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318
CHAP TER11 The upper jaw and midface
Common presentations
Some common problems in the upper jaw/ midface:
• Infections
• Injuries
• Numbness
• Pain
• Paralysis
• Swellings/ lump.
Although the term ‘midface’ refers to those structures situated between
the skull base and the occlusal plane, for the purposes of this chapter, the
nose and naso- orbitoethmoid (NOE) region, and the cheek s and orbits
are excluded as they are covered elsewhere (see E Chapters7 and 9,
respectively). Inevitably, however, there is some overlap between injuries and pathologies in all these regions, including theteeth.
Common problems and theircauses
Infections
Common
• Odontogenic (dental) infections
• Parotitis
• Sinusitis.
Uncommon
• Osteomyelitis.
Injuries
Common
• Dentoalveolar
• Soft tissue bruising/ lacerations.
Uncommon
• Le Fort fractures
• Craniofacial/ panfacial fractures.
Numbness
Common
• Idiopathic
• Iatrogenic (following dental treatment)
• Post- trigeminal neuralgia
• Viral trigeminal neuropathy.
COMMON PROBLEMS AND THEIRCAUSES
Uncommon
• Demyelinating diseases
• Tumours (sinus, intr acranial, skull base, nerve sheath)
• Sinus pathology (including large odontogeniccysts)
• AVM
• Hypothyroidism
• Peripheral neuropathy.
Pain
Common
• At ypical facialpain
• Trau m a
• Infected tooth/ dental cyst/ sinusitis/ parotitis
• Trigeminal neuralgia.
Uncommon
• Atypical odontalgia
• Tumours— sinus/ parotid/ nose
• Herpeszoster
• Maxillary osteomyelitis
• Bisphosphonate- related osteonecrosis of the jaw (BRONJ).
Paralysis
Common
• Cerebrovascular accidents
• Bell’spalsy
• Trau m a
• Iatrogenic (following surgery)
• Temporal bone fracture.
Uncommon
• Cerebral tumours
• Acute/ chronic otitis media, other middle ear disease
• Ramsay Hunt syndrome
• Congenital or birthinjury
• Neoplastic (middle ear/ acoustic neuroma/ parotid malignancy)
• Parotid disease (tumours/ inltrative disease)
• Sarcoidosis
• MS
• Guillain– Barré syndrome.
319
Swellings/ lump
Common
• Odontogenic (dental) cysts/ tumours
• Parotidtumour
• Post traumatic.
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CHAP TER11 The upper jaw and midface
Uncommon
• Osteomyelitis
• BRONJ
• Fibrous dysplasia
• Extramedullary haematopoiesis
• Paget’s disease
• Metastases/ myeloma/ lymphoma.
Useful questions and what
tolookfor
Infections
Askabout
• Onset and duration
• Recent injuries, dental infections or treatment
• Pain, erythema, and swelling
• Changes inbite
• Systemic symptoms
• Medical history/ medicationstaken.
Lookfor
• Site and extension
• Skin erythema and swelling
• Systemic involvement (pyrexia, sweating, lethargy)
• Numbness of thecheek
• Intraoral/ dental examination.
Injuries
Askabout
• Mechanism ofinjury
• Loss of consciousness
• Any other injur ies
• Lost/ looseteeth
• Change inbite
• Numbness of the cheek or change in vision/ diplopia
• Alcohol or medicationstaken.
Lookfor
• Assess GCS/ C- spine
• CSFleaks
• Assess visual acuit y/ eye movements
• Lacerations or foreignbodies
• Assess bones of orbit, maxilla, forehead, and mandible
• Intercanthal distance>40mm
• Numbness ofcheek.
USEF UL QU ESTI ONS AND WHAT TO LOOKFOR
Numbness
Askabout
• Onset/ duration
• Recent injury/ dental treatment
• Pain/ swelling
• Denesite
• Other neurological symptoms.
Lookfor
• Cranial nerve decits
• Facial asymmetry/ swellings
• Intraoral masses/ upper dental pathology
• Peripheral neuropathy.
Pain
Askabout
• Onset / duration/ type ofpain
• Recent injury/ dental treatment
• Swelling/ deformity
• Denesite
• Other neurological symptoms
• Any other symptoms.
Lookfor
• Cranial nerve decits
• Intraoral masses/ upper dental pathology
• Infections/ tumours/ exposed bone (intraorally).
