Chapter
31
Resection of the Floor of the Mouth
Eugene N. Myers
The floor of the mouth is the second most common site
of cancer of the oral cavity, and more than 95% of these
cancers are squamous cell carcinoma. Local control of
early lesions (T1/T2) is favorable when treated by
surgery. Studies suggest that surgery affords good local
control, facilitates histologic staging of the tumor
(thereby offering the opportunity to modify therapy),
and is associated with fewer long-term side effects (such
as xerostomia, loss of taste, trismus, and osteoradionecrosis) than radiation therapy is. Unfortunately,
however, patients frequently have locally advanced
cancer (T3/T4) at initial evaluation, often with involvement of the tongue, the mandible, or both. Increasing
tumor size correlates with poorer prognosis, as well as
increased treatment morbidity. Metastasis to the cervical lymph nodes is also common in oral cavity carcinoma. Cervical metastatic disease occurs in 30% to 40%
of patients with T1/T2 tumors and is associated with
worsening of the prognosis.1,2
Carcinoma of the oral cavity is principally a disease
of the middle-aged and elderly. The average age at
diagnosis is 60 years, with 95% of lesions occurring
in persons 40 years or older.2 The majority of these
patients have a history of long-term tobacco and alcohol
use.
The therapeutic goals in the management of cancer
of the oral cavity are elimination of the tumor with
return of the patient to the best possible form and function.3 Speech is often impaired after excision of cancers
of the oral cavity.4 A number of treatment factors may
have an impact on this impairment. The extent of surgical resection, particularly the amount of oral tongue
resected, has been implicated as the primary correlate
of speech impairment, although fibrosis with lack of
tongue mobility is also an important factor. Larger
resection volumes and a greater percentage of oral
tongue resection have been correlated with reduced
intelligibility and articulation.5-9 Other retrospective
studies suggest that postoperative speech function is
more dependent on the method of reconstruction than
on the degree of resection.10 Patients who underwent
reconstruction with pedicled or free flaps appeared to
have worse postsurgical speech function than those
whose wounds were closed primarily or with split-thickness skin grafts.11-15
Schliephake and associates16 in 1996 studied a series
of 85 consecutive patients with squamous cell carcinoma of the floor of the mouth. Reconstruction was
carried out with local tissue, jejunal grafts, and cutaneous and myocutaneous flaps. Thirty percent of these
patients underwent marginal mandibulectomy and
31.7% underwent segmental resection of the mandible.
They concluded that rehabilitation of patients operated
on for cancer of the oral cavity is particularly difficult
in the case of large soft tissue defects and is not always
accomplished completely even with primary microsurgical flap reconstruction.
Treatment decisions in patients with carcinoma of
the floor of the mouth is dependent on the size and
depth of the tumor, the presence of invasion of the
mandible, and the presence or absence of cervical
lymph node metastasis. Over the years, treatment programs have consisted of
• Resection of the primary tumor with or without elective neck dissection
• Radiotherapy of the primary tumor and neck
• Radiotherapy of the primary tumor with or without
elective neck dissection
• Combination therapy, including resection of the
primary tumor followed by radiotherapy of the neck
Excellent local control of early-stage cancer of the
oral cavity (T1/T2) has been achieved with either
surgery or radiotherapy.2 Resection of T1/T2 lesions is
usually performed transorally, and the defect is resurfaced with a split-thickness skin graft. A marginal mandibulectomy may be necessary, depending on the
location of the cancer. Three-dimensional en bloc
241
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242
Section 2
Oral Cavity/Oropharynx
resection through an anterior mandibulotomy approach
is usually necessary for T3/T4 tumors because these
larger tumors may involve adjacent structures, such as
the tongue and tonsil, and require improved visualization. Infiltration of cancer into the mandible requires
segmental mandibulectomy for local control. A combination of external beam radiation followed by brachytherapy has been used with good results, although this
regimen requires a tracheostomy, is associated with
morbidity, and carries with it the potential complication of osteonecrosis of the adjacent mandible.
It is now recognized that although T1/T2 cancers
of the floor of the mouth can be locally controlled in a
high percentage of patients with minimal morbidity,
the untreated, clinically negative neck may be the site
of recurrent disease in 30% to 40% of patients. Failure
to control neck disease then leads to death of the
patient. Studies comparing survival rates of patients
with node-negative necks who have undergone elective
and therapeutic neck dissection seem to indicate
improved survival for those who undergo elective neck
dissection. Spiro and Strong17 have indicated that it is
beneficial to remove occult cervical lymph node metastasis before it becomes clinically apparent. These
authors reported that patients with stage N0 necks who
were subsequently discovered to have occult nodal
metastasis after elective neck dissection had longer survival than did patients with cervical metastasis at the
time of initial examination. Silver and Moisa18 reported
that both control of neck disease and patient survival
may be significantly increased if neck dissection is performed before cervical metastases become clinically
evident. Dias and colleagues studied a series of patients
with T1 squamous cell carcinoma of the tongue and
floor of mouth.19 The authors concluded that patients
who underwent elective neck dissection had a 23%
higher disease-free survival rate than did those who
underwent resection of the tumor only.
