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The Importance of Ratios of Maxillary Anterior Permanent Teeth in Esthetic Rehabilitation
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Sillas Duarte, Jr, DDS, MS, PhD Associate Professor, Department of Comprehensive Care Case School of Dental Medicine, Case Western Reserve University Cleveland, Ohio, USA
Patrick Schnider, CDT Oral Design Montreux Montreux, Switzerland
Ana Paula Lorezon, DDS Private Practice Campinas, São Paulo, Brazil
Correspondence to: Dr Sillas Duarte, Jr Department of Comprehensive Care, Case School of Dental Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4905; phone: 216 368 67367; e-mail:
[email protected].
224 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
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CASE REPORT
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Abstract The aim of this study was to investigate the
and length measurements varied between
importance of the width/length (W/L) ratio
maxillary anterior teeth in the following or-
of maxillary anterior permanent teeth in an-
der: central incisors > canines > lateral in-
terior esthetic rehabilitation. Digital photo-
cisors. Maxillary central incisors displayed
graphs were taken of the anterior teeth for
the largest W/L ratio (85%), maxillary later-
each participant (approximately 20 years
al incisors (LI) displayed the smallest W/L
old). A maxillary impression was taken with
ratio (79%), and canines displayed the in-
irreversible hydrocolloid and cast in die
termediate W/L ratio (83%). These dimen-
stone under vacuum. The widest mesiodis-
sions have a positive effect on the final
tal width and incisogingival length of the
restoration; therefore, it is suggested that
tested teeth were measured. The data were
the specific width, length, and W/L ratio
submitted to analysis of variance, which
should be used in esthetic rehabilitations of
showed significant statistical differences
maxillary anterior teeth.
within each parameter (P < .05). The width
(Eur J Esthet Dent 2008;3:224–234.)
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225 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
CASE REPORT
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thetic rehabilitation is establishing a harmo-
n
One of the most challenging tasks in esnious distribution of teeth shapes, sizes,
Undergraduate dental students (approxi-
and proportions. Maxillary anterior teeth
mately 20 years old) of São Paulo State
are considered to be the key elements for
University at Araraquara volunteered for
a pleasant smile.
1
Some studies have
this study. The students were selected
shown differences in the widths, lengths,
based on the following inclusion criteria: (1)
and width/length (W/L) ratios of maxillary
healthy marginal tissue with no evidence of
anterior teeth.2–6 For this reason, under-
gingival alteration, (2) presence of all ante-
standing the relationship between the
rior teeth, (3) no history of periodontal sur-
width, length, and W/L ratio of anterior teeth
gery or orthodontics, (4) no noticeable in-
would be helpful to achieve natural esthet-
cisal wear or anterior restorations, and (5)
ic restorations.3,6 In addition, more and
absence of anterior restorations.
more aged patients are searching for an
A digital camera (Fujifilm FinePix S2 Pro,
opportunity to reverse the signs of aging
Fuji Film) was used to produce standard-
and to restore a youthful appearance.7,8
ized photographs of the facial surfaces of
Thus, an analysis was carried out to in-
the maxillary teeth sextant (1:1) and close-
vestigate the mean width, length, and W/L
up photographs (2:1) of central incisors
ratio in unworn maxillary anterior teeth of
(Fig 1), lateral incisors, and canines (Fig 2).
young patients. The parameters found will
Subsequently, a maxillary impression was
be applied to restore the dimensions of
taken of each participant with irreversible
maxillary anterior teeth.
hydrocolloid (Orthoprint, Zhermack) and vacuum-poured in type IV synthetic die stone
(GC
Fujirock
EP).
The
widest
mesiodistal width and incisogingival length of the tested teeth were measured with a digital caliper (Mitutoyo). The data were submitted to analysis of variance (ANOVA) with a 5% level of significance.
Fig 1
Measuring the mesiodistal width and incisogin-
gival length of the maxillary central incisor.
