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RESEARCH ARTICLE
Study of the frequency and location of incidental findings of the
maxillofacial region in different fields of view in CBCT scans
1
Ivna A Lopes,
1
Rosana M A Tucunduva,
1
Roberta H Handem and
1
Ana Lucia A Capelozza
1
Department of Stomatology, Bauru School of Dentistry, University of S~
ao Paulo, Bauru, S~
ao Paulo, Brazil
Objectives: The aim of this study was to identify the type and frequency of incidental
findings (IFs) in the maxillofacial region of CBCT scans with different sizes of field of view
(FOV), and the clinical relevance of the findings was classified as requirement or not of
monitoring, treatment or referral to a specialist.
Methods: We analyzed 150 CBCT examinations, divided according to the size of the FOV
into 3 groups: 6-cm maxilla, 6-cm mandible and 13-cm maxilla/mandible. The IFs were
categorized into six areas: airway, temporomandibular joint (TMJ), bone, lesions of the jaws,
teeth and soft-tissue calcifications.
Results: The results showed 560 IFs that were found in 92% of the samples studied. A total
of 225 IFs were found in examinations of the maxilla group, 99 findings in the mandible
group and 236 findings in the maxilla/mandible group. The IFs were most frequent in the
tooth zone (27.32%), followed by airways, soft-tissue calcifications, TMJ, bone, lesions of the
jaw and other findings. We also found that 43.46% of the IFs did not need treatment or
referral to another professional, 28.97% findings required the acquisition of new images for
monitoring and 27.55% findings needed treatment or referral.
Conclusions: The present study confirmed the high frequency of IFs in CBCT scans. It was
concluded that it is necessary to interpret and report the total volume obtained in CBCT
examinations and not only the purpose of the examination region.
Dentomaxillofacial Radiology (2016) 45, 20160215. doi: 10.1259/dmfr.20160215
Cite this article as: Lopes IA, Tucunduva RMA, Handem RH, Capelozza ALA. Study of the
frequency and location of incidental findings of the maxillofacial region in different fields of
view in CBCT scans. Dentomaxillofac Radiol 2016; 45: 20160215.
Keywords: incidental finding; CBCT; diagnostic imaging
Introduction
CBCT, used to capture images in the maxillofacial region,
was developed in the 1990s and since then, it has evolved.
This scan imaging is used in dentistry because it can
provide excellent images with high contrast of the bone
and tooth structures with lower radiation dose and low
cost for the patient compared with examinations obtained
by helical CT. Obtaining the image for CBCT still has
advantages when compared with conventional X-rays,
because it eliminates most of the problems related to im-
age distortion and superimposition of structures.
1
During the acquisition of a CBCT image, the field of
view (FOV) can be modified and determined as the
region of interest. The images obtained on a CBCT
scanner with a small FOV are used for interpreting
limited areas of the maxillofacial region, while the
images obtained with a large FOV include the paranasal
sinuses, airways and intracranial and cranial base
structures.
2
With the growing indication of CBCT in various
dental specialities, much has been asked about the role
of the dentist in evaluating the image obtained in the
examination. Although often overlooked, the evalua-
tion of all structures included in the examination is
required according to the guidelines of the American
Correspondence to: Mrs Ivna Albano Lopes. E-mail: ivnalbano@hotmail.com
Received 19 May 2016; revised 20 August 2016; accepted 5 September 2016
Dentomaxillofacial Radiology (2016) 45, 20160215
ª2016 The Authors. Published by the British Institute of Radiology
birpublications.org/dmfr
and European Academies of Dentomaxillofacial Ra-
diology. Therefore, knowledge is needed of not only
the dentomaxillary complex, but also the adjacent
structures.
3,4
As imaging techniques evolve, the ability to identify
incidental findings (IFs) increases. An IF can be defined
as a radiographic or tomographic image with any dis-
covery that is unrelated to the original purpose of the
examination, which can range from anatomical varia-
tions to benign and malignant lesions.
2
The inability to identify, inform or provide follow-
up and care related to the IFs may have negative
consequences for the patient and result in dentists
neglecting their legal responsibility.
2
The recognition
of IFs in CBCT images allows the identification of
occult lesions, thereby improving the accuracy of the
diagnosis and enabling the most appropriate thera-
peutic approach.