McGuirt and coworkers1 performed a retrospective
outcome analysis of 129 patients with TxN0 squamous
cell carcinoma of the floor of the mouth to evaluate the
role of neck dissection. The majority consisted of T1/
T2 lesions, and all were treated by transoral excision
with a split-thickness skin graft with or without marginal
mandibulectomy. Elective neck dissection was performed in 26 patients. Histologic evaluation revealed
occult metastases in 23%. In contrast, of 103 patients
managed without elective neck dissection, cervical
lymph node metastasis eventually developed in 37%.
The determinant survival rate at 3 years was 100% for
patients with occult disease who underwent elective
neck dissection, whereas the 3-year determinant survival rate in patients receiving no initial treatment of
the neck was 85%. The salvage rate for those in whom
metastases to the neck did develop was 59%. We believe
that a more aggressive approach that includes elective
neck dissection in node-negative necks is warranted
because the limited morbidity of selective neck dissection seems to be a reasonable tradeoff to the high
failure rate in patients in whom metastasis to the neck
eventually develops.
Ch031-X2445.indd 242
We routinely perform selective neck dissection on
patients with cancer of the floor of the mouth and an
N0 neck. Levels I to III are dissected (supraomohyoid).
It does not appear to be necessary to dissect level IV
because this level seems vulnerable only to metastasis
from cancer of the lateral tongue.20 If the lesion is in
the midline, both sides of the neck should be dissected.
Care must be taken to include the prevascular and postvascular lymph nodes associated with the facial artery
and vein adjacent to the mandible in the dissection.
This requires identification and preservation of the
ramus mandibularis of the facial nerve. These are firstechelon lymph nodes for metastatic cancer from the
floor of the mouth. Some surgeons may not routinely
dissect this area because of the risk of injury to the facial
nerve, which is adjacent to these lymph nodes, thereby
leaving potentially involved nodes in situ.
A major limitation in the evaluation of patients with
oral cavity carcinoma is the inability to detect which
patients with node-negative necks harbor occult cervical lymph node metastasis. Simple physical examination
leads to substantial error. Studies carried out with
computed tomography (CT) and magnetic resonance
imaging (MRI) have established criteria for malignancy,
such as lymph nodes greater than 1 cm in diameter,
matted nodes, or nodes with a hypodense center. Nevertheless, imaging studies fail to detect microscopic
metastasis. Hence, we routinely perform selective (bilateral in midline lesions) neck dissection in all patients
with floor of the mouth carcinoma.
PATIENT SELECTION
Carcinoma of the floor of the mouth is best managed
surgically. Rodgers and coworkers21 demonstrated that
although locoregional control rates for early lesions
(T1/T2) were similar for both surgery and radiation
therapy, radiotherapy was associated with a higher
overall incidence of complications, such as bone and
soft tissue necrosis. We concur with the recommendation that surgery be used for the management of early
cancer and that a combination of surgery followed by
radiation therapy be used for more advanced cancer. It
is worthwhile noting that in the approximately 15 years
that we have systematically been performing selective
neck dissection in patients with T1/T2 lesions (stage
I-II), approximately a third of the patients have been
upstaged to stage III based on pN1-N2 in a clinically N0
neck.
Surgical removal of the cancer plus selective neck
dissection is offered to all patients who are physically fit
enough to undergo an extensive surgical procedure
under general anesthesia. Patients who do not qualify
for surgery because of ill health or because they refuse
surgery are referred for radiation therapy.
The success rate in achieving control of the primary
cancer in patients treated by transoral wide excision
and skin grafting is related to tumor depth of invasion,
as well as T stage. Patients with superficial cancer have
better survival than do those with deeply infiltrating
cancer. Schramm and colleagues22 found that the
5/29/2008 1:53:59 PM
Chapter 31
surface size of the cancer, even when it was larger than
4 cm, did not influence local control if complete excision was achieved. Brown and associates23 demonstrated
that tumor with a depth of invasion greater than 7 mm
was more likely to be accompanied by occult cervical
metastases than were thinner lesions.
PREOPERATIVE EVALUATION
History and physical examination remain the mainstay
of evaluation in patients with cancer of the floor of the
mouth. The anterior floor of the mouth is the most
common anatomic location of these tumors, although
cancer of the anterolateral or lateral area occurs occasionally (Fig. 31-1). Most patients with symptoms of
pain or bleeding from the oral cavity or ill-fitting dentures go to their dentist rather than their physician for
initial evaluation.
