|Review Article (Open access)
SSR Inst. Int. J. Life. Sci.,
and its Management- A Review
Abhishek Roy1*, Bhargava
Kashyap2, Pranav Nakra3
of Oral Surgery, Post Graduate in Oral and Maxillofacial Surgery, Pacific Dental
College and Hospital, Pacific University, Debari, Udaipur, India
of Public Health Dentistry, KLE Academy
of Higher Education and Research (KLE University’s) KLE VK Institute of Dental
Sciences, Belagavi, India
3BDS, Dental Surgeon, Pacific Dental College and
Hospital, Pacific University, Debari, Udaipur, India
*Address for Correspondence: Dr. Abhishek Roy, MDS
(Oral Surgery), 9 Janak Road, Lake Market, Kolkata - 700029, West Bengal, India
ABSTRACT- In the modern, fast-paced world the
concept of aesthetics is very important to all people. The degree of aesthetic
value may vary from person to person but the basic idea of it is more or less
equivalent in all people. Similarly, in dentistry, the value of aesthetics is
very high. Open gingival embrasures or black triangle cause complex functional
and aesthetic problems. Management of such problems requires careful evaluation
of the underlying causes. In today’s aesthetic environment where both the
dentist and the patient are aware of aesthetic value, the real challenge was to
reconstruct this lost papilla and moreover to obtain stable and sustainable
results. This review was carried out after electronic searches in databases such
as PubMed, PubMed Central, MEDLINE, Google Scholar, and MeSH. Manual searches
of hard copies were also done. Studies included ranged from a time period of
1992 - 2016 and included clinical trial researches. A total of 19 articles were
chosen for this review. These articles satisfied the various inclusion criteria
and were taken after a detailed assessment of the full-length articles. Black
Triangles pose multiple problems both to the dentist and to the patient. The
causes of them are multifactorial and they can occur after various dental
therapies. A strong connection is found between their occurrence and
post-orthodontic treatment patients. Various methods to treat these problems
are present. The clinician and the patient should discuss these problems and
solutions in depth before starting the treatment.
Aesthetics, Black triangles, Open gingival embrasure, Periodontal treatment,
importance of aesthetics in modern dentistry is paramount. Aesthetics has its different
values and perceptions, which may be different from the eyes of the patient and
those of the clinician . It is dependent on the socio-economic
status and the upbringing and mentality of each individual person. In spite of
this, there are certain universal standards of aesthetics that must be
maintained while performing any dental procedure [2,3].
Various aesthetic factors have to be
considered while performing dental treatment which include shade of teeth,
contour of teeth, positioning of appliances, occlusal level, and absence of
high points, gingival colour and contour, contour of lips, outline of mouth and
smile line [1,4-6]. One of the factors that hamper proper aesthetics
is the presence of “Black Triangles” [2,7,8].
It is referred to as the gap seen at the
cervical embrasure, below the contact point of some teeth, which are
cervically located with respect to the interproximal contact point and not
occupied with gingival tissue [9-11]. This gap has many causes
including gingival recession and periodontal disease. Hence, these areas
present some unique aesthetic and functional problems [12,13]. These
problems include the fact that they are noticeably unaesthetic which negatively
affects the smiling profile. They also lead to retention of food debris and
also to the aggregation of dental plaque [14-17].
Prevalence – One
third people were affected by black triangles . Some studies
reported that the preponderance of black triangles were [1,10,13,18]-
>67% of people above 20 years
<= 18% of people under 20 years
A recent study conducted by Geld et al.  of patient
attitudes found patient displeasure with black triangles to rank quite high
among aesthetic flaws, ranking 3rd following cariogenic lesions and
dark crown margins. Fig. 1 depicts the aesthetic concerns caused by black
1: Black Triangles in incisors
Papilla- The interdental papilla is formed by a dense
connective tissue covered by oral epithelium and it occupies the physiological
space between the teeth. Interdentally, the gingiva that occupies the space
coronal to the alveolar crest is known as interdental gingiva [2,19,20].
