Parametros para reoperacao

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DENTOALVEOLAR SURGERY
*Gradu
Pelotas, RS
yReside
Pelotas, Pe
zProfes
of Pelotas,
xProfes
University
Conflic
relevant fi
What Are the Parameters for
Reoperation in Mandibular Third
Molars Submitted to Coronectomy?
A Systematic Review
Bh�arbara Marinho Barcellos, BDent,* Bibiana Dalsasso Velasques, BDent,y
Lucas Borin Moura, PhD,z and Cristina Braga Xavier, PhDx
Purpose: Coronectomy is an alternative technique to conventional lower third molar removal that aims
to decrease inferior alveolar nerve impairment. The purpose of this studywas to identify factors associated
with reoperation after mandibular third molar coronectomy.
Materials and Methods: This systematic review sought scientific articles in the MEDLINE (PubMed),
Scopus (Elsevier), and Cochrane Library databases. Studies that evaluated reoperation after coronectomy
and reported a minimum follow-up of 6 months were included. The Preferred Reporting Items for System-
atic Reviews and Meta-Analyses (PRISMA) quality assessment of the included articles was performed, and
the following data were analyzed: demographic characteristics, reason for reoperation, and time from
coronectomy to reoperation. The data were subjected to descriptive analysis.
Results: The initial search yielded 362 studies and 15 were included in the final review. In total, 1,664
patients and 2,062 teeth underwent coronectomy. Most patients were women (60.58%). The follow-up
period for reoperation ranged from 6 months to 10 years and the mean time until the second procedure
was 10.4 months (quartile 1, 3; quartile 3, 8.5). Only 105 teeth (5.1%) were reoperated on. The main rea-
sons for reoperation were root exposure (53.33%), infection (10.47%), pain (9.52%), and enamel residual
(9.52%). In the PRISMA quality evaluation, only 1 article presented a low risk of bias.
Conclusions: Reoperation after mandibular third molar coronectomy was low (cases, �5%); the main
reasons for reoperation were residual root exposure and symptomatology. Owing to the possibility of
late exposure or symptomatology, a follow-up longer than 6 months is recommended until root exposure
or the end of the migration process.
� 2019 American Association of Oral and Maxillofacial Surgeons
J Oral Maxillofac Surg 77:1108-1115, 2019
Surgical removal of impacted mandibular third mo-
lars that present dental roots in close proximity
to the inferior alveolar nerve (IAN) can result in
its injury. Imaging modalities such as panoramic
radiography and cone-beam computed tomography
are important diagnostic tools in these cases.1
ate Program in Dentistry, Federal University of Pelotas,
, Brazil.
nt in Maxillofacial Surgery Program, Federal University of
lotas, RS, Brazil.
sor of Oral Surgery, Dentistry Course, Catholic University
Pelotas, RS, Brazil.
sor of Oral and Maxillofacial Surgery Department, Federal
of Pelotas, Pelotas, RS, Brazil.
t of Interest Disclosures: None of the authors have any
nancial relationship(s) with a commercial interest.
1108
Radiographic signs that indicate close proximity be-
tween the dental roots and the IAN are deviation of
the canal, narrowing of the canal, a periapical radio-
lucent area, narrowing of roots, darkening of roots,
curving of roots, and loss of the lamina dura of
the canal.2,3
Address correspondence and reprint requests to Dr Xavier:
Department of Oral and Maxillofacial Surgery, Federal University of
Pelotas, Brasil Rua Goncalves Chaves, 457, 96015-560 Pelotas, RS,
Brazil; e-mail: cristinabxavier@gmail.com
Received July 13 2018
Accepted January 7 2019
� 2019 American Association of Oral and Maxillofacial Surgeons
0278-2391/19/30016-3
https://doi.org/10.1016/j.joms.2019.01.013
mailto:cristinabxavier@gmail.com
https://doi.org/10.1016/j.joms.2019.01.013
http://crossmark.crossref.org/dialog/?doi=10.1016/j.joms.2019.01.013&domain=pdf
BARCELLOS ET AL 1109
The coronectomy technique is an alternative to the
conventional removal of impacted teeth and aims to
decrease the risk of IAN damage. This technique con-
sists of removal of the dental crown and intentional
retention of the residual roots inside the alveolar
bone.4,5 Migration of residual roots is a possible
outcome of coronectomy. This occurs in 14 to 81%
of cases, with an average migration of 2 to 4 mm at
2 years toward the oral cavity.4-9 Root migration is
intense in the first 6 postoperative months,10 is sub-
stantial in the first 2 postoperative years, and then sta-
bilizes between the second and third years.1 If a
continuous migration occurs, it can result in root
exposure in the oral cavity up to 7 years after the pro-
cedure and can cause inflammation or localized
infection.4,10,11
The purpose of this study was to verify the inci-
dence and patterns that indicate reoperation after
mandibular third molar coronectomy. The authors hy-
pothesized that the main reasons for reoperation
would be related to clinical symptomatology and not
to radiographic changes such as root migration. The
specific aims of the study were to verify the incidence
rate of reoperation after mandibular third molar coro-
nectomy and to define clinical and radiographic pa-
rameters indicating the stage for reoperation.
