Condylar Fractures

Dr. Ahmed M. Adawy Professor Emeritus, Dep. Oral & Maxillofacial Surg.

Former Dean, Faculty of Dental MedicineAl-Azhar University

Condylar Fractures

Condylar FracturesFractures of mandibular condyle can be counted among the most controversial issues in maxillofacial traumatology regarding classification, diagnosis and therapeutic management.Despite the fact that the temporomandibular joint is well protected in the glenoid fossa, and that the condylar process is relatively well protected by the zygomatic arch against direct injury, condylar injuries are relatively common. Condylar fractures represent 29-40% of the fractures of the facial skeleton, and about 20-35% of all mandibular fractures .

(1)

In terms of strength, the condylar neck constitutes the weakest region of the entire mandible and is therefore the most susceptible to fracture as a result of indirect forces, where the forces of impact are transmitted along the mandible from distant sites such as the angle, body or symphysis to the condylar neck. The central force in the middle of chin can cause a bilateral condylar fracture. The most common causative factors are physical trauma, accident, fall, sports injury, gunshot wounds and industrial hazard. Unilateral fractures occur approximately 3 times more frequently than bilateral fractures do, but bilateral fractures are not uncommon

Condylar Fractures

Several classification systems have been developed. Generally, there are two types of fracture, intracapsular and extracapsular, but for practical purposes, the anatomical level of the fracture is divided into three sites: the condylar head (intracapsular), the condylar neck (high or low) and the subcondylar region (2). The fracture is farther classified as: undisplaced, deviated, displaced (with medial or lateral overlap, or complete separation), and dislocated (outside the glenoid fossa) (3)

Condylar Fractures; classifications


One of the most commonly used classifications was that developed by Spiessel and Schroll (4). They distinguish between fractures of the condylar base and neck, and based on the fracture position and the relationship between the fracture fragment and glenoid fossa


Type I, condylar neck fracture, without deviation/ displacement of the fragments.

Condylar Fractures; classificationsSpiessel and Schroll, 1972

Type II, low condylar neck fracture with deviation/displacement.Frequently there is still contact between the bone fragments


Type III, high condylar neck fracture with anterior, posterior, medial, or lateral deviation/displacement. As a rule, there is no contact between the fragments


Type IV, low condylar neck fracture with dislocation


Type V, high condylar neck fracture with dislocation


Type VI, intracapsular fracture. These occur mostly in children younger than 6 years.


In addition, according to Lindahl (5), fractures of the condyles can be classified into six classes, vertical slit of the head (class I), horizontal break but mildly or not displaced (II), displacement of the segments (III), there may be medial overlap (IV) or lateral overlap (V) of the displaced smaller proximal segment and a possible partial or complete dislocation of the segment. Rarely, fractures of the condyle may also be communited (class VI) especially with gunshot injuries


History of falls, blows to the contralateral face or ipsilateral preauricular area, or chin injuries should alert the examiner to the possibility of a condylar/subcondylar injury. Because of the U-shaped mandibular anatomy, patients thought to have a single mandibular fracture often have others. Also, the patient with a subcondylar fracture often has another mandibular fracture. Nevertheless, an isolated subcondylar or intracapsular fracture is quite possible

Condylar Fractures; diagnosis

By inspecting patients with a fracture of the mandibular condyle, one or more of the following clinical signs and symptoms could usually be noticed:1) Swelling over the preauricular region2) Possible bleeding from the ear3) A laceration or contusion of the chin4) Facial asymmetry due to soft tissue edema or secondary to shortening of the mandibular ramus5) Varying degree of limited mandibular movement6) Pain and tenderness to palpation over the affected TMJ 7) Deviation of the mandibular midline with posterior open bite8) Marked anterior open bite may indicate bilateral condylar fractures


Chin injury, the associated condylar fracture

A fractured condyle does not translate down the articular eminence on jaw opening. The unopposed translation of the opposite condyle deviates the chin toward the fractured side