Research shows that when two-dimensional images
are interpreted, IFs are identified in 6–43% of
patients.
5–7
CBCT examinations contain more in-
formation than images in two dimensions, so it is to be
expected that in these examinations, the radiologist will
find higher occurrence of IFs.
Although there are some studies that have already
found many IFs in the maxillofacial region,
1,8–13
there
are no studies with Brazilian samples yet. In addition,
these studies did not use examinations showing different
sizes of FOV in their samples. Therefore, it would be
a great contribution to carry out more studies aimed at
recognizing the types and frequency of IFs in each type
of FOV in order to avoid underestimation or over-
estimation of substantial abnormalities.
The objectives of our study were to identify the type,
frequency and location of IFs in the maxillofacial region
of CBCT scans with different sizes of FOV and classify
the findings into the requirement or not of monitoring,
treatment or referral to another professional.
Methods and materials
This study was approved by the Ethics Committee of
the Bauru School of Dentistry, University of S~
ao Paulo.
A total of 150 CBCT examinations were selected from
the image files of the Department of Stomatology of this
institution.
The inclusion criteria for sample selection were: (1)
images with an FOV 6-cm high involving only the
maxilla; (2) images with an FOV 6-cm high involving
only the mandible; and (3) images with an FOV 13-cm
high involving both the maxilla and mandible. The ex-
clusion criteria were: examinations without reasons for
their requests and examinations with bad picture
quality.
The sample was divided into 3 groups: (1) 50 exami-
nations covering the maxilla; (2) 50 examinations cov-
ering the mandible; and (3) 50 examinations covering the
maxilla and mandible. The examinations showed varying
voxels (0.2, 0.25, 0.3 and 0.4) and the diameter of the
FOV was 16 cm.
The equipment used in this research was an i-CAT
Classic
®
(Imaging Science International, Hatfield, PA)
and for the interpretation of the examinations, i-Cat
Vision
®
software (Imaging Sciences International,
Hatfield, PA) was used on a multiplanar reformat-
ting screen.
2 researcher radiologists performed the analysis of
the examinations in 2 stages: 21 examinations (15%
of the sample) were observed first and after 15 days,
a new assessment was performed. Thus, an intra-
calibration and an intercalibration were performed
through the kappa test. Thereafter, a single dentist
radiologist examiner, followed the study and evalu-
ated all the CBCT examinations and reported the
possible IFs, which were not associated with the
reason. Findings directly related to the preliminary
indications of the CBCT were excluded. A list con-
taining the most common IFs in CBCT examinations
based on the literature
1,8–13
was developed for a bet-
ter classification of images. In the few cases of doubt
about the image, other experienced radiologists were
consulted.
Data about the patients (gender and age) and the
indication of each CBCT examination were also col-
lected. All diagnoses were based on CBCT findings.
Comparisons and associations with conventional radi-
ography and histopathological examinations were not
performed.
Table 1 Indications of CBCT examinations in the sample
Indications of CBCT examination
Amount
n%
Planning for implant 61 40.67
Evaluation/control of cysts/tumours 21 14.00
Pre-operative assessment of third molar 12 8.00
Unerupted tooth assessment 14 9.33
Supernumerary tooth location 6 4.00
Others 36 24.00
Total 150 100.00
Table 2 Distribution of the number of incidental findings (IFs) in accordance with the field of view (FOV) used
FOV Total number of IFs Average of findings per examination Number of examinations with findings
Maxilla 225 4.50 49
Mandible 99 1.98 42
Maxilla/mandible 236 4.72 47
Total 560 3.73 138
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The IFs were divided into six zones: (1) airway, (2)
temporomandibular joint (TMJ), (3) bone, (4) lesions of
the jaw, (5) teeth and (6) soft-tissue calcifications.
The TMJ and the airways were not analyzed in
Group 2 (mandible) because they were not visible in
this FOV. When the IF did not fit in any of the six
zones shown, it was included in the “Other”group.
Findings such as missing teeth, dental caries and bone
loss were excluded. An IF that was observed more
than once in the examination was recorded to be
observed.