Paralysis
Askabout
• Onset/ duration
• Previous episodes
• Recent treatments
• Painful vs painless
• Otalgia/ discharge/ aural fullness/ loss of hearing/ dizziness
• Other neurological symptoms.
Lookfor
• Cranial nerve decits
• Peripheral neurological decits
• Parotid lumps/ swelling
• Examine the ear (including vesicle formation)
• Determine extent of weakness.
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CHAP TER11 The upper jaw and midface
Swellings/ lump
Askabout
• Onset/ duration/ progression
• Single episode or recurrent
• Recent dental infections or treatments
• Painful/ painless
• Change in bite/ nasal obstruction/ discharge
• Systemic symptoms.
Lookfor
• Assess lump/ swelling
• Relevant cranial nerve decit
• Intraoral masses/ upper dental pathology
• Infections/ tumours/ exposed bone (intraorally)
• Systemic involvement (pyrexia/ malaise).
Examination ofthe upper jaw
(and midface)
Applied anatomy
Although the term ‘midface’ refers to those structures situated between
the skull base and the occlusal plane, for the purposes of this chapter, the
nose, NOE, cheeks, and or bits are excluded. Inevitably, however, there
is some overlap between injuries and pathologies in all these regions,
including theteeth.
Unlike the mandible (the lower jaw), the upper jaw is not a single bone,
but a complex structure composed of a number of dierentbones:
• maxillae
• palatinebones
• the pter ygoid plates of the sphenoid.
It support s the upper teeth. The remainder of the midface is madeupof:
• inferior conchae
• ethmoidvomer
• lacrimalbones
• zygomatic processes of the temporalbones
• zygomas
• nasalbones.
The two maxillary bones are joined in the midline. They support the
teeth and along with the palatine bones separate the mouth from the
nose. Not surprisingly therefore, pathology in one region can cause
symptoms in the other. The maxillary bones also make up part of the
lateral wall of the nasal cavit y, contain the ma xillary sinus (antrum), and
make up part of the infraorbital rim and orbital oor. High- energy frac-
tures can therefore propagate between these dierent sites. Tumours and
infections in any one of these cavities can also extend into another.
The overall arrangement of all these bones, together with the presence of the sinuses, essentially converts the midface into a series of
EX AMIN ATION OF THE UPPER JAW (AND MI DFACE)
vertical bony struts, known as ‘buttresses’. These pass upwards from
the teeth and attach to the skull base. Three pairs of buttresses act as
‘pillars’, supporting the load of any vertically applied force (i.e. during
biting). Theseare:
• Anterior— which form the piriform fossa lateral to the nose, passing
into the frontonasal process.
• Middle — which is formed by the buttress of the z ygoma passing
between the maxilla inferiorly and the frontal boneabove.
• Posterior— which is made up by the pterygoid plates att aching the
maxilla to the base ofskull.
Between these buttresses lie the sinuses, eyes, and part of the upper
respiratory tract. They are joined together by wafer- thin bone, to which
the sof t tissues of the face are attached. Consequently, the face has
evolved into a structure that is very good at resisting ver tically directed
forces (i.e. chewing). However, there are very few strong horizontally
directed buttresses and the face is therefore not as good at resisting horizontally directed forces (i.e. a signicant vector in most trauma). It has
been argued that the function of the sinuses is to eectively convert the
face into a ‘crumple zone’, thereby absorbing kinetic energy and protecting the brain from injur y (much like the chassis of a car protects the driver
by crumpling). Physiologically, Wol’s law would have also contributed
to their development. This arrangement denes the three- dimensional
shape of theface.
Because the mid- facial skeleton sits on the inclined skull base (at
45 degrees to the hor izontal plane), severe injuries can result in the
bones collapsing along this plane, in a downwards and backwards direction. Clinically this result s in an elongated face and a deranged bite where
the back teeth meet prematurely (anter ior open bite). In severe cases,
there may be signicant swelling, severe bleeding, and airway compromise (particularly in the supine patient).
Embedded in the lower par t of the maxilla are the roots of the upper
teeth. Not surprising therefore, disease in one can aect the other (not ably dental infections and sinusitis).
Examination
Examination of the upper jaw is really just one aspect of the examination of
the face. It also includes examination of the oral cavity (se e E Chapter 13).
The entire face should be inspected from the front and the side of the
patient. It should also be viewed from above, look ing down over the brow.
If there is any orbital involvement, early assessment of the eye is essential— its
management initially takes priority.
