Effect of age, impaction types and operative time on inflammatory tissue reactions following lower third molar surgery.

RESEARCH Open Access
Effect of age, impaction types and operative time
on inflammatory tissue reactions following lower
third molar surgery
Seidu A Bello1*, Wasiu L Adeyemo2†, Babatunde O Bamgbose3†, Emeka V Obi1† and Ademola A Adeyinka1†
Abstract
Background: Postoperative mobidity following third molar surgery is affected by a number of factors. The study of
these factors is essential for effective planning and limitation of morbidity. The aim of this study was to determine
the effect of age, type of impaction and operative time on immediate postoperative tissue reactions following
mandibular third molar surgery.
Methods: Consecutive patients with impacted mandibular third molar teeth were studied. All the third molars
were classified according to Winter’s classification. Surgical extraction was performed on all the patients by a single
surgeon under local anaesthesia. The operation time was determined by the time lapse between incision and
completion of suturing. Postoperative pain, swelling and trismus were evaluated.
Results: There were 120 patients with an age range of 19-42 years. Patients in the age range of 35-42 years
recorded a lower pain score (p = 0.5) on day 1. The mouth opening was much better in the lower age group on
day 2 and 5 (p = 0.007 and p = 0.01 respectively). Pain, swelling and trismus increased with increasing operative
time. Distoangular impaction was significantly associated with higher VAS score on day 1 and 2 (p = 0.01, 0.0, 04).
Distoangular and horizontal impaction are associated with a higher degree of swelling and reduced mouth
opening on postoperative review days. Vertical impaction was associated with the least degree of facial swelling
and best mouth opening.
Conclusions: Increasing operating time and advancing age are associated with more postoperative morbidity,
likewise distoangular and horizontal impaction types.
Background
The quality of life experienced by patients following
third molar surgery is increasingly becoming a health
concern [1]. Third molar surgeries are associated with
unpleasant experience by the patients, referred to as
postoperative morbidity, which could be divided into
immediate postoperative tissue reactions and complica-
tions [2,3]. The immediate postoperative tissue reactions
are characterized by pain, swelling, trismus and dyspha-
gia [4]. Pain, swelling and trismus are normal reactions
following third molar surgery and are frequent indices
of researches both in the methodology of the surgery
and the pharmacology of drugs used [5].
Factors affecting postoperative morbidity could be
patient factors, tooth related factors and operative fac-
tors [6]. Patient factors include age, sex, size or build,
ethnic background, smoking, contraceptives and oral
hygiene [7]. Tooth related factors include existing infec-
tion (pericoronitis), type of impaction, depth of impac-
tion, relationship to inferior alveolar nerve, density of
surrounding bone and associated pathology like cyst or
neoplasm [8]. The operative factors include the use of
drugs, type and extent of incision, wound closure tech-
nique, surgeons experience and duration of operation
[9,10]. Winter’s classification [11] of impacted third
molar is based on its orientation to an imaginary line
passing through the occlusal surfaces of first and second
molars to the retromolar areas as seen on a periapical
* Correspondence: sabello2004@yahoo.com
† Contributed equally
1Department of Dental & Maxillofacial Surgery, State House Medical Centre,
Asokoro, Abuja, Nigeria
Full list of author information is available at the end of the article
Bello et al. Head & Face Medicine 2011, 7:8
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HEAD & FACE MEDICINE
© 2011 Bello et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in
any medium, provided the original work is properly cited.

radiograph (or an orthopanthomograph) [12]. The
impactions are classified into horizontal, mesioangular,
vertical, distoangular, buccolingual and ectopic. Pell and
Gregory [13] similarly classified spatial relationship of
impacted third molar into vertical, horizontal, inverted,
mesioangular and distoangular.
The surrounding bone in young patients is relatively
soft and more resilient compared to older patients,
where the bone is harder, necessitating more bone
removal, with more difficulty in separating tooth from
bone, resulting in more postoperative pain, swelling and
trismus [2,14]. Bruce et al, [15] while investigating the
role of age on postoperative morbidity associated with
mandibular third molar, found that the patients above
35 years recorded more swelling and trismus. Duration
of surgery is an operative factor that has been found to
influence the immediate postoperative factors following
impacted third molar surgery. Definition of operating
time varies among different reports. Akinwande [16]
defined this as the time lapse between the beginnings of
bone drilling to the end. Raprastikul et al [17] on the
other hand defined it as the time lapse between incision
and completion of suturing. A range of 11.03 minutes to
25.0 minutes has been reported in the literatures [16,17].
Age of patients, type of impaction and duration of
operation have been mentioned in scientific literatures
as factors that influence the immediate postoperative
reactions following third molar surgery but objective
assessment are lacking. This study aims to determine
the effect of these factors on pain, swelling and trismus
following mandibular third molar surgeries.
