INTRODUCTION: The incidence of impacted wisdom teeth is
high, with some 72% of Swedish people aged 20 to 30 years having at least one
impacted third molar. Impacted wisdom teeth occur because of a lack of space,
obstruction, or abnormal position, and can cause inflammatory dental disease
manifested by pain and swelling of infected teeth and may destroy adjacent teeth
and bone. METHODS AND OUTCOMES: We conducted a systematic review and aimed to
answer the following clinical questions: Should asymptomatic and disease-free
impacted wisdom teeth be removed prophylactically? What are the effects of
different surgical methods of removing impacted wisdom teeth? We searched:
Medline, Embase, The Cochrane Library, and other important databases up to July
2009 (Clinical Evidence reviews are updated periodically, please check our
website for the most up-to-date version of this review). We included harms
alerts from relevant organisations such as the US Food and Drug Administration
(FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We
performed a GRADE evaluation of the quality of evidence for interventions.
RESULTS: We found 25 systematic reviews, RCTs, or observational studies that met
our inclusion criteria. CONCLUSIONS: In this systematic review we present
information relating to the effectiveness and safety of the following
interventions: prophylactic extraction, active surveillance, and different
surgical methods of removing impacted wisdom teeth.

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Impacted wisdom
teeth.

(PMCID:PMC2907590)

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Clin Evid (Online). 2010; 2010: 1302.

Published online 2010 April 8.

PMCID:
PMC2907590

Copyright
© BMJ Publishing Group Ltd, All Rights Reserved

Impacted wisdom teeth

Thomas B Dodson, Associate Professor and Visiting Oral and Maxillofacial
Surgeon # and Dr Srinivas M Susarla, Department of Oral & Maxillofacial
Surgery#

Thomas B Dodson, Harvard School of Dental Medicine and Centre for Applied
Clinical Investigation Surgery, Massachusetts General Hospital, Boston,
USA;

Contributor
Information.

#Contributed equally.

TBD is the co-author of two
evidence-based review articles referenced in this review. SMS declares
that she has no competing interests.

We would like to acknowledge the
previous contributors of this review, including Stephen Worrall, Marco
Esposito, and Paul Coulthard.

Other
Sections▼

Abstract

Key
Points

About
this condition

References

Abstract

Introduction

The incidence of impacted
wisdom teeth is high, with some 72% of Swedish people aged 20 to 30 years
having at least one impacted third molar. Impacted wisdom teeth occur
because of a lack of space, obstruction, or abnormal position, and can
cause inflammatory dental disease manifested by pain and swelling of
infected teeth and may destroy adjacent teeth and bone.

Methods and outcomes

We conducted a systematic
review and aimed to answer the following clinical questions: Should
asymptomatic and disease-free impacted wisdom teeth be removed
prophylactically? What are the effects of different surgical methods of
removing impacted wisdom teeth? We searched: Medline, Embase, The Cochrane
Library, and other important databases up to July 2009 (Clinical Evidence
reviews are updated periodically, please check our website for the most
up-to-date version of this review). We included harms alerts from relevant
organisations such as the US Food and Drug Administration (FDA) and the UK
Medicines and Healthcare products Regulatory Agency (MHRA). We performed a
GRADE evaluation of the quality of evidence for interventions.

Results

We found 25 systematic reviews,
RCTs, or observational studies that met our inclusion
criteria.

Conclusions

In this systematic review we
present information relating to the effectiveness and safety of the
following interventions: prophylactic extraction, active surveillance, and
different surgical methods of removing impacted wisdom
teeth.

Other
Sections▼

Abstract

Key Points

About
this condition

References

Key Points

Impacted wisdom teeth occur because
of a lack of space, obstruction, or abnormal position.

They can cause pain, swelling, and infection, and may destroy
adjacent teeth and bone.

The incidence of impacted wisdom teeth is high, with some 72%
of Swedish people aged 20 to 30 years having at least one impacted third
molar.

Non-RCT evidence indicates that about one
third of asymptomatic, unerupted wisdom teeth will change position
resulting in wisdom teeth that are partially erupted, but non-functional
or non-hygienic.

Between 30% and 60% of people who retain their asymptomatic
wisdom teeth proceed to extraction of one or more of them between 4 to
12 years after their first visit.

Removal of impacted third molars (symptomatic
and asymptomatic) is a common procedure performed by oral and
maxillofacial surgeons.

While symptomatic or diseased impacted wisdom
teeth should be recommended for removal, current evidence neither refutes
nor confirms the practice of prophylactic removal of asymptomatic, disease-free
wisdom teeth.

Some non-RCT evidence indicates that extraction of the
asymptomatic tooth may be beneficial when disease, such as caries, are
present in the adjacent second molar, or if periodontal pockets are
present distal to the second molar.

We do not know whether active surveillance is effective for
asymptomatic, disease-free wisdom teeth, as we found no RCTs or
prospective cohort studies on this topic.

We do not know which is the most
effective method for extracting impacted wisdom
teeth.

Other
Sections▼

Abstract

Key
Points

About this
condition

References

About this condition

Definition

Wisdom teeth are present in
most adults, and they generally become apparent between the ages of 18 and
24 years, although there is wide variation in the age of presentation.
Impacted wisdom teeth are third molars that are not ordinarily expected to
erupt into functional teeth. Wisdom teeth become partially or completely
impacted owing to lack of space, obstruction, or abnormal position.
Impacted wisdom teeth may be diagnosed because of symptoms such as
pressure, pain, or swelling; by physical examination with probing or
direct visualisation; or incidentally by routine dental
radiography.