Materials and Methods
To address the research purpose, the authors
designed and implemented a systematic review
modeled after the Preferred Reporting Items for
Systematic Reviews and Meta-Analyses (PRISMA) state-
ment12 and the Cochrane Collaboration’s recommen-
dations for systematic reviews.13
In accordance with the PRISMA statement for
systematic reviews, the following focus question of
research was established: what are the clinical and
Table 1. SEARCH STRATEGY USED FOR EACH DATABASE
Database S
MEDLINE (coronectomy) AND third molar; (coronectom
reoperation; (coronectomy) AND root migra
SCOPUS (TITLE-ABS-KEY (coronectomy) AND TITLE-AB
AND TITLE-ABS-KEY (complications); TITLE
(reoperation); TITLE-ABS-KEY (coronectomy
Cochrane
Library
‘‘coronectomy’’ in Title, Abstract, Keywords an
Reviews’; ‘‘coronectomy’’ in Title, Abstract, K
in Cochrane Reviews’; ‘‘coronectomy’’ in Tit
Abstract, Keywords in Trials’; ‘‘coronectomy
Title, Abstract, Keywords in Other Reviews’
Barcellos et al. Reoperation After Third Molar Coronectomy. J Oral Max
radiographic parameters for reoperation of mandib-
ular third molars after coronectomy?
STUDY DESIGN
This study is a systematic review and the samplewas
composed of all publications on the topic of third
molar coronectomy without time limitation until
June 2018. The electronic search was performed in
the following databases: MEDLINE (PubMed), SCOPUS
(Elsevier), and the Cochrane Library.
The final search was performed on June 13, 2018.
The search terms initially used were coronectomy,
third molar, complications, reoperation, and root
migration. From the keywords, detailed search strate-
gies were developed for each database (Table 1). A
manual search also was conducted based on the refer-
ence lists of the included studies and previ-
ous reviews.
VARIABLES
The following variables were analyzed from
the studies:
� Number of patients and gender distribution
� Mean age of patients
� Number of teeth subjected to coronectomy
� Follow-up
� Number of reoperations
� Reason for reoperation
� Time until reoperation
� Follow-up after reoperation
DATA COLLECTION METHODS
For the initial selection, 2 independent reviewers
(B.M.B. and B.D.V.) analyzed the title or abstract of
all searched studies, which were subjected to the
earch Strategy
y) AND complications; (coronectomy) AND
tion
S-KEY (third AND molar)); TITLE-ABS-KEY (coronectomy)
-ABS-KEY (coronectomy) AND TITLE-ABS-KEY
) AND TITLE-ABS-KEY (root AND migration)
d ‘‘third molar’’ in Title, Abstract, Keywords in Cochrane
eywords and ‘‘complications’’ in Title, Abstract, Keywords
le, Abstract, Keywords and ‘‘root migration’’ in Title,
’’ in Title, Abstract, Keywords and ‘‘reoperation’’ in
illofac Surg 2019.
1110 REOPERATION AFTER THIRDMOLAR CORONECTOMY
inclusion and exclusion criteria established before the
beginning of the study. To be included in the study
sample, publications had to adopt the following inclu-
sion criteria: studies in English, clinical trials (prospec-
tive, retrospective, or randomized), studies that
reported a minimum postoperative period of
6 months, and studies that evaluated the outcomes
that required reoperations. There was no time restric-
tion for the date of publication. Systematic reviews,
meta-analyses, narrative reviews, case reports, and
case series were excluded from the analyses.