Patients with cancer in the anterior floor of the
mouth may complain of bleeding, low-grade pain, difficulty with ill-fitting dentures, loosening of the teeth,
fetid breath, alteration of speech because of decreased
mobility of the tongue, or a mass in the neck. Unfortunately, most patients who wear dentures are used to a
certain amount of discomfort in the oral cavity, and
they may seek to relieve the pain in the floor of the
mouth by simply removing their dentures. Although
this eases the discomfort, such patients may not seek
timely evaluation by their dentist, thereby resulting in
a delay in diagnosis. Further reduction in the number
of patients initially seen with advanced-stage oral cavity
cancer will depend on greater emphasis on examination of the oral cavity by primary care practitioners.
Complete examination of the head and neck must
be performed. Examination of the floor of the mouth
should consist of inspection and palpation (Fig. 31-2).
Palpation of the lesion is also of utmost importance
because it gives an indication of whether the lesion is
superficial and therefore easily excised through the oral
cavity or more deeply infiltrative and requiring a “pullthrough” type of operation. Palpation should be used
to determine whether the mandible is involved by the
Resection of the Floor of the Mouth
243
tumor. Lesions are generally ulcerative but may also be
exophytic or deeply infiltrative. The patient should be
asked to protrude the tongue to determine whether
infiltration of muscles has resulted in fixation of the
tongue because this influences the treatment program.
The surface dimension of the cancer must be measured
to assign the proper tumor stage. The location of the
lesion should be clearly described and marked appropriately on a diagram of the oral cavity.
Mental nerve hypoesthesia may indicate invasion of
bone. Primary carcinoma of the oral cavity with mandibular involvement sometimes infiltrates the skin of
the overlying mentum. This must be carefully palpated,
and infiltration must be noted (Fig. 31-3A and B).
Attention must be paid to evaluation of the patient’s
dentition. Any salvageable teeth should be restored.
Patients with fractured or carious teeth or advanced
periodontal disease should undergo tooth extraction at
the time of the surgical procedure, particularly if radiation therapy will be administered postoperatively. This
requires advanced planning with dental colleagues to
avoid unnecessary intraoperative delays.
The neck must be examined in detail, and any
masses palpated in the neck should be measured to
assign a proper nodal stage. Fine-needle aspiration
biopsy may be necessary to verify the presence of metastatic cancer (Fig. 31-4). Examination of the neck is of
the utmost importance. A high percentage of patients
with T1/T2N0 tumors have occult metastasis. The
reported incidence of recurrent carcinoma in the
untreated cervical lymph nodes after treatment of only
the primary tumor is 15% to 50%.1
Imaging plays two major roles in the evaluation of
patients with carcinoma of the anterior floor of the
mouth. CT may be helpful in determining whether the
mandible is infiltrated by cancer and, if so, to what
extent (Fig. 31-5). MRI may help estimate marrow
involvement by tumor, but like CT, it may overlook
subtle cortical involvement. If palpation indicates that
the cancer involves only the soft tissues of the floor of
Figure 31-1. Squamous cell carcinoma involving the anterior floor
Figure 31-2. Palpation of cancer of the tongue and floor of the
of the mouth.
mouth should be done routinely.
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244
Section 2
Oral Cavity/Oropharynx
A
B
Figure 31-3. A, Patient with advanced cancer of the floor of the mouth. B, Destruction of the anterior mandible and infiltration of cancer
into the skin of the chin.
R
A
L
B
Figure 31-4. A, Patient with advanced cancer of the floor of the mouth with metastasis to the neck. B, Computed tomography scan demonstrating necrotic lymph nodes.
the mouth, imaging is not required because palpation
gives adequate information for planning treatment.
The second indication for scanning is to assist with
staging of the neck. This may also be unnecessary
because selective neck dissection is contemplated in all
patients regardless of the clinical status of the neck.
Imaging does help in staging a “hard to examine” (muscular or obese) neck. Because most primary cancers
occur in the midline, there is a real risk of bilateral
lymph node metastasis.
Evaluation of the lungs is essential because patients
with squamous cell carcinoma of the upper aerodigestive tract frequently have synchronous second primaries
in the upper or lower aerodigestive tract (Fig. 31-6).
Many surgeons obtain a chest CT scan in all patients.
Positron emission tomography (PET) or PET/CT scanning has begun to play a greater role in the diagnosis
Ch031-X2445.indd 244
of cancer of the head and neck because PET may identify unexpected lesions in the neck or lungs, which
would influence the treatment program.
The cancer must be biopsied, or if it has been biopsied elsewhere, the slides must be reviewed and the
diagnosis verified. Biopsy may be done under local
anesthesia in the outpatient setting. Panendoscopy
should be carried out to evaluate the other areas of the
upper and lower aerodigestive tract to rule out synchronous second primaries. Endoscopy is usually performed
at the time of extirpative surgery.