Incidence/ Prevalence

Third molar impaction is
common. Over 72% of Swedish people aged 20 to 30 years have at least one
impacted lower third molar.[1] Removal of impacted third molars (symptomatic
and asymptomatic) is a common operation performed by oral and
maxillofacial surgeons. The incidence of wisdom tooth removal is estimated
to be 4 per 1000 person-years in England and Wales, making it one of the
top 10 inpatient and day-case procedures.[2] [3] [4]In a report from 1994, up to 90% of people on
oral and maxillofacial surgery hospital waiting lists were awaiting
removal of wisdom teeth.[3] Fewer operations are now done, possibly
because of guidance.[5]

Aetiology/ Risk factors

Wisdom tooth impaction may be
more common now than in the past, as modern diet tends to be softer.[6]

Prognosis

Impacted wisdom teeth can cause
pain, swelling, and infection, and may destroy adjacent teeth and bone.
The removal of diseased or symptomatic wisdom teeth alleviates pain and
suffering, and improves oral health and function. About one third of
asymptomatic, unerupted wisdom teeth have been found to change position
with time, resulting in wisdom teeth that are partially erupted, but
non-functional or non-hygienic.[7] Three prospective cohort studies have also
demonstrated that 30% to 60% of people with previously asymptomatic
impacted wisdom teeth will undergo extraction of one or more of their
wisdom teeth because of symptoms or disease, between 4 and 12 years
following study enrolment.[8] [9] [10] In another cohort study, a surprisingly high
percentage (25%) of people with asymptomatic wisdom teeth had peridontal
disease, as evidenced by probing depths greater than 5 mm.[11] Probing depths could be an indicator of
future peridontal status. One prospective cohort study demonstrated that
40% of people with asymptomatic wisdom teeth with probing depths of
greater than 4 mm had clinically significant progression of their
periodontal status (probing depth increase of greater than 2 mm) in
the subsequent 24 months.[12] The same study also found that, for those
people with wisdom teeth with a probing depth of <4 mm, only 3% of
teeth demonstrated progression of peridontal disease. [12]

Aims of intervention

To maximise the benefits and
minimise the adverse effects of wisdom-tooth management.

Outcomes

Dental disease:
development or progression of asymptomatic or symptomatic
inflammatory dental disease (e.g., caries, acute and chronic periodontal
disease, pain); incisor crowding; disruption to regular activities of
daily living (e.g., chewing, speaking, and missing work or education);
damage to adjacent teeth or restorations; maxillofacial lesions (e.g.,
odontogenic cysts or tumours); facial cellulitis of odontogenic origin;
need for future treatment (e.g., extraction) of initially asymptomatic
wisdom teeth. Complications or adverse effects of
extraction: pain; swelling; prolonged or persistent trismus;
persistent or excessive bleeding; surgical-site infection with or without
cellulitis or osteomyelitis; disruption to regular activities of daily
living (e.g., chewing, speaking, and missing work or education); wound
dehiscence; alveolar osteitis; new or persistent periodontal defects on
the adjacent teeth; damage to adjacent teeth or restorations; temporary or
permanent inferior alveolar or lingual nerve injuries; maxillary
tuberosity fracture; temporary or persistent oro-antral communication with
or without sinusitis.

Methods

Clinical Evidence
search and appraisal July 2009. The following databases were used to
identify studies for this systematic review: Medline 1966 to July 2009,
Embase 1980 to July 2009, and The Cochrane Database of Systematic Reviews
and Cochrane Central Register of Controlled Clinical Trials 2009, Issue 1
(1966 to date of issue). We also searched for retractions of studies
included in the review. Abstracts of the studies retrieved from the
initial search were assessed by an information specialist. For the option
on active surveillance, active surveillance was defined as scheduled
clinical and radiographical evaluations of the wisdom teeth on a regular
basis with the examination completed by a healthcare professional trained
to discern the disease status of wisdom teeth. Selected studies were then
sent to the contributor for additional assessment, using pre-determined
criteria to identify relevant studies. Study design criteria for inclusion
in the question on the effectiveness of prophylactic removal of impacted
wisdom teeth were: published systematic reviews of RCTs, RCTs, and
prospective cohort studies with a control group in any language containing
more than 20 individuals. There was no minimum length of follow-up, no
minimum level of blinding, or no maximum loss to follow-up required to
include studies. Study design criteria for inclusion in the question on
surgical extraction of impacted wisdom teeth were: published systematic
reviews of RCTs and RCTs in any language containing more than 20
individuals. There was no minimum length of follow-up or level of blinding
required to include studies. There was a maximum loss to follow-up of 20%.
We included systematic reviews of RCTs, RCTs, and prospective cohort
studies with a control group where harms of an included intervention were
studied applying the same study design criteria for inclusion as we did of
benefits. In addition, we use a regular surveillance protocol to capture
harms alerts from organisations such as the US Food and Drug
Administration (FDA) and the UK Medicines and Healthcare products
Regulatory Agency (MHRA), which are added to the reviews as required. To
aid readability of the numerical data in our reviews, we round many
percentages to the nearest whole number. Readers should be aware of this
when relating percentages to summary statistics such as relative risks
(RRs) and odds ratios (ORs). We have performed a GRADE evaluation of the
quality of evidence for interventions included in this review (see table ). The categorisation
of the quality of the evidence (into high, moderate, low, or very low)
reflects the quality of evidence available for our chosen outcomes in our
defined populations of interest. These categorisations are not necessarily
a reflection of the overall methodological quality of any individual
study, because the Clinical Evidence population and outcome of
choice may represent only a small subset of the total outcomes reported,
and population included, in any individual trial. For further details of
how we perform the GRADE evaluation and the scoring system we use, please
see our website (www.clinicalevidence.com).

Table
1

GRADE evaluation of
interventions for impacted wisdom teeth

Glossary

Low-quality evidence

Further research is very likely to have an important impact on
our confidence in the estimate of effect and is likely to change the
estimate.

Very low-quality
evidence

Any estimate of effect is very
uncertain.

Contributor Information

Thomas B Dodson, Harvard School of Dental Medicine and Centre for Applied
Clinical Investigation Surgery, Massachusetts General Hospital, Boston,
USA.

Dr Srinivas M Susarla,
Massachusetts General Hospital, Boston,
USA.

