10 Facial Trauma Flashcards
1
Q
1 What is the first step in treating every trauma patient?
A
Ensure the patient has a safe and adequate airway (airway, breathing, circulation, or ABCs)
2
Q
2 List the contraindications to cricothyrotomy.
A
- Cricotracheal separation
- Laryngeal fracture
- Young age.
Children younger than 5 to 12 years of age should have needle cricothyrotomy or primary tracheostomy because of anatomical differences.
3
Q
3 Describe the Glasgow Coma Scale (GCS) score scoring system. (▶ Table 10.1)
A
The GCS maximum score is 15, and the minimum score is 3. The GCS is based on the cumulative score from three categories: eye opening, verbal responses, and motor responses.
4
Q
4 What measure is a good indicator of the resuscitation status of a trauma patient with significant blood loss?
A
Urine output
5
Q
5 Based on the physiology of a 70-kg man, roughly how much blood loss must occur before hypo tension results?
A
1.5 to 2 L
6
Q
6 In an adult patient who is unsure of his or her vaccination history, what tetanus prophylaxis should be provided after a deep cut to the hand with a rusty knife? (▶ Table 10.2)
A
Tetanus-diphtheria and tetanus immune globulin
7
Q
7 What radiographic examination is most helpful in evaluating maxillofacial trauma?
A
- CT face fine cuts (1 to 3 mm)
- CT brain and neck if concern for intracranial or neck/laryngeal injury
8
Q
8 List the bacteria commonly present in dog bites.
A
Pasteurella multocida, Staphylococcus aureus, Streptococcus viridans, and oral anaerobes
9
Q
9 As a general rule, how long after initial injury can simple lacerations be closed?
A
Up to 3 days
10
Q
10 What are the benefits of applying a negative pressure wound VAC to a partial avulsion injury?
A
- Decrease bacterial counts
- Promote granulation tissue formation
- Improve the rate of contracture
11
Q
11 Cleaning soft tissue injuries with hydrogen per oxide, modified Dakin’s solution, or povidone iodine has been shown (in vitro) to be toxic to what cell types?
A
Fibroblasts and keratinocytes
12
Q
12 Pigmented debris left in a wound bed may lead to what complication?
A
Traumatic tattooing
13
Q
13 What is the mechanism of a pincushion (trapdoor) deformity after soft tissue trauma?
A
- When elevated or redundant tissue abuts a curvilinear shaped scar
- Most likely results from concentric wound contracture and lymphedema
14
Q
14 Why should eyebrows be trimmed conservatively (not shaved) when treating patients with extensive facial trauma?
A
Regrowth of eyebrow hair may take as long as 6 months, and hair regrowth may be incomplete.
15
Q
15 What suture technique is best for everting skin edges when closing a soft tissue laceration?
A
Vertical mattress
16
Q
16 As a general rule, what suture type should be used to close the epidermis of young pediatric patients?
A
Absorbable suture is used because permanent suture will be difficult to remove in the office setting.
17
Q
17 Which wound adhesive is approved by the Food and Drug Administration (FDA) for closure of skin?
A
Octyl-2-cyanoacrylate (Dermabond)
18
Q
18 What is the mechanism of action of the tissue adhesive octyl-2-cyanoacrylate?
A
On exposure to moisture, octyl-2-cyanoacrylate undergoes an exothermic reaction as it polymerizes to form a strong tissue bond.
19
Q
19 How does the location of a facial laceration influence whether or not wound exploration should be carried out for facial nerve neuror rhaphy?
A
Because of the extensive distal arborization of the facial nerve, injuries medial to the lateral canthus are unlikely to result in significant facial nerve deficits and generally do not warrant wound exploration.
20
Q
20 What is the preferred management of a trau matically avulsed segment of the proximal extra temporal facial nerve?
A
Mobilization with primary (end-to-end) neurorrhaphy is preferred. If a tension-free anastomosis cannot be obtained, then an interposition cable graft using greater auricular nerve or sural nerve should be used.
21
Q
21 What treatment options can be used to decrease the risk of sialocele after traumatic parotid duct transection?
A
Options include primary anastomosis over a stent, duct ligation, or fistulization of the duct into the oral cavity.
22
Q
22 What length of the lower lip can be managed with primary closure without significant distortion or microstomia?
A
Loss of up to one-third, or even one-half, of the lower lip can be managed with primary closure without significant distortion or resultant microstomia.
23
Q
23 How much of the eyelid can be closed primarily after an avulsion injury?
A
25%
24
Q
24 What must be done to the avulsed segment of the auricle before its burial in a postauricular pocket for delayed reconstruction?
A
De-epithelialization of the avulsed segment
25
25 What antibiotic class should be used for injuries involving cartilage?
Fluoroquinolones should be used in adult and adolescent patients to adequately cover Pseudomonas aeruginosa. Fluoroquinolones represent the only oral antibiotic class with reliable activity against Pseudomonas spp. Parenteral anti-psuedomonal cephalosporins (ceftazidime and cefe pime) should be used in children if perichondritis or chondritis is suspected.
26
26 What is the definition of a first-degree burn?
Damage no deeper than the epidermis, resulting in pain and erythema, but little or no permanent injury
27
27 What is the definition of a second-degree burn?
Injury involves the epidermis and a portion of the dermis (partial thickness) and is accompanied by pain, erythema, and blistering. The depth of dermal injury is used to further stratify second-degree burns as being either superficial or deep.