The timing of surgical excision and neck dissection
is not critical, but with proper planning, efficient use of
operative time can be optimized. If the primary tumor
is resected at the time of endoscopy, before neck dissection, the pathologist can examine and review the
specimen while the neck dissection is performed. The
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Chapter 31
Resection of the Floor of the Mouth
245
Figure 31-6. A patient with synchronous primary cancers of the
larynx and floor of the mouth treated by laryngectomy, excision of
the floor of the mouth, and skin grafting.
include marginal mandibulectomy. Indications for marginal mandibulectomy include
Figure 31-5. Computed tomography scan demonstrating erosion
of the anterior mandible.
defect can be reconstructed at the completion of the
neck dissection after the margins have been carefully
examined.
TRANSORAL EXCISION OF
LIMITED LESIONS OF THE
FLOOR OF THE MOUTH
Surgical Technique
The patient is placed supine on the operating table,
and a folded blanket is placed under the shoulders to
extend the neck. Perioperative antibiotics are begun
before the start of the procedure. General endotracheal
anesthesia is induced, and endoscopic evaluation of the
upper and lower aerodigestive tract is carried out if it
has not been done previously. Neck dissection can be
performed at this time or can be delayed until after
tumor excision.
The patient is then prepared and draped, including
the thigh for the skin graft. A tracheostomy is performed if a skin graft or flap is to be used for reconstruction. The endotracheal tube is then placed in the
tracheostomy site. A Jennings mouth gag is placed in
the oral cavity and opened to provide exposure. Rightangled retractors are used to retract the buccal mucosa.
A suture is placed in the tip of the tongue in the exact
midline, and upward traction is placed on the tongue
to expose the anterior floor of the mouth.
Preoperative evaluation would have revealed
whether the plan of management would or would not
Ch031-X2445.indd 245
• Inability to obtain an anterior margin of resection
without removing the alveolar process of the mandible, which is especially important in dentulous
patients
• Attachment of the cancer to the lingual aspect of the
mandibular periosteum
• A superficial tumor that crosses the mandible and
involves the gingival buccal sulcus in an edentulous
patient
If only soft tissue is being resected, a margin of
resection of at least 1 cm of normal tissue from the
periphery of the tumor is outlined with methylene blue
or a marking pen. The mucosa is incised with coagulation current or a scalpel. Size 2-0 silk suture is then
placed through the anterior margin of resection (Fig.
31-7), and the circulating nurse is told to note this
marker on the pathology form. The soft tissue is sharply
dissected in an anterior-to-posterior direction with small
dissecting scissors. The deep margin of resection in
superficial cancers in this area is the sublingual glands.
Deep dissection will also transect Wharton’s ducts. The
remainder of the lesion is then excised from the ventral
surface of the tongue. There is always bleeding from
veins, as well as from branches of the lingual artery.
These vessels should be individually ligated to obtain
meticulous hemostasis so that the skin graft can heal
properly. Ligation can be done with 3-0 chromic catgut
suture in figure-of-eight fashion over the hemostats on
the bleeding vessels. No attempt is made to reconstruct
the submandibular gland ducts if the submandibular
glands will be excised as part of the neck dissection. In
complex cases, the pathologist comes into the operating room to see the operative site and to examine the
specimen with the surgeon. Margins for frozen section
examination are selected. If a margin appears close, it
is preferable to excise additional tissue and examine the
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246
Section 2
Oral Cavity/Oropharynx
A
B
Figure 31-7. A, Soft tissue margins are marked and incised. B, The specimen.
additional margin. It is a great error to fail to accurately
identify any positive or close margins. Such error is
prevented by careful registration of the specimen in the
pathology department and on-site communication with
the pathologist.
The surgeon who will be taking the skin graft and
the surgeon’s assistant change into new gowns and
gloves and harvest the skin graft with freshly sterilized
instruments and supplies uncontaminated by oral secretions. We use a Brown dermatome set at 61/100 of an
inch.24 The skin graft should be thick enough to handle
easily and not tear and yet thin enough to be pliable
and have a high possibility of a good take. Using a “piecrusting” technique (Fig. 31-8), the skin graft is sewn to
the mucosa of the floor of the mouth with a 3-0 silk
suture, with every other suture left long to tie over (Fig.
31-9). One or two “tacking” stitches of absorbable catgut
suture are placed in the floor of the mouth to aid adherence of the skin graft to the underlying tissue. Several
antibiotic-impregnated gauze packs are used as a bolus
and tied over with the long sutures. A nasogastric tube
is inserted and sutured into place, and this aspect of the
procedure is terminated.
