10 Facial Trauma

Question 1

1 What is the first step in treating every trauma patient?

Answer 1

Ensure the patient has a safe and adequate airway (airway, breathing, circulation, or ABCs)

Question 2

2 List the contraindications to cricothyrotomy.

Answer 2

• 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.

Question 3

3 Describe the Glasgow Coma Scale (GCS) score scoring system. (▶ Table 10.1)

Answer 3

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.

Question 4

4 What measure is a good indicator of the resuscitation status of a trauma patient with significant blood loss?

Answer 4

Urine output

Question 5

5 Based on the physiology of a 70-kg man, roughly how much blood loss must occur before hypo tension results?

Answer 5

1.5 to 2 L

Question 6

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)

Answer 6

Tetanus-diphtheria and tetanus immune globulin

Question 7

7 What radiographic examination is most helpful in evaluating maxillofacial trauma?

Answer 7

• CT face fine cuts (1 to 3 mm)
• CT brain and neck if concern for intracranial or neck/laryngeal injury

Question 8

8 List the bacteria commonly present in dog bites.

Answer 8

Pasteurella multocida, Staphylococcus aureus, Streptococcus viridans, and oral anaerobes

Question 9

9 As a general rule, how long after initial injury can simple lacerations be closed?

Answer 9

Up to 3 days

Question 10

10 What are the benefits of applying a negative pressure wound VAC to a partial avulsion injury?

Answer 10

• Decrease bacterial counts
• Promote granulation tissue formation
• Improve the rate of contracture

Question 11

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?

Answer 11

Fibroblasts and keratinocytes

Question 12

12 Pigmented debris left in a wound bed may lead to what complication?

Answer 12

Traumatic tattooing

Question 13

13 What is the mechanism of a pincushion (trapdoor) deformity after soft tissue trauma?

Answer 13

• When elevated or redundant tissue abuts a curvilinear shaped scar
• Most likely results from concentric wound contracture and lymphedema

Question 14

14 Why should eyebrows be trimmed conservatively (not shaved) when treating patients with extensive facial trauma?

Answer 14

Regrowth of eyebrow hair may take as long as 6 months, and hair regrowth may be incomplete.

Question 15

15 What suture technique is best for everting skin edges when closing a soft tissue laceration?

Answer 15

Vertical mattress

Question 16

16 As a general rule, what suture type should be used to close the epidermis of young pediatric patients?

Answer 16

Absorbable suture is used because permanent suture will be difficult to remove in the office setting.

Question 17

17 Which wound adhesive is approved by the Food and Drug Administration (FDA) for closure of skin?

Answer 17

Octyl-2-cyanoacrylate (Dermabond)

Question 18

18 What is the mechanism of action of the tissue adhesive octyl-2-cyanoacrylate?

Answer 18

On exposure to moisture, octyl-2-cyanoacrylate undergoes an exothermic reaction as it polymerizes to form a strong tissue bond.

Question 19

19 How does the location of a facial laceration influence whether or not wound exploration should be carried out for facial nerve neuror rhaphy?

Answer 19

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.

Question 20

20 What is the preferred management of a trau matically avulsed segment of the proximal extra temporal facial nerve?

Answer 20

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.

Question 21

21 What treatment options can be used to decrease the risk of sialocele after traumatic parotid duct transection?

Answer 21

Options include primary anastomosis over a stent, duct ligation, or fistulization of the duct into the oral cavity.

Question 22

22 What length of the lower lip can be managed with primary closure without significant distortion or microstomia?

Answer 22

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.

Question 23

23 How much of the eyelid can be closed primarily after an avulsion injury?

Answer 23

25%

Question 24

24 What must be done to the avulsed segment of the auricle before its burial in a postauricular pocket for delayed reconstruction?

Answer 24

De-epithelialization of the avulsed segment

Question 25

25 What antibiotic class should be used for injuries involving cartilage?

Answer 25

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.

Question 26

26 What is the definition of a first-degree burn?

Answer 26

Damage no deeper than the epidermis, resulting in pain and erythema, but little or no permanent injury

Question 27

27 What is the definition of a second-degree burn?

Answer 27

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.

Question 28

28 What is the definition of a third-degree burn?

Answer 28

Injury involves the epidermis and the full thickness of the dermis, destroying adnexal structures, blood vessels, and nerve endings.

