2. 1126 LINGUAL FLAP RETRACTION FOR THIRD MOLAR REMOVAL
either be bone removal distal to the third molar or
where the crown of the third molar would need to be
sectioned. The technique was not used when teeth
could be elevated whole, either without any bone
removal, or with buccal bone removal only. In some
cases the decision to use lingual retraction was made
intraoperatively if crown sectioning or distal bone
removal was found to be necessary. Patients were
studied for access and ease of tooth removal and also
for the presence of any postoperative lingual or
chorda tympani nerve involvement. All patients were
questioned 1 week postoperatively regarding lingual
nerve sensory impairment or taste impairment. Pa-
tients reporting a change were tested with von Freys FIGURE 2. The double-ended Walters lingual retractor (KLS-Martin,
order no. 92-380-00) with a Molt bone curette (above) and a Ward’s
hairs.5 Human Research Committee approval was ob- periosteal elevator (below).
tained for this study. Pogrel and Goldman. Lingual Flap Retraction for Third Molar
In the technique used, an incision was made down Removal. J Oral Maxillofac Surg 2004.
the external oblique ridge of the mandible approxi-
mately 1.5 to 2 cm in length down to the distobuccal
line angle of the lower second molar, and then a
releasing incision was made into the buccal sulcus
(Fig 1). A buccal flap was raised and an appropriate
buccal retractor placed (usually a Minnesota-type re-
tractor). The lingual flap was then raised by means of
a Molt or Ward’s periosteal elevator (ie, a spoon-
shaped elevator). Once an adequate lingual flap was
raised, a Walter’s lingual retractor was placed (KLS-
Martin LP, Jacksonville, FL). This is a double-ended
instrument (one end for the left side, one end for the
right side) shaped to fit the lingual contour of the
mandible of the third molar region, broad enough to
protect the whole area in which bone may be re-
moved, and also has a small lip on it that engages the
medial oblique ridge and prevents the retractor from
migrating too deeply (Figs 2, 3).
Results
In the 250 patients studied there were no cases of
permanent lingual nerve injury. There were 4 cases of
transient lingual nerve injury consisting of sensation
only (not taste). These 4 cases were tested with von
Frey’s hairs,5 and in 3 of the cases the difference in
von Frey’s hairs between the normal side and the
abnormal side was 3 von Frey’s hairs or less,6 denot-
ing a minor loss of sensation. In all 3 of these cases the
paresthesia resolved within 21 days. In the fourth
case, the difference in feeling with von Frey’s hairs
between the normal and abnormal side was 7 hairs,
which indicates a more substantial loss of sensation,
and in this case normal sensation did not return for 2
months. On review of this case there appeared to be
FIGURE 1. Diagram of the standard incision used to raise buccal
and lingual flaps (right side).
nothing abnormal about the case that might have
Pogrel and Goldman. Lingual Flap Retraction for Third Molar given this result. Ease of access was confirmed and is
Removal. J Oral Maxillofac Surg 2004. shown in the clinical photograph which shows that
3. POGREL AND GOLDMAN 1127
FIGURE 3. A, Lingual retractor in place viewed from the buccal side showing excellent access to the tooth and surrounding bone. B, Lingual
retractor in place viewed from the lingual aspect showing excellent coverage of the lingual tissues and the lip (arrow), which engages the internal
oblique ridge and prevents the retractor migrating inferiorly. Also note the contour of the retractor that follows the contour of the lingual plate in the
third molar region.
Pogrel and Goldman. Lingual Flap Retraction for Third Molar Removal. J Oral Maxillofac Surg 2004.
both the crown of the tooth and the bone surround- This study suggests a transient lingual paresthesia
ing the third molar are fully displayed both buccally rate of 1.6% and 0% permanent lingual nerve damage,
and lingually (Fig 4). With this retractor in place no using this particular lingual retraction technique.
additional tongue retractor is required. Figure 5 is
interesting in that it does show the results after the
Discussion
third molar was removed in 1 case and shows that
there has been a minor fracture of the lingual plate Since the 1980s most protocols for removal of third
with loss of a small piece of the superior lingual plate molars have recommended a buccally based flap with
(arrowed). It can be envisaged that if a lingual retrac- buccal retraction only and removal of teeth with a
tor had not been placed in this region, and this small drill from the buccal approach. It is recommended
flake of bone had been displaced, it could have dam- that impacted teeth are sectioned multiply to remove
aged a highly placed lingual nerve. This may show the all fragments without the necessity of removing distal
additional value of lingual retraction in that it not only or lingual bone.1-3 A major reason for this is an at-
protects the lingual nerve from damage from instru- tempt to avoid lingual nerve damage while removing
mentation, but also from minor fractures of the lin- the teeth. It has been realized since the mid 1980s
gual plate. that in around 15% to 20% of patients the lingual
FIGURE 5. View of the lingual plate after tooth removal. Note the
FIGURE 4. Lingual retractor in place clinically showing excellent small fracture of the lingual plate (arrow) that could have inadvertently
visualization and access to bone and tooth removal. Also note the lip damaged a lingual nerve that was superiorly positioned, had the
of the retractor engaging the internal oblique ridge. lingual retractor not been in place.
Pogrel and Goldman. Lingual Flap Retraction for Third Molar Pogrel and Goldman. Lingual Flap Retraction for Third Molar
Removal. J Oral Maxillofac Surg 2004. Removal. J Oral Maxillofac Surg 2004.