28
28 What is the definition of a third-degree burn?
Injury involves the epidermis and the full thickness of the dermis, destroying adnexal structures, blood vessels, and nerve endings.
29
29 The head and neck make up what percentage of the total body surface area (TBSA)?
9% The “rule of nines” for calculating TBSA: ● Each leg = 18% TBSA ● Each arm = 9% TBSA ● Anterior trunk = 18% TBSA ● Posterior trunk = 18% TBSA ● Head and neck = 9% TBSA
30
30 What is the Parkland formula for fluid resuscitation of burn victims?
Total volume is administered in the first 24 hours of resuscitation (with lactated Ringer's solution) = 4 mL x weight (kg) x %TBSA burned. Half of the calculated volume is given over the first 8 hours, and the remaining volume is delivered at an even rate over the next 16 hours.
31
31 In addition to IV antibiotics, why are topical antibiotics recommended to prevent superinfec tion in burn patients?
Burn eschar has a poor blood supply, decreasing the likelihood that therapeutic levels of systemically delivered antibiotic will penetrate the wound bed.
32
32 When should burns involving the oral commissure be reconstructed?
Most surgeons recommend initial observation with con servative wound care and waiting to surgically intervene only after full scar maturation.
33
33 What treatment should be considered for patients with oral commissure electrical burns to decrease the risk of microstomia?
Oral appliance use is designed to splint the oral commis sure.
34
34 The Battle sign refers to what physical examination finding?
Postauricular ecchymosis that suggests a basilar skull fracture
35
35 After a head trauma, the patient experiences massive hemorrhage from the ear canal with postauricular ecchymosis. What is the next step in this patient's treatment?
Pack the ear canal to control bleeding, and perform an arterial angiogram to examine for petrous carotid injury.
36
36 Subcutaneous emphysema that extends from the neck into the face travels in what plane?
Along the platysma and subcutaneous musculoaponeurotic system (SMAS)
37
37 Describe the anatomical boundaries of the three zones of the neck used for the evaluation and treatment of penetrating neck trauma. (▶ Fig. 10.1)
● Zone I: Clavicle and sternal notch to cricoid cartilage ● Zone II: Cricoid cartilage to angle of mandible ● Zone III: Angle of mandible to skull base
38
38 With penetrating injuries to zone I of the neck, what structures are at risk of damage?
Aortic arch, carotid and vertebral arteries, subclavian vessels, innominate vessels, lung apices, esophagus, tra chea, brachial plexus, recurrent laryngeal nerves, and thoracic duct are at risk.
39
39 With penetrating injuries to zone II of the neck, what structures are at risk of damage?
Common carotid artery with both internal and external branches, phrenic nerve, vagus nerve, hypoglossal nerve, internal jugular vein, larynx, hypopharynx, and proximal esophagus are at risk.
40
40 With penetrating injuries to zone III of the neck, what structures are at risk of damage?
Distal internal carotid artery, external carotid artery with major branches, vertebral artery, jugular vein with contribu ting venous drainage (retromandibular, facial, etc.), prever tebral venous plexus, parotid gland, and facial nerve are at risk.
41
41 Of the neck zones, which is the most surgically accessible?
Zone II
42
42 Describe the main factors that influence the injury incurred from ballistic strike.
Kinetic energy (KE) (velocity is more important than mass), design of projectile, composition of receiving tissue KE = (½) (mass) (velocity)2
43
43 What commonly used radiographic technique has been shown to reduce significantly the number of negative surgical neck explorations in penetrating neck trauma?
CT angiography
44
44 When performing esophagography in a patient with penetrating neck trauma, why is it important to use a water-soluble contrast agent?
Extravasation of barium into the mediastinum can cause mediastinitis and fibrosis. This risk is mitigated by the use of water-soluble contrast agents (Gastrografin). However, barium is less toxic to the lungs if it is aspirated.
45
45 In penetrating neck trauma, which structure, if it is not violated, significantly decreases the probability of aerodigestive or vascular injury?
Platysma
46
46 Review the signs of carotid vascular injury after penetrating neck trauma.
Hematoma/ecchymosis, hypovolemic shock, external hemorrhage, absent carotid pulse, carotid bruit or thrill, diminished ipsilateral radial pulse, contralateral hemipare sis, and altered mental status
47
47 Review the signs of aerodigestive injury in penetrating neck trauma.
Dysphagia, hoarseness, subcutaneous emphysema/crepi tus, hemoptysis, hematemesis, gas escape from neck wound, dyspnea, airway obstruction, and stridor
48
48 What are the indications for immediate surgical exploration after penetrating neck injury?
An unstable patient with significant hemorrhage, expand ing hematoma, nonexpanding hematoma with hemody namic instability, hemomediastinum, hemothorax, airway decompensation
49
49 What are common findings in blunt laryngeal trauma?
Subcutaneous emphysema, dysphagia, dysphonia, dyspnea, stridor, hemoptysis, neck swelling
50
50 Describe the Schaefer classification system of laryngeal injury.
● Group I: Minor endolaryngeal hematoma without de tectable fracture ● Group II: Edema, hematoma, minor mucosal disruption without exposed cartilage, nondisplaced fractures ● Group III: Massive edema, mucosal disruption, exposed cartilage, vocal fold immobility, displaced fracture ● Group IV: Group III with two or more fracture lines or massive trauma to laryngeal mucosa ● Group V: Complete laryngotracheal separation