Other
Sections▼

Abstract

Key
Points

About
this condition

References

References

1.
Hugoson A, Kugelberg CF. The prevalence of third
molars in a Swedish population: an epidemiological study. Community
Dental Health1988;5:121–138. [PubMed]

2.
Mercier P, Precious D. Risks and benefits of removal
of impacted third molars. Int J Oral Maxillofac
Surg1992;21:17–27. [PubMed]

3.
Shepherd JP, Brickley M. Surgical removal of third
molars. BMJ1994;309:620–621. [PMC free
article] [PubMed]

4.
Worrall SF, Riden K, Corrigan AM. UK National Third
Molar project: the initial report. Br J Oral Maxillofac
Surg1998;36:14–18. [PubMed]

5.
Scottish Intercollegiate Guidelines Network.
Management of unerupted and impacted third molar teeth. SIGN publication
no 43, 2000. Initial search date 1997 updated before
2000.

6.
Silvestri AR Jr, Singh I. The unresolved problem of
the third molar: would people be better off without it? J Am Dent
Assoc2003;134:450–455. [PubMed]

7.
Phillips C, Norman J, Jaskolka M, et al. Changes over
time in position and periodontal status of retained third molars. J
Oral Maxillofac Surg2007;65:2011–2017. [PubMed]

8.
Hill CM, Walker RV. Conservative, non-surgical
management of patients presenting with impacted lower third molars: a
5-year study. Br J Oral Maxillofac Surg2006;44:47–50. [PubMed]

9.
von Wowern N, Nielsen HO. The fate of impacted lower
third molars after the age of 20. A four-year clinical followup. Int J
Oral Maxillofac Surg1989;18:277–280. [PubMed]

10.
Venta I, Ylipaavalniemi P, Turtola L. Long-term
evaluation of estimates of need for third molar removal. J Oral
Maxillofac Surg2000;58:288–291. [PubMed]

11.
Blakey GH, Marciani RD, Haug RH, et al. Periodontal
pathology associated with asymptomatic third molars. J Oral Maxillofac
Surg2002;60:1227–1233. [PubMed]

12.
Blakey GH, Jacks MT, Offenbacher S, et al.
Progression of periodontal disease in the second/third molar region in
subjects with asymptomatic third molars. J Oral Maxillofac
Surg2006;64:189–193. [PubMed]

13.
Song F, Landes DP, Glenny AM, et al. Prophylactic
removal of impacted third molars: an assessment of published reviews.
Br Dent J1997;182:339–346. [PubMed]

14.
Song F, O'Meara S, Wilson P, et al. The effectiveness
and cost-effectiveness of prophylactic removal of wisdom teeth. Health
Technology Assessment (Winchester, England)2000;4:1–55. [PubMed]

15.
Norwegian Knowledge Centre for the Health Services.
Prophylactic removal of wisdom teeth (structured abstract). NOKC
Oslo 2003.

16.
Mettes DT, Nienhuijs MM, van der Sanden WJ, et al.
Interventions for treating asymptomatic impacted wisdom teeth in
adolescents and adults. In: The Cochrane Library, Issue 1, 2009.
Chichester, UK: John Wiley & Sons, Ltd. Search date 2004. [PubMed]

17.
Harradine N, Pearson M, Toth B. The effect of
extraction of third molars on late lower incisor crowding: a randomised
controlled trial. Br J Orthodont1998;25:117–122. [PubMed]

18.
Lindqvist B, Thilander B. Extraction of third molars
in cases of anticipated crowding in the lower jaw. Am J
Orthodont1982;81:130–139. [PubMed]

19.
van de Waal I. Free University Amsterdam Department
of Oral and Maxillofacial Surgery. Effects and costs of prophylactic
removal of third molars versus removal according to morbidity. Ongoing
study. 1999.

20.
Chuang SK, Perrott DH, Susarla SM, et al. Risk
factors for inflammatory complications following third molar surgery in
adults. J Oral Maxillofac Surg2008;66:2213–2218. [PubMed]

21.
Phillips C, White RP, Shugars DA, et al. Risk factors
associated with prolonged recovery and delayed healing after third molar
surgery. J Oral Maxillofac Surg2003;61:436–448. [PubMed]

22.
Dodson TB, Richardson DT. Risk of periodontal defects
after third molar surgery: An exercise in evidence-based clinical
decision-making. Oral Maxillofac Surg Clin North Am2007;19:93–98.
[PubMed]

23.
Bramley P. Sense about wisdoms? J R Soc
Med1981;74:867–868. [PMC
free article] [PubMed]

24.
Capuzzi P, Montebugnoli L, Vaccaro MA. Extraction of
impacted third molars. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod1994;77:341–343. [PubMed]

25.
Schultze-Mosgau S, Reich RH. Assessment of inferior
alveolar and lingual nerve disturbances after dentoalveolar surgery, and
recovery of sensitivity. Int J Oral Maxillofac
Surg1993;22:214–217. [PubMed]

26.
Rood JP. Permanent damage to inferior alveolar nerves
during the removal of impacted mandibular third molars: comparison of two
methods of bone removal. Br Dent J1992;172:108–110. [PubMed]

27.
Blackburn CW, Bramley PA. Lingual nerve damage
associated with removal of lower third molars. Br Dent
J1989;167:103–107. [PubMed]

28.
Robinson PP, Smith KG. Lingual nerve damage during
lower third molar removal: a comparison of two surgical methods. Br
Dent J1996;180:456–461. [PubMed]

29.
Sisk AL, Hammer WB, Shelton DW, et al. Complications
following removal of impacted third molars: the role of the experience of
the surgeon. J Oral Maxillofac Surg1986;44:855–859. [PubMed]

30.
Larsen PE. Alveolar osteitis after surgical removal
of impacted mandibular third molars. Identification of the patient at
risk. Oral Surg Oral Med Oral Pathol1992;73:393–397. [PubMed]

31.
Christiaens I, Reychler H. Complications after third
molar extractions: retrospective analysis of 1,213 teeth [In French].
Rev Stomatolo Chir Maxillofac 2002;103:269–274. [PubMed]

32.
Chiapasco M, Crescentini M, Romanoni G. Germectomy or
delayed removal of mandibular impacted third molars: the relationship
between age and incidence of complications. J Oral Maxillofac
Surg1995;53:418–422. [PubMed]

33.
Osborn TP, Frederickson G, Small IA, et al. A
prospective study of complications related to mandibular third molar
surgery. J Oral Maxillofac Surg1985;43:767–769. [PubMed]

