removing and replacing the implants which may require bone regeneration —
expensive and difficult options. Neither is as good an option as
waiting for the correct time in the first place, even if it means
waiting a little longer.