51
51 List conservative therapies that should be consid ered when treating a patient with a laryngeal fracture.
Voice rest, humidified blow-by, steroids, antibiotics, anti reflux medications
52
52 Review the symptoms of laryngeal fracture.
Dysphonia, neck pain, odynophagia, dyspnea, dysphagia
53
53 Review the signs of laryngeal fracture.
Hemoptysis, neck tenderness, subcutaneous emphysema, anterior neck ecchymosis, laryngeal deviation, loss of laryngeal prominence, stridor
54
54 What is the most important imaging study for evaluating laryngeal trauma?
Fine-cut CT
55
55 Which age group tends to have the highest mortality after laryngeal trauma?
Patients older than 70 years of age
56
56 Describe the reasons why children rarely sustain laryngeal fractures.
Their larynx is situated higher in the neck and is therefore more protected by the mandible; cartilages are not ossified and therefore are more resistant to fracture.
57
57 Describe the mechanism of injury for laryngeal fractures.
Compression of the larynx between an intrusive object and the rigid cervical spine The degree of injury depends on the amount of compressive force and degree of cartilage ossification.
58
58 What is the preferred method of airway management for patients with advanced laryngeal trauma?
Awake tracheotomy in the operating room
59
59 List the potential pitfalls and complications asso ciated with endotracheal intubation in patients with laryngeal trauma.
Cervical spine injuries, laryngeal lacerations and hemor rhage, displaced laryngeal architecture, and cricotracheal separation
60
60 Describe the steps to repair advanced laryngeal fractures.
Secure the airway with awake tracheotomy, direct lar yngoscopy with rigid bronchoscopy, neck exploration, laryngotracheal/endolaryngeal repair, cartilage stabilization
61
61 How long are stents usually left in place after laryngeal fracture repair?
In general, 2 to 3 weeks
62
62 During an open laryngeal repair, a keel is useful in preventing what type of complication?
Anterior glottic web
63
63 What are the general treatment goals of facial reconstruction following trauma?
Restoration of form (facial height, facial width, and facial projection) and function (airway, occlusion, mastication)
64
64 What must fracture fixation accomplish to allow for direct (primary) bone healing?
Fixation must overcome natural forces acting across the fracture site that would lead to mechanical instability and poor apposition of the fractured segments.
65
65 Name the two major types of plating materials.
● Metal ● Resorbable
66
66 What material is most commonly used in metal plating systems?
Titanium alloy
67
67 How do the various trauma plate types differ?
● Alloy composition ● Plate hole size ● Screw head type
68
68 What is the importance of bone fragment contact in fracture healing?
Bone contact allows direct (primary) bone healing to occur at a fracture site. Direct bone healing is a combination of “contact healing” and “gap healing” in which there is no formation of an intervening callus during repair. Indirect (secondary) bone healing results from mechanical instability and lack of close apposition of bone segments at a fracture site. Secondary healing requires callus formation for bone healing to occur.
69
69 The term miniplate refers to what plate character istic?
Plate thickness of 1.3 mm or less
70
70 What characteristic does a locking plate possess?
As the screws are tightened into the plate, the screw heads "lock" to the plate, thus stabilizing the segments without the need to compress the bone to the plate and does not require perfect contour with the underlying bone.
71
71 What is the purpose of a compression plate?
It enhances interfragmentary compression by drawing bone fragments together by using eccentric drill/screw place ment. It should be noted that trends in fracture manage ment are moving away from using dynamic compression plates because of the higher complication rates secondary to greater technique sensitivity.
72
72 What is the primary disadvantage of conventional trauma plates?
They require precise contouring of the plate to the underlying bone. If there are gaps between the plate and bone segments, tightening the screws will pull the bone segments toward the plate, which can alter reduction.
73
73 What is the potential disadvantage of bicortical screw placement?
Damage of deeper structures including tooth roots and underlying neurovascular structures
74
74 What are the two basic types of fracture fixation?
● Load-bearing: Fixation that provides sufficient strength to bear the entire physiologic load applied to the bone during function ● Load-sharing: Fixation that relies on inherent bony buttressing on either side of the fracture line to share some of the load during physiologic function
75
75 When is load-bearing fixation necessary?
Fractures with missing fragments, comminuted fractures, and fractures with inadequate bone buttressing to allow for a load-sharing construct to be used (i.e., atrophic man dibular fractures)
76
76 When is load-sharing fixation used?
In simple linear fracture repair where two opposing bone fragments provide sufficient bony buttressing to allow for adequate sharing of the physiologic forces across the fracture site without leading to fracture dislocation
77
77 When applying a compression plate, what type of screw placement is required?
Eccentric drilling with the pilot hole away from the fracture site so that when the screws are tightened there is a vector that draws the bone fragments together
78
78 What are the two basic types of screws?
● Self-drilling: Possess a sharp tip and do not require a pilot hole. These screws require more force for initial place ment, so they are less ideal for comminuted or very dense bone. ● Self-tapping: Possess a blunt tip that requires an initial pilot hole. They do not require as much force for insertion as self-drilling screws.
79
79 What is an emergency screw?
An emergency screw is used when a standard screw strips (continues to turn and will not tighten). The shaft is fractions of a millimeter wider, increasing the chance of bone purchase in a hole that has previously stripped.