After analyzing the CBCT examinations, the IFs
were classified in relation to their clinical manage-
ment into three groups: (1) does not need treatment/
referral to another professional; (2) monitoring is
suggested; and (3) needs treatment/referral to another
professional.
The descriptive and inferential analyses of the data
were performed using the Statistica v. 5.1 program (Stat
Soft Inc, Tulsa, OK) and by adopting a significance
level of 5%.
Results
Intraexaminer and interexaminer calibration
Kappa test was performed and the agreement was al-
most perfect, with a 0.87 intraexaminer calibration and
0.81 interexaminer calibration.
Sample profile
Patients in the sample were aged between 8 and 91 years
(mean 37 ± 18.3 years). The females were predominant
in the sample (n582) with 54.7% while 45.3%
were males.
Reason for requesting CBCT examination
The prevailing indication of CBCT examinations was
planning implants (n561) with a frequency of 40.67%
of the sample (Table 1).
Incidental findings
A total of 560 IFs were obtained; the maxilla/mandible
group had the largest number of IFs, followed by the
Table 3 Descriptive analysis and frequency of incidental findings (IFs) of CBCT examinations with the field of view encompassing the maxilla
Zone IFs Number (%) of IF Number of patients with IF Clinical management
a
Airway Thickening maxillary sinus mucosa 41 (18.22) 30 .2 mm: Y
Alveolar extension of the maxillary sinus 17 (7.55%) 17 N
Deviated septum 8 (3.55%) 8 Y
Cyst retention/pseudocyst/polyp 6 (2.66%) 6 N
Turbinate hypertrophy 4 (1.77%) 4 Y
Antrolith 3 (1.33%) 3 N
Thickening sphenoid sinus mucosa 3 (1.33%) 3 Y
Tuber extension of the maxillary sinus 3 (1.33%) 3 N
Bucosinusal communication 2 (0.89%) 2 Y
Total opacification of the maxillary sinus 1 (0.44%) 1 Y
Total opacification of the sphenoid sinus 1 (0.44%) 1 Y
Concha bullosa 1 (0.44%) 1 Y
Nasal polyposis 1 (0.44%) 1 N
Total 91 (40.44%) 80
TMJ Osteophytes 25 (11.11%) 17 F
Flattening condyle 24 (10.67%) 17 F
Away zone
b
12
Total 49 (21.78%) 34
Bone Palatal torus 9 (4.00%) 9 N
Bone sclerosis 2 (0.89%) 2 N
Total 11 (4.89%) 11
Lesions of the jaw Periapical cyst 4 (1.78%) 4 Y
Odontoma 1 (0.44%) 1 Y
Total 5 (2.22%) 5
Teeth Root dilaceration 16 (7.11%) 10 N
Apical lesion 9 (4.00%) 9 Y
Impacted tooth 3 (1.33%) 2 F
Pulp calcification 1 (0.44%) 1 N
Endoperio lesion 1 (0.44%) 1 Y
Condensing osteitis 1 (0.44%) 1 Y
External resorption 1 (0.44%) 1 Y
Total 32 (14.22%) 25
Soft-tissue calcifications Calcification of the style–hyoid complex 33 (14.67%) 18 N
Tonsillolith 1 (0.43%) 1 N
Total 34 (15.11%) 19
Others Residual root 2 (0.89%) 2 Y
Amalgam fragment 1 (0.44%) 1 N
Total 3 (1.33%) 3
F, need follow-up; N, do not require treatment/referral; TMJ, temporomandibular joint; Y, need treatment/referral to another professional.
a
Many findings were classified as being asymptomatic. Treatment may be changed according to the symptoms and complaints of patients.
b
It was not possible to analyze the zone because the region was not visible in the examination.
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maxilla group and the mandible group. The distribution
of the number of IFs between sample groups is shown in
Table 2. The zone with the highest number of IFs was
the teeth, with 27.32%, and the most common IF in the
sample was thickening of the maxillary sinus mucosa
(n570), with 12.5%. The frequency of IFs among the
six zones evaluated in the sample is illustrated in
Figure 2. The IFs of each group evaluated can be seen
in Tables 3–5.
Number of incidental findings and gender of patients
There was no statistically significant result for any zone
and gender using the Mann–Whitney U-test to correlate
the number of IFs with male and female gender.