After determining the studies included in the
systematic review, the 2 trained researchers collected
and tabulated all data using Excel 2016 (Microsoft,
Redmond, WA). The results were imported to Endnote
(Thomson Reuters, Toronto, ON, Canada) and, after
duplicate removal, the titles and abstracts were evalu-
ated by the 2 independent reviewers. In case of diver-
gence, 2 expert researchers (C.B.X. and L.B.M.) were
consulted. After the initial selection, the 4 examiners
read the full texts of the studies and, using the same
selection criteria, determined the final inclusion of
studies in the systematic review. Disagreements
between reviewers were resolved through further
discussion.
DATA ANALYSES
The following data were extracted: year, author,
gender and number of patients, mean age (years),
number of teeth subjected to coronectomy, follow-
up, number of reoperations, reason for reoperation,
time until reoperation, and follow-up after reopera-
tion. The extracted data were subjected to descriptive
analysis.
The quality assessment evaluation was performed
using the PRISMA method. The following criteria
were used to classify the potential risk of bias in
each study: random population selection, definition
of inclusion and exclusion criteria, report of loss to
follow-up, validated measurements, and statistical
analysis. Studies that met all these criteria were classi-
fied as having a low risk of bias; those that did not meet
1 of these criteria were classified as having a moderate
risk of bias; and those that did not meet at least 2 of
these criteria were classified as having a high risk
of bias.
Results
The electronic search was conducted on June 13,
2018, and 362 studies were retrieved. After exclusion
of 254 duplicates, 108 studies remained. Titles and
abstracts were read, and 39 studies were selected for
full-text reading and evaluation according to the inclu-
sion and exclusion criteria defined earlier. Twenty-four
studies were excluded because they did not fulfill at
least 1 selection criterion. Therefore, 15 studies were
included in this systematic review. Figure 1 presents
the flowchart of the systematic review process.
For quality evaluation, only 1 article presented a low
risk of bias,14 5 studies showed a medium risk of
bias,9,15-18 and 9 studies showed a high risk of
bias2-4,7,19-23 (Table 2).
In total, 1,664 patients underwent coronectomy
procedures, most of whom were women (68.58%;
Table 3). Three studies did not document the gender
of the included patients4,7,20 and only 1 did not
report the total number of patients.20
Of 2,062 teeth subjected to coronectomy, 105 teeth
(5.1%) underwent reoperation. Most reported causes
for reoperation were residual root exposure owing
to migration (n = 56 [53.33%]), infection (n = 11
[10.47%]), pain (n = 10 [9.52%]), and residual enamel
(n = 10 [9.52%]). Only 1 article mentioned the need for
residual root removal because of orthognathic sur-
gery.3 Two studies did not specify the reasons for the
reoperations2,14; the other studies reported
reoperation because of root migration without
exposure or the presence of symptomatology.
The follow-up after the procedure ranged from
6months to 10 years. However, only 1 article reported
follow-up after reoperation.15 Using the data from 7
studies,2,4,7,9,18,20,23 the mean time until reoperation
was calculated as 10.4 months (quartile 1, 3; quartile
3, 8.5; Fig 2). Three studies did not report time until
reoperation.16,17,19 Figure 3 presents the time until re-
operation according to the data available in each study;
most reoperations occurred within the first 2 years of
follow-up.
Discussion
The purpose of this study was to verify the patterns
related to reoperation after mandibular third molar
coronectomy. The authors’ hypothesis was that clin-
ical features would predict the reoperation. Moreover,
the specific goals were to determine the percentage of
cases reoperated on after coronectomy and to define
the clinical and radiographic parameters indicating
the stage for reoperation. As result, it was possible to
observe a small rate of reoperation after mandibular
third molar coronectomy. The usual reasons were
root exposure with or without symptomatology.
Also, considerable reoperation was performed after
6 months of follow-up (mean, 10.4 months), which in-
dicates a longer follow-up is necessary.
The results of this study confirm in part the hypoth-
esis that the clinical characteristics would predict the
reoperation. The clinical parameters predominated,
although residual enamel (a radiographic feature)
also predicted reoperation. The main reasons for a sec-
ond procedure were related to symptomatology, root
FIGURE 1. Systematic review process showing numbers of included and excluded articles.
Barcellos et al. Reoperation After Third Molar Coronectomy. J Oral Maxillofac Surg 2019.
BARCELLOS ET AL 1111
exposure, and presence of residual enamel. Based on
the reoperation rate of 5.1%, the second procedure,
despite being a technical disadvantage, does not repre-
sent a failure, and coronectomy remains a safe alterna-
tive for the extraction of mandibular third molars
closely connected to the mandibular canal.