80
80 In general, what is the minimum number of screws that should be used on either side of a fracture fragment for load-sharing fixation?
At least two screws need to be used; however, three screws are desirable, particularly when using a single plate.
81
81 Define rigid fixation.
Any form of fixation that is strong enough to prevent interfragmentary motion across the fracture site when actively using the skeletal structure With true rigid fixation, direct (primary) bone healing occurs (i.e., without callus formation).
82
82 What are the goals of open reduction and internal rigid fixation?
● Accurate anatomical reduction ● Atraumatic operative technique preserving the viability of bone and soft tissue ● Rigid internal fixation that produces a mechanically stable skeletal unit allowing for early, active, and pain-free mobilization of the skeletal unit
83
83 Define nonrigid fixation.
Any form of fixation that permits interfragmentary move ment Healing occurs from indirect (secondary) bone healing, which occurs via formation of a subperiosteal callus.
84
84 Define Angle class I molar occlusion.
Mesiobuccal cusp of the maxillary first molar interdigitates with the mesiobuccal (central) groove of the mandibular first molar
85
85 Define the occlusal relationships of overjet and overbite.
● Overbite is the vertical distance that the incisal edges of the maxillary anterior teeth overlap the incisal edges of the mandibular anterior teeth in an inferosuperior direction. ● Overjet is the horizontal distance that the incisal edges of the anterior maxillary teeth project beyond the incisal edges of the mandibular anterior teeth in an anteropos terior direction.
86
86 Define crossbite.
Under normal occlusal relationships, the maxillary dentition should be located in a position more buccal than the mandibular counterparts. For the anterior teeth (incisiors and canines), the maxillary teeth should be more anterior than the mandibular teeth. For the posterior teeth (premolars and molars), the maxillary teeth should be more lateral than the mandibular teeth. A crossbite is when these occlusal relationships are reversed.
87
87 Sublingual ecchymosis at the floor of the mouth after trauma usually indicates what type of injury?
Mandibular fracture
88
88 What nerve provides sensory innervation to the mandible?
The inferior alveolar nerve, a branch of the mandibular division of the trigeminal nerve (V3)
89
89 Which cranial nerve (CN) innervates the muscles of mastication?
Trigeminal nerve (CN V3)
90
90 List the muscles that insert into the mandible and their respective functions.
The digastric muscles and the geniohyoid extert poster oinferior pull on the mandible. The masseters, medial pterygoids, and temporalis muscles elevate the mandible. The lateral pterygoids cause translation of the condylar processes of the mandible and facilitate mandibular open ing. The mylohyoid serves to elevate the tongue and floor of mouth and also has the ability to depress the mandible if the position of the hyoid is fixed.
91
91 Describe the embryologic development of the mandible
During the 4th week of embryologic development, the mandibular processes (first branchial arch derivatives) fuse in the midline. The mandibular processes then develop into the mandible and lower face.
92
92 What are the subsites of the mandible?
Symphysis, parasymphysis, body, alveolar process, angle, ramus, coronoid, and condyle
93
93 What are the two most common sites of mandibular fracture?
The mandibular condyle and the mandibular body
94
94 With respect to frequency, how common are mandible fractures compared with other facial trauma injuries?
Nasal fractures are most common, followed by mandible fractures. Mandible fractures are two to three times more common than midface fractures.
95
95 What constitutes a favorable or unfavorable fracture?
Fragments of the fracture are either pulled together (favorable) or apart (unfavorable) by the tension from the muscles of mastication.
96
96 Define the term horizontally unfavorable in the context of classifying mandibular fractures. (▶ Fig. 10.2)
A horizontally unfavorable fracture is one that is unable to resist the upward displacing forces on the mandible by the muscles of mastication when viewed in the horizontal plane. Muscles typically responsible for horizontally unfav orable fractures are the temporalis, masseter, and medial pterygoid.
97
97 Define the term vertically unfavorable in the context of classifying mandibular fractures.
A vertically unfavorable fracture is one that is unable to resist medial displacing forces on the mandible by the muscles of mastication when viewed in a vertical plane. Muscles typically responsible for vertically unfavorable fractures are the medial pterygoids, the spurahyoid muscles, and the digastric muscles.
98
98 Outline the dental classification for mandibular fractures.
● Class I: Teeth are present on both sides of the fracture line. ● Class II: Teeth are present on only one side of the fracture line. ● Class III: No teeth are in proximity of either side of the fracture line.
99
99 How would you manage a displaced fracture of the body of the mandible in a 5-year-old child?
Closed reduction with fixation using orthodontic splints
100
100 Review the complications associated with inter maxillary fixation (IMF) of mandible fractures.
Dental injury, periodontal injury, potential for airway compromise, weight loss or malnutrition
101
101 List the contraindications to IMF.
Alcoholism, epilepsy, mental retardation, nutritional defi ciency, advanced respiratory disease, psychosis, pregnancy, noncompliant patient
102
102 List the disadvantages of closed reduction repair of mandible fractures.
Fractures lines are not rigidly fixed, which leads to indirect (secondary) bone healing. Prolonged IMF may result in temporomandibular joint (TMJ) ankylosis, and IMF fixation renders oral hygiene and adequate oral intake difficult.