Number of incidental findings and age of patients
Using Spearman correlation to correlate the age of
patients with the number of findings by zone, it was
found to be a statistically significant result that older
patients had a larger number of IFs in the soft-tissue
calcification zone (p50.001).
Clinical relevance of incidental findings
Most of the findings with a 43.46% frequency do not
require treatment or referral to another professional. A
total of 28.97% of the findings need monitoring by the
dentist and 27.97% of them need treatment or referral to
another professional. In Tables 3–5, the classification of
each IF is established.
Discussion
In the present study, we evaluated 150 CBCT exami-
nations performed as a complementary examination
for diagnosis in dentistry. Planning for implant place-
ment was the most frequent reason for the request for
examinations, with 40.07% of the total sample (Table 1).
This result was also reported by other authors with
52.7–73% of frequency.
1,10,14
The current criteria
for the prescription of images obtained by CBCT were
established by SEDENTEXCT in 2011, an evidence-
based guidelines on use of CBCT in Dentistry, in-
cluding referral criteria, quality assurance guidelines
and optimisation strategies.
The sample was divided into three groups according
to the size of the FOV in this study. This division was
aimed at differentiating the type and frequency of
findings between the dental arches. Most of the studies
of IFs in the literature are performed with a large
FOV.
10,15
Some authors do not describe the size of the
FOV,
11–13
as shown in Table 6.
With regard to the profile of the sample of this re-
search, the majority of patients were female, with
54.7%, which corroborates with findings in the
literature.
1,8–13
With regard to age, we had a very large age range in
the sample (8–91 years). In the literature, there are
similar results, since in these studies there were no cri-
teria for inclusion or exclusion in relation to age
(Table 6).
1,10–13,15
Table 4 Descriptive analysis and frequency of incidental findings (IFs) of CBCT examinations with the field of view encompassing the mandible
Zone IFs Number (%) of IF Number of patients with IF Clinical management
a
Bone Bone sclerosis 12 (12.12%) 9 N
Mandibular torus 1 (1.01%) 1 N
Total 13 (13.13%) 10
Lesions of the jaw Osteoma 1 (1.01%) 1 F
Dentigerous cyst 1 (1.01%) 1 Y
Odontoma 1 (1.01%) 1 Y
Total 3 (3.03%) 3
Teeth Apical lesion 10 (10.10%) 8 Y
Endoperio lesion 5 (5.05%) 3 Y
Impacted tooth 5 (5.05%) 5 F
Giroversion 4 (4.04%) 4 N
Root dilaceration 3 (3.03%) 3 N
Furcation lesion 3 (3.03%) 3 Y
Pulp calcification 2 (2.02%) 2 N
Condensing osteitis 2 (2.02%) 2 Y
External resorption 1 (1.01%) 1 Y
Taurodontism 1 (1.01%) 1 N
Supernumerary tooth 1 (1.01%) 1 N
Total 37 (37.37%) 33
Soft-tissue calcifications Calcification of the style–hyoid complex 18 (18.18%) 16 N
Tonsillolith 14 (14.14%) 14 N
Calcification of triticeous cartilage 7 (7.07%) 7 N
Greater horn thyroid calcification 2 (2.02%) 2 N
Total 41 (41.41%) 39
Others Residual root 4 (4.04%) 3 Y
Increased pericoronal space 1 (1.01%) 1 F
Total 5 (5.05%) 4
F, need follow-up; N, do not require treatment/referral; Y, need treatment/referral to another professional.
a
Many findings were classified as being asymptomatic. Treatment may be changed according to the symptoms and complaints of patients.
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The frequency of the IFs depends on the sample, age
group, criteria and categories of IFs that are considered
by each researcher. In this study, a high frequency of
IFs was obtained, i.e. findings not related to the purpose
of the examination, similar to results found in the lit-
erature (Table 6).
1,10–12
A total of 560 IFs were found in 138 of the 150 exami-
nations. Therefore, 92% of the examinations showed at
least one IF and 8% examinations did not present any
findings. The average number of IFs per examination was
3.73. We observed that the maxilla/mandible group (n5
236) had a higher number of IFs than the maxilla group (n
5225) and the mandible group (n599) (Table 2). This can
be explained by the fact that the maxilla/mandible group
has FOV of the largest size (13 cm), thereby providing more
visible structures and a greater likelihood of IFs. The
maxilla group showed the greatest number of findings in
relation to the mandible, and this can be attributed to the
absence of airway zone and TMJ in the mandible group.