Question 29

29 The head and neck make up what percentage of the total body surface area (TBSA)?

Answer 29

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

Question 30

30 What is the Parkland formula for fluid resuscitation of burn victims?

Answer 30

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.

Question 31

31 In addition to IV antibiotics, why are topical antibiotics recommended to prevent superinfec tion in burn patients?

Answer 31

Burn eschar has a poor blood supply, decreasing the likelihood that therapeutic levels of systemically delivered antibiotic will penetrate the wound bed.

Question 32

32 When should burns involving the oral commissure be reconstructed?

Answer 32

Most surgeons recommend initial observation with con servative wound care and waiting to surgically intervene only after full scar maturation.

Question 33

33 What treatment should be considered for patients with oral commissure electrical burns to decrease the risk of microstomia?

Answer 33

Oral appliance use is designed to splint the oral commis sure.

Question 34

34 The Battle sign refers to what physical examination finding?

Answer 34

Postauricular ecchymosis that suggests a basilar skull fracture

Question 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?

Answer 35

Pack the ear canal to control bleeding, and perform an arterial angiogram to examine for petrous carotid injury.

Question 36

36 Subcutaneous emphysema that extends from the neck into the face travels in what plane?

Answer 36

Along the platysma and subcutaneous musculoaponeurotic system (SMAS)

Question 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)

Answer 37

● 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

Question 38

38 With penetrating injuries to zone I of the neck, what structures are at risk of damage?

Answer 38

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.

Question 39

39 With penetrating injuries to zone II of the neck, what structures are at risk of damage?

Answer 39

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.

Question 40

40 With penetrating injuries to zone III of the neck, what structures are at risk of damage?

Answer 40

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.

Question 41

41 Of the neck zones, which is the most surgically accessible?

Answer 41

Zone II

Question 42

42 Describe the main factors that influence the injury incurred from ballistic strike.

Answer 42

Kinetic energy (KE) (velocity is more important than mass), design of projectile, composition of receiving tissue KE = (½) (mass) (velocity)2

Question 43

43 What commonly used radiographic technique has been shown to reduce significantly the number of negative surgical neck explorations in penetrating neck trauma?

Answer 43

CT angiography

Question 44

44 When performing esophagography in a patient with penetrating neck trauma, why is it important to use a water-soluble contrast agent?

Answer 44

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.

Question 45

45 In penetrating neck trauma, which structure, if it is not violated, significantly decreases the probability of aerodigestive or vascular injury?

Answer 45

Platysma

Question 46

46 Review the signs of carotid vascular injury after penetrating neck trauma.

Answer 46

Hematoma/ecchymosis, hypovolemic shock, external hemorrhage, absent carotid pulse, carotid bruit or thrill, diminished ipsilateral radial pulse, contralateral hemipare sis, and altered mental status

Question 47

47 Review the signs of aerodigestive injury in penetrating neck trauma.

Answer 47

Dysphagia, hoarseness, subcutaneous emphysema/crepi tus, hemoptysis, hematemesis, gas escape from neck wound, dyspnea, airway obstruction, and stridor

Question 48

48 What are the indications for immediate surgical exploration after penetrating neck injury?

Answer 48

An unstable patient with significant hemorrhage, expand ing hematoma, nonexpanding hematoma with hemody namic instability, hemomediastinum, hemothorax, airway decompensation

Question 49

49 What are common findings in blunt laryngeal trauma?

Answer 49

Subcutaneous emphysema, dysphagia, dysphonia, dyspnea, stridor, hemoptysis, neck swelling

Question 50

50 Describe the Schaefer classification system of laryngeal injury.

Answer 50

● 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

Question 51

51 List conservative therapies that should be consid ered when treating a patient with a laryngeal fracture.

Answer 51

Voice rest, humidified blow-by, steroids, antibiotics, anti reflux medications

Question 52

52 Review the symptoms of laryngeal fracture.

Answer 52

Dysphonia, neck pain, odynophagia, dyspnea, dysphagia

Question 53

53 Review the signs of laryngeal fracture.

Answer 53

Hemoptysis, neck tenderness, subcutaneous emphysema, anterior neck ecchymosis, laryngeal deviation, loss of laryngeal prominence, stridor

Question 54

54 What is the most important imaging study for evaluating laryngeal trauma?

Answer 54

Fine-cut CT

Question 55

55 Which age group tends to have the highest mortality after laryngeal trauma?

Answer 55

Patients older than 70 years of age

Question 56

56 Describe the reasons why children rarely sustain laryngeal fractures.

Answer 56

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.