103
103 What are the primary reasons for pursuing early (within 24 to 36 hours) repair of mandible fractures?
Earlier return to function and to manage pain
104
104 Which mandible fracture has the highest incidence of infection?
Mandibular angle fractures
105
105 Review the primary indications for open reduction of mandible fractures.
● Unfavorable or unstable fractures ● Concurrent comminuted facial fractures ● Edentulous mandible with severe displacement ● Delayed treatment with interposing soft tissue that prevents adequate closed reduction ● Patients with contraindications to IMF
106
106 Describe the Champy technique of mandible fracture repair. (▶ Fig. 10.3)
Use of miniplate fixation in simple fractures along the ideal lines of osteosynthesis to form load-sharing or semi-rigid fixation constructs
107
107 How should a lag screw be placed relative to a mandibular fracture?
Always place the lag screw perpendicular to the line of fracture to prevent fragments from overriding and dis placement.
108
108 Review the indications for external pin-fixation repair of mandible fractures.
● Severely comminuted fractures ● Pathological fractures ● Grossly infected fracture sites or fractures with a high propensity for future infection (e.g., gunshot wounds) ● Comminuted edentulous mandible fractures
109
109 Name the complications associated with open reduction internal fixation of mandible fractures.
Osteomyelitis, plate infection/loosening/extrusion/failure, malunion, nonunion, malocclusion, trismus, scaring (exter nal approach), paresthesia
110
110 What is the time period for primary bony healing to occur in facial fractures treated with open reduction and internal fixation?
Primary bony healing of repaired facial fractures takes place over 4 to 10 weeks. If healing does not take place by this time, the diagnosis of nonunion can be suspected.
111
111 What are the radiographic characteristics of nonunion (mandibular fractures) on panoramic X ray?
● Sclerotic bone margins ● Osteolytic changes within the bone adjacent to the fracture site ● A persistent radiolucent gap where bone has not bridged the fracture site
112
112 What factors contribute to nonunion after mandible fracture repair?
● Inadequate immobilization ● Incomplete reduction ● Infection ● Poor blood supply ● Nutritional or metabolic alterations
113
113 What structure protects the coronoid process of the mandible when in occlusion?
The zygomatic arch
114
114 What muscular force tends to distract high condylar fractures out of alignment?
Medial displacement of the condyle by the pull of the lateral pterygoid muscle
115
115 Review the absolute indications for open reduction of condylar neck fractures.
Invasion of joint by foreign body Lateral extracapsular displacement Inability to achieve occlusion with closed reduction Involvement of the middle cranial fossa or external auditory canal
116
116 What is the most common subunit location of condylar process fractures?
Subcondylar \> condylar neck \> condylar head (intracapsular)
117
117 What is the immediate concern with bilateral condylar process fractures?
Airway compromise
118
118 Review the primary reasons to consider tooth extraction during repair of mandible fractures.
Evidence of periapical or gross periodontal infection, tooth preventing fracture reduction, root fracture, exposure of root apex after fracture reduction, teeth without adequate bone support, partially erupted third molars with evidence of active pericornitis
119
119 What is the definition of periodontal concussion?
Injury to the periodontium resulting in sensitivity to percussion without loosening or displacement of the tooth
120
120 What is the definition of periodontal subluxation?
Injury to the periodontium resulting in loosening of the tooth without tooth displacement
121
121 What is the definition of periodontal luxation?
Injury to the supporting structures of a tooth resulting in loosening and clinical or radiographic displacement Luxation can be extrusive, intrusive, mesial, distal, buccal, or lingual.
122
122 What is the most commonly avulsed tooth?
Maxillary central incisor due to its vulnerability as the most anteriorly positioned tooth in either arch (presuming a normal occlusal relationship)
123
123 What physiologically compatible solutions are best for storing avulsed teeth?
Hank's balance salt solution, ViaSpan, milk, saliva, saline
124
124 What arteries contribute to the primary blood supply of the maxilla?
● Internal maxillary artery ● Ascending pharyngeal artery ● Ascending palatine branch of the facial artery
125
125 What is the most common complication associ ated with maxillary fractures?
Hemorrhage, which may be self-limiting but may require nasal packing for control
126
126 What test should be performed in a patient who develops delayed intermittent epistaxis following severe midface trauma?
Angiography to evaluate for aneurysms or pseudoaneu rysms that can result in immediate or delayed postoperative bleeding
127
127 Describe a Le Fort I fracture. (▶ Fig. 10.4)
A Le Fort I fracture is a horizontal fracture of the maxilla extending through the nasal septum, lateral nasal walls, lateral maxillary sinus walls, extending posteriorly to the pterygomaxillary junction. The fracture involves the naso maxillary, zygomaticomaxillary, and pterygomaxillary verti cal buttresses of the face.
128
128 Describe a Le Fort II fracture.
A Le Fort II fracture is a pryramidal fracture involving the nasofrontal suture, medial and inferior orbital walls, zygomaticomaxillary suture, lateral maxillary sinus walls, and the pterygomaxillary junction.
129
129 Describe a Le Fort III fracture.
A Le Fort III fracture is a craniofacial dysjunction; the fracture passes through the nasofrontal suture, frontal process of the maxilla, lacrimal bones, ethmoid sinus, and lamina papyracea. It then extends across the orbital floor to the inferior orbital fissure. From this point, it extends in three directions: across the lateral orbital wall through the zygomaticofrontal suture, through the zygomatic arch, and through the pterygoid plates.