Airway findings
In this study, the airway was the zone with the second
highest number of findings and represented 24.46% of
the IFs (n5137). In the literature, there is a high fre-
quency of IFs in the airways, commonly the zone with
the first or second highest incidence of findings in re-
search (Table 6). In previous studies, frequencies of
findings in the airways of 35, 51.8, 18.8 and 73.2, re-
spectively, were reported.
1,8,11,12
The most frequent finding in this area was the
thickening of the maxillary sinus mucosa (n570)
(Figure 1), similar to studies in the literature.
1,11,15
In
a previous study, the majority of cases of sinusitis pre-
sented thickenings of the sinus mucosa bigger than
2 mm, so this value can be considered an important
indicator of maxillary sinusitis.
16
The large number and variety of findings in the air-
ways zone in this study shows how important it is for
dentists (Figure 1), especially radiologists, to understand
Table 5 Descriptive analysis and frequency of incidental findings (IFs) of CBCT examinations with the field of view encompassing the maxilla/
mandible
Zone IFs Number (%) of IF Number of patients with IF Clinical management
a
Airway Thickening maxillary sinus mucosa 29 (12.28%) 20 .2 mm: Y
Alveolar extension of the maxillary sinus 5 (2.11%) 5 N
Cyst retention/pseudocyst/polyp 4 (1.69%) 4 N
Turbinate hypertrophy 3 (1.27%) 3 Y
Deviated septum 2 (0.84%) 2 Y
Antrolith 1 (0.42%) 1 N
Total opacification of the maxillary sinus 1 (0.42%) 1 Y
Concha bullosa 1 (0.42%) 1 N
Total 46 (19.49%) 37
TMJ Flattening condyle 22 (9.32%) 15 F
Osteophytes 20 (8.47%) 16 F
Bifid condyle 1 (0.43%) 1 N
Total 43 (18.22%) 32
Bone Bone sclerosis 10 (4.23%) 10 N
Palatal torus 5 (2.11%) 5 N
Mandibular torus 1 (0.43%) 1 N
Exostosis 1 (0.43%) 1 N
Total 17 (7.20%) 17
Lesions of the jaw Periapical cyst 2 (0.84%) 2 Y
Bone dysplasia 1 (0.43%) 1 F
Total 3 (1.27%) 3
Teeth Impacted tooth 40 (16.94%) 16 F
Root dilaceration 13 (5.50%) 9 N
Giroversion 11 (4.66%) 6 N
Apical lesion 8 (3.38%) 6 Y
Supernumerary tooth 4 (1.69%) 2 F
Endoperio lesion 3 (1.27%) 3 Y
Agenesis 2 (0.89%) 1 N
Dens in dente 1 (0.42%) 1 Y
Enamel pearl 1 (0.42%) 1 N
External resorption 1 (0.42%) 1 Y
Total 84 (35.59%) 46
Soft-tissue calcifications Calcification of the style–hyoid complex 31 (13.13%) 17 N
Calcification of triticeous cartilage 5 (2.11%) 5 N
Tonsillolith 2 (0.89%) 2 N
Atheroma 2 (0.89%) 2 Y
Total 40 (35.59%) 26
Others Residual root 2 (0.89%) 2 Y
Increased pericoronal space 1 (0.42%) 1 F
Total 3 (1.27%) 3
F, need follow-up; N, do not require treatment/referral; TMJ, temporomandibular joint; Y, need treatment/referral to another professional.
a
Many findings were classified as being asymptomatic. Treatment may be changed according to the symptoms and complaints of patients.
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the nature of sinus changes. According to a systematic
review of the use of CBCT in airways, there has been
a significant increase in the number of publications on
this subject in the past 5 years and the results indicate
that CBCT can be used to accurately and reliably assess
the airways.
17
Temporomandibular joint findings
The TMJ was the fourth most frequent zone of IFs in
this sample (n592) with a frequency of 16.42%
(Figure 2), which is similar to previous studies with
a frequency of 15.4
1
and 11.1%
2
and less than that in
another study, with a frequency 39.31%.