Question 57

57 Describe the mechanism of injury for laryngeal fractures.

Answer 57

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.

Question 58

58 What is the preferred method of airway management for patients with advanced laryngeal trauma?

Answer 58

Awake tracheotomy in the operating room

Question 59

59 List the potential pitfalls and complications asso ciated with endotracheal intubation in patients with laryngeal trauma.

Answer 59

Cervical spine injuries, laryngeal lacerations and hemor rhage, displaced laryngeal architecture, and cricotracheal separation

Question 60

60 Describe the steps to repair advanced laryngeal fractures.

Answer 60

Secure the airway with awake tracheotomy, direct lar yngoscopy with rigid bronchoscopy, neck exploration, laryngotracheal/endolaryngeal repair, cartilage stabilization

Question 61

61 How long are stents usually left in place after laryngeal fracture repair?

Answer 61

In general, 2 to 3 weeks

Question 62

62 During an open laryngeal repair, a keel is useful in preventing what type of complication?

Answer 62

Anterior glottic web

Question 63

63 What are the general treatment goals of facial reconstruction following trauma?

Answer 63

Restoration of form (facial height, facial width, and facial projection) and function (airway, occlusion, mastication)

Question 64

64 What must fracture fixation accomplish to allow for direct (primary) bone healing?

Answer 64

Fixation must overcome natural forces acting across the fracture site that would lead to mechanical instability and poor apposition of the fractured segments.

Question 65

65 Name the two major types of plating materials.

Answer 65

● Metal ● Resorbable

Question 66

66 What material is most commonly used in metal plating systems?

Answer 66

Titanium alloy

Question 67

67 How do the various trauma plate types differ?

Answer 67

● Alloy composition ● Plate hole size ● Screw head type

Question 68

68 What is the importance of bone fragment contact in fracture healing?

Answer 68

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.

Question 69

69 The term miniplate refers to what plate character istic?

Answer 69

Plate thickness of 1.3 mm or less

Question 70

70 What characteristic does a locking plate possess?

Answer 70

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.

Question 71

71 What is the purpose of a compression plate?

Answer 71

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.

Question 72

72 What is the primary disadvantage of conventional trauma plates?

Answer 72

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.

Question 73

73 What is the potential disadvantage of bicortical screw placement?

Answer 73

Damage of deeper structures including tooth roots and underlying neurovascular structures

Question 74

74 What are the two basic types of fracture fixation?

Answer 74

● 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

Question 75

75 When is load-bearing fixation necessary?

Answer 75

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)

Question 76

76 When is load-sharing fixation used?

Answer 76

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

Question 77

77 When applying a compression plate, what type of screw placement is required?

Answer 77

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

Question 78

78 What are the two basic types of screws?

Answer 78

● 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.

Question 79

79 What is an emergency screw?

Answer 79

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.

Question 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?

Answer 80

At least two screws need to be used; however, three screws are desirable, particularly when using a single plate.

Question 81

81 Define rigid fixation.

Answer 81

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).

Question 82

82 What are the goals of open reduction and internal rigid fixation?

Answer 82

● 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

Question 83

83 Define nonrigid fixation.

Answer 83

Any form of fixation that permits interfragmentary move ment Healing occurs from indirect (secondary) bone healing, which occurs via formation of a subperiosteal callus.

Question 84

84 Define Angle class I molar occlusion.

Answer 84

Mesiobuccal cusp of the maxillary first molar interdigitates with the mesiobuccal (central) groove of the mandibular first molar

Question 85

85 Define the occlusal relationships of overjet and overbite.

Answer 85

● 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.

Question 86

86 Define crossbite.

Answer 86

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.