The inclusion of marginal mandibulectomy modifies the operation somewhat. At the outset of the operation, the margins of resection are outlined on the
mucosal surface with a marking pen (Fig. 31-10) (see
Chapter 32 for figures). The initial incisions are then
made in the soft tissue and carried over the alveolar
process down to bone and connected anteriorly. The
mucoperiosteum of the mandible is then elevated inferiorly to facilitate a precise osteotomy. In patients who
are dentulous, the location of the osteotomy must be
considered. If the patient has full or almost full lower
dentition, the osteotomies for an anterior marginal
mandibulectomy will usually encompass the central and
lateral incisors. In such cases, both canine teeth should
be extracted, and the osteotomy should be made in the
middle of the socket or medial to it. This preserves bone
around the remaining teeth, which will allow later
application of partial removable dentures with clasps. If
the incision is made just immediately adjacent to the
Ch031-X2445.indd 246
Figure 31-8. Suture with the “pie-crusting” technique. The skin is
sewn around the cut edge of the mucosa to ensure proper healing.
remaining teeth, lack of bone support will eventually
result in loss of these teeth.
Because the alveolar process is not involved with
the tumor but is a margin of resection around the
tumor, it is necessary to resect only the alveolar process
and not the body of the mandible. The vertical dimension of the mandible is substantial, even in edentulous
patients, but only the alveolar process should be taken.
The osteotomies are then traced on the bone with a
marking pen. A Stryker saw with a right-angled blade
should be used, first to make the vertical osteotomies
(see Chapter 32) and then to connect them with a
horizontal osteotomy. It is important that the buccal
and lingual plates of bone be cut all the way through.
It may be tempting to use an osteotome or a heavy elevator to try to pry the bone open before the lingual cortex
is cut through, but this could fracture the mandible and
thus should be avoided.
Once the lingual cortex is cut through and the
mandibular fragment is freed, the bone is retracted
superiorly and posteriorly along with the soft tissue, and
the rest of the resection is then carried out as described
earlier (Fig. 31-11A and B). The sublingual glands are
identified and included as a deep margin of resection.
The bony margins of the mandible are smoothed with
a cutting burr to remove any spicules or sharp corners.
A split-thickness skin graft can be used to resurface both
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Chapter 31
A
Resection of the Floor of the Mouth
247
certainly develop. In such cases we prefer reconstruction with a radial forearm free flap with microvascular
anastomosis. If a microvascular surgeon is not available,
a pectoralis major myofascial flap may be applied
without a skin graft. This is done to avoid the bulk
associated with a pectoralis major myocutaneous flap,
which interferes with oral cavity function. Local flaps
such as the nasolabial flap25 or regional flaps such as
the temporal fasciocutaneous island flap,26 infrahyoid
myocutaneous flap, sternocleidomastoid flap, and platysma flap can be used.27
If neck dissection is to be performed at this time,
the patient is reprepared and draped and the appropriate neck dissections carried out. We perform selective
neck dissection in levels I to III while being certain that
the prevascular and postvascular lymph nodes adjacent
to the mandible and anterior and posterior to the facial
artery and vein are taken because these nodes are part
of the first echelon of lymph node drainage in cancer
of the floor of the mouth.
POSTOPERATIVE MANAGEMENT
B
C
Figure 31-9. A, The skin graft is sewn into place with 3-0 silk suture.
B, Gauze bolus secured with silk tie-over sutures. C, Skin graft healed
nicely.
the soft tissue and the residual mandibular bone. This
is possible because most of the residual bone of the
mandible is cancellous bone with a thin rim of cortical
bone on the buccal and lingual sides. The skin graft
heals nicely in this area if care is taken to provide immobilization of the graft over the bone and soft tissue
(Fig. 31-11C). Use of the skin graft provides a strong
epithelial lining to accommodate dentures in the future
(Fig. 31-11D).
Skin grafting is contraindicated in patients who
have had radiation therapy in this area because if the
skin graft fails, the relatively avascular irradiated bone
will become exposed and osteoradionecrosis will almost
Ch031-X2445.indd 247
Critical in postoperative management is routine tracheostomy care, including frequent suctioning, because
patients in this group all have tethering of their tongue
as a result of the skin graft, which makes it difficult
for them to handle their secretions. Frequent tracheal
suctioning is necessary to prevent atelectasis and
pneumonia. The nasogastric tube is placed on suction
until bowel sounds are present, at which time the patient
is fed through the nasogastric tube. Intraoral care is
provided by frequent suctioning and oral irrigation
with sprays of half-strength hydrogen peroxide. Perioperative antibiotics are administered for 24 hours.
The bolus is removed by cutting the tie-over sutures
on the fifth postoperative day. Usually, the patient
can be decannulated when the bolus is removed.
The stoma is generally closed within a week after decannulation. The patient may then begin a soft diet.
The average length of stay in the hospital is 7 to 10 days.
The patient is seen back in the office, and the remainder of the silk sutures are removed from the oral cavity
and the graft is débrided. Any residual edema will
recede in time.
Postoperative care specific to neck dissections is
discussed in Chapter 78 and that specific to tracheostomy in Chapter 68.
COMPLICATIONS
Elective neck dissection is required for all patients.
Examination of the margins via frozen section is
necessary.