15
44 cases of flattening condyle and 47 cases of osteo-
phytes were observed in this study (Figure 3). Flattening
is represented by the loss of convexity of the condyle
and is a signal of a remodelling bone or a physiological
response to the increase of load in the region. An
osteophyte is a marginal excrescence on the surface of
the condyle that appears in the later stage of de-
generative changes in the TMJ, when the body is
adapting to repair the joint (Figure 3).
18
Degenerative
diseases of the TMJ detected on CBCT can be an IF,
and patient history, clinical findings and symptoms are
important in determining disease activity. Patients with
symptoms such as pain and limited mouth opening need
referral or intervention, while those without such
symptoms do not need treatment, only monitoring.
1
One case of unilateral bifid condyle (Figure 3), in
a 23-year-old patient, was also found. A bifid condyle is
a rare anomaly and may be unilateral or bilateral and
anteroposterior or mediolateral. Although the aetiology
Table 6 Previous studies of prevalence of incidental findings (IFs) in CBCT examinations
Study CBCT scanner
Mean age
(range) (years) FOV
Number of examinations
with IF (%)
Number of IF
a
Zone with the highest
number of findings
Price et al 2011
1
NewTom 3G
Sirona Galileos 3D
Comfort
49.3 (9–80) 6 or 9 cm 272 examinations
(90.7%)
881 findings
Airway
Pette et al 2012
15
i-CAT Males 64.7; females
62.4 (16–91)
13 cm 789 findings Paranasal sinuses
Allareddy
et al 2012
10
i-CAT 5–87 (not reported) 13 cm 943
examinations (94.3%)
Teeth
Ça˘
glayan;
Tozo˘
glu 2012
11
NewTom 3G 30.3 (9–74) Not reported 192
examinations (92.8%)
Airway
Drage et al 2013
9
i-CAT Classic
®
(Imaging
Science International,
Hatfield, PA)
14.5 (not reported) 4 cm 66% examinations
370 findings
Teeth
Edwards
et al 2014
12
i-CAT Next Generation 6.3 (5–46) Large: size not
reported
356 examinations
(83.4%)
842 findings
Airway
Rheem
et al 2013
13
Hitachi CB MercuRay
Care stream 9300
Mean age not
reported (8–80)
Not reported 59
examinations (40.1%)
Paranasal sinuses
Present study i-CAT Classic 37 (8–91) 6-cm: maxilla
6-cm: mandible
13-cm: maxilla and
mandible
138 examinations (92%)
560 findings
Teeth
FOV, field of view.
a
Some authors describe their results only with the total number of examinations with IFs or with only the total number of IFs; NewTom 3G
(Quantitative Radiology, Verona, Italy); Sirona Galileos 3D Comfort (Sirona Dental Systems, Charlotte, NC); i-CAT (Imaging Sciences,
Hatfield, Pennsylvania, PA); i-CAT Classic
®
(Imaging Sciences, Hatfield, Pennsylvania, PA); i-CAT Next Generation (Imaging Sciences,
Hatfield, Pennsylvania, PA); Hitachi CB MercuRay (Hitachi Medical Corporation, Tokyo, Japan); Care stream 9300 (Carestream Health Inc,
Rochester, NY).
Figure 1 An antrolith (arrow) associated with mucosal thickening of the right maxillary sinus and mucosal thickening of the left maxillary sinus in
coronal reformatting (a); the arrow is indicating mucosal thickening of the sphenoid sinus in the axial reformatting (b); nasal septum deviation, alveolar
extension of the maxillary sinus bilateral and bucosinusal communication in the left maxillary sinus in coronal reformatting are indicated by the arrow (c).
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is not fully understood, evidence suggests development
change or traumatic aetiology. No treatment was in-
dicated for that patient.
1
Bone findings
This zone corresponds to 7.32% (n542) of the IFs in
this study and was the zone with the fifth highest in-
cidence of findings (Figure 2). In the literature, we ob-
served a greater number of findings in this zone with
a frequency of 15–17%.
1,13
24 cases of bone sclerosis were observed in this study
(Figure 4). This condition is considered asymptomatic
and does not cause expansion of the cortical bone.