Question 87

87 Sublingual ecchymosis at the floor of the mouth after trauma usually indicates what type of injury?

Answer 87

Mandibular fracture

Question 88

88 What nerve provides sensory innervation to the mandible?

Answer 88

The inferior alveolar nerve, a branch of the mandibular division of the trigeminal nerve (V3)

Question 89

89 Which cranial nerve (CN) innervates the muscles of mastication?

Answer 89

Trigeminal nerve (CN V3)

Question 90

90 List the muscles that insert into the mandible and their respective functions.

Answer 90

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.

Question 91

91 Describe the embryologic development of the mandible

Answer 91

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.

Question 92

92 What are the subsites of the mandible?

Answer 92

Symphysis, parasymphysis, body, alveolar process, angle, ramus, coronoid, and condyle

Question 93

93 What are the two most common sites of mandibular fracture?

Answer 93

The mandibular condyle and the mandibular body

Question 94

94 With respect to frequency, how common are mandible fractures compared with other facial trauma injuries?

Answer 94

Nasal fractures are most common, followed by mandible fractures. Mandible fractures are two to three times more common than midface fractures.

Question 95

95 What constitutes a favorable or unfavorable fracture?

Answer 95

Fragments of the fracture are either pulled together (favorable) or apart (unfavorable) by the tension from the muscles of mastication.

Question 96

96 Define the term horizontally unfavorable in the context of classifying mandibular fractures. (▶ Fig. 10.2)

Answer 96

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.

Question 97

97 Define the term vertically unfavorable in the context of classifying mandibular fractures.

Answer 97

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.

Question 98

98 Outline the dental classification for mandibular fractures.

Answer 98

● 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.

Question 99

99 How would you manage a displaced fracture of the body of the mandible in a 5-year-old child?

Answer 99

Closed reduction with fixation using orthodontic splints

Question 100

100 Review the complications associated with inter maxillary fixation (IMF) of mandible fractures.

Answer 100

Dental injury, periodontal injury, potential for airway compromise, weight loss or malnutrition

Question 101

101 List the contraindications to IMF.

Answer 101

Alcoholism, epilepsy, mental retardation, nutritional defi ciency, advanced respiratory disease, psychosis, pregnancy, noncompliant patient

Question 102

102 List the disadvantages of closed reduction repair of mandible fractures.

Answer 102

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.

Question 103

103 What are the primary reasons for pursuing early (within 24 to 36 hours) repair of mandible fractures?

Answer 103

Earlier return to function and to manage pain

Question 104

104 Which mandible fracture has the highest incidence of infection?

Answer 104

Mandibular angle fractures

Question 105

105 Review the primary indications for open reduction of mandible fractures.

Answer 105

● 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

Question 106

106 Describe the Champy technique of mandible fracture repair. (▶ Fig. 10.3)

Answer 106

Use of miniplate fixation in simple fractures along the ideal lines of osteosynthesis to form load-sharing or semi-rigid fixation constructs

Question 107

107 How should a lag screw be placed relative to a mandibular fracture?

Answer 107

Always place the lag screw perpendicular to the line of fracture to prevent fragments from overriding and dis placement.

Question 108

108 Review the indications for external pin-fixation repair of mandible fractures.

Answer 108

● 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

Question 109

109 Name the complications associated with open reduction internal fixation of mandible fractures.

Answer 109

Osteomyelitis, plate infection/loosening/extrusion/failure, malunion, nonunion, malocclusion, trismus, scaring (exter nal approach), paresthesia

Question 110

110 What is the time period for primary bony healing to occur in facial fractures treated with open reduction and internal fixation?

Answer 110

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.

Question 111

111 What are the radiographic characteristics of nonunion (mandibular fractures) on panoramic X ray?

Answer 111

● 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

Question 112

112 What factors contribute to nonunion after mandible fracture repair?

Answer 112

● Inadequate immobilization ● Incomplete reduction ● Infection ● Poor blood supply ● Nutritional or metabolic alterations

Question 113

113 What structure protects the coronoid process of the mandible when in occlusion?

Answer 113

The zygomatic arch

Question 114

114 What muscular force tends to distract high condylar fractures out of alignment?

Answer 114

Medial displacement of the condyle by the pull of the lateral pterygoid muscle

Question 115

115 Review the absolute indications for open reduction of condylar neck fractures.

Answer 115

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

Question 116

116 What is the most common subunit location of condylar process fractures?

Answer 116

Subcondylar > condylar neck > condylar head (intracapsular)