34.
Bruce RA, Frederickson GC, Small GS. Age of patients
and morbidity associated with mandibular third molar surgery. J Am
Dent Assoc1980;101:240–245. [PubMed]

35.
Sackett DL, Rosenberg WM, Gray JA, et al. Evidence
based medicine: what it is and what it isn't. BMJ1996;312:71–72.
[PMC free
article] [PubMed]

36.
Montori VM, Guyatt GH. Progress in evidence-based
medicine. JAMA2008;300:1814–1816. [PubMed]

37.
Pichler JW, Beirne OR. Lingual flap retraction and
prevention of lingual nerve damage associated with third molar surgery: a
systematic review of the literature. Oral Surg Oral Med Oral Pathol
Oral Radiol Endod2001;91:395–401. [PubMed]

38.
Abu-Serriah M, Critchlow H, Whitters CJ, et al.
Removal of partially erupted third molars using an Erbium (Er):YAG laser:
a randomised controlled clinical trial. Br J Oral Maxillofac
Surg2004;42:203–208. [PubMed]

39.
Absi EG, Shepherd JP. A comparison of morbidity
following the removal of lower third molars by the lingual split and
surgical bur methods. Int J Oral Maxillofac Surg1993;22:149–153.
[PubMed]

40.
Mocan A, Kisnisci R, Ucok C. Stereophotogrammetric
and clinical evaluation of morbidity after removal of lower third molars
by two different surgical techniques. J Oral Maxillofac
Surg1996;54:171–175. [PubMed]

41.
Praveen G, Rajesh P, Neelakandan RS, et al.
Comparison of morbidity following the removal of mandibular third molar by
lingual split, surgical bur and simplified split bone technique.
Indian J Dent Res2007;18:15–18. [PubMed]

42.
Jakse N, Bankaoglu V, Wimmer G, et al. Primary wound
healing after lower third molar surgery: evaluation of 2 different flap
designs. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod2002;93:7–12. [PubMed]

43.
Kirk DG, Liston PN, Tong DC, et al. Influence of two
different flap designs on incidence of pain, swelling, trismus, and
alveolar osteitis in the week following third molar surgery. Oral Surg
Oral Med Oral Pathol Oral Radiol Endodont2007;104:e1–e6. [PubMed]

44.
Suarez-Cunqueiro MM, Gutwald R, Reichman J, et al.
Marginal flap versus paramarginal flap in impacted third molar surgery: a
prospective study. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod2003;95:403–408. [PubMed]

45.
Gomes AC, Vasconcelos BC, de Oliveira e Silva ED, et
al. Lingual nerve damage after mandibular third molar surgery: a
randomized clinical trial. J Oral Maxillofac
Surg2005;63:1443–1446. [PubMed]

46.
Gargallo-Albiol J, Buenechea-Imaz R, Gay-Escoda C, et
al. Lingual nerve protection during surgical removal of lower third
molars. a prospective randomised study. Int J Oral Maxillofac
Surg2000;29:268–271. [PubMed]

47.
Greenwood M, Langton SG, Rood JP, et al. A comparison
of broad and narrow retractors for lingual nerve protection during lower
third molar surgery. Br J Oral Maxillofac Surg1994;32:114–117.
[PubMed]

48.
Sweet JB, Butler DP, Drager JL, et al. Effects of
lavage techniques with third molar surgery. Oral Surg Oral Med Oral
Pathol1976;41:152–168. [PubMed]

49.
Butler DP, Sweet JB, Butler DP, et al. Effect of
lavage on the incidence of localized osteitis in mandibular third molar
extraction sites. Oral Surg Oral Med Oral Pathol1977;44:14–20.
[PubMed]

50.
Rakprasitkul S, Pairuchvej V, Rakprasitkul S, et al.
Mandibular third molar surgery with primary closure and tube drain.
Int J Oral Maxillofac Surg1997;26:187–190. [PubMed]

51.
de-Brabander EC, Cattaneo G. The effect of surgical
drain together with a secondary closure technique on postoperative
trismus, swelling and pain after mandibular third molar surgery. Int J
Oral Maxillofac Surg1988;17:119–121. [PubMed]

52.
Chukwuneke FN, Oji C, Saheeb DB, et al. A comparative
study of the effect of using a rubber drain on postoperative discomfort
following lower third molar surgery. Int J Oral Maxillofac
Surg2008;37:341–344. [PubMed]

53.
Cerqueira PR, Vasconcelos BC, Bessa-Nogueira RV, et
al. Comparative study of the effect of a tube drain in impacted lower
third molar surgery. J Oral Maxillofac Surg 2004;62:57–61. [PubMed]

54.
Xavier RL, Vasconcelos BC, Caubi AF, et al. Passive
drainage through the vestibular oblique incision in impacted inferior
third molar surgery: a preliminary study. Acta Odontologica
Latinoamericana 2008;21:57–63. [PubMed]

55.
Renton T, Hankins M, Sproate C, et al. A randomised
controlled clinical trial to compare the incidence of injury to the
inferior alveolar nerve as a result of coronectomy and removal of
mandibular third molars. Br J Oral Maxillofac Surg2005;43:7–12.
[PubMed]

56.
Richardson DT, Dodson TB. Risk of periodontal defects
after third molar surgery: An exercise in evidence-based clinical
decision-making. Oral Surg Oral Med Oral Pathol Oral Radiol Endod
2005;100:133-137. [PubMed]

Clin Evid
(Online). 2010; 2010: 1302. > Sub-article
1

Copyright
notice

Extraction of asymptomatic impacted wisdom teeth

Summary

DENTAL DISEASE Compared with no
extraction: We don't know whether early third-molar extraction in children
aged 13 to 19 years with asymptomatic impacted wisdom teeth is more
effective at preventing late crowding of the lower incisors at 3 to 5
years ( very low-quality evidence ). COMPLICATIONS OR ADVERSE EFFECTS OF
EXTRACTION Compared with no extraction: We don't know whether early
third-molar extraction in children aged 13 to 19 years with asymptomatic
impacted wisdom teeth is more effective at reducing pain, infection, or
limited mouth opening at 3 years post extraction of impacted wisdom teeth
(very low-quality evidence). NOTE Guidelines based on non-RCT evidence
suggest that extraction is not advisable in people with deeply impacted
wisdom teeth who have no history of pertinent local or systemic pathology.
Permanent numbness of the lower lip or tongue may be as high as 1% after
wisdom tooth removal.

