IN THE NAME OF GOD

Frontal Sinus Fractures Cummings Otolaryngology 2015 CHAPTER 23 – Maxillofacial Trauma Dr .Akhtar Kavan

Introduction The term maxillofacial trauma is generally used to refer to the injuries of the facial skeleton Craniomaxillofacial trauma might be a better term because the anterior wall and floor of the anterior cranial fossa are included in these injuries management of these injuries is sometimes thought of as “facial orthopedics.”

Embryology Absent at birth Doesn’t begin development until about 2 years Radiographically evident at about 8 years Adults size at about 12 years ; but pneumatization continues slowly until 40 years Consists of one or more compartments Irregular shapes & asymmetric

Embryology Lined by respiratory epithelium Intimate relation with cranial fossa Volume approx 5 - 15 mls Ant. wall thickers / stronger than post. wall Dura adheres to deep surface of post. table Mucosal lining continous with ethmoidal air cells & Nasofrontal ducts

Embryology Foramina of Breschet = venous drainage of mucosa are site of potential intracranial spread of infection Mucosa deeply invaginates foramina

Anatomical Variation 10 % unilateral 5 % rudimentary 4 % absent 20 % of people “abnormal frontal sinus anatomy

Nasofrontal Duct Drains frontal sinus Located posteromedial floor of sinus Very variable course True duct is absent in 85% people - FS drains indirectly via ethmoidal air cells to middle meatus

Anatomy The face can be divided into 3 sections the frontal bones are generally considered the upper third of the face The maxillae, zygomas, and orbits comprise the middle third, or midface, which may include the nose The mandible is considered the lower third

Physiology Upper Third Displaced fractures of Frontal bone can create various deformities, the most common of which is a central forehead depression (Fig. 1).

Pathophysiology Frontal bone fractures may involve only the anterior sinus walls, in which case the fractures are significant only for sinus function and cosmesis or they may involve the posterior wall of the sinus or extend beyond the sinus, in which case they are true skull fractures and become neurosurgical concerns as well

Pathophysiology The supraorbital rims and roofs are also part of the frontal bones, which are therefore also related to the orbits, and fractures can thus affect orbital and ocular functions. This thick glabellar bone protects the underlying frontal outflow tracts and the cribriform plates, which house the branches of the olfactory nerves

Pathophysiology The supraorbital and supratrochlear nerves pass through notches or foramina in the supraorbital rims and can be injured from trauma or, more commonly, from surgical manipulation.

Evaluation and Diagnosis Physical Examination performing a good physical examination. the initial assessment must address the ABCs and any other potentially life-threatening injuries

Evaluation and Diagnosis In the upper third of the face, the forehead is evaluated for sensation and motor function. In some cases, fractures may be visible as depressions (see Fig.1) or palpable as step-offs, although typically these fractures are more readily seen on CT scans.

Radiographic Evaluation With some exceptions, the CT scan has replaced other forms of radiographic imaging for the assessment of craniomaxillofacial injuries. The exception here is for simple nasal fractures (simple meaning without evidence of involvement of other facial bones)

Radiographic Evaluation For frontal fractures, a high-resolution axial CT gives good information about the anterior and posterior walls When the posterior wall is displaced (regardless of the degree of displacement), and there is soft tissue density within the sinus, the inside of the sinus be visualized

Associated injuries Neurological Closed head injury Pneumocephalus Cerebral contusions Hematomas Open brain

Associated injuries Ophthalmological - Up to 25 % Full ophthalmological examination mandatory

Associated injuries Maxillofacial injuries - NOE - ZMC - Le Fort fractures - Panfacial fractures

Classification Schema Many classification system Can get very detailed classification ; However not useful clinically most useful classification, which predicts the likelihood of disruption of the frontal sinus drainage passages, was presented by Stanley and Becker.