Question 117

117 What is the immediate concern with bilateral condylar process fractures?

Answer 117

Airway compromise

Question 118

118 Review the primary reasons to consider tooth extraction during repair of mandible fractures.

Answer 118

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

Question 119

119 What is the definition of periodontal concussion?

Answer 119

Injury to the periodontium resulting in sensitivity to percussion without loosening or displacement of the tooth

Question 120

120 What is the definition of periodontal subluxation?

Answer 120

Injury to the periodontium resulting in loosening of the tooth without tooth displacement

Question 121

121 What is the definition of periodontal luxation?

Answer 121

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.

Question 122

122 What is the most commonly avulsed tooth?

Answer 122

Maxillary central incisor due to its vulnerability as the most anteriorly positioned tooth in either arch (presuming a normal occlusal relationship)

Question 123

123 What physiologically compatible solutions are best for storing avulsed teeth?

Answer 123

Hank’s balance salt solution, ViaSpan, milk, saliva, saline

Question 124

124 What arteries contribute to the primary blood supply of the maxilla?

Answer 124

● Internal maxillary artery ● Ascending pharyngeal artery ● Ascending palatine branch of the facial artery

Question 125

125 What is the most common complication associ ated with maxillary fractures?

Answer 125

Hemorrhage, which may be self-limiting but may require nasal packing for control

Question 126

126 What test should be performed in a patient who develops delayed intermittent epistaxis following severe midface trauma?

Answer 126

Angiography to evaluate for aneurysms or pseudoaneu rysms that can result in immediate or delayed postoperative bleeding

Question 127

127 Describe a Le Fort I fracture. (▶ Fig. 10.4)

Answer 127

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.

Question 128

128 Describe a Le Fort II fracture.

Answer 128

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.

Question 129

129 Describe a Le Fort III fracture.

Answer 129

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.

Question 130

130 Describe a palatal split fracture.

Answer 130

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.

Question 131

131 What is a Gunning splint?

Answer 131

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.

Question 132

132 In complicated palatal fractures with bone loss or severe comminution, what can be used to main tain the palatal arch?

Answer 132

Dental splints created from premorbid impressions or dentures (in edentulous patients)

Question 133

133 What structures make up the vertical buttresses of the midface?

Answer 133

● Three paired buttresses: Zygomaticomaxillary (lateral), nasomaxillary (medial), pterygomaxillary (posterior) ● Single unpaired structure: Septovomerian buttress (mid line)

Question 134

134 What structures constitute the horizontal but tresses of the midface?

Answer 134

● Frontal buttress: Supraorbital rims ● Zygomatic buttress: Infraorbital rims, body of the zygoma, and zygomatic arch ● Maxillary buttress: Maxillary alveolus and palatine pro cesses

Question 135

135 What is the characteristic deformity associated with a midface fracture?

Answer 135

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

Question 136

136 How do you reduce an impacted maxilla after a midface fracture?

Answer 136

Early reduction may be performed using a Rowe or Hayton Williams forceps. Delayed repair is more likely to require osteotomies and surgical down-fracture.

Question 137

137 Why is nasal packing generally contraindicated in treating nasal bone fractures in young children?

Answer 137

Young infants are obligate nose breathers.

Question 138

138 What landmark demarcates the transition point between the thicker nasal bone superiorly and the thinner bone inferiorly?

Answer 138

Intercanthal line Most nasal bone fractures occur below this level.

Question 139

139 What role does age play in the pathophysiology of nasal trauma?

Answer 139

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.

Question 140

140 What is the most common cause of facial fractures in children over the age of 5 years?

Answer 140

Motor-vehicle accident

Question 141

141 What are the complications associated with failure to identify a septal fracture when evaluating a patient with nasal bone fractures?

Answer 141

Decreased projection, septal deviation, septal hematoma

Question 142

142 What other associated injuries may occur with nasal bone fractures?

Answer 142

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

Question 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?

Answer 143

Is the patient a victim of domestic abuse? About 30% to 60% of women with facial trauma from assault are victims of domestic violence.

Question 144

144 What are the potential causes of hyposmia after nasal bone fractures?

Answer 144

● 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.