130
130 Describe a palatal split fracture.
A palatal split fracture begins anteriorly at the anterior pyriform aperture and extends posteriorly to the posterior aspect of the hard palate. Palatal fractures are more likely to manifest as true sagittal palatal split fractures in pediatric patients because of an unfused midpalatal suture. Para sagittal palatal fractures are more common in adults because this is the area where the palatal bone is the thinnest.
131
131 What is a Gunning splint?
A Gunning splint is a plate fabricated to the existing edentulous ridge with arch bars or suspension brackets used to establish intermaxillary fixation in edentulous or partially edentulous patients.
132
132 In complicated palatal fractures with bone loss or severe comminution, what can be used to main tain the palatal arch?
Dental splints created from premorbid impressions or dentures (in edentulous patients)
133
133 What structures make up the vertical buttresses of the midface?
● Three paired buttresses: Zygomaticomaxillary (lateral), nasomaxillary (medial), pterygomaxillary (posterior) ● Single unpaired structure: Septovomerian buttress (mid line)
134
134 What structures constitute the horizontal but tresses of the midface?
● Frontal buttress: Supraorbital rims ● Zygomatic buttress: Infraorbital rims, body of the zygoma, and zygomatic arch ● Maxillary buttress: Maxillary alveolus and palatine pro cesses
135
135 What is the characteristic deformity associated with a midface fracture?
Midface retrusion and an anterior open bite resulting from the posterior and inferior traction of the medial and lateral pterygoids on the mobile maxillary fragment
136
136 How do you reduce an impacted maxilla after a midface fracture?
Early reduction may be performed using a Rowe or Hayton Williams forceps. Delayed repair is more likely to require osteotomies and surgical down-fracture.
137
137 Why is nasal packing generally contraindicated in treating nasal bone fractures in young children?
Young infants are obligate nose breathers.
138
138 What landmark demarcates the transition point between the thicker nasal bone superiorly and the thinner bone inferiorly?
Intercanthal line Most nasal bone fractures occur below this level.
139
139 What role does age play in the pathophysiology of nasal trauma?
Younger patients are more likely to sustain cartilaginous injuries and greenstick fractures because of the greater proportion of nasal cartilage and incomplete ossification of nasal bones. Older patients generally have greater degrees of comminution.
140
140 What is the most common cause of facial fractures in children over the age of 5 years?
Motor-vehicle accident
141
141 What are the complications associated with failure to identify a septal fracture when evaluating a patient with nasal bone fractures?
Decreased projection, septal deviation, septal hematoma
142
142 What other associated injuries may occur with nasal bone fractures?
Epiphora, fractures of the lacrimal bones and ethmoid complex, widening of intercanthal distance (NOE fracture), malocclusion and open bite deformity (Le Fort fracture), frontal sinus fracture, cribriform plate fracture, dural tears leading to pneumocephalus and CSF rhinorrhea
143
143 In addition to a history and physical examination, what other social history should be obtained in patients who sustain a blunt facial trauma?
Is the patient a victim of domestic abuse? About 30% to 60% of women with facial trauma from assault are victims of domestic violence.
144
144 What are the potential causes of hyposmia after nasal bone fractures?
● Nasal obstruction secondary to edema, septal dislocation, epistaxis, brain contusion or shearing of olfactory filaments ● Up to two-thirds of patients with severe head trauma experience some degree of olfactory dysfunction.
145
145 What effect does telescoping of the bony or cartilaginous fragments after nasal bone fracture have on the nasolabial angle?
It increases the nasolabial angle.
146
146 Regardless of trauma history, what percentage of patients will have a clinically apparent septal deviation on nasal examination?
Approximately 80%
147
147 Why is it difficult to distinguish old fractures from new ones on plain films?
Only 15% of nasal bone fractures heal by ossification.
148
148 When is the optimal window of time to perform closed reduction of a nasal bone fracture?
If it is not performed immediately after the injury (before edema occurs), then it is best to wait 2-10 days after the injury to allow swelling to subside. The development of fibrous connective tissue within the fracture decreases the likelihood of optimal fracture reduction. This occurs 10 to 14 days after the injury.
149
149 What is the mechanism of septal perforation after a hematoma?
Septal cartilage receives its vascular supply from the mucoperichondrium. Septal hematoma results in subper ichondrial dissection, which deprives the cartilage of blood supply and results in ischemic necrosis.
150
150 Describe the potential complications of infected septal hematoma (abscess).
Necrosis and subsequent perforation, contiguous spread or retrograde thrombophlebitis leading to osteomyelitis, orbital and intracranial abscess, meningitis, and cavernous sinus thrombosis
151
151 What is the gold standard for establishing the diagnosis of CSF leak?
β2-transferrin
152
152 What is the natural history of most CSF leaks after nasal trauma?
More than 50% resolve spontaneously within 1 to 2 weeks with conservative management, including bed rest, head elevation, and stool softeners to reduce strenuous valsalva. Coughing, sneezing, and nose blowing should be avoided.
153
153 What can be instilled into the frontal sinus to assess patency of the nasofrontal recess?
Methylene-blue or fluorescein
154
154 What is an alternative to open reduction and internal fixation of moderately displaced anterior table frontal sinus fractures?
Endoscopic reduction with miniplate fixation or fracture camouflage with porous polyethylene sheets (MEDPOR, Porex Surgical, Inc., Newnan, GA) or hydroxyapatite placement
155
155 Anterior frontal sinus wall fractures are typically not aesthetically noticeable if they are displaced less than \_\_\_\_\_?