Benefits

Extraction versus no extraction plus no
active surveillance:

We found four systematic reviews
evaluating the extraction of impacted third molars (search dates 1997,[13] 2000,[14] 2003[15] and 2004[16]), which between them identified two RCTs
that met Clinical Evidence inclusion criteria. The reviews did
not conduct a meta-analysis of the results of the two RCTs because of
differences in outcomes, and so we report data from the individual RCTs.[17] [18]

The first RCT (164 people, aged 14–18 years
with asymptomatic impacted wisdom teeth) compared early third-molar
extraction versus no extraction of third molars.[17] It found no significant difference between
extraction and no extraction in the mean change between baseline and 5
years in incisor irregularity or inter-canine width (mean change in
incisor irregularity: 0.80 mm with extraction v 1.10 mm
with no extraction; P = 0.55; mean change in inter-canine width:
–0.37 mm with extraction v –0.38 mm with no extraction;
P = 0.92). The RCT found a small but significant difference
between the two groups in incisor crowding measured by the mean change in
arch length (–1.1 mm with extraction v –2.13 mm with no
extraction; P = 0.001); however, the authors of the RCT did not
consider this difference to be clinically important. There was a large
loss to follow-up in the RCT, which limits reliability (77 [47%] people
were followed up, for an average of 66 months).

The second RCT (52 people with unerupted third
molars, aged 13–19 years) compared extraction of impacted wisdom teeth
versus no extraction (people had impacted third molars on both sides of
the lower jaw, and one molar was randomly selected for removal, and the
non-extraction side acted as a control).[18] The RCT reported that incisor crowding
(measured using the length of the arch; a straight line between the
central fossa of the second molar and the incisal cross) did not change
differently on the extraction side compared with the no extraction side at
3 years (absolute results not reported and significance not assessed). The
RCT reported that 19 teeth in the control side were extracted "for various
reasons" (timescale not clear, further details not reported).

The fourth systematic review also
identified a further RCT[19] that was discontinued, the results of which
have not yet been published.[16]

Extraction versus active
surveillance:

We found no systematic review,
RCTs, or prospective cohort studies with a control group comparing
extraction versus active surveillance in people with asymptomatic impacted
wisdom teeth.

Harms

Extraction versus no extraction plus no
active surveillance:

The first RCT gave no
information on adverse effects of wisdom-tooth extraction.[17]The second RCT found that postoperative
adverse effects (pain, infection, or limited mouth opening) occurred in
4/52 (8%) teeth and secondary haemorrhage in 2/52 (4%) teeth in the
extraction group; adverse effects in the control group were not
reported.

Extraction versus active
surveillance:

We found no systematic review, RCTs,
or prospective cohort studies with a control group.

See also harms of extraction of
impacted wisdom teeth: different surgical methods.

Comment

Clinical guide:

Prospective cohort studies have
shown that 30% to 60% of asymptomatic patients may develop disease or
become sufficiently symptomatic to warrant extraction.[8] [9] [10] Delaying extraction of asymptomatic teeth
could result in an increased risk for postoperative inflammatory
complications [20] and prolonged recovery after extraction.[21] One treatment guideline for managing
unerupted and impacted wisdom teeth (search date 2000; 8 clinical studies
of different designs; number of people not reported) [5] suggested that removal of asymptomatic
disease-free wisdom teeth may be beneficial in the presence of caries in
the adjacent second molar, which cannot be properly treated without the
removal of the wisdom teeth. Extraction may also be beneficial in the
presence of periodontal pockets distal to the second molar.[22]

The harms associated with prophylactic
extraction of asymptomatic, disease-free wisdom teeth are the expected
adverse effects associated with any operation (e.g., costs, pain and
swelling, loss of work or school time, and undergoing unnecessary
surgery).[23] [24] The removal of the lower wisdom teeth also
carries the risk of damage to the inferior alveolar nerve (injured in 1–8%
of people[25] [26] and permanently damaged in up to 1% of
people[27]), and to the lingual nerve (permanently
damaged in up to 1% of people).[28] The risks seem to be greater with greater
depth of impaction, and the risks are the same whether the wisdom tooth is
symptomatic or asymptomatic. Observational studies have found limited
evidence that the complications associated with the removal of wisdom
teeth are more frequent when operators are less experienced, and in older
people with deeply impacted teeth.[29] [30] [31] [32] [33] [34]See also harms of Extraction of impacted
wisdom teeth: different surgical methods.

Of note, the four systematic reviews
identified offer three different recommendations for management.[13] [14] [15] [16] This variation may be attributable to the
different data identified by each review. The first review identified 12
literature reviews,[13] the second review identified two RCTs and 34
literature reviews,[14] the third review identified five cohort
studies,[15] and the fourth review identified two RCTs.[16] The first and second systematic reviews both
advocated against prophylactic removal, but acknowledged the evidence
supporting their position was weak.[13] [14]The third systematic review recommended
against prophylactic removal, but, given the low level of evidence
supporting this position, deferred to patient preference regarding
treatment choice.[15]The fourth systematic review concluded that
there was no evidence to support or refute prophylactic removal of
asymptomatic wisdom teeth.[16]

When managing asymptomatic,
disease-free wisdom teeth, no RCT data are available to guide therapeutic
choices. Consistent with the application of evidence-based medicine
principles, after a thorough review of the risks and benefits of the
treatment alternatives, patient preference should be the factor driving
the clinical decision.[15] [35] [36]

Substantive changes

Extraction of
asymptomatic impacted wisdom teeth: prophylactic Three new
systematic reviews added (search dates 1997,[13] 2000,[14] and 2003[15]), none of which identified any new RCTs or
prospective cohort studies with a control group. Previously reported
evidence was re-evaluated, and was determined to be of insufficient
strength to guide therapeutic decision making. Categorisation therefore
changed from "Likely to be ineffective or harmful" to "Unknown
effectiveness".