Swellings should be examined both externally and intraorally. Cysts
related to the teeth are a common cause of swelling in the upper jaw.
Be careful during your palpation, some cysts are covered only by a thin
layer of bone and may deceptively feel like sof t tissue cysts, rather than
cyst s arising within the bone. Always request imaging (usually an OP T).
Even if a c yst is palpable externally, it may also be expanding internally. It may therefore be palpable within the mouth, either in the upper
sulcus (between the soft tissues of the cheeks and teeth) or expanding into the palate (within the oral cavity). The teeth themselves will
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CHAP TER11 The upper jaw and midface
need to be assessed and this aspect of the examination is described
in E Chapter 13). Some cysts/ tumours may also bulge into the
nasal cavit y, which itself may also require careful examination (see
E Chapter 7).
Examination followinginjury
Specically following injur y, the ‘level’ of any midface fracture (usually
classied using the ‘Le Fort’ classication) can in theory be determined
by detailed clinical examination. However, in practice, ‘pure’ fractures
are uncommon. Other fractures of the facial skeleton are often present. The clinical picture can therefore be a little uncertain. This is not
a major concern nowadays, since such high- energy injuries usually
require CT evaluation, which will ultimately dene the fracture pattern.
Never theless, a thorough examination is still required, not so much to
decide which level the fracture is, but to assess for associated problems.
For the inexperienced, a simplied ‘check list’ can be useful. This list is
applicable to all injuries to the midface, not just the upperjaw.
Abnormal mobility of the midface can be detected by grasping the
anterior maxillar y bone and gently rocking the upper jaw. At the same
time the other hand palpates the sites commonly known to fr acture
(nasal bridge, inferior orbital margins, or frontozygomatic sutures). Care
is required if the neck has not been ‘cleared,’ and if concerns exist about
the neck this part of the examination is best defer red. Alternatively, the
head must be fully suppor ted:
• If the teeth and palate move but the nasal bones are stable, a Le Fort
Ifracture is present (or it is a denture!).
• If the teeth, palate, and nasal bones move but the lateral orbital rims
are stable, it is a Le Fort II fracture.
• If the whole midface feels unstable, it is probably a Le Fort III or some
other complex fracture pattern.
Splitpalate
This is an important par t of the examination following an injury to the
upper jaw, yet something that can easily be overlooked. Midline or segmental splits of the palate occur following high- energ y impacts and are
often associated with widespread fractures of the midface. They rarely
occur in isolation. If the palatal fragments are separated laterally they can
sometimes act as a wedge, displacing the zygomatic buttresses laterally
as well. If this is not recognized during repair, the bones may be plated in
the wrong position. Clues to a split palate include palatal bruising in the
region of the greater palatine vessels (Guerin’s sign), palatal mobility, or the
patient having diculty getting their teeth together normally.
Clinical examination of the midface following injuries
• General features:
•
ATL S®/ ABCs, notably progressive facial swelling, active bleeding,
and cer vical spine injuries
• Neurosurgical:
•
GCS
•
CSF rhinorrhoea/ otorrhoea (cranial fossa fractures).
•
Complications of CSF leaks (meningitis or aerocoele)
INVESTIGATIONS
• Ophthalmic:
•
Visual acuity, signs of globe injury, pupil reaction tolight
•
Enophthalmos/ ocular dystopia
•
Diplopia
• Maxillofacial:
•
Abnormal mobility of the midface
•
Posterior oropharyngeal collapse
•
Anterior openbite
•
Apparent trismus— premature contacts in the molarregion
•
Lengthening of the midface
•
Is the palatesplit?
•
‘Dishfaced’ deformity
•
Crepitus.
Investigations
Laborator ytests
A FBC with dierential is usually required for any infective, inammatory,
systemic, or neoplastic pathologies.
Plainlms
Occipitomental (OM) views may provide some useful information in
the assessment of swellings and injuries. Similarly an OPT often includes
much of the upper jaw and is a useful ‘rst- line’ investigation. These will
identify most cysts and bony tumours in the upperjaw.
Patients with suspected midface fr actures and those with large c ysts
should ideally undergo CT scanning. ACXR and soft tissue views of the
neck may be required if teeth are missing and cannot be accounted for.
Specialized periapical and upper occlusal views are useful in the assessment of dentoalveolar fractures.