Bone sclerosis consists of hyperdense intraosseous
lesions that do not result from infection or systemic
disease and have an unknown aetiology. Ignorance of
the frequency and location of these images can result in
erroneous diagnosis suggestions. No treatment is re-
quired in cases of bone sclerosis.
1
14 cases of palatal torus (Figure 4), 1 case of man-
dibular torus and 1 exostosis were also found in this
study. Torus and exostosis are anatomical variations
characterized by hard bony prominences located on the
hard palate (palatal torus), the lingual plate of the
mandible (mandibular torus) or the buccal plate of the
maxilla and mandible (exostosis).
19
Because they are
asymptomatic, they usually do not require treatment,
but they may be removed for prosthetic reasons and for
use as biomaterials in periodontics and implantology.
1
Lesions of the jaw findings
We noted in this sample a low frequency of IFs in this
zone (1.96%) (Figure 2), similar to the results found in
the literature, with frequency ranging from 0.1 to
3.5%.
1,20
It is important to emphasize that the findings
were described only with tomographic characteristics
and there was no clinical and histopathological exami-
nation of these. Therefore, the diagnosis is suggestive
and not definitive.
One case of osteoma was found in this study at the
lower border of the mandible (Figure 5). Osteomas are
benign and asymptomatic tumours. However, they can
increase in size causing cosmetic disfigurement and
functional impairment and therefore require radio-
graphic follow-up. It is important to evaluate their
possible relationship with Gardner’s syndrome.
1,21
Two cases of odontomas were found in this study. An
odontoma is a tumour formed by the dental tissue that
presents itself as a calcified mass, with a rounded or
irregular shape.
22
The treatment consists of surgical
removal.
23
Six cases of periapical cyst (Figure 5) and one dentig-
erous cyst were found in this study. These cysts can cause
cortical expansion, root resorption and displacement of
adjacent teeth. None of the cysts observed were large and
the treatment normally recommended is enucleation. A
diagnosis of the dentigerous cyst was considered in this
study when the follicular space was .5mm and the peri-
apical cysts when the apical lesion was .10 mm.
23
We also found one case of bone dysplasia in a 54-
year-old female patient. This fibro-osseous lesion rarely
produces symptoms and requires no treatment. However,
regular monitoring with periodic radiographs is recom-
mended to evaluate the development of the injury.
1
Figure 2 Frequency of distribution of incidental findings by zone
evaluated in the total sample.
Figure 3 Coronal reformatting: flattening condyle (a); osteophytes (b); and bifid condyle (c).
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Tooth findings
The largest number of IFs in this research was found in
the tooth zone, with 27.32% of the findings (Figure 2),
similar to a previous study.
9
A total of 153 IFs were
observed, involving dental anomalies and pulp, peri-
apical and periodontal changes.
105 cases of dental anomalies were found. Teeth
with taurodontism, supernumerary roots and root
dilaceration do not require treatment. However, in
cases of endodontic treatment or surgery, such teeth
require better evaluation. Patients with agenesis re-
quire treatment only in cases of aesthetic or functional
disability. In teeth with giroversion, orthodontic
treatment may be indicated depending on their degree
of rotation.
23
A case of dens in dente of a maxillary central in-
cisor was found. The invagination often communi-
cates with the oral cavity, allowing the entry of
irritants and microorganisms directly into the
pulp tissues. In such cases, restorative treatment is
necessary, or in more severe cases, endodontic
treatment.
23
Cases of supernumerary teeth and impacted teeth
were also observed (Figure 6), and the treatment of
these teeth depends on their position and their effects on
the adjacent teeth. Diagnosis and early treatment are
important to minimize the risk of complications.
1
Furthermore, we also observed 48 cases of end-
odontic and periapical changes. Pulp calcifications
are asymptomatic and do not need treatment,
whereas apical lesions, endoperio lesions (Figure 6)
and furcation lesions require treatment by a
dentist.
23
Soft-tissue calcification findings
The soft-tissue calcification zone is the third most
prevalent finding in the sample, with 20.53% of the
findings (Figure 2), which is similar to a previous study
with 20%
1
and above the amount found by another
study
13
with 12.92%.