Deviated Midline

A fractured condyle usually is distracted antromedially by the lateral ptergoid muscle. This produces a shortened functional height of the ramus by the pull of the elevator muscles. The ipsilateral molar teeth act as a fulcrum to produce a slight contralateral anterior open bite

Picture of open bite

Plain radiography (most commonly) and CT scanning help to ascertain the location of the fracture, the degree and direction of displacement, and the presence or absence of associated injuries. Panoramic radiography is a useful study. Anteroposterior (AP) Towne’s view is particularly helpful for ascertaining the mediolateral position of the respective fractured segments, information not readily available from a panoramic view


Subcondylar fracture ; Panorama

AP Towne’s View

CT scanning in axial and coronal planes can yield much information about this area provided that the sections are sufficiently close to obtain images of the area and provided the practitioner is intimately familiar with the pertinent anatomy. CT scanning does provide the most information about intracapsular fractures


Coronal section, CT Scan

Treatment ranges from observation, jaw exercises to closed or open interventions (6). In almost every instance, unless associated with other mandibular fractures, isolated intracapsular fractures, should be treated solely with physical therapy. If properly rehabilitated, most of the patients regain proper occlusion and full range of mandibular movements. In the early rehabilitative phase, controlling the occlusion (usually by means of arch bars and elastics) while emphasizing return of normal range of motion is important. The patient should be instructed in wide range of motion exercises immediately post injury

Condylar Fractures; treatment

Subcondylar Fractures

Treatment of subcondylar condyle is among the most controversial issues in maxillofacial trauma (7). Ideally, treatment of condylar fractures must realize three main aims: consolidation of the bony fragments , anatomic correction of the segments, and restoration of joint function which typically involves pain-free movement mouth opening beyond 40 mm. and the restoration of the preoperative occlusion and facial symmetry. Of these three goals, the restoration of joint function is the most important (8)

Closed reductionFor years, closed treatment using inter maxillary fixation was the preferred method of treatment and was thought to be essentially complication free. Basically, the technique is conservative nonsurgical one. Thus it eliminates the need for hospital stay and prevents the possible intra and postoperative complications associated with open reduction, namely bleeding, infection, auriculotemporal nerve injury, facial nerve paralysis, and visible scaring. Although anatomic reduction is not possible with closed reduction, it was believed that the selective exercises lead to functional adaptation and remodeling of the bony structures and the surrounding soft tissues (9)

For closed reduction, intermaxillary fixation is conducted using arch bar and wire, followed by maintaining of the fixation of the maxilla and mandible for 2 to 4 weeks. Elastic traction is then used for additional 2 weeks to maintain normal occlusion. Aggressive physical therapy and close follow-up is then conducted for a period of 6-12 weeks. Closed reduction is indicated for pediatric and geriatric patients and for medically compromised patients as well. Of the utmost importance for all patients, is the physical therapy regimens. Physical therapy consists of a series of opening exercises. Some devices on the market, such as the Therabite, can assist a patient with these exercises. An alternative and inexpensive method consists of a stack of tongue blades that can be increased in number each day

Closed reduction

Closed reduction Jaw exercise regimen

However, serious complications have been reported in cases treated with closed reduction including, temporomandibular Joint ankylosis, malocclusion, mandibular deviation, and pathological changes to the condylar process (10). Further, it has been noted that patients treated by closed methods, compared to those treated by open methods, developed asymmetries characterized by significantly shorter posterior facial and ramus heights on the side of injury, and more tilting of the occlusal plane (11)

Closed reduction

Open reductionOpen reduction means principally, exact anatomical reduction under direct vision and at the same time retention and internal fixation of the fracture by means of functionally stable osteosynthesis.Zide and Kent (12) summarized the indications for treating subcondylar fractures in open manner as absolute and relative: Absolute Indications: a. Displacement into the middle cranial fossa b. Impossibility of obtaining adequate occlusion by closed reduction c. Lateral extracapsular displacement of the condyle d. Invasion of a foreign body (e.g.: gunshot wound)