Clin Evid
(Online). 2010; 2010: 1302. > Sub-article
2

Copyright
notice

Active surveillance of asymptomatic impacted wisdom
teeth

Summary

We found no direct information
from RCTs or prospective cohort studies with a control group to provide
guidance as to whether active surveillance is better than no extraction
plus no active surveillance, or whether active surveillance is better than
extraction, in people with asymptomatic impacted wisdom teeth.

Benefits

Active surveillance versus no extraction
plus no active surveillance:

We found no systematic review,
RCTs, or prospective cohort studies with a control group comparing active
surveillance versus no extraction plus no active surveillance in people
with asymptomatic impacted wisdom teeth.

Active surveillance versus
extraction:

We found no systematic review,
RCTs, or prospective cohort studies with a control group comparing active
surveillance versus extraction.

Different forms of active surveillance
versus each other:

We found no systematic review,
RCTs, or prospective cohort studies with a control group comparing
different forms of active surveillance versus each other in people with
asymptomatic impacted wisdom teeth.

Harms

Active surveillance versus no extraction
plus no active surveillance:

We found no systematic review,
RCTs, or prospective cohort studies with a control group.

Active surveillance versus
extraction:

We found no systematic review,
RCTs, or prospective cohort studies with a control group.

Different forms of active surveillance
versus each other:

We found no systematic review, RCTs,
or prospective cohort studies with a control group.

See also harms of extraction of
impacted wisdom teeth: different surgical methods.

Comment

Clinical guide:

Active surveillance is defined for
this review as scheduled clinical and radiographical evaluations of wisdom
teeth on a regular basis by a healthcare professional trained to discern
the disease status of wisdom teeth. The goal of active surveillance is to
detect and treat disease early. The benefits of active surveillance
include avoiding the costs and adverse effects of prophylactic removal of
asymptomatic wisdom teeth. The risks of active surveillance include
failure to detect disease in a timely manner due to clinical error or
oversight, and failure of the patient to comply with the recommended
follow-up schedule, which can lead to delayed extraction. Extraction in
people older than 24 years can lead to decreased postoperative quality of
life compared with extraction at a younger age.[21]

Who should complete the active surveillance
evaluations (either generalist or specialist), and the optimum frequency
of the evaluations, are open to question: we found no RCTs on these
issues. The benefit of having a specialist evaluate the patient lies in
having an experienced clinician who will share in the responsibility and
consequences of the management choice. However, there is concern that the
specialist will remove impacted wisdom teeth unnecessarily. The benefits
of having a generalist evaluate patients are decreased cost and increased
patient convenience; however, there is concern that the generalist may
miss disease or delay referral in a timely manner.

The benefits of more-frequent visits are the
opportunity to detect and treat disease prior to the development of
symptoms or damage to adjacent teeth or bone, and to prevent the
progression of disease requiring treatment additional to the removal of
the wisdom teeth (e.g., restoration or extraction of a carious second
molar or the development of a jaw cyst or tumour). However, longer
intervals between visits decrease costs, reduce exposure to radiation, and
improve patient convenience. Non-RCT evidence indicates that clinically
important changes in peridontal status can occur over a 26-month interval,
and provides some basis for selecting examinations every 2 years.[12]

Based on non-RCT evidence, when
active surveillance is the recommended management option, the interval for
follow-up should be 24 months. In addition to assessing the patient's
symptoms, the examination should include physical and radiographical
components.

Substantive changes

Active surveillance of
asymptomatic impacted wisdom teeth New option for which we found
no systematic review, RCTs, or prospective cohort studies with a control
group. Categorised as "Unknown effectiveness".

Clin Evid
(Online). 2010; 2010: 1302. > Sub-article
3

Copyright
notice

Extraction of impacted wisdom teeth: different
surgical methods

Summary

COMPLICATIONS OR ADVERSE
EFFECTS OF EXTRACTION Different bone removal techniques compared with each
other: We don't know whether Erbium (Er):YAG laser is more effective than
surgical bur at reducing postoperative pain at 7days. We don't know
whether distolingual alveolectomy is more effective than chisel and tooth
division with surgical bur at reducing pain, swelling, or temporary
lingual sensory disturbances at up to 7 days ( low-quality evidence ).
Different soft-tissue flap designs compared with each other: Modified
triangular flap may be more effective than classic envelope flap at
producing fewer postoperative wound dehiscences, but we don't know whether
it is more effective at improving mouth opening at 7 days, pain at 24 to
72 hours, swelling at 2 weeks, or alveolar osteitis. Marginal flaps may be
more effective than paramarginal flaps at producing fewer dehiscences at 5
days, but we don't know whether they are more effective at improving pain,
swelling, trismus, or periodontal pocket depth of the adjacent second
molar at 5 days, 10 days, or 3 months in people with impacted wisdom teeth
( very low-quality evidence ). Lingual nerve protection versus no lingual
nerve protection or standard retractor: We don't know whether buccal
approach with lingual retractor is more effective than buccal approach
without lingual retractor; or whether operation with lingual flap
retractor technique or lingual nerve protection by retractor is more
effective than with no lingual retractor; or whether standard retractor is
more effective than broad retractor at reducing permanent lingual nerve
injury (very low-quality evidence). Different wound-irrigation techniques
compared with each other: We don't know whether manual irrigation is more
effective than mechanical irrigation, or whether using a larger irrigation
volume is more effective than a smaller irrigation volume at reducing
postoperative infections or osteitis (very low-quality evidence). Drain
compared with no drain: Placing a surgical drain to a wound may be more
effective at reducing swelling at 24 hours to 7 days, but we don't know
whether it is more effective at improving pain and mouth opening at 24
hours to 15 days. We don't know whether passive drainage (through the
oblique vestibular incision) or no passive drainage (suture of the oblique
vestibular incision) is more effective at improving swelling and pain at
72 hours to 15 days or mouth opening at 72 hours, but it may be more
effective at improving mouth opening at 7 to 15 days (very low-quality
evidence). Complete removal of wisdom tooth compared with coronectomy:
Complete removal of a wisdom tooth may be less effective than successful
coronectomy at reducing inferior alveolar nerve damage in people thought
to be at high risk of injury to inferior alveolar nerve (very low-quality
evidence).