Patients and Methods
Consecutive patients scheduled to undergo surgical
removal of impacted mandibular third molars in the
Maxillofacial Surgery Unit of State House Medical
Centre, Abuja, Nigeria from February to November 2009,
were recruited into the study. Clearance was obtained
from the Ethics and Privileges Committee of the hospital
and informed consent was signed by the patients before
enrolment. Smokers, patient with systemic diseases and
patients with active pericoronal lesions were excluded
from the study. Orthopantomographic images were used
to classify all the impacted mandibular third molars into
Mesioangular, Distoangular, Vertical and Horizontal
impactions based on Winter’s classification.
Surgical extraction of a tooth per session was per-
formed on all the patients by the same surgeon under
local anaesthesia. For the patients that required bilateral
extraction, a gap of at least 15 days was allowed between
the two procedures to allow for total recovery from the
first one. Access was gained through a 3-sided mucoper-
iosteal flap and ostectomy was carried out with a fissure
bur and normal saline irrigation. With adequate
ostectomy, elevation of the tooth was carried out and
was followed by socket toileting. Sectioning of the tooth
was carried out whenever necessary. They were then
discharged home with standard postoperative
instructions.
The operation time was determined by the time lapse
between incision and completion of suturing. They were
all placed on broad spectrum antibiotics and analgesics
of diclofenac Potassium (cataflam Novartis) 50 mg 8
hourly for 3 days.
Postoperative pain, swelling and trismus were evalu-
ated. Pain was estimated subjectively by asking the
patient to rate the nociceptive experience on a visual
analog scale of 0 to 5. The leaflets were handed over to
them for daily entry with day 1 being the operation day
and the assessment was done for 7 days.
Swelling was assessed by a modification of a 3 line
measurements (Figure 1) using 5 fixed points on surgi-
cal side of the face and finding the average. (Ustun Y,
Erdogan O, Esen E, Karshi E. Comparison of the effects
of 2 doses of methylprednisolone on pain, swelling and
trismus after third molar surgery Oral Surg Oral Med
Oral Pathol Oral Radiol Endo 2003; 96: 535-539). The
fixed points used were A; the most posterior point at
the midline on the tragus, B; lateral canthus of the eye,
C; the most lateral point on the corner of the mouth, D;
soft tissue pogonium which is the most prominent point
at the midline on the chin and E; most inferior point on
the angle of the mandible. The 3 lines were AC, AD
and BE. A baseline measurement was carried out just
before the surgery and similar measurements were car-
ried out on days 2 (48 hours), 5 and 7 post surgery. The
difference between the postoperative and preoperative
measurements was calculated.
Figure 1 Three-Line Facial swelling measurement.
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Maximum inter-incisal distance was used as the index
of trismus using Boyle’s gauge-a venier calibrated calli-
per. Percentage mouth opening was calculated on each
postoperative review days. The measurement of MID
was taken from the incisal edge of the upper right cen-
tral incisor (or a prosthethic equivalent) to the incisal
edge of the lower right central incisor. Three readings
were taken for each patient and the average was deter-
mined. This constitutes the reading for the particular
day. Baseline measurements were taken just before the
surgery and similar readings were carried out on days 2
(48 hours), 5 and 7 postoperatively. Percentage mouth
opening was calculated thus: postoperative minus preo-
perative measurement multiplied by 100.
Data analysis was carried out with Statistical Package
for Social Sciences (SPSS) 15.0 for Windows. A multi-
variate analysis of the effect of patients’ age, sex, type of
impaction and operative time on pain, swelling and tris-
mus was also carried out. Mean values are presented
with 95% confidence interval.
Results
A total of 120 patients comprising 42 male and 78
females were studied.
The age range of the patients was 19 to 42 years with
a mean (SD) age of 26.7 years. Fifty-eight (48.3%)
patients were in the age range of 19-26 years, fifty-three
(44.2%) were in the age range of 27-34 years and nine
(7.5%) were in the age range of 35-42 years. The
effect of age on pain, swelling and trismus is shown in
Figure 2A, 2B and 2C. Patients in the age range of 35-42
years recorded a significantly lower pain score (p = 0.5)
compared with lower age groups on day 1, but subse-
quently the pain recorded was significantly higher than
that recorded for the lower age groups (P = 0.01,0.2 on
day 3 and 4 respectively). The mouth opening was much
better in the lower age group on day 2 and 5 (p = 0.007
and p = 0.01 respectively). There was a steady increase in
the swelling recorded with increasing age but the differ-
ence in swelling between the age group ranges were not
statistically significant.