Table 2. RISK OF BIAS ASSESSED USING THE PREFERRED REP
ANALYSES QUALITY STATEMENT
Study Year
Random
Selection in
Population
Definition of
Inclusion and
Exclusion Criteria
O’Riordan7 2004 No No
Pogrel et al4 2004 No Yes
Hatano et al2 2009 No Yes
Leung et al9 2009 Yes Yes
Cilasun et al20 2011 No Yes
Goto et al15 2012 No Yes
Leung and Cheung14 2012 Yes Yes
Monaco et al23 2012 No Yes
Agbaje et al19 2015 No Yes
Frenkel et al21 2015 No No
Kohara et al16 2015 No Yes
Monaco et al17 2015 No Yes
Kouwenberg et al22 2016 No No
Leung and Cheung3 2016 Yes Yes
Vignudelli et al18 2017 No Yes
Barcellos et al. Reoperation After Third Molar Coronectomy. J Oral Max
Leaving the roots in situ after a coronectomy pro-
cedure can have consequences, such as the need for
reoperation. There was a discussion in the literature
about the concept of success and failure in coronec-
tomy. Some investigators considered coronectomy a
failure when a second procedure was needed.5,9
ORTING ITEMS FOR SYSTEMATIC REVIEWS AND META-
Report of
Loss to
Follow-Up
Valid
Measurements
Statistical
Analysis
Estimated
Potential
Risk of Bias
Yes No No High
No No No High
No No Yes High
No Yes Yes Medium
No No No High
Yes Yes Yes Medium
Yes Yes Yes Low
Yes No Yes High
No No Yes High
Yes Yes Yes High
Yes Yes Yes Medium
Yes Yes Yes Medium
Yes Yes Yes High
Yes No No High
Yes Yes Yes Medium
illofac Surg 2019.
Table 3. DATA EXTRACTED FROM STUDIES INCLUDED IN THE FINAL REVIEW
Study (Year) Patients, N Gender, n Age (yr), Mean Teeth, n Follow-Up
Reoperation,
n (%)
Reason for
Reoperation, n
Time to
Reoperation,
Mean
Follow-Up
(Reoperation)
O’Riordan7 (2004) 52 — — 52 10 yr 3 (6.0) Infection, 1; periodontal
disease, 1; pain and edema, 1
34.1 mo —
Pogrel et al4 (2004) 41 — — 50 22 mo 3 (5.8) Incomplete healing, 2;
root exposure, 1
6 mo —
Hatano et al2 (2009) 102 M, 27; F, 75 32.3 (SD, 10.3) 102 12 mo 5 (4.9) Infection, 4; not specified, 1 3 mo —
Leung et al9 (2009) 171 M, 70; F, 101 27.2 171 10.6 mo 1 (1.7) Root exposure, 1 9 mo —
Cilasun, et al20 (2011) — — 27.1 88 16.3 mo
(6-29 mo)
1 (1.1) Pain, 1 10 days —
Goto etal15 (2012) 101 M, 37*; F, 79 —y 116 12 mo 9 (7.8) Root exposure, 8; pain, 1 1-12 mo 12 mo
Leung and Cheung14
(2012)
98 M, 35; F, 63 27.6 135 36 mo 4 (3.0) Not specified, 3; root
exposure, 1
9-24 mo —
Monaco et al24 (2012) 37 M, 17; F, 20 31.0 43 12 mo 1 (2.3) Pain, 1 10 mo —
Agbaje et al19 (2015) 64 M, 28; F, 36 — (range, 15-
55)
96 12 mo 9 (9.4) Root exposure, 5;
infection, 4
— —
Frenkel et al21 (2015) 173 M, 110*; F, 75 27.6 (range, 17-
65)
185 6-12 mo 10 (5.4) Enamel retention, 6; pain, 2;
root exposure, 1; root moved
during procedure, 1
1-12 mo —
Kohara et al16 (2015) 92 M, 29; F, 63 33.8 111 36 mo 10 (9.0) Palpable root, 7; root
exposure, 2; pain, 1
3-24 mo —
Monaco et al17 (2015) 94 M, 37; F, 57 28.9, (SD, 8.9) 116 36 mo 8 (6.9) Root exposure, 4; enamel
retention, 3; hyperplasia
distal to second molar, 1
— —
Kouwenberg et al22
(2016)
151 M, 59; F, 92 30.8 151 6 mo 17 (11.3) Root exposure, 17 — —
Leung and Cheung3
(2016)
458 M, 172; F, 286 28.9 612 60 mo 20 (3.3) Root exposure, 14; infection, 2;
pain, 2; enamel retention, 1;
orthognathic procedure, 1
2 wk to
60 mo
—
Vignudelli et al18
(2017)
30 M, 9; F, 21 28.0 (SD, 7.0;
range, 17-56)
34 9 mo 4 (11.8) Root exposure, 2; pain, 1;
palpable root, 1
8 mo —
Abbreviations: F, female; M, male; SD, standard deviation.