Benefits

We found one systematic review
(search date 1999, 1 RCT, 771 people) [37] and 18 further RCTs (for full details of the
RCTs and numerical and statistical results see
table 1 ).[38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55]The review and RCTs all assessed comparative
rates of postoperative adverse effects (see harms).

Table
1

RCTs comparing
different surgical methods for the extraction of impacted wisdom
teeth

Harms

Bone-removal techniques versus each
other:

We found four RCTs comparing
different bone removal techniques (see
table 1 ).[38] [39] [40] [41]

One RCT (42 people) compared Erbium (Er):YAG
laser versus surgical bur for removal of bone during surgery.[38]It found that postoperative pain was more
common in the bur group at 7 days, although the difference between groups
was not significant. The RCT reported no serious complications, and no
cases of bleeding, alveolar osteitis, or infection.

Two RCTs compared distolingual alveolectomy
versus chisel and tooth division with surgical bur.[39] [40]One RCT (52 people) found no significant
difference between groups in temporary lingual sensory disturbance at day
7, and no significant difference between groups in pain or swelling at 6,
24, 48 hours, or 7 days.[39] The RCT reported no significant difference
between groups at 4 weeks in infection rates or socket healing.

The other RCT (20 people) comparing
distolingual alveolectomy versus chisel and tooth division with surgical
bur found no cases of sensory impairment of the inferior alveolar or
lingual nerves in either group, and no significant difference between
groups in mean pain intensity or swelling at 1 to 6 days.[40]The RCT reported no cases of postoperative
infection, dry socket, or delayed healing.

One RCT (90 people with symptomatic
impacted mandibular wisdom teeth aged 14–62 years) compared three
interventions: surgical bur technique, lingual-split technique, and
simplified split bone technique.[41] There was a significant difference in
postoperative pain among the three groups at 24 hours, 48 hours, and 7
days (the lingual-split group had the highest pain score at all
intervals). There was a significant difference in swelling among the three
groups at 24 hours (the surgical bur group had the highest swelling
score), but no significant difference at 48 hours and 7 days. There was no
significant difference in labial sensation among the three groups at 24
hours, 48 hours, and 7 days. The RCT found a significant difference in
lingual sensation among the three groups at 24 hours (the lingual-split
group had the lowest sensation score), but not at 48 hours and 7 days.
Statistical results for direct comparisons between any two groups were not
reported. The RCT also found that more people with the lingual-split
technique had delayed wound healing, probably due to wound infection,
compared with the simplified bone technique or the surgical bur technique,
although significance was not assessed.

Different soft-tissue flap designs versus
each other:

We found three RCTs comparing
different soft-tissue flap designs used for surgical access (see
table 1 ).[42] [43] [44]

One RCT (60 people) compared a modified
triangular flap versus the classic envelope flap. It found that the
modified triangular flap produced a significantly smaller proportion of
postoperative wound dehiscences compared with the classic envelope flap.[42] However, wound dehiscence may not be of
particular interest as an outcome, as teeth are frequently removed without
primary closure, and healing progresses satisfactorily.

Another RCT (32 people with bilateral impacted
mandibular molars aged 18–34 years) compared a buccal envelope-flap
approach versus a modified triangular-flap approach. The RCT found no
significant difference between the two groups in mouth opening at 7 days;
pain at 24, 48, or 72 hours; or alveolar osteitis; however, it found that
people in the envelope group had significantly less buccal cheek swelling
at 2 weeks compared with the modified-flap group.[43]The RCT reported no impairment of sensation
over the lingual or inferior alveolar nerve.

One RCT (27 people) compared two
different flap designs, marginal versus paramarginal.[44] It found no significant difference between
groups in, pain, trismus, or swelling at 5 days, 10 days, and 3 months,
and little difference between groups in dehiscence at 5 days. The RCT
found no significant difference between groups in bleeding.

Lingual nerve protection versus no
lingual nerve protection or standard retractor:

We found one systematic review
(search date 1999, 1 RCT, 771 people)[37] and three RCTs[45] [46] [47] comparing lingual nerve protection versus no
lingual nerve protection or standard retractor (see
table 1 ).

The systematic review compared a buccal
approach with lingual retractor versus a buccal approach without a lingual
retractor.[37]The included RCT found a higher rate of
temporary and permanent lingual nerve injury with the lingual retractor
compared with no retractor, but the review did not report a statistical
analysis between groups for the RCT.[37]The review did not report a quality
assessment of the RCT.[37]

Two RCTs compared lingual flap retraction plus
nerve protection with a subperiosteal retractor versus no lingual flap
retraction or nerve protection.[45] [46]One of the RCTs (55 people) found that
lingual flap retraction significantly increased temporary lingual nerve
damage at 24 hours and 7 days compared with no flap retraction. [45] The other RCT (300 people) found no
significant difference between groups in temporary lingual nerve damage at
7 days.[46] No permanent lingual nerve disturbances were
found in either RCT.

Another RCT (150 people) compared a
standard retractor versus a wider subperiosteal retractor for lingual
nerve protection.[47] There was a significantly lower incidence of
lingual nerve injury with the broader retractor at 4 weeks, although it
required a much larger soft-tissue flap to be raised to facilitate its
placement.

Different wound irrigation regimens
versus each other:

We found two RCTs comparing
different types of wound irrigation regimens (see
table 1 ).[48] [49]

The first RCT (103 people) compared manual
(using 50 mL syringe to total of 350 mL) versus mechanical
(350 mL) intraoperative wound irrigation, and found some evidence
that mechanical irrigation was preferable, as there was a slightly reduced
incidence of postoperative infections. However, a statistical analysis
between groups was not reported.[48]

The second RCT (211 people) compared
different irrigation volumes (25 mL v 175 mL) and found
proportionately fewer postoperative infections with the larger volume,
although differences between groups were not significant.[49]

Drain versus no drain:

We found four RCTs[50] [51] [52] [53] comparing placement of a surgical drain to
the wound versus no drain, and one RCT[54] comparing passive drainage (no suture of the
oblique vestibular incision) versus no passive drainage (suture of the
oblique vestibular incision) (see
table 1 ).