It presents as a pyramidal shape in the interdental area with the tip located
immediately below the contact point, is narrower and called as dental papilla.
It is broader in the posterior region. In the absence of a contact point or
when interdental papilla migrates apically as a result of inflammation, the
contouring disappears and interdental papilla takes on a pyramidal shape, which
is dysfunctional and unaesthetic. Loss of interdental papilla leads to
different problems, which include aesthetics, enunciation and food lodgement
Factors - There are multiple causes as to the etiology of open
gingival embrasures. These include aging, periodontal disease, loss
of height of alveolar bone relative to interproximal contact, length of
embrasure area, root angulations, interproximal contacts and triangular shaped
crowns [6,23,24]. However, black triangles may also arise following
periodontic and orthodontic therapy [7,9,25].
Its management varies depending on the
etiological factor, but is favourably managed by a team work usually including
restorative, orthodontic and periodontic treatment. Sometimes, correction of
these problems is not straightforward and may increase both the complexity and
duration of treatment. [1,2,5,16] Sometimes, the decision to close
the embrasures or not is difficult especially when the open embrasures are
small, as displayed in Fig. 2.
2: Small embrasure openings affecting the smile line
of loss of Interdental Papilla - Nordland and Tarnow put forward a classification using 3 reference
points- Contact point, Facial apical extent of CEJ, and Interproximal CEJ
By these 3 cardinal points, they gave
the following classification-
Interdental papilla fills embrasure space to the apical extent of the interdental
The tip of interdental papilla lies between the interdental contact point and
the most coronal extent of CEJ.
The tip of the interdental papilla lies at/or the apical to the iCEJ but
coronal to the apical extent of the facial CEJ.
The tip of the interdental papilla lies at level with or apical to the facial
of Black Triangles - The treatment of open gingival
embrasures requires the reconstruction of interdental papilla. This is usually
achieved by the following methods [20,26-28]-
methods- Orthodontic treatment is used to close interdental
spaces. Forced eruption can also be done.
methods- Free gingival grafts, flap pedicles and guided bone
regeneration are different methods used. However, free gingival grafts have a
low success rate due to the minor blood supply in the interdental papilla.
methods- Prosthetic or operative dentistry is used to change
the morphology or relocate the contact point apically. As a result,
interproximal spaces can be closed. This method is followed when periodontal defects
are too extensive or region of missing teeth is too large. [29,30]
The treatment benefits
are appropriately highlighted in Fig. 3, which shows a significant post
treatment enhancement of aesthetics.
3: Correction of black triangles leading to marked improvement in smile design
literature search was carried out in the electronic databases available such as
PubMed, PubMed Central, MEDLINE, Google Scholar, and MeSH. The keywords used in
this search included “black triangles”, “open gingival embrasure”, “orthodontic
role”, “orthodontic problems”, “periodontic role”, “periodontal problems”,
“aesthetics”, “patient evaluation”. In addition to this, manual search of hard
copies of journals was carried out. Studies were included from time period
ranging from 1992 - 2016. The various studies were studied and clinical trial
studies were included for this review.
A total of 19 studies
were taken for the purposes of this review. These studies satisfied all the
criteria and were chosen after a thorough check of the full length articles.
of Literature - Kokich
and Kurth  were conducted a study in 2001 to examined
post-treatment open gingival embrasures in adult orthodontic patients and to
examine the association of different etiological factors that they considered
important with open gingival embrasures. Post-treatment intraoral photographs
of 337 adult orthodontic patients were examined to determine the prevalence of
open gingival embrasures. Digital images of the pre-treatment maxillary models
and post-treatment maxillary central incisor periapical radiographs were made
to measure the pre-treatment and post-treatment variables. The prevalence of
post-treatment open gingival embrasures in adult orthodontic patients was 38%.