CT/ M RI
Although CT is undoubtedly more accurate in dening facial fractures,
its true value in the early stages of assessment is in determining the presence of ‘deep’ or occult injuries (those that may not be apparent on clinical examination):
• Cervical spine injuries
• Skull base fractures/ intracranial air (CSFleaks)
• Skull base fractures around va scular foramina (not ably carotidtears)
• Globe rupture/ vitreous haemorrhage
• Orbital apex fractures/ optic nerve compression.
Patients may be neurologically impaired, very swollen, or already intubated and clinical examination can therefore be dicult and unreliable.
CT helps overcome some of these limitations. Disimpaction and manipulation of midface fractures can also potentially manipulate deep, mobile
fragment s around the skull base and optic nerve. Only with CT will
these fractures be conrmed (or excluded) and the risks of manipulation
recognized.
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CHAP TER11 The upper jaw and midface
CT is also essential in the assessment of suspected cyst , tumours,
and some spreading infections. Some cysts can be surprisingly larger
than expected on clinical examination, and present with relatively few
symptoms.
MRI may also be of value in the assessment of the associated soft tissues. It is commonly used in the assessment of patients presenting with
facial pain and palsy. Although uncommon, skull base tumour s and demyelinating conditions can present with either of these symptoms and must
be therefore excluded before the patient is diagnosed with ‘atypical’
facial pain/ Bell’spalsy.
Ultrasound
This may help in the assessment of the associated soft tissues, but it provides less information than a MRI or CT. However, it will distinguish an
abscess from a tumour in mostcases.
cFractures tothe upper jaw
and midface
Fractures of the midface tend to result from high- energy impacts and can
therefore be both life - threatening as well as disguring. But not all do.
Patients may also walk into an emergency depar tment with these injuries
even if they are signicant.
Upper jaw and midface fractures overlap somewhat and may also
include dentoalveolar fractures. Conventionally fractures to the upper
jaw and midface are referred to as Le Fort frac tures, although in reality
injuries are often more widespread. With higher- energy impacts there
may also be fractures of the nose, NOE region, and zygoma. Fr actures
may also extend upwards, into the anterior cr anial fossa. From a practical point of view injuries in this site can be consideredas:
• Dentoalveolar fractures
• Le Fort fractures
• Extended fractures.
cDentoalveolar fractures
These can occur in both the upper and lower jaw. Injuries to the teeth
themselves are discussed in E Chapter 13. Dentoalveolar fractures are
dened as fr actures to the teeth and their supporting bone (‘alveolar
bone’) (see Figure11.1).
The involved teeth may also have fractures of the crown or root, or
may be loosened or avulsed. Clinical signs include intraor al bleeding,
tooth malposition or mobility, a change in the patients bite and pain.
Dentoalveolar fractures should be regarded as open fractures. Any missing
teeth should be accounted for. Consider the possibility of an associated
fracture to the supporting jaw. Management includes appropriate imaging (OM/ OPT/ CT as indicated), antibiotics, tetanus prophylaxis (when
necessary), and reduction and support of the fractures. Refer urgently
to the patient’s own dentist, dent al school, or maxillofacial department
(depending on local circumstances).
FRAC TURES TO THE UPPER JAW AND MIDFACE
Figure11.1 Signicant dent oalveolar t rauma wit h loss of t eeth , ging ival t ears,
and damage to t he sup por tingb ones .
Splinting the teeth is usually the treatment of choice, although ver y
occasionally lar ge dentoalveolar fractures may be plated. Many types of
splint are available. Since the bone is fractured splinting may be required
for around 4 – 6 weeks. During this time the patient should eat soft
foods, avoid biting on the splinted teeth, and keep the mouth as clean
as possible.
Consider antibiotics and tetanus prophylaxis in patients with accompanying
signicant soft tissue injuries. Mucosal tears should be repaired to cover any
exposedbone.
cLe Fort fractures
The levels described in this classication refer to the level of the frac ture
in relation to the skull base (see Figure 11.2). Often these fractures occur
in various combinations.
Le Fort I(‘low level’)
The fracture is or ient ated horizontally at a level just above the nasal
oor, passing around from the piriform aperture, above the alveolar
(tooth suppor ting) bone, to below the z ygomatic buttress. It passes
along the lower third of the nasal septum and lateral walls of the nose
to join the lateral aspects of the fracture across the lower third of the
pter ygoid plates. This is essentially the tooth baring part of the midface
(think of a denture).
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