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Dental implants and skeletal growth
Dental implants can ankylose in the jawbone. Their
placement should be delayed until the completion
of skeletal growth. Skeletal growth is generally com-
pleted in girls at around age 17, and in boys around
age 19, but there may be some residual growth for
a few years [1].
We all remember our orthodontics lectures and
the impressive images of metallic implants inserted
in order to analyse skeletal development [2]. Metal
implants showed that the maxilla and mandible
develop in an anterocaudal direction.
If the dental implant is inserted before skeletal
growth is complete, there will be a vertical ledge
between the implant-supported crown and the
adjacent teeth (Fig. 1). The ankylosed implant cannot
follow the further development of the dentoalveolar
complex. The logical consequence is that the implant
crown, when in the posterior jaw, will be in infra -
occlusion, which can result in functional problems.
In the visible part of the dentition, aggravating aes-
thetic problems can develop.
There are several methods of determining skeletal
maturity: ultrasound exams of the arm [3], analysis
of the cervical vertebrae [4] and the frontal sinus [5],
and X-rays of the hand [6,7]. In the dental office,
especially in orthodontics and, more recently, in
implantology, hand X-ray is the most widely applied
method. Radiological signs of completed skeletal
growth are diaphyseal-epiphyseal fusion of the
radius and ulna [7]. However, the literature states
that residual growth can continue for about two
years, especially in boys. What amount of growth –
especially vertical growth – of the dentoalveolar
complex must be expected?
EDI
Case Studies
2
Treatment of an 18-year-old female patient with a congenitally missing tooth
Implant placement in the
aesthetic zone upon completion
of growth
Dr Dr Snjezˇana Pohl, Rijeka, Croatia
Skeletal growth is generally completed in girls at around age 17, and in boys around age 19. However, with completion of
skeletal growth radiologically established, there will still be residual vertical growth of the dentoalveolar complex, which is
why dental implant placement should be postponed somewhat beyond this time. This case presents an 18-year-old female
patient with a H.1.i defect of the alveolar ridge according to the Cologne Classification of Alveolar Ridge Defects (CCARD),
where implant placement in the aesthetic zone was delayed for a year after the completion of growth as radiologically estab-
lished. Using minimally invasive surgical techniques, some horizontal alveolar ridge volume was built, and the following year
an implant was placed in the expanded alveolar ridge.
Fig. 1
Diagram of
implant 21
inserted before
completion of
jaw growth.
The implant
crown is shorter,
and the gingival
margin is higher.
Fig. 2
Average
smile line.
Of particular interest were the results of a radio -
graphic and cephalometric analysis of 56 subjects
observed over five years [8]. After establishing com-
pletion of skeletal growth based on hand X-rays,
81 per cent of subjects showed less than 1 mm of
dentoalveolar complex growth in a vertical and sagit-
tal direction. However, the other 19 per cent exhibited
growth of more than 1 mm, averaging 1.6 mm. One
patient showed a full 2.5 mm of vertical “growth after
growth was completed”.
Since even a “mere” 1 mm is not negligible in the
aesthetic zone, the authors of this study recommend
delaying the insertion of implants in the aesthetic
zone for a few years after the completion of growth
has been radiologically established.
Case report
An 18-year-old female patient was referred for im -
plant placement at site 12 after completion of ortho-
dontic treatment; tooth 12 was congenitally missing.
There was also microdontia of the contralateral tooth
22. Orthodontic treatment had created a space at
the site of the missing tooth that was sufficient for
implant placement. A retainer with an attached com-
posite tooth served as a provisional.
The smile line was average (Fig. 2). There was
pronounced horizontal atrophy of the alveolar ridge
(Figs. 3 and 4). The orthopantomograph showed diver-
gent roots of adjacent teeth, which was convenient
for implant placement. As an additional finding, an
asymptomatic apical lesion of tooth 46 was diag-
nosed (Fig. 5). The CT showed an alveolar ridge width
of 4 mm, which, in the maxilla, is sufficient for im -
plant placement with careful bone expansion (Fig. 6).
However, our lovely patient sitting in the dental
chair seemed very young. She looked more like a girl
than a young woman (Fig. 7).
EDI
Case Studies
3
Fig. 3 Horizontal atrophy of the alveolar ridge at site 12.
Aesthetically inadequate composite restoration on tooth 22.
Fig. 4 Retainer that also carries the provisional tooth 12.
Pronounced horizontal atrophy due to agenesis of tooth 12.
Fig. 6
CT shows 4 mm
wide alveolar process.
Fig. 7
The patient
appears to
be younger
than her
chronological
age of 18 years.
Fig. 5 Divergent roots of adjacent teeth. Apical lesion of
tooth 46.
A hand X-ray showed a visible transition zone
between the epiphysis and diaphysis of the ulna and
radius, but no visible lateral notches (Fig. 8). This find-
ing indicated that growth had just been completed.
Given that the final aesthetic result in this case was
very important and that there was a significant risk
of further vertical growth, the patient was advised to
postpone treatment for a year.
Due to the extreme horizontal atrophy of the alve-
olar ridge, a free connective-tissue graft was used for
reconstruction.