Relative Indications: a. Bilateral condylar fracture in edentulous patients

when splinting is impossible b. Unilateral or bilateral condylar fractures when

splinting is not recommended for medical reasons or adequate post operative physiotherapy is impossible

c. Bilateral condylar fractures associated with comminuted mid-facial fractures

d. Bilateral condylar fractures associated with significant pre-injury malocclusion

Open reduction

Multiple approaches are possible in order to visualize and reduce submandibular fractures. Extraoral approaches include the preauricular, retroauricular, retromandibular, and submandibular incisions, often in combination. Intraoral approaches include the mandibular vestibular incision with or without the use of an endoscope. In both cases, a transbuccal trocar for the placement of some or all of the screws is usually necessary. Whatever approach is chosen, once the fracture is exposed, it must be reduced. Whether the fracture must be fixated and how stable that fixation should be are also topics of much debate

Open reduction

Wire fixation and intramedullary pins have been used to stabilize these fractures. More recently, miniplates and screws are in use. Argument exists as to whether these constitute rigid fixation. Certainly, a miniplate that rigidly fixates the condylar segment in a nonphysiologic position sets up the patient for pain, poor function, and degenerative joint disease. Again, occlusal control and physiotherapy remain crucial to successful outcomes

Open reduction

position of two plates used to stabilize a subcondylar fracture

Condylar fractureThe debate between the supporters of open or closed reduction is still continuing and the issue has not been resolved. At present, except for the highly located intraarticular fractures, open surgery appears to be the main stream approach for treating mandibular fractures at the condylar neck or subcondylar level. However, the final choice of treatment modality for each individual patient should takes into account a number of factors, including position of the condyle, location of the fracture, age of the patient, presence or absence of other associated injuries, presence of other systemic medical conditions, history of previous joint disease, cosmetic impact of the surgery, and desires of the patient

1.Villarreal PM, Monje F, et al: Mandibular condyle fractures: determinants of treatment and outcome. J Oral Maxillofac Surg 62:155, 2004.

2. Silvennoinen U, Iizuka T, et al: Different patterns of condylar fractures: an analysis of 382 patients in a 3- year period. J Oral Maxillofac Surg. 50: 1032, 1992.

3. Newman L: A clinical evaluation of the long-term outcome of patients treated for bilateral fracture of the mandibular condyles. Brit J Oral Maxillofac Surg 36: 176, 1998.

4. Spiessl B, Schroll K. Gelenkfortsatz- und Gelenkkoepfchenfrakturen. In: Nigst H, editor. Spezielle Frakturen- und Luxationslehre Bd. I/I. Stuttgart, Germany: Thieme; 1972.

5. Lindahl L: Condylar fractures of the mandible. Int J Oral Surg 6: 12, 1977.

6. Alkan A, Metin M, et al: Biomechanical Comparison of Plating Techniques for Fractures of the Mandibular Condyle. Brit J Oral Maxillofac Surg. 45: 145, 2007.

References:

7. Cascone P, Spallaccia F, et al. Rigid versus semirigid fixation for condylar fracture: experience with the external fixation system. J Oral Maxillofac Surg 66: 265, 2008.8. Park J M, Jang Y W, et al. Comparative study of the prognosis of an extracorporeal reduction and a closed treatment in mandibular condyle head and/or neck fractures. J Oral Maxillofac Surg 68: 2986, 2010. 9. Umstadt H E, Ellers M, et al. Functional reconstruction of the TM joint in cases of severely displaced fractures and fracture dislocation. J Craniomaxillofac Surg. 28: 97, 2000. 10. Ellis E. Complications of mandibular condyle fractures. Int J Oral Maxillofac Surg 27: 255, 1998.11. Ellis E, Throckmorton G: Facial symmetry after closed and opentreatment of fractures of the mandibular condylar process.J Oral Maxillofac Surg 58: 719, 2000. 12. Zide MF, Kent JN. Indications for open reduction of mandibular condyle fractures. J Oral Maxillofac Surg. 41:89, 1983.

References:

Condylar Fractures

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