226 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
Fig 2
Measuring the mesiodistal width and incisogin-
gival length of the maxillary lateral incisor and canine.
n
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Table 1
n
Width (mm)
Length (mm)
W/L ratio
Central incisors
34
8.14 (0.56)
9.57 (0.60)
0.85 (0.09)
Lateral incisors
34
6.54 (0.54)
8.38 (1.01)
0.79 (0.10)
Canines
34
7.52 (0.74)
9.08 (0.88)
0.83 (0.10)
7.4 (0.9)
9.01 (0.97)
0.82 (0.10)
Total
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Table 2 Multiple comparisons of maxillary anterior W/L ratios*
Results
n
The mean, standard deviation, and range
Subset 1 a
Subset 2
of the width, length, and W/L ratio are pre-
Lateral incisors
34
.790
–
sented in Table 1. ANOVA revealed statisti-
Canines
34
.834a,b
.834b
Central incisors
34
–
.853b
.064
.423
cally significant differences in each category: width (P < .0001), length (P < .0001), and
P
*Same superscript letters indicate no statistically significant difference.
W/L ratio (P = .026) of maxillary anterior teeth. Multiple comparisons for width and length showed that for maxillary anterior teeth these dimensions fall into the following sequence: central incisors > canines > lateral incisors (P > .05). Duncan multiple comparisons were performed to rank the W/L
ratios
of
maxillary
anterior
teeth
(Table 2). Two statistically significant subsets of W/L ratios were found. Maxillary central incisor width corresponded to 85% of the length, resulting in the largest W/L ratio of the three maxillary anterior teeth. The
Fig 3
Preoperative view of the maxillary central incisors.
Fig 4
All crowns were sectioned and removed.
smallest W/L ratio was in maxillary lateral incisors (79%), while canines showed an intermediate W/L ratio (83%).
Case 1 A 45-year-old male patient presented for treatment because he was dissatisfied with his smile. The clinical exam revealed porcelain-fused-to-metal crowns (maxillary left central and lateral incisors) and allceramic crowns (maxillary right central and lateral incisors) that showed inappropriate width/length ratios (Fig 3). The old crowns
227 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
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Cast metal post and core after crown removal.
Fig 6
Esthetic post and core used to improve light
transmission.
a Fig 7
b
Fig 8
b
c
b
c
(a to c) Try-in of the waxup.
a Fig 9
c
(a to c) Waxup of the maxillary incisors.
a
(a to c) Provisional crowns fabricated from the waxup.
228 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
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Fig 5
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a
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b
Fig 10
Soft tissues after removal of the provisionals. (a) The first retraction cord was packed in. (b) Second re-
traction cord in place.
were sectioned (Fig 4), and the existing
tions, the provisional crowns had a W/L
cast post and core was removed (Fig 5). To
ratio similar to the data displayed in Table 1.
improve light transmission, the metallic
After 6 months, the soft tissues had sta-
post and core was substituted with a zirco-
bilized (Fig 10), and the final impression
nia post and composite core (Fig 6).9 In the
was taken with polyvinyl siloxane (Figs 11a
same appointment, cosmetic soft tissue re-
to 11c). To ensure accurate soft tissue re-
contouring was performed for the right
production, a Geller master cast was pro-
central and lateral incisors. Provisional
duced (Figs 11d to 11f).12 Four all-ceramic
crowns were carefully crafted to assist in
feldspathic crowns were fabricated based
the physiologic remodeling of the soft tis-
on individual tooth proportion (ITP). The
sue complex.
concept of ITP depends on the available
After 6 months of healing, an impression
space for tooth width. Therefore, to main-
of the abutment teeth was taken and a wax-
tain the correct ITP, some modifications of
up was made (Fig 7), taking into consider-
anterior teeth arrangement may be re-
ation previous reports of an optimal 80%
quired. For instance, in situations with re-
3,10
ratio of maxillary anterior teeth.