Figure 9 shows a connective-tissue graft harvested
from the palate using a single-incision technique. A
long transplant was made to overlap several times in
order to get as much volume as possible. The graft was
inserted using the tunnelling technique to avoid unnec-
essary incisions and papillae elevation (Fig. 10). Figure 11
shows the result immediately after surgery. The palatal
wound was closed with compression sutures.
A year later, at age 19, there were no visible epiphy-
seal transitions of the radius and ulna left (Fig. 12).
Figures 13 and 14 indicate the vertical and horizontal
dimensions of site 12 prior to implant placement.
EDI
Case Studies
4
Fig. 13
Appearance of
the alveolar
ridge one year
following
reconstruction.
Fig. 14
Horizontal
dimensions of
the alveolar
ridge.
Fig. 11
Result immedi-
ately after rein-
forcement of the
alveolar ridge.
Fig. 12
One year after
the first X-ray,
no demarcations
of radius and
ulna epiphyses
are visible.
Fig. 8 The hand X-ray shows a discrete
demarcation of the radius and ulna
epiphyses. No lateral notches.
Fig. 9 Free subepithelial connective-
tissue graft, made to overlap a few
times.
Fig. 10 Placing the graft using the
tunnelling technique.
11 12
13 14
EDI
Case Studies
5
A minimally invasive technique without flap reflec-
tion and papilla elevation was used to prepare the
implant site. Given the reduced volume of the alve-
olar ridge, the preparation was carried out using
osteotomes and bone spreaders (Fig. 15). This is not
only a non-invasive form of implant-site prepara-
tion, but also accomplishes further gains in the hori-
zontal dimension of the entire ridge (Fig. 16). Thanks
to proper implant placement in the 3D comfort zone,
there were no difficulties in creating the emergence
profile of the crown.
Figure 17 shows the harmoniously integrated
implant-supported crown eight months after the
definitive prosthetic rehabilitation. Both papillae are
visible; the level and shape of the gingival margin are
identical to those of tooth 22. Gingival colour and
texture are indistinguishable from the surrounding
gingiva.
Again we were able to observe how the smile line
becomes higher when a satisfied patient becomes
more self-confident. This patient ended up develop-
ing a high smile line (Fig. 18).
Fig. 15 Bone expansion using bone
spreaders.
Fig. 16 Implant (Astra, Dentsply Implants) placed using a minimally invasive
technique.
Fig. 17
Status eight
months after
definitive
prosthetic
rehabilitation.
Fig. 18
The smile line of
the satisfied
patient is signifi-
cantly higher
than at the
beginning of
therapy.
EDI
Case Studies
6
A ceramic veneer was placed on tooth 22. Tooth 46
was successfully endodontically treated (Fig. 19).
The final image shows that the satisfied patient no
longer looks like a girl, but rather like an adult young
woman (Fig. 20).
Conclusion
It is well known that dental implant placement
should wait until skeletal growth is completed. In the
dental office, the most common method of establish-
ing the growth phase is by hand X-ray. The disap-
pearance of the ulnar and radial epiphysis markings
is one of the most reliable signs of completed skele-
tal growth. However, there will be some residual
growth, especially vertical, of the dentoalveolar
process, which is critical in oral implantology. Usually
it will be less than 1 mm, but in approximately 20 per
cent of the population it will amount to an average
of 1.6 mm [8]. It is therefore advisable to postpone
dental implant placement, especially in the aesthetic
zone, even if the completed growth has been radio-
logically established.
A defect code of H.1.i according to the Cologne
Classification of Alveolar Ridge Defects (CCARD) had
been diagnosed [9]. The abbreviations mean: H1 –
“small defect up to 4 mm”; i – “inside the ridge con-
tour”. In this case, it is possible to prepare the im -
plant bed using bone expansion as a sole treatment
Fig. 20
The final photo. The patient
looks less like a young girl
and more like a young
woman.
Fig. 19 Successful endodontic therapy of tooth 46 (Dr Bakarcˇi ´c, Dental
clinic Rident).
adjunct if the oral and vestibular bone lamellae are
sufficiently flexible.
Where the dimension of the alveolar ridge is suf-
ficient for implant placement in the correct pros-
thetic axis, but a lack of volume threatens the aes-
thetic outcome, an elegant solution is to reinforce it
by inserting a free connective-tissue graft using
the tunnelling technique. Flapless implant insertion
using the tunnel reconstruction technique mini-
mizes postoperative alveolar-ridge shrinkage and
prevents scars [10].
If the implant is placed correctly in the 3D comfort
zone and the soft-tissue volume is sufficient, it is pos-
sible to reduce the number of visits and the financial
burden on the patient.
Visit the web to find the list of references (www.teamwork-media.de).
Follow the link “Literaturverzeichnis“ in the left sidebar.
Dr Dr Snjezˇana Pohl
Oral surgeon, EDA Expert for Implantology,
EDA Expert for Periodontology
Dental clinic Rident
Franje C
ˇandeka 39
51000 Rijeka
Croatia
Phone: +385 51 648900
snjezana.pohl@rident.hr
Contact address