A skin graft in this area will not be lost if the following details of the surgical technique are respected:
• Proper thickness of the skin graft
• Meticulous hemostasis
• Immobilization of the graft by proper suturing and
application of the bolus
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Section 2
248
Oral Cavity/Oropharynx
Figure 31-10. Proposed excision
of a tumor with (A) and without (B)
marginal mandibulectomy.
A
B
A
B
C
D
Figure 31-11. A, Cancer of the floor of the mouth attached to the mandibular periosteum. B, Marginal mandibulectomy and excision of the
cancer of the floor of the mouth. C, The healed skin graft. D, Dentures in place.
EXTENSIVE LESIONS OF THE
FLOOR OF THE MOUTH WITH OR
WITHOUT BONE INVOLVEMENT
SURGICAL TECHNIQUE
Patients who have advanced lesions (T3/T4) that deeply
involve the substance of the tongue or involve the mandible may require a composite resection, often includ-
Ch031-X2445.indd 248
ing segmental mandibulectomy, to achieve locoregional
control. Preoperative evaluation of these patients
requires assessment by both physical examination and
imaging for evidence of bone involvement.
Patients with lesions of advanced stage are also
frequently found to have clinically evident cervical
lymph node metastases in one or both necks. If nodes
are positive, these patients will require radical or modified neck dissection and contralateral selective neck
dissection. If the necks are clinically negative (N0),
5/29/2008 1:54:06 PM
Chapter 31
these patients will require bilateral selective neck dissection. Patients who have deep infiltration of the floor
of the mouth without bone invasion are not candidates
for transoral resection, and the approach should be
external via a “pull-through” operation or midline
mandibulotomy.
In these cases, endoscopic evaluation and dental
extractions are carried out as described earlier. Tracheostomy is performed and the patient is prepared and
draped for neck dissection. In the oral cavity, if soft
tissue only is involved, we often approach these tissues
through an anterior mandibulotomy. Therefore, an
anterior cervical flap is fashioned to allow a lip-splitting
incision. After neck dissection (see Chapter 78), anterior mandibulotomy is carried out (see Chapters 33 and
34). Once the bone fragments are separated, as much
mucosa covering the lingual plate of the alveolus as
possible is preserved to facilitate closure. After these
anterior incisions in the mucosa have been made
around the perimeter of the tumor, the upper cervical
flaps are retracted and the mylohyoid muscle and digastric muscles are transected to enter the deep aspect of
the floor of the mouth (Fig. 31-12). Then, working from
both the oral cavity and the neck, three-dimensional
excision of the lesion is carried out (Fig. 31-13). If the
tumor has infiltrated deeply into the tongue, total or
subtotal glossectomy may be required (see Chapter 28).
It is helpful to retain at least one hypoglossal nerve and
lingual artery when possible, but not at the expense of
compromising tumor resection. During neck dissection, the hypoglossal nerves and the lingual arteries
should be isolated so that during dissection in the
depths of the neck, these structures can be identified
and, when possible, preserved. After complete excision
of the tumor and examination of the specimen by
frozen section, the appropriate reconstructive techniques are carried out. Such techniques may include a
pectoralis major myocutaneous flap or a radial forearm
free flap with microvascular anastomosis (see Chapter
81).
PATIENTS WITH INVOLVEMENT OF
THE MANDIBULAR ALVEOLUS
Some deeply infiltrative carcinomas arising in the floor
of the mouth invade the mandible (Fig. 31-14). If the
mandible is involved, segmental resection of the mandible should be carried out because penetration of the
mandible by cancer may involve the bone marrow. The
tumor is approached as described earlier with a lip-splitting incision. In some patients, a visor flap may be
created, which is cosmetically superior to a lip-splitting
incision (Fig. 31-15) but places the potentially uninvolved mental nerve at risk. The visor flap is created by
developing superior cervical flaps to the inferior margin
of the mandible. The lower gingivobuccal sulcus is then
excised intraorally from angle of mandible to angle of
mandible. The periosteum of the mandible is undermined, and the skin of the face, chin, and lower lip is
elevated with Penrose drains to elevate the flap upward
Ch031-X2445.indd 249
Resection of the Floor of the Mouth
249
A
B
Figure 31-12. The digastric (A) and mylohyoid (B) muscles are
transected for access to the depth of the floor of the mouth.
off the mandible. Care should be taken to preserve an
uninvolved mental nerve. Vertical osteotomies are then
made and the anterior portion of the mandible is
removed as a block. If the patient has residual teeth, a
tooth adjacent to the tooth to be preserved is extracted,
and the osteotomy is placed in the extraction site (Fig.
31-16) to preserve bone support for the residual teeth.
Preoperative planning is helpful to give an idea of how
much margin of bone is necessary to clear the tumor.
The patient will benefit by preservation of the mental
nerves, although this is not always possible. After the
osteotomies, the bone fragments of the remaining mandible are distracted while leaving the anterior segment
of the mandible attached to the soft tissues. The tumor
itself is then approached as described earlier by entering the deep aspects of the floor of the mouth through
the digastric and mylohyoid muscles.