The wax-
duced interdental space, maxillary teeth
up was clinically tried-in to allow for correc-
could be rotated to produce a satisfactory
tions of tooth shape and proportion by
W/L ratio. It is important that the rotation is
adding or removing wax (Fig 8). After clin-
not symmetrical; instead, it should be ac-
ical try-in, the waxup was duplicated using
centuated more on side than the other. Fig-
polymethyl methacrylate resin (New Out-
ure 12 shows teeth that were rotated to fit
line, Anaxdent) and cemented in place with
reduced interdental space. The final restorations were then bonded
non-eugenol cement (Fig 9). The provisional crowns were evaluated
to the abutment teeth (Fig 13). The final out-
by the patient for 30 consecutive days. In-
come showed a satisfactory esthetic result,
traoral
mainly due to the incorporation of the prop-
adjustments
of
the
provisional
restorations were performed to meet the 11
patient’s expectations.
er ITP for the restored teeth (Fig 14).
After final correc-
229 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
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d Fig 11
b
c
e
f
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a
(a to c) Final impressions showing adequate soft tissue deflection. (d to f) A Geller master cast was
produced for all abutments.
a
Fig 12
(a and b)
Examples of modified
anterior
teeth
arrangement for reduced interproximal space. The concept of
individual
tooth
proportions depends on the space availb
230 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
able for tooth width.
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(a) Preoperative and
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Fig 13
(b) postoperative photographs of
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the central incisors.
a Fig 14
a
b
b
c
(a to c) Final restorations were fabricated using the following W/L ratios: central incisors = 85% and
lateral incisors = 79%.
Case 2
maxillary teeth.13 After 1.5 years of treatment, some deficiencies in the soft tissue
A 41-year-old female patient presented
were observed. Loss of interdental papillae
with advanced periodontal disease with
resulting in large black triangles was evi-
attachment loss and mobility of the maxil-
dent (Fig 16). The old crowns and defec-
lary anterior teeth (Fig 15). The patient un-
tive cast post and core were removed. An
derwent intense periodontal therapy asso-
impression was taken, a waxup was made
ciated with orthodontic extrusion of the
as described in case 1, and provisional
Fig 15
Fig 16
Preoperative view of the maxillary anterior
After periodontal treatment, large interdental
sextant with advanced periodontal disease and defec-
black triangles were evident due to the loss of interdental
tive porcelain-fused-to-metal crowns.
papillae.
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17
A
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Fig
slight
mesial rotation of the central incisors was required
to
over-
come the excess interproximal space.
a Fig 18
b (a) Gingival view of the porcelain-fused-to-metal crowns before the mini-wings were fabricated.
(b) Delicate mini-wings were produced to close the interproximal black triangles.
crowns were fabricated based on the wax-
wings17; Fig 18) was utilized to overcome
up and relined every 2 weeks to stimulate
the excess interproximal space. The areas
14,15
interdental papillae formation.
However,
alongside
the
defined
ITP
were
also
after 6 months no interdental papillae had
shaped to generate areas of shadow to
formed between the maxillary central inci-
contribute a more pleasant arrangement
sors. This was due to the reduced vertical
of the anterior teeth. Porcelain-fused-to-
distance from the crest of bone to the
metal crowns were fabricated with a re-
height of the interproximal contact.16 To
duced framework and cemented on the
achieve a better esthetic outcome, the
prepared teeth. The final restorations met
concept of ITP was applied to the final
the patient’s approval (Fig 19).
restorations.
However,
the
interdental
space available was larger than the required mean width of the individual teeth.
Discussion
Minor rotation of the maxillary central incisors (Fig 17) associated with slight inter-
The findings of the present study show the
dental extension of the restorations (mini-
importance of tooth width, length, and W/L
232 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
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Fig 19
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Final results achieved using the concept of individual tooth proportion.
ratio when creating an esthetic rehabili-
tively.5 These differences in perception
tation. The mean tooth width and length
may explain why patients sometimes dis-
data in this study are consistent with the
approve of the final outcome. To avoid this
data found in the literature for permanent
situation, knowledge of width, length, and
dentition.
3,4,6
Determining the width and
W/L ratio is imperative.
length measurements facilitates the fabri-
Studies of patient judgment of smiles
cation process of an esthetic restoration.
report a tendency for acceptance of W/L
Therefore, to achieve a better distribution
ratios ranging from 75% to 85%,2,5 which
of the maxillary teeth into the sextant, the
is in accordance with the present findings.