With regard to age, it was found as a statistically
significant difference that the older the patient, the
greater the number of calcifications. This corrobo-
rates with a systematic review of research of IFs, in
which the authors concluded that soft-tissue calcifi-
cations were much more common where there was
a sample with older people.
2
Patients in another
CBCT study demonstrated that atheroma was 13.4
times more common in patients older than 65 years.
In our study, 50% of the sample was patients more
than 40 years.
15
A diagnosis of ossification of the style–hyoid
complex was made in 82 cases (Figure 7), which
was considered in this study to be cases above 3-cm
long.
24,25
Usually, it shows no symptoms and no
treatment is necessary. However, if there are any
symptoms, they may be associated with Eagle’s
syndrome.
25
Figure 4 Palatal torus in coronal reformatting (a) and bone sclerosis in sagittal reformatting (b).
Figure 5 A periapical cyst in sagittal reformatting (a); arrow is indicating osteoma in the panoramic reformatting (b).
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17 cases of tonsilloliths were diagnosed in this study.
These calcifications are present in the tonsils and can
be single or multiple. They are usually asymptomatic
and no treatment is usually necessary. Larger ones can
cause bad breath, a sore throat, dysphagia or for-
eign body sensation, thereby requiring medical
treatment.
1,24
Two cases of atheroma were observed in this study
(Figure 7). Atheromas present as single or multiple rice
grains, with homogeneous density, and lateral cervical
vertebrae in positions ranging between C3 and C4.
2
Referral of these patients to a specialist to confirm the
diagnosis contributes significantly to reducing stroke
and its sequelae.
26
The calcification of the triticeous cartilage and
greater horn thyroid calcification was observed in
14 patients (Figure 7). Thyroid cartilage is part of the
skeleton of the upper larynx and triticeous cartilage is
located in the thyrohyoid ligament. They are bilateral
ovoid structures that have a tendency to calcify with
increasing age and are IFs without clinical symptoms.
No treatment is necessary.
1
Clinical management of incidental findings
In this study, most of the IFs do not require treatment or
referral to another professional. This shows that not all
IFs in CBCT examinations have a great impact on the
health of the patient and only a minority need medical or
dental work. In the literature, we observed similar results.
In a previous study, 43.46% of IFs did not require
treatment, 28.97% findings required monitoring and
a minority of findings, with 22.57%, needed treatment or
referral to another professional.
1
In another study, only
two results were significant enough to cause changes in
orthodontic treatment in the sample.
9
In another previous
study, only 1 IF of high importance was reported, with
the other 97 findings being of intermediate importance
and 242 findings of low importance.
20
We observed a large variety and quantity of IFs in this
sample, which shows the importance of a dentist/
radiologist evaluating the entire volume of the CBCT ex-
amination. In addition, the results reinforce the need for
dentists to study and recognize the entire anatomy and
anatomical variations of the maxillofacial region. In the
literature, there are some researches with the same
Figure 6 The arrows are indicating supernumerary teeth in sagittal reformatting (a); an endoperio lesion in the sagittal reformatting (b); and
a tooth retained causing external resorption in the adjacent tooth in the sagittal reformatting (c).
Figure 7 Ossification of the styloid complex (white arrows), calcification of the triticeous cartilage (long black arrow) and calcification of the
greater horn of the thyroid (short black arrow) in sagittal reformatting (a); the arrow is indicating atheroma in sagittal reformatting (b).
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approach, but none with a Brazilian sample. There is
a variation in the frequency and type of IFs between
different samples. For example, in a study that used an
Indian sample, the most frequent IFs were malignant
lesions.
14
Conclusions
–A total of 560 IFs were found in 92% of the samples
studied, with the maxilla/mandible group presenting
more findings, followed by the maxilla and finally the
mandible group.
–The most frequent zone of IFs was the teeth zone,
followed by airways, soft-tissue calcification, TMJ,
bone and lesions of the jaws.
–Most of the IFs of this sample do not require
treatment or referral to another professional.
–A statistically significant difference in the soft-tissue
calcification zone was found, where there were
a greater number of IFs with increasing age.
–This study showed a high frequency of IFs in CBCT
examinations for dental purposes. The findings showed the
importance for dentists/radiologists to examine the entire
volume of the CBCT examination, in the three reforma-
tions, not only the purpose of the examination region.
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