2 mm
156
156 When performing open-reduction internal fixation of a frontal sinus fracture via a coronal approach, it is important to preserve a vascularized pericranial flap because it might be used for what purpose, if necessary?
For dural repair, as a tissue filler for frontal sinus obliteration and as a tissue barrier for isolation of the neurocranium from the nasophyarynx during frontal sinus cranialization
157
157 The blood supply to the pericranium comes from what three sources?
Vessels arising from the underlying cranial bones, deep branches of the superficial temporal, supratrochlear, and supraorbital vessels, and interconnecting vessels arising from superficial branches
158
158 What percentage of patients with a nondisplaced posterior table frontal sinus fracture with a confirmed CSF leak will have the leak resolve spontaneously with observation?
50%
159
159 Moderate to severe comminution involving greater than 25% of the posterior table is generally considered an indication for what type of repair?
Frontal sinus cranialization, particularly if there is commi nution of the floor of the sinus.
160
160 What are the treatment options for traumatic nasofrontal recess injury?
For mild injuries, endoscopic surgical exploration or observing for the development of frontal sinusitis and/or mucocele can be considered. For severe injury, frontal sinus obliteration should be considered.
161
161 As a general rule, why are displaced fractures of the posterior table of the frontal sinus explored?
Depressed fragments may cause intracranial hemorrhage or CSF leak, and there is possibility of mucocele formation.
162
162 Why is it necessary to remove all the mucosa of the frontal sinus before adipose tissue obliteration when treating severe frontal sinus fractures?
To decrease risk of mucocele/pylocele formation
163
163 What are the potential sequelae of trauma-related frontal sinus mucoceles?
Secondary mucoceles may enlarge and erode bone with invasion of the orbit or intracranial space. If the mucoid contents of the mucocele become infected (mucopyocele), orbital abscess, osteomyelitis of the frontal bone, epidural abscess, meningitis, or brain abscess may occur.
164
164 What are the primary vertical and horizontal buttresses of the NOE complex?
● Vertical: Frontal process of the maxillary bone ● Horizontal: Superior and inferior orbital rims
165
165 What is a normal intercanthal distance?
Approximately 30 to 35 mm or one-half the interpupillary distance or the width of the alar base
166
166 What are the typical facial deformities seen in patients with acute NOE fractures?
Nasal dorsum flattening, traumatic telecanthus, increased nasal tip rotation, and decreased nasal projection
167
167 What is the best management of epiphora in a patient with an obstruction distal to the common canaliculus of the lacrimal drainage system?
Endoscopic dacryocystorhinostomy
168
168 Describe the classification system of NOE fractures. (▶ Fig. 10.5)
Markowitz classification: ● Type 1: A single, noncomminuted central fragment without medial canthal tendon (MCT) disruption. ● Type 2 fractures: Comminution of the central fragment, but the MCT remains attached to a definable segment of bone. ● Type 3 fractures: Severe central fragment comminution with disruption of the MCT insertion
169
169 Describe the treatment of type 1 NOE fractures.
● Nondisplaced fractures without an increase in intercanthal distance may be observed; however, development of delayed telecanthus may still occur. ● Displaced fractures require open reduction and internal fixation, which can be accomplished via coronal, trans conjunctival, sublabial, or external eyelid approaches. Existing lacerations may also be used. Because type 1 fractures are noncomminuted by definition, one-, two-, or three-point fixation can often be utilized. Three-point fixation will require plating at the nasofrontal, nasomax illary, and infraorbital buttresses. Often, for type I NOE fractures, a coronal approach is not necessary to obtain adequate exposure.
170
170 What is a common complication of malpositioned transnasal wire placement when treating NOE fractures?
Placement of transnasal wires anterior to the lacrimal fossa results in rotation of the central fragment laterally, resulting in iatrogenic telecanthus. The wires should be placed posterior and superior to the lacrimal fossa. Wire placement should also be placed below the frontoethmoid suture line to avoid intracranial injury.
171
171 What examination findings are characteristic for avulsion of the medial canthal tendon?
● Absent bowstring sign ● Proptosis ● Rounding of the medial canthal angle
172
172 Describe the technique of transnasal canthopexy for repair of an avulsed medial canthal tendon.
Transnasal canthopexy is typically accomplished after open reduction and internal fixation of the fractured bony segments of the NOE complex. The medial canthopexy is completed using the wire anchor technique with or without use of a transcaruncular barb. Canthal dissection is required if a transcaruncular barb is not used. Once secured, the wire anchoring the canthal tendon should be directed posteri orly, superiorly, and medially and secured to a titanium plate along the medial wall of the orbit.