Classification Schema They separated frontal sinus fractures into linear horizontal and linear vertical and comminuted anterior and posterior walls, with and without NEC or supraorbital rim fractures

Clincal Classification Anterior Table - Displassed - un -displaced Posterior Table - Displaced - Un- displaced

Clincal Classification Anterior & Posterior Table - Displaced - Un - displaced Nasofrontal duct - Involved - Un involved

Simplified Clinical Classification 1- Fracture of anterior table 2- Fracture with disruption of posterior wall 3- Fracture involving floor of sinus

Management General Antibiotic treatment should be initiated at the time the patient initially presents Typically, antibiotics that cover oral organisms such as penicillins, cephalosporins, or clindamycin are selected

Management Many surgeons have suggested that surgery should be delayed until swelling resolves Certainly, logic seems to suggest that early intervention to restore the hard and soft tissues to their normal anatomic positions would be beneficial

Surgical Access There is also an additional challenge in craniomaxillofacial surgery, which is the inability to make incisions directly over most fractures, because unacceptable scars and facial nerve injuries would result

Surgical Access Coronal flap preferable Generally avoid using laceration or local incisions Avoid “ Gull Wing “ & “ Open Sky “ approaches In the patient with hair, irregularizing the incision with a running W or a wavy line

Surgical Access Shaving the hair is not required When full exposure of the zygomas is required, the incision begins in the preauricular crease When zygomatic exposure is not needed, the incision starts above the auricle When a long pericranial flap is needed , the incision should not violate the pericranium

Surgical Access As the flap is elevated anteriorly, care must be used to avoid injury to the temporal (frontalis) branches of the facial nerve The supraorbital and supratrochlear nerves are encountered as the flap is elevated to the supraorbital rims.

Biomechanics of the Facial Skeleton In the upper third, the anterior wall of the frontal sinus is thin and there are no significant forces acting on this area. The supraorbital rims and the frontal bones lateral and superior to the frontal sinuses are thicker , It requires more force to fracture these bones

Surgical Management Cranialization Vs Oblitration

Oblitration Frontonasal ducts oblitrated , Mucosal lining removed And sinus “ packed “ Various materials advocated : -Fat -Muscle -Bone -Hydroxyapatite

Fracture Repair Most repairs are performed using titanium plates and screws a variety of absorbable plates and screws are used as well there is no contraindication to the use of stainless steel wires when needed

Fracture Repair A number of algorithms have been published The key issues in frontal sinus trauma relate to two fundamental questions: (1) Is exploration necessary? (2) Is obliteration necessary?

Fracture Repair Keep in mind the purposes of the bone being repaired The sinus outflow tracts must function to drain the sinuses Thus pure anterior wall fractures that do not extend into the nasofrontal ducts are repaired for cosmetic purposes only.

Fracture Repair These should be explored if they are significantly depressed, because even in the absence of acute deformity, they are likely to lead to deformities when the swelling resolves. The smallest plates available are generally used, because there are little or no force Use of the endoscope may allow repair of selected anterior wall fractures with minimal incisions

Fracture Repair When the ducts are involved but the posterior wall is intact, judgment allows more than one option 1- Frontal sinus obliteration is always acceptable 2-Allow the sinus to function to see what happens

Fracture Repair A nondisplaced posterior wall fracture can be observed if the posterior wall is displaced, it is difficult to determine the status of the dura and underlying brain In the absence of apparent ductal injury, it is still wise to consider trephination and transcutaneous endoscopy

Fracture Repair In the absence of posterior wall displacement and with no soft tissue abnormalities associated with such a nondisplaced fracture, it is unclear that obliteration is mandatory Careful follow-up including interval CT scans will demonstrate whether or not aeration of the sinus ensues

Fracture Repair Numerous complications have been encountered using hydroxyapatite cements but in one series using it in combination with live pericranial flaps, no complications were seen they can be used to repair the frontal contour in the presence of severe comminution and/or bone loss of the anterior wall

Cranialization Frontal craniotomy Dural repair Removal of posterior wall Removal of mucosal lining Plugging of nasofrontal ducts Galeal flap placed

CSF Rhinorrhea CSF rhinorrhea is not rare and may occur via the frontal sinuses, or through the cribriform plate, ethmoid sinuses, and/or sphenoid sinuses Large defects should be repaired at the time of facial fracture repair. Small defects should be identified endoscopically and can usually be repaired using this approach

Skull Base Disruption Prophylactic Antibiotics Incidence of meningitis between 3-50% Mortality about 10% Usually pneumococcus spp. Prophylactic Antibiotics not recommended

CSF leak Fracture reduction often stops leak Most traumatic leaks close spontaneously Leak more than 72 h.= lumbar drain Surgical repair -Endoscopic -Intracranial

Skull Base Disruption The use of the Transglabellar Subcranial Approach may allow for earlier intervention It also allows direct visualization of the cribriform area without disarticulating it completely