* The study reported gender according to the number of teeth subjected to coronectomy.
y In this study, 48 patients (41.4%) were no older than 29 years, 42 (36.2%) were 30 to 39 years old, and 26 (22.4%) were at least 40 years old.
Barcellos et al. Reoperation After Third Molar Coronectomy. J Oral Maxillofac Surg 2019.
1
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FIGURE 2. Boxplot of mean time until reoperation.
Barcellos et al. Reoperation After Third Molar Coronectomy. J Oral
Maxillofac Surg 2019.
BARCELLOS ET AL 1113
However, others judged that the potential of IAN
injury during a second operation is decreased when
the residual roots migrate from the mandibular
canal.8,15 Leung and Cheung14 observed that none of
the reoperations to remove an exposed root resulted
in an IAN neurosensory disturbance. Thus, this could
be considered a success because the main objective
was achieved. Cilasun et al20 reported a 95.5% success
rate for coronectomy cases, and Frenkel et al21
achieved success in 97.0% of cases in their study.
Despite the success, there is a lack of data in the liter-
ature to define which cases require reoperation.
The literature showed intimate correlations among
age, gender, tooth morphology, and root migra-
tion.3,11,21 After coronectomy, 30% of roots migrate
from the mandibular canal,4 moving up to 4 mm dur-
ing the first 2 years.8 Furthermore, Kohara et al16
found that 82.2% of cases showed no root migration
between the second and third postoperative years.
Moreover, Frenkel et al21 and Goto et al15 reported
that patients older than 40 years exhibited decreased
root migration compared with patients in their 20s.
In addition, studies that compared the association of
patient’s age and gender with root migration rates
observed that root migration was markedly higher
in younger and female patients.14,16,21,23 Most
coronectomy cases reported in the literature
involved root migration, although most roots
remained asymptomatic and covered by bone.15,16,23
Root migration is considered a reason for reopera-
tion only when it leads to exposure of residual roots
in the oral cavity.23-25 In this systematic review, the
main reason for reoperation was exposure of roots in
the oral cavity. Root exposure was reported in most
included studies as a reason to reoperate.3,9,14-19,21,22
In the literature, the rates of root exposure were low
(1.3 to 2.3% of cases).3,26 In contrast, root exposure
occurred in more than half the reoperations in this
study. It is established that residual roots stop
migrating after 2 years; therefore, some investigators
believe there is almost no chance of late
complications 2 to 3 years after coronectomy.14,16,20
However, O’Riordan7 reported a case in which root
exposure occurred after 7 years, requiring removal.
These data indicate that a longer follow-up is essential
for patients after coronectomy, although a follow-up of
only 6 months is recommended.10
Most researchers agree with the need for root
removal after exposure, although it has been stated
that exposed roots can remain if the patient can main-
tain a clean area.15,22 Also, Leung and Cheung3 re-
ported a case in which the residual roots erupted
after 2 years, and the exposed edges were trimmed
without root removal. The authors believe that resid-
ual roots should be removed to avoid inflammatory
complications, such as periodontal disease or even
infection. Also, the authors support the logical
thinking that, as the residual roots move closer to
the surface, they will be farther from the IAN and
the risk of nerve injury will be decreased compared
with the original situation. Therefore, even when it
is necessary to remove the exposed roots, coronec-
tomy remains successful.
Many studies evaluated the association between
postoperative events and the anatomic characteristics
of mandibular third molars.2,4,15 Renton et al5 re-
ported that teeth with vertical impaction and narrow
roots have a higher risk of undergoing a second pro-
cedure. In addition, Leung and Cheung14 observed
that distoangular impaction carried a higher risk of
root eruption compared with other patterns of impac-
tion. Furthermore, Goto et al15 stated that migration of
conical roots is considerably greater than that of
enlarged roots, with greater chances of erupting in
the oral cavity.