Pre-treatment maxillary central incisor rotation and overlap were found to not
be statistically significant when related to post-treatment open gingival
embrasures. A post-treatment alveolar bone-interproximal contact distance
greater than 5.5 mm as well as short, incisally placed post-treatment
interproximal contacts were associated were found to be statistically
significant and associated with occurrence of black triangles. Increased
divergence of root angulations, more divergent or triangular-shaped crown forms
and embrasure areas larger than 5.09 mm2 were also correlated with
open gingival embrasures. Furthermore, black triangles found in this study were
seen to have the greatest association with increased alveolar
bone-interproximal contact distance and increased root angulation. This investigation
indicated that black triangles are common in adults who have undergone
orthodontic treatment and that post-treatment results were expressive in their
and Kurth  further examine whether the approximal contact point
to the crest of bone distance affected the amount of the interproximal papilla.
Through his study, the following data was received-
5 mm or less- Interdental papilla always
6 mm- Papilla present 56% of the
7 mm or more- Papilla usually
and Kurth  found that the mean prevalence of cervical diastemas
in post-treatment adult orthodontic patients is about 38%. Tanaka et al.  found in 2008
that the prevalence of open gingival embrasures are greater in orthodontic
patients over 20 years of age, and also that the resorption of the alveolar
crest is much more likely to lead to this problem. Open gingival embrasures
were found in 43.7% of the subjects undergoing orthodontic treatment. On
radiographic examination, it was found that patients who had undergone
orthodontic treatment had decidedly more bone loss than the subjects who were
not given such treatment. Thus, this study indicated that the occurrence of
open gingival embrasure is significantly related to alveolar bone loss
secondary to orthodontic treatment.
Ko-Kimura et al.  conducted
a study including 80 orthodontic patients (33 males, 47 females) between 15 and
31 years of age. Open gingival embrasures were found in 43.7% of all subjects,
with the prevalence being 66.7% in subjects over 20 years. The amount of
crowding was taken into consideration and it was found that the occurrence of
black triangles was related to it in the following manner-
than 4 mm crowding- 42.8%
mm to 8 mm crowding- 41.2%
mm and more crowding- 50%
The period of orthodontic treatment was
also considered and was found not to be statistically significant at 42% of
patients in shorter treatment and 44.4% of patients in the longer treatment
group had the problem. In conclusion, it was reported that black triangles were
more frequently found in patients over 20 years of age than in younger
patients, and were associated to a greater degree with the resorption of the
Agarwal et al.  conducted a case series which included
reconstruction of open gingival embrasures; the distance between the tip of
interdental papilla and incisal edge were measured at follow-up visits.
Distance between interdental papilla and incisal edge at 3 months and 6 months
remained stable. Results showed an increase in sulcus depth by about 1.19 mm
and improvement in the contour of interdental tissues in 51% of cases and in
38.46%, the interdental papilla completely obliterated the open embrasures.
conclusion, open gingival embrasures or black triangle pose complex design and
functional problems that are noticeably unaesthetic and negatively affect the
smile pattern. A multidisciplinary approach involving restorative,
prosthodontic and orthodontic specialties must be considered if a successful
clinical outcome is to be achieved. Non-surgical methods are also important if
the amount of loss is minimal and periodontal health is good. All etiological
factors and treatment alternative must be discussed with the patient before starting
CONTRIBUTION OF AUTHORS
Research concept- Dr. Roy
Research design- Dr.
Roy, Dr. Pranav
Roy, Dr. Pranav
Roy, Dr. Bhargava
Data collection- Dr.
Roy, Dr. Bhargava
Data analysis and Interpretation- Dr. Roy, Dr. Bhargava
Literature search- Dr. Roy, Dr. Bhargava
Writing article- Dr.
Roy, Dr. Bhargava, Dr. Pranav
Critical review- Dr.
Roy, Dr. Bhargava, Dr. Pranav
Article editing- Dr.
Roy, Dr. Bhargava, Dr. Pranav
approval- Dr. Roy, Dr. Bhargava, Dr.
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Ahmad I. Anterior
dental aesthetics: Gingival perspective. Br. Dent. J., 2005; 199: 195-202.
Oosterveld P, Van Heck G, Kuijpers-Jagtman AM. Smile attractiveness:
Self-perception and influence on personality. Angle Orthod., 2007; 77: 759-65.