The mean (SD) duration of operation was 22.63 (7.4)
minutes with a range of 11 to 35 minutes. The distribu-
tion of operative time and its effect on postoperative
pain, swelling and trismus is shown in tables 1 and 2.
The pain increased progressively with increasing opera-
tive time on day 1 (p = 0.04). Even though the differ-
ence between the operative time ranges was not
statistically significant, there was a progressive increase
in swelling and trismus with increasing operative time.
The distribution of types of impaction and its effect on
pain, swelling and trismus is shown in tables 3 and 4.
Distoangular impaction is significantly associated with
higher VAS score on Day 1 and 2 (p = 0.01, 0.004) when
compared with the other types of impaction.
Distoangular and Horizontal impaction are associated
with a higher degree of swelling (p = 0.2, 0.5 and 0.0 on
days 2, 5 and 7 respectively), and reduced mouth opening
(p = 0.0, 0.0, 0.0 on days 2, 5 and 7 respectively) on post-
operative review days when compared with vertical and
mesioangular impaction. Vertical impaction was asso-
ciated with the least degree of facial swelling and best
mouth opening among the types of impaction
A multivariate analysis of the effect of patients’age,
sex, type of impaction and operative time on pain, swel-
ling and trismus is shown in table 5. Using Pillai’s
Figure 2 Effect of age on postoperative pain, swelling and
trismus. A. Influence of age on Postoperative pain. B: Effect of age
on Postoperative swelling. C: Influence of age on postoperative
trismus.
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Trace, patients’sex, with an eigen value of 0.65, contrib-
uted least to the dependent variables of pain, swelling
and trismus while operative time as a single factor,
affected the dependent factors most with an eigenvalue
of 1.46. Interaction of operative time and type of impac-
tion had the highest eigenvalue of 2.66 compared to
other factors matrix tests, indicating that the interac-
tions of operative time and types of impaction affected
swelling, trismus and pains observed in operated
patients most. The significance of all the model matrixes
(p < 0.5) is an indication that the effects of age, sex, type
of impaction and operative on pain, swelling and tris-
mus were not due to chance. However, Roy’s largest
root is equal to Hotelling’s trace (0.352), in the case of
operative time and sex interaction, which implies that
sex effect does not contribute much to the output of
variables of pain, swelling and trismus.
Discussion
Severity of pain, amount of swelling and degree of tris-
mus are the primary indicators of patients discomfort
following surgical extraction of an impacted third molar
tooth [17].
This study recorded a significant influence of age on
post operative morbidity following surgical extraction of
impacted third molar teeth. A higher degree of trismus
and facial swelling was recorded in patients with advan-
cing age. This finding is in agreement with some studies
[15,18,19]. Bruce et al, [15] while investigating the role
of age on postoperative morbidity associated with man-
dibular third molar, found that patients above 35 years
recorded more swelling and trismus. According to de
Boer [18], older patients appeared to complain of more
post operative symptoms after removal of their third
molar than did young patient. The reason might be that
Table 1 Influence of operative time on Postoperative pain
Operative Time/Minutes VAS SCORE
DAY1 DAY2 DAY3 DAY4 DAY5 DAY6 DAY7
≤ 17 Mean 3.2667 1.6333 1.5000 1.2000 .9333 .7333 .5333
N 30 30 30 30 30 30 30
Std. Deviation 1.22990 1.09807 1.13715 .76112 .52083 .63968 .50742
18-23 Mean 3.3784 2.1351 1.7838 1.7568 1.6757 1.1892 .9459
N 37 37 37 37 37 37 37
Std. Deviation 1.55190 1.39766 1.22781 1.47959 1.56443 1.15079 1.02594
24-29 Mean 3.8421 1.2105 1.1053 .9474 1.2105 .4211 .4211
N 19 19 19 19 19 19 19
Std. Deviation .83421 1.22832 .56713 .62126 .78733 .50726 .50726
30-35 Mean 4.0882 1.8235 1.3824 1.2353 1.3529 1.1471 1.1471
N 34 34 34 34 34 34 34
Std. Deviation 1.23993 1.40282 1.45674 1.07475 1.17763 .85749 .85749
P value 0.04 0.08 0.224 .041 .073 .005 .003
Table 2 Effect of operative time on postoperative swelling and trismus
Operative Time/Minutes Swelling/mm Mouth Opening/%
DAY2 DAY5 DAY7 DAY2 DAY5 DAY7
≤ 17 Mean 6.8900 2.1500 1.4567 63.6450 72.1510 79.4743
N 30 30 30 30 30 30
Std. Deviation 5.72968 2.65664 2.70933 18.61544 22.43444 22.35302
18-23 Mean 7.6189 3.4541 2.6649 66.5241 73.4819 81.7759
N 37 37 37 37 37 37
Std. Deviation 4.37168 3.73189 3.55162 23.08559 22.64894 22.45892
24-29 Mean 9.9632 4.2316 3.0158 56.5837 61.1089 67.7526
N 19 19 19 19 19 19
Std. Deviation 7.65014 4.31110 2.75606 15.73888 17.23444 21.27848
30-35 Mean 9.5218 2.9853 2.1441 59.2153 64.4185 68.9188
N 34 34 34 34 34 34
Std. Deviation 7.63341 3.61605 2.51603 20.02752 21.30764 22.86510
P value .217 .223 .246 0.257 0.102 .032
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erupted molars in older patient have been used for
mastication and are therefore more tightly connected to
the alveolar bone by the periodontal ligament which
requires more aggression to remove. Third molar sur-
gery result in physical injury to the tissues and are
therefore followed by inflammatory reaction [5,20]. It
has been proposed that following tissue injury or inflam-
mation, there is a sequential release of mediators from
mast cells, the vasculature and other cells. Histamine
and serotonin appear first, followed shortly after by bra-
dykinnin and later prostaglandins and other eicosanoids.