W/L ratio should be carefully evaluated
It was believed that W/L ratio is homoge-
before the delivery of the restorations.
neous for the three anterior maxillary tooth
Variations in the optimal W/L ratio are 2,3,5,6
present in the literature.
groups.2,3 However, the data show that
In addition, the
each maxillary anterior tooth has its own
perception of the optimal W/L ratio varies
W/L ratio (Tables 1 and 2), and can be
greatly between professionals and pa-
ranked as follows: central incisors > ca-
tients, ranging from 66% to 80%, respec-
nines > lateral incisors. If these dimen-
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Conclusions
bilitation, the final outcome will show supe-
n
sions are reproduced in an anterior reharior esthetics and a more natural appear-
Each maxillary anterior tooth has its own
ance. Therefore, it is strongly suggested
width, length, and W/L ratio. A more pre-
that specific widths, lengths, and W/L ra-
dictable restoration of the maxillary anteri-
tios should be used in the esthetic rehabil-
or region can be achieved using the prop-
itation of maxillary anterior teeth.
er dimensions.
Acknowledgments The authors thank Dr Bernard Tandler for editorial assistance.
References 1. Rufenacht C. Fundamentals of Esthetics. Chicago: Quintessence, 1990. 2. Brisman AS. Esthetics: A comparison of dentists’ and patients’ concepts. J Am Dent Assoc 1980;100:345–352. 3. Sterrett JD, Oliver T, Robinson F, Fortson W, Knaak B, Russell CM. Width/length ratios of normal clinical crowns of the maxillary anterior dentition in man. J Clin Periodontol 1999; 26:153–157. 4. Magne P, Gallucci GO, Belser UC. Anatomic crown width/ length ratios of unworn and worn maxillary teeth in white subjects. J Prosthet Dent 2003; 89:453–461. 5. Wolfart S, Thormann H, Freitag S, Kern M. Assessment of dental appearance following changes in incisor proportions. Eur J Oral Sci 2005;113: 159–165. 6. Chu SJ. Range and mean distribution frequency of individual tooth width of maxillary anterior dentition. Pract Proced Aesthet Dent 2007;19:209–215. 7. Davis BK. Dental aesthetics and the aging patient. Facial Plast Surg 2006;22:154–160.
8. Morley J. The role of cosmetic dentistry in restoring a youthful appearance. J Am Dent Assoc 1999;130:1166–1172. 9. Raptis NV, Michalakis KX, Hirayama H. Optical behavior of current ceramic systems. Int J Periodontics Restorative Dent 2006;26:31–41. 10. Snow SR. Esthetic smile analysis of maxillary anterior tooth width: The golden percentage. J Esthet Dent 1999;11:177–184. 11. Magne P, Magne M. Use of additive waxup and direct intraoral mock-up for enamel preservation with porcelain laminate veneers. Eur J Esthet Dent 2006;1:10–19. 12. Kopp FR. Esthetic principles for full crown restorations. Part II: Provisionalization. J Esthet Dent 1993;5:258–264. 13. Salama H, Salama M. The role of orthodontic extrusive remodeling in the enhancement of soft and hard tissue profiles prior to implant placement: A systematic approach to the management of extraction site defects. Int J Periodontics Restorative Dent 1993;13: 312–333.
234 THE EUROPEAN JOURNAL OF ESTHETIC DENTISTRY VOLUME 3 • NUMBER 3 • AUTUMN 2008
14. Bichacho N. Papilla regeneration by noninvasive prosthodontic treatment: Segmental proximal restorations. Pract Periodontics Aesthet Dent 1998;10:75, 77–78. 15. Bichacho N, Eylat Y, Dadi M, Jacoby Y, Weiss E. Restoration modalities of severely injured anterior teeth—Gingival integration, papillae support, and predictable imperfections. Compend Contin Educ Dent 2003;24:891–894, 896–898, 900–894. 16. Tarnow D, Elian N, Fletcher P, et al. Vertical distance from the crest of bone to the height of the interproximal papilla between adjacent implants. J Periodontol 2003;74:1785–1788. 17. Magne P, Magne M, Belser U. The esthetic width in fixed prosthodontics. J Prosthodont 1999;8:106–118.