Question 145

145 What effect does telescoping of the bony or cartilaginous fragments after nasal bone fracture have on the nasolabial angle?

Answer 145

It increases the nasolabial angle.

Question 146

146 Regardless of trauma history, what percentage of patients will have a clinically apparent septal deviation on nasal examination?

Answer 146

Approximately 80%

Question 147

147 Why is it difficult to distinguish old fractures from new ones on plain films?

Answer 147

Only 15% of nasal bone fractures heal by ossification.

Question 148

148 When is the optimal window of time to perform closed reduction of a nasal bone fracture?

Answer 148

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.

Question 149

149 What is the mechanism of septal perforation after a hematoma?

Answer 149

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.

Question 150

150 Describe the potential complications of infected septal hematoma (abscess).

Answer 150

Necrosis and subsequent perforation, contiguous spread or retrograde thrombophlebitis leading to osteomyelitis, orbital and intracranial abscess, meningitis, and cavernous sinus thrombosis

Question 151

151 What is the gold standard for establishing the diagnosis of CSF leak?

Answer 151

β2-transferrin

Question 152

152 What is the natural history of most CSF leaks after nasal trauma?

Answer 152

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.

Question 153

153 What can be instilled into the frontal sinus to assess patency of the nasofrontal recess?

Answer 153

Methylene-blue or fluorescein

Question 154

154 What is an alternative to open reduction and internal fixation of moderately displaced anterior table frontal sinus fractures?

Answer 154

Endoscopic reduction with miniplate fixation or fracture camouflage with porous polyethylene sheets (MEDPOR, Porex Surgical, Inc., Newnan, GA) or hydroxyapatite placement

Question 155

155 Anterior frontal sinus wall fractures are typically not aesthetically noticeable if they are displaced less than _____?

Answer 155

2 mm

Question 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?

Answer 156

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

Question 157

157 The blood supply to the pericranium comes from what three sources?

Answer 157

Vessels arising from the underlying cranial bones, deep branches of the superficial temporal, supratrochlear, and supraorbital vessels, and interconnecting vessels arising from superficial branches

Question 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?

Answer 158

50%

Question 159

159 Moderate to severe comminution involving greater than 25% of the posterior table is generally considered an indication for what type of repair?

Answer 159

Frontal sinus cranialization, particularly if there is commi nution of the floor of the sinus.

Question 160

160 What are the treatment options for traumatic nasofrontal recess injury?

Answer 160

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.

Question 161

161 As a general rule, why are displaced fractures of the posterior table of the frontal sinus explored?

Answer 161

Depressed fragments may cause intracranial hemorrhage or CSF leak, and there is possibility of mucocele formation.

Question 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?

Answer 162

To decrease risk of mucocele/pylocele formation

Question 163

163 What are the potential sequelae of trauma-related frontal sinus mucoceles?

Answer 163

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.

Question 164

164 What are the primary vertical and horizontal buttresses of the NOE complex?

Answer 164

● Vertical: Frontal process of the maxillary bone ● Horizontal: Superior and inferior orbital rims

Question 165

165 What is a normal intercanthal distance?

Answer 165

Approximately 30 to 35 mm or one-half the interpupillary distance or the width of the alar base

Question 166

166 What are the typical facial deformities seen in patients with acute NOE fractures?

Answer 166

Nasal dorsum flattening, traumatic telecanthus, increased nasal tip rotation, and decreased nasal projection

Question 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?

Answer 167

Endoscopic dacryocystorhinostomy

Question 168

168 Describe the classification system of NOE fractures. (▶ Fig. 10.5)

Answer 168

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

Question 169

169 Describe the treatment of type 1 NOE fractures.

Answer 169

● 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.

Question 170

170 What is a common complication of malpositioned transnasal wire placement when treating NOE fractures?

Answer 170

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.

Question 171

171 What examination findings are characteristic for avulsion of the medial canthal tendon?

Answer 171

● Absent bowstring sign ● Proptosis ● Rounding of the medial canthal angle

Question 172

172 Describe the technique of transnasal canthopexy for repair of an avulsed medial canthal tendon.

Answer 172

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.