173
173 A ZMC ("tripod") fracture involves which struc tures?
Tripod fracture is a misnomer because a ZMC fracture involves four sites (tetrapod fracture is a more accurate description): ● Temporal bone (zygomaticotemporal suture) ● Maxilla (zygomaticomaxillary suture) ● Frontal bone (zygomaticofrontal suture) ● Sphenoid bone (zygomaticosphenoid suture)
174
174 In ZMC fractures, what usually causes restricted mandibular opening?
Impingement of the zygomatic arch on the coronoid process and temporalis muscle
175
175 List surgical complications associated with ZMC fracture repair.
Lid malposition (ectropion, entropion), persistent diplopia, facial and malar asymmetry, plate palpability, malunion/ nonunion, enophthalmos, cheek numbness (V2), and blindness (extremely rare)
176
176 What approaches are the most appropriate for an isolated zygomatic arch fracture with no commi nution?
Gilles approach or Keen approach
177
177 What is the most prominent portion of the ZMC, and where is it located?
Malar eminence located 2 cm inferior to the lateral canthus
178
178 Describe the Zingg classification of ZMC fractures.
● Type A: Isolated to one segment of the ZMC ○ A1: Zygomatic arch ○ A2: Lateral orbital wall ○ A3: Inferior orbital rim ● Type B: Classic tetrapod fracture involving all four processes of the zygoma ● Type C: Complex fracture with comminution of zygo matic bone
179
179 Namethe weakest bone involved in the ZMC fracture.
Orbital floor
180
180 Rotation of the ZMC is due primarily to the pull of which muscle?
The masseter muscle
181
181 What is the gender distribution of ZMC fractures?
Male-to-female: 80%:20%
182
182 Name the common approaches to the zygomati cofrontal buttress.
● Lateral brow incision ● Upper blepharoplasty incision ● Hemicoronal incision ● Existing lacerations
183
183 What contraindications exist for the immediate repair of orbital floor fractures?
● Globe rupture ● Hyphema ● Retinal detachment ● Traumatic optic neuropathy ● Involvement of the patient's only seeing eye (relative contraindication)
184
184 What physical examination findings would neces sitate urgent surgical intervention of an orbital floor fracture?
Muscular entrapment (particularly in children), soft tissue herniation with nonresolving oculocardiac reflex, significant soft tissue emphysema leading to increased intraocular pressure, and visual impairment
185
185 How should traumatic retrobulbar hematoma with vision loss initially be managed?
Lateral canthotomy and inferior cantholysis
186
186 What pharmacologic agents can be used to help manage high intraocular pressure?
IV mannitol, acetazolamide, corticosteroids, ophthalmic β- blockers, ophthalmic α-agonists, cholinergic medications
187
187 What are common findings associated with retrobulbar hematoma?
Eye pain, proptosis, chemosis, diplopia, increased intra ocular pressure, tense globe, decreasing visual acuity, loss of direct pupillary light reflex and ophthalmoplegia, papilledema
188
188 What is the gold standard for diagnosis of inferior rectus or oblique muscle entrapment after orbital floor fracture?
Forced duction test
189
189 What is the gold standard test to confirm carotid cavernous fistula after orbital trauma?
Angiogram
190
190 Describe the hydraulic and buckling theories with respect to the pathogenesis of orbital floor fractures.
● Buckling theory: Fracture occurs as result of transmission of force directly to the orbital floor via the orbital rim. ● Hydraulic theory: Fracture occurs due to transfer of kinetic energy to the orbital floor via the noncompressible orbital soft tissue.
191
191 V2 division trigeminal nerve paresthesia is a common finding in which type of facial fracture?
Orbital floor fractures
192
192 What is the most common complication of orbital floor fracture repair?
Inferior orbital nerve injury
193
193 Approximately what percentage of the orbital floor must be involved for enophthalmos to occur after orbital floor fracture?
More than 50%
194
194 Name the structures that pass through the superior orbital fissure
Oculomotor nerve (III), trochlear nerve (IV), abducens nerve (VI), V1 divisions of the trigeminal nerve, ophthalmic vein
195
195 Describe the signs and the treatment of traumatic optic neuropathy.
● Marcus Gunn pupil (relative afferent pupillary defect), central scotoma, and decreased visual acuity ● Steroids and/or surgical decompression is sometimes used, but a high rate of spontaneous recovery may obviate the need for intervention.
196
196 In the setting of traumatic optic neuropathy from orbital fracture, what fracture type is more favorable for visual recovery?
Absence of fracture (most favorable) \> anterior orbital fracture \> posterior orbital fracture (least favorable)
197
197 Describe common findings associated with orbital apex syndrome.
Ophthalmoplegia from damage to the oculomotor, troch lear, and/or abducens nerves (CN III, IV, and VI), mydriasis from damage to oculomotor nerve (CN III), pain/anesthesia of the eye and forehead from damage to the ophthalmic branch of the trigeminal nerve (V1), and decreased visual acuity from optic nerve dysfunction (CN II)
198
198 What is the orbital septum?
An extension of the periosteum at the orbital rim that forms the anteriormost border of the orbital contents. It blends with the levator palpebrae superioris in the upper lid, and the tarsal plate in the lower lid.
199
199 Describe common approaches to the inferior orbital rim and orbital floor. (▶ Fig. 10.6)
* Transconjunctival approach: An incision inferior to the tarsal plate for preseptal approach and incision just anterior to the fornix for postseptal approach. Carries risk for entropion
* Subciliary (blepharoplasty) approach: An incision 1 to 2 mm below the gray line of the lower eyelid, high risk of ectropion, and greater technical difficulty
* Subtarsal/mid-eyelid approach: Straightforward approach, direct access to floor, carries risk of ectropion, and has a visible scar
* Infraorbital approach: Straightforward approach, most visible scar, associated with greater postoperative edema, and carries risk of ectropion. For the aforementioned reasons, the infraorbital approach has fallen out of favor compared with the first three orbital approaches unless an existing laceration is already present in this area.