Bradykinnin has been shown to produce pain in man
when given intradermally, intraarterially or intraperito-
neally and the hyperalgesia associated with prostaglan-
din is also due to its potentiation of Bradykinnin effect
[20]. Postoperative swelling results from accumulation
of protein rich exudates within the surrounding tissue
and trismus occurred as a result of spasm of muscle
fibres following inflammatory processes. These reactions
(pain, swelling and trismus) may be a consequence of
the formation of prostaglandins and other mediators of
inflammation derived from membrane phospholipids,
which are released following surgery [5]. Chiapasco et al
[2] believe that the correlation between age and post
operative complications might be related to increased
bone density which may result in more manipulation
during the operation.
This study recorded a lower score of pain perception
in the older patient than the younger ones within the
first 24 hours of surgery. Pain following third molar sur-
gery has been shown to peak within 24 hours of surgery
which has equally been confirmed with this study [4].
Table 3 Relationship of type of impaction and postoperative pain
TYPE OF IMPACTION VASUAL ANALOGUE SCALE SCORE
DAY1 DAY2 DAY3 DAY4 DAY5 DAY6 DAY7
MA Mean 3.3721 1.6744 1.4419 1.1163 .9767 .8372 .6744
N 43 43 43 43 43 43 43
Std. Deviation 1.34560 1.04017 .98325 .76249 .63577 .65211 .60635
V Mean 3.2174 1.7391 1.3913 1.3913 1.2174 .8261 .7826
N 23 23 23 23 23 23 23
Std. Deviation 1.44463 1.32175 1.43777 1.33958 .99802 1.11405 1.12640
DA Mean 4.3333 2.5833 1.8750 1.6667 1.6667 1.1667 1.0417
N 24 24 24 24 24 24 24
Std. Deviation .81650 1.83958 1.51263 1.30773 1.09014 1.04950 .85867
H Mean 3.7333 1.3000 1.3333 1.3667 1.6333 1.0000 .8667
N 30 30 30 30 30 30 30
Std. Deviation 1.33735 .91539 1.02833 1.21721 1.71169 .94686 .86037
P value .011 .004 .372 .289 .041 .475 .380
Key
MA-Mesioangular, V-Vertical, DA-Distoangular, H-Horizontal
Table 4 Influence of type of impaction on postoperative swelling and Trismus
TYPE OF IMPACTION SWELLING/mm Mouth Opening/%
DAY2 DAY5 DAY7 DAY2 DAY5 DAY7
Mesioangular Mean 7.2372 2.6814 .9070 59.4644 65.2314 71.4926
N 43 43 43 43 43 43
Std. Deviation 5.39210 3.21864 2juoop.04709 19.82389 22.11400 21.36244
Vertical Mean 6.3261 1.9478 .7435 78.0052 84.9270 93.1578
N 23 23 23 23 23 23
Std. Deviation 6.06549 2.08324 1.54090 15.42520 15.00169 11.78812
Distoangular Mean 8.9475 3.2417 1.6750 56.1121 63.0758 69.7213
N 24 24 24 24 24 24
Std. Deviation 7.23615 4.03570 2.04605 17.48335 23.35297 25.98941
Horizontal Mean 11.0067 4.5433 4.0200 58.7123 65.4190 71.6787
N 30 30 30 30 30 30
Std. Deviation 6.41555 4.24408 3.50698 20.75739 19.14016 23.29330
P value .026 .047 .000 .000 .001 .000
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