Question 173

173 A ZMC (“tripod”) fracture involves which struc tures?

Answer 173

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)

Question 174

174 In ZMC fractures, what usually causes restricted mandibular opening?

Answer 174

Impingement of the zygomatic arch on the coronoid process and temporalis muscle

Question 175

175 List surgical complications associated with ZMC fracture repair.

Answer 175

Lid malposition (ectropion, entropion), persistent diplopia, facial and malar asymmetry, plate palpability, malunion/ nonunion, enophthalmos, cheek numbness (V2), and blindness (extremely rare)

Question 176

176 What approaches are the most appropriate for an isolated zygomatic arch fracture with no commi nution?

Answer 176

Gilles approach or Keen approach

Question 177

177 What is the most prominent portion of the ZMC, and where is it located?

Answer 177

Malar eminence located 2 cm inferior to the lateral canthus

Question 178

178 Describe the Zingg classification of ZMC fractures.

Answer 178

● 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

Question 179

179 Namethe weakest bone involved in the ZMC fracture.

Answer 179

Orbital floor

Question 180

180 Rotation of the ZMC is due primarily to the pull of which muscle?

Answer 180

The masseter muscle

Question 181

181 What is the gender distribution of ZMC fractures?

Answer 181

Male-to-female: 80%:20%

Question 182

182 Name the common approaches to the zygomati cofrontal buttress.

Answer 182

● Lateral brow incision ● Upper blepharoplasty incision ● Hemicoronal incision ● Existing lacerations

Question 183

183 What contraindications exist for the immediate repair of orbital floor fractures?

Answer 183

● Globe rupture ● Hyphema ● Retinal detachment ● Traumatic optic neuropathy ● Involvement of the patient’s only seeing eye (relative contraindication)

Question 184

184 What physical examination findings would neces sitate urgent surgical intervention of an orbital floor fracture?

Answer 184

Muscular entrapment (particularly in children), soft tissue herniation with nonresolving oculocardiac reflex, significant soft tissue emphysema leading to increased intraocular pressure, and visual impairment

Question 185

185 How should traumatic retrobulbar hematoma with vision loss initially be managed?

Answer 185

Lateral canthotomy and inferior cantholysis

Question 186

186 What pharmacologic agents can be used to help manage high intraocular pressure?

Answer 186

IV mannitol, acetazolamide, corticosteroids, ophthalmic β- blockers, ophthalmic α-agonists, cholinergic medications

Question 187

187 What are common findings associated with retrobulbar hematoma?

Answer 187

Eye pain, proptosis, chemosis, diplopia, increased intra ocular pressure, tense globe, decreasing visual acuity, loss of direct pupillary light reflex and ophthalmoplegia, papilledema

Question 188

188 What is the gold standard for diagnosis of inferior rectus or oblique muscle entrapment after orbital floor fracture?

Answer 188

Forced duction test

Question 189

189 What is the gold standard test to confirm carotid cavernous fistula after orbital trauma?

Answer 189

Angiogram

Question 190

190 Describe the hydraulic and buckling theories with respect to the pathogenesis of orbital floor fractures.

Answer 190

● 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.

Question 191

191 V2 division trigeminal nerve paresthesia is a common finding in which type of facial fracture?

Answer 191

Orbital floor fractures

Question 192

192 What is the most common complication of orbital floor fracture repair?

Answer 192

Inferior orbital nerve injury

Question 193

193 Approximately what percentage of the orbital floor must be involved for enophthalmos to occur after orbital floor fracture?

Answer 193

More than 50%

Question 194

194 Name the structures that pass through the superior orbital fissure

Answer 194

Oculomotor nerve (III), trochlear nerve (IV), abducens nerve (VI), V1 divisions of the trigeminal nerve, ophthalmic vein

Question 195

195 Describe the signs and the treatment of traumatic optic neuropathy.

Answer 195

● 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.

Question 196

196 In the setting of traumatic optic neuropathy from orbital fracture, what fracture type is more favorable for visual recovery?

Answer 196

Absence of fracture (most favorable) > anterior orbital fracture > posterior orbital fracture (least favorable)

Question 197

197 Describe common findings associated with orbital apex syndrome.

Answer 197

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)

Question 198

198 What is the orbital septum?

Answer 198

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.

Question 199

199 Describe common approaches to the inferior orbital rim and orbital floor. (▶ Fig. 10.6)

Answer 199

• 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.