4. 1128 LINGUAL FLAP RETRACTION FOR THIRD MOLAR REMOVAL
nerve lies in an abnormally high position and may be clearly where one is drilling, and the lingual nerve is
level with or superior to the crest of the lingual protected.4,11,16,37,38 Robinson and Smith39 stated that
plate.7-10 To avoid damage to a lingual nerve in this permanent lingual nerve injury often results from di-
aberrant position, it has been recommended that all rect damage from a rotating bur. In a more recent
incisions are made well to the buccal side of the ridge, article, Robinson et al40 found that the affected nerves
and only a buccal flap is elevated and no attempt is were always found trapped in scar tissue and some-
made to elevate a lingual flap. Similarly, all bone times expanded to form a neuroma. Complete divi-
removal is recommended to be carried out from the sion of the nerves was evident in approximately 50%,
buccal side and, following removal of the tooth, ex- and small fragments of metal were sometimes found
treme care should be taken in removing follicular embedded within the epineurium of scar tissue, pre-
remnants on the lingual side of the socket, and if the sumably having been shaved from the lingual retrac-
socket is to be sutured postoperatively, there should tor (Howarth’s elevator, a narrow elevator used in
only be very superficial sutures on the lingual side. All much of Europe) during the initial operation. The
the above are recommended to avoid damage to the technique described in this article is not the same as
lingual nerve. Historical studies have shown variable the lingual split technique where lingual bone is de-
results for lingual nerve damage following removal of liberately removed with a chisel and the tooth deliv-
lower third molars with temporary lingual nerve dam- ered lingually.41 The technique described in this arti-
age ranging from 0% to 22%, and permanent damage cle involves lingual retraction only, but with bone
ranging from 0% to 2% of all lower third molar remov- removal from the buccal side with a drill. The weak-
als, depending on a number of factors, including the ness of this technique in the past has been that the
techniques used.11-32 Several studies, however, have retraction itself was often provided by a periosteal
tended to show that since these policies were elevator such as a Howarth’s elevator, which is poorly
adopted in the late 1980s, there has been no signifi- designed for the purpose in that it is too narrow to
cant decrease in the incidence of lingual nerve dam-
protect the whole of the lingual nerve, has sharp
age following third molar removal, which has vari-
edges that themselves can damage the nerve, and is
ously been estimated between 0.2% and 1.6% of all
incorrectly shaped to fit the lingual aspect of the
lower third molars having some degree of change of
mandible.12 Nevertheless, studies with this technique
lingual nerve sensation postoperatively.13-15,18,19,33,34
are variable, but do tend to show that approximately
Although it is known that most cases recover sponta-
11% of patients may have some form of transient
neously, and one study shows that 83% of lingual
paresthesia of the tongue, but there are virtually no
nerve injuries resolve spontaneously,35 there does not
cases of permanent nerve involvement.11,15,22,25 This
appear to be any significant decrease in the number of
cases of permanent lingual nerve involvement. Cer- would suggest that there may be some traction inju-
tainly if medicolegal experience is any guide, the ries of the nerve, but they are still mild and transient.
number of cases has certainly not decreased (L. Esta- Another issue has been that the Howarth or similar
brooks, Oral and Maxillofacial Surgeons National In- elevator can be placed or can migrate too deeply and
surance Company, personal communication, 2003). A can go down far enough to affect the mylohyoid
recent study in California (where replies were ob- nerve and cause a paresthesia (usually temporary)
tained from 86% of all practicing oral and maxillofa- over the appropriate area innervated by the mylohy-
cial surgeons in California), where the vast majority of oid nerve.42 Because of problems with the Howarth
practitioners use a buccal approach, showed that 53% elevator, the issue of lingual nerve retraction has be-
of oral and maxillofacial surgeons were aware of a come controversial.39,43-50
case of lingual nerve damage that had occurred with To circumvent these problems, a new lingual re-
them during the preceding year (temporary and per- tractor (KLS Martin LP, No. 92-380-00) and compli-
manent). Additionally, 46% of all the oral and maxil- mentary periosteal elevators were designed in the mid
lofacial surgeons studied were aware of having caused 1990s by Dr Hugh Walters, a consultant oral and
a permanent lingual nerve injury following third mo- maxillofacial surgeon in the United Kingdom (since
lar removal during their professional lifetime. In 57% deceased), which appears to eliminate these potential
of the cases, the practitioner involved had no idea of problems.45 The right- and left-sided periosteal eleva-
the actual cause of the injury.36 An alternative tech- tors are designed to be used with the lingual retractor
nique is to practice elevation and retraction of a to initially retract the lingual flap. In fact, we have
lingual flap, and the placement of a retractor down found the periosteal elevators awkward to use be-
the lingual periosteum of the mandible to improve cause the actual working tip is at right angles to the
access to the area and also to protect the lingual handle, making its moment of force inefficient. A
nerve. Bone can still be removed with the drill in the straight periosteal elevator is much more efficient and
normal way, but with better access one can see more effective and an elevator with a spoon-shaped tip,
5. POGREL AND GOLDMAN 1129
such as a straight Molt bone curette or Ward’s eleva- from drills, instruments, or inadvertent lingual plate
tor, adapts just as well to the shape of the lingual or tooth fracture or displacement. These may be re-
plate. The elevator itself is then placed, and it is broad sponsible for the cases of permanent nerve involve-
enough to protect the whole aspect of the lingual ment seen following lower third molar removal. It
nerve in the third molar region, has no sharp edges on may be appropriate to re-examine the techniques and
it, and has a notch that fits into the internal oblique principles of lingual flap elevation and retraction.
ridge of the mandible and prevents the instrument
from slipping too deeply and possibly involving the
mylohyoid nerve. It allows excellent access to the References
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