The comparison of dental characteristics, such as
the position, angulation, and pattern of impaction
and root morphology, with the possible outcomes
could bring benefits, such as prediction of root expo-
sure and its prognosis. Renton et al5 found that female
patients who had conical roots presented a higher risk
of reoperation. In this review, the authors tried to
extract data related to tooth characteristics. Although
some investigators classified the third molars involved
in the studies,2,3,9,14-16,18 it was not possible to collect
FIGURE 3. Distribution of reoperation time (years) according to each study.
Barcellos et al. Reoperation After Third Molar Coronectomy. J Oral Maxillofac Surg 2019.
1114 REOPERATION AFTER THIRD MOLAR CORONECTOMY
quantitative data to define parameters that predict
reoperation. Kouwenberg et al22 analyzed the out-
comes of coronectomy of mandibular third molars
with an increased risk of IAN damage on preoperative
panoramic radiographs, but they could not identify
any parameter that might predict reoperation. Howev-
er, a recent study observed that the classification of
Winter27 is intimately related to the root migration
pattern after coronectomy in the first 6 months after
the procedure. However, no statistically relevant dif-
ferences were found after 6-month follow-up.28
Pain was a reason for reoperation in 10 cases
(9.52%) in this review. Cilasun et al20 reported a pa-
tient’s request for root removal because of pain on
the 10th postoperative day. In another study, after
10 months of intermittent pain, a patient requested
root removal.23 These data could lead one to reflect
that if a patient presents persistent pain that is no
longer considered normal owing to the minor oral sur-
gery procedure, then pain is a reason to remove the
roots. Immediate postoperative pain within the first
week is generally expected by patients. Because it
varies from days to years, the literature does not
dictate how long reoperation should be postponed,
and there is no standardized guide that indicates reop-
eration after a certain duration of chronic pain after
coronectomy.
Infection was a reason for reoperation in 10.47% of
cases.2,3,7,19 Another systematic review reported no
relevant differences in postoperativeinfection rates
between coronectomy and total extraction.26
Infection occurrence is difficult to predict because it
is intimately correlated with physiopathologic re-
sponses and oral hygiene. This complication has
been treated by the removal of residual roots.29
Residual enamel had to be removed with a second
procedure in only 5 cases in this review. Pogrel et al4
stated horizontal molars contraindicated a coronec-
tomy because the dental sectioning could damage the
IAN, and if not all enamel is removed, then a lack of
bone healing and infection might occur. In the present
review, only 2 studies reported reoperation for residual
enamel.17,21 Therefore, immediate postoperative
panoramic radiography is recommended to evaluate
the procedure and diagnose any residual enamel. If it
is identified, then the patient should undergo a
second procedure to remove the enamel, optimize
bone healing, and prevent infection.21
The reoperation rate was 5.1%, and the reasons for a
second procedure were related to symptomatology,
root exposure, and presence of residual enamel.
None of the studies mentioned reoperation for only
migration of the roots without any signs of exposure,
pain, infection, or residual enamel. The limitation of
this systematic review is the lack of studies with a
low risk of bias and specified data. The rate of reopera-
tion was mentioned but not completely explained,
indicating the findings should be interpreted carefully
and studied with more defined parameters. Ideally,
studies should determine more accurately the right
stage for reoperation using more objective criteria,
such as the position and radicular morphology of
BARCELLOS ET AL 1115
mandibular third molars. In addition, future studies
should apply a longer follow-up to verify
late outcomes.
According to the analysis of these studies, it was
possible to conclude that the reoperation rate is low
and that, when it occurs, it is due to symptomatology,
root exposure, or presence of residual enamel. Root
migration is not indicative of reoperation as long as
there is no exposure or symptomatology. Most reoper-
ations were performed after 6 months, indicating that
long-term follow-up should be applied. Reoperation,
despite being a technical disadvantage, is not a failure,
and coronectomy remains a safe alternative for the
extraction of mandibular third molars closely con-
nected to the mandibular canal. Therefore, future
studies might focus on specific data correlating reoper-
ation to preoperative clinical and radiographic features
to define surgical predictability and longer follow-up
evaluation to properly analyze the outcomes.
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	What Are the Parameters for Reoperation in Mandibular Third Molars Submitted to Coronectomy? A Systematic Review
	Materials and Methods
	Study Design
	Variables
	Data Collection Methods
	Data Analyses
	Results
	Discussion
	References