A modification of this approach is necessary when
the cancer penetrates through the floor of the mouth
and the mandible (Fig. 31-17A) into the skin of the
chin. In this case, the skin of the chin is excised as far
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Section 2
Oral Cavity/Oropharynx
Figure 31-13. A and B, Excision
of the tumor working from the neck
and intraoral approach.
A
B
Figure 31-15. A visor flap may be used to obtain wide exposure
while preserving cosmesis.
Figure
31-14. Computed tomography scan demonstrating
advanced cancer of the floor of the mouth with mandibular
invasion.
peripherally as necessary to gain what appear to be clear
margins. The skin is left on the anterior segment of the
mandible and included in the en bloc resection (see
Fig. 31-17B). If the lower lip itself is not involved, preservation is possible, but care must be taken to not interrupt the vascular supply of the lower lip. If it is necessary
to take all or part of the lip, appropriate reconstructive
techniques will be required.
Ch031-X2445.indd 250
Reconstruction of the anterior mandible is best performed immediately by free flap reconstruction with
microvascular anastomosis (see Fig. 31-17C). Several
options may be used by the microvascular team for
reconstruction, including a fibular osseocutaneous free
flap, perforator flaps from the lateral aspect of the
lower part of the leg,28 a radial osseocutaneous free flap,
or a scapular osseocutaneous free flap. If microvascular
surgeons are not available, plating of the bone plus
epithelial coverage with a pectoralis major myocutaneous flap is an option. Both the regional and free flaps
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Chapter 31
Resection of the Floor of the Mouth
251
Figure 31-16. A tooth is extracted adjacent to the tooth to be preserved,
and the osteotomy is placed in the extraction site.
A
B
C
D
Figure 31-17. A, Advanced cancer of the floor of the mouth with destruction of
the mandible and infiltration of the skin of the chin. B, Surgical specimen, including
the floor of the mouth, mandible, and skin. C, Reconstruction with a bivalved fibular
osseocutaneous free flap. D, Good intraoral healing (including implants). E, Replacement of the skin of the chin with the same flap.
E
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Section 2
Oral Cavity/Oropharynx
have skin paddles that can be bivalved to provide external coverage in patients requiring excision of the skin
of the chin (see Fig. 31-17D).
• Thorough clinical assessment and imaging studies
POSTOPERATIVE MANAGEMENT
Postoperative management in these cases is similar to
that described for transoral excision of limited lesions
and includes the usual care of the tracheostomy. Suction
drains are always necessary in these cases, similar to
neck dissections (see Chapter 78). Patients are fed
through a nasogastric tube once bowel sounds are
audible. Intraoral management of the patient is similar
to that described earlier. Monitoring and care of the
flaps are described in the chapters on reconstruction
(see Chapter 81).
•
•
are necessary for evaluating whether the cancer has
infiltrated the mandible. If the mandible is involved
and segmental resection is necessary, proper
preoperative plans have to be made for
reconstruction of the mandible.
Soft tissue specimens must be properly marked for
frozen section evaluation, which should be carried
out systematically. On-site discussion with the
pathologist will reduce the likelihood of error
because of miscommunication.
Because frozen section is not available for bone
margins, generous margins of bone must be resected
to obtain adequate tumor clearance.
PEARLS
References
• Transoral excision of early squamous cell carcinoma
1. McGuirt WF Jr, Johnson JT, Myers EN, et al: Floor of mouth carcinoma: The management of the clinically negative neck. Arch
Otolaryngol Head Neck Surg 121:278-282, 1995.
2. Myers EN, Cunningham MJ: Treatments of choice for early carcinoma of the oral cavity. Oncology 2:18-36, 1988.
3. Muñoz Guerra MF, Naval Gías L, Rodríguez Campo F, Sastre
Pérez J: Marginal and segmental mandibulectomy in patients with
oral cancer: A statistical analysis of 106 cases. J Oral Maxillofac
Surg 61:1289-1296, 2003.
4. Pauloski BR, Logemann JA, Colangelo L, et al: Surgical variables
affecting speech in treated patients with oral and oropharyngeal
cancer. Laryngoscope 108:908-916, 1998.
5. Massengill R, Maxwell S, Pickrell K: An analysis of articulation
following partial and total glossectomy. J Speech Hear Disord
35:170-173, 1970.
6. Skelly M: Glossectomy Speech Rehabilitation. Springfield, IL,
Charles C Thomas, 1973.
7. Rentschler GJ, Mann MB: The effects of glossectomy on intelligibility of speech and oral perceptual discrimination. J Oral Surg
38:348-354, 1980.
8. LaBlance GR, Kraus K, Steckol KF: Rehabilitation of swallowing
and communication following glossectomy. Rehabil Nurs 16:266270, 1991.
9. Zieske LA, Johnson JT, Myers EN, et al: Composite resection
reconstruction: Split thickness skin graft—a preferred option.