The first RCT (23 people who had bilateral
operations and randomised to receive drains unilaterally) found that the
drain significantly reduced facial swelling at 3 and 7 days compared with
no drain. However, the RCT found no significant difference between groups
in pain at 3 days, and at 4 to 7 days. [50]The RCT found that the surgical drain
significantly improved mouth opening compared with no drain at 7
days.

The second RCT (21 people) found no
significant difference in pain, swelling, or mouth opening at 2 and 7
days.[51] It also found no significant difference
between drain and no drain groups in dry socket (alveolar osteitis).

The third RCT (100 people with asymptomatic
impacted lower third molars aged 18–40 years) found no significant
difference between drain and no drain in pain at 24 hours. However, at 72
hours, the drain significantly increased pain compared with no drain; and
at 5 days the drain significantly decreased postoperative pain compared
with no drain. The drain significantly reduced the percentage of buccal
cheek swelling compared with no drain at 24 hours, 72 hours, and 5 days,
and significantly increased mean mouth opening compared with no drain at
24 hours, 72 hours, and 5 days. [52]

The fourth RCT (53 people with bilateral
impacted lower third molars aged 14–30 years) found no significant
differences between drain and no drain in the proportion of people with
pain at 24 hours, 72 hours, 7 days, and 15 days.[53] The drain significantly reduced the
percentage of buccal swelling compared with no drain at 24 and 72 hours;
however, there were no significant differences between the two groups at 7
days and 15 days. The RCT also found no significant differences between
the two groups in mean mouth opening at 24 hours, 72 hours, 7 days, and 15
days.

The fifth RCT (20 people with
bilateral impacted lower third molars aged 18–40 years) compared no suture
of the oblique vestibular incision (passive drainage) versus suture of the
oblique vestibular incision (no passive drainage).[54] It found that a higher proportion of people
with suture had postoperative pain at 48 hours compared with no suture,
but the significance was not assessed. At 72 hours, 7 days, and 15 days
there were no differences in pain between the two groups (significance not
assessed). The RCT found no significant differences between the two groups
in the percentage of swelling at 72 hours, 7 days, and 15 days. The RCT
also found no significant differences between the two groups in mouth
opening at 72 hours. However, at 7 and 15 days, people in the
passive-drainage group had significantly increased mouth opening compared
with people in the no passive-drainage group.

Coronectomy versus complete removal of
wisdom tooth:

We found one RCT (128 people)
comparing complete removal of a wisdom tooth versus coronectomy (planned
division of tooth and retention of root; see
table 1 ).[55] A large proportion of coronectomies failed
(36/94 [38%]) as roots were dislodged during surgery. The RCT reported
data for three groups: complete removal, failed coronectomy, and
successful coronectomy. The RCT found a significant difference among the
three groups in proportion of extractions with inferior alveolar nerve
damage, with the highest rate occurring in the complete-removal group:
this result is to be expected as there is no surgical manipulation near
the nerve with complete removal of the impacted tooth. The RCT found a
similar incidence of dry socket among groups, although statistical
analysis was not reported. The RCT found that infection rates were
greatest in the complete-removal group, although statistical analysis was
not reported. The length of follow-up was about 2 years, which is not
sufficient for the assessment of delayed eruption of the root fragments,
as this process may continue for up to 10 years.

Comment

Of the RCTs identified, most did not
specify whether people were symptomatic or asymptomatic. Two RCTs reported
that extraction was for prophylactic or orthodontic reasons, while four
RCTs reported that people with pericoronitis (infections) were excluded.
For the RCTs evaluating swelling, trismus, and pain postoperatively, a
number noted statistically significant results between groups with regard
to these outcomes, although the clinical significance of such differences
is debatable.

Clinical guide:

While there has been
disagreement about the removal of asymptomatic teeth, there has been no
controversy about the need to remove symptomatic teeth and those showing
pathological changes such as infection, non-restorable caries, cysts,
tumours, or destruction of adjacent teeth and bone. Most commonly, wisdom
teeth are removed because they are impacted against bone or soft tissue,
preventing them from fully erupting. Bacteria and debris collect under the
overlying flap of tissue and cause infections (pericoronitis), and removal
of wisdom teeth in this situation is the management of choice. Wisdom
teeth are also removed if they are causing caries of the adjacent tooth.
This happens when the tooth is partially erupted, and its position in
relation to the adjacent tooth or soft tissues makes the area inaccessible
to usual oral hygiene measures. The symptoms of pericoronitis are pain,
bad taste, swelling of the gum and face, and restricted mouth opening
(trismus). The local infection may spread, resulting in a regional
lymphadenopathy, pyrexia, and malaise. Rarely, the swelling may threaten
the patency of the airway and breathing. Wisdom tooth caries may also
cause pain and, if unmanaged, will ultimately lead to death of the tooth
and to abscess formation. Abscess, like pericoronitis, may result in pain,
lymphadenopathy, pyrexia, malaise, and, rarely, also threaten the patency
of the airway. Removal of the tooth alleviates the symptoms and prevents
progress of the disease. It also permits restoration of the adjacent tooth
caries. We found one systematic review (search date not reported)
including eight studies (6 RCTs and 2 prospective cohorts), which
suggested that, overall, the second-molar periodontal probing depth or
attachment levels either remained unchanged or improved after wisdom-tooth
removal.[56] However, for the subset of people with
healthy second-molar periodontium before surgery, the review found an
increased risk for worsening of probing depths or attachment levels after
wisdom-tooth removal. The clinical significance of this is not clear.
There is currently insufficient evidence to show meaningful clinical
benefit for one type of surgery versus another.

Substantive changes

Extraction of impacted
wisdom teeth: different surgical methods Five RCTs added
comparing different surgical techniques versus each other.[41] [43] [52] [53] [54] None of the RCTs found a definitive benefit
for one technique compared with another. Considered with previously
reported evidence, it remains unclear whether any individual surgical
method is more effective than another. Categorisation unchanged (Unknown
effectiveness).

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Journal ListClin Evid (Online)v.2010; 2010

BioEntities in Full Text

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development (3)

death (1)

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