Otolaryngol Head Neck Surg 98:170-173, 1988.
10. Allison GR, Rappaport I, Salibian AH, et al: Adaptive mechanisms
of speech and swallowing after combined jaw and tongue reconstruction in long-term survivors. Am J Surg 154:419-422, 1987.
11. Schramm FL, Johnson JT, Myers EN: Skin grafts and flaps in oral
cavity reconstruction. Arch Otolaryngol 109:175-177, 1983.
12. Baek S, Lawson W, Biller H: An analysis of 133 pectoralis major
myocutaneous flaps. Plast Reconstr Surg 69:460-467, 1982.
13. Haribhakti V, Kavarana NM, Tibrewala AN: Oral cavity reconstruction: An objective assessment of function. Head Neck 15:119124, 1993.
14. Logemann JA, Pauloski BR, Rademaker AW, et al: Speech and
swallow function after tonsil/base of tongue resection with
primary closure. J Speech Hear Res 36:918-926, 1993.
15. Teichgraeber J, Bowman J, Goepfert H: New test series for the
functional evaluation of oral cavity cancer. Head Neck Surg 8:920, 1985.
16. Schliephake H, Rüffert K, Schneller T: Prospective study of the
quality of life of cancer patients after intraoral tumor surgery. J
Oral Maxillofac Surg 54:664-669, 1996.
17. Spiro RH, Strong EW: Epidermoid carcinoma of the oral cavity
and oropharynx. Elective versus therapeutic radical neck dissection as treatment. Arch Surg 107:383-384, 1973.
18. Silver CE, Moisa II: Elective treatment of the neck in cancer of
the oral tongue. Semin Surg Oncol 7:14-19, 1991.
•
•
•
•
•
of the floor of the mouth plus reconstruction with a
split-thickness skin graft results in excellent survival
and normal or nearly normal speech and
articulation.
Successful healing of the skin graft depends on
proper thickness of the skin graft, meticulous
hemostasis, and immobilization of the graft by
proper suturing and application of the gauze bolus.
Despite advances in imaging modalities, palpation
of the mandible is the most accurate method of
determining whether cancer of the floor of the
mouth has infiltrated into the mandible.
It is not necessary to reconstruct submandibular
salivary ducts because these glands may be removed
during selective neck dissection.
Extensive infiltration of the floor of the mouth and
tongue may require total glossectomy with excision
of the floor of the mouth. If this seems likely from
clinical evaluation and imaging studies, the patient
should be counseled accordingly.
The quality of life of patients with extensive cancer
of the floor of the mouth can be maximized with
the use of free flap reconstruction and early
intervention by a speech pathologist experienced in
swallowing therapy for head and neck cancer
patients.
PITFALLS
• Thorough clinical evaluation and imaging studies are
necessary to determine the depth of infiltration in
squamous cell carcinoma of the floor of mouth so
that the proper surgical procedure can be planned.
Performing too large a procedure for a limited
cancer is almost as bad as performing too small a
procedure for a deeply infiltrative cancer.
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19. Dias FL, Kligerman J, Matos de Sá G, et al: Elective neck dissection versus observation in stage I squamous cell carcinomas of the
tongue and floor of the mouth. Otolaryngol Head Neck Surg
125:23-29, 2001.
20. Medina JE: A rational classification of neck dissections. Otolaryngol Head Neck Surg 100:169-176, 1989.
21. Rodgers LW Jr, Stringer SP, Mendenhall WM, et al: Management
of squamous cell carcinoma of the floor of mouth. Head Neck
15:16-19, 1993.
22. Schramm VL, Myers EN, Sigler BA: Surgical management of early
epidermoid carcinoma of the anterior floor of the mouth. Laryngoscope 90:207-215, 1980.
23. Brown B, Barnes L, Mazariegos J, et al: Prognostic factors in
mobile tongue and floor of mouth carcinoma. Cancer 64:11951202, 1989.
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253
24. Schramm VL, Myers EN: Skin grafts in oral cavity reconstruction.
Arch Otolaryngol Head Neck Surg 106:528-531, 1980.
25. Maurer P, Eckert AW, Schubert J: Functional rehabilitation following resection of the floor of the mouth: The nasolabial flap
revisited. J Craniomaxillofac Surg 30:369-372, 2002.
26. Lopez R, Dekeister C, Sleiman Z, Paoli JR: The temporal fasciocutaneous island flap for oncologic oral and facial reconstruction. J Oral Maxillofac Surg 61:1150-1155, 2003.
27. Zhao YF, Zhang WF, Zhao JH: Reconstruction of intraoral defects
after cancer surgery using cervical pedicle flaps. J Oral Maxillofac
Surg 59:1142-1146, 2001.
28. Wolff KD, Hölze F, Nolte D: Perforator flaps from the lateral
lower leg for intraoral reconstruction. Plast Reconstr Surg
113:107-113, 2004.
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