by: dr. Ali Mohammed Hasan BDS, MSc oral surgery
The condyle presents an articular surface for articulation with the articular disk of the temporomandibular joint; it is convex from before backward and from side to side, and extends farther on the posterior than on the anterior surface. Its long axis is directed medialward and slightly backward. At the lateral extremity of the condyle is a small tubercle for the attachment of the temporomandibular ligament. The articular surface of the condyle is covered by fibrous tissue, and interfaces with an articular disk (or meniscus) of avascular, non-innervated fibrous tissue (collagen, fibroblasts).
The neck is flattened from before backward, and strengthened by ridges which descend from the forepart and sides of the condyle. Its posterior surface is convex; its anterior presents a depression for the attachment of the lateral pterygoid muscle.
It prevents posterior displacement of the mandible and prevents the condyloid process from being driven upward by a blow and fracturing the base of the skull. It also act as a suspenders that holds the jaw in place.
Simple Greenstick fracture (rare, exclusively in children) Fracture with no displacement (Linear) Fracture with minimal displacement Displaced fracture Comminuted fracture Extensive breakage with possible bone and soft tissue loss Compound fracture Severe with two or more fractures Pathological fracture (osteomyelities, neoplasm and generalized skeletal disease)
Cycling trauma. Car traffic accident. Interpersonal violence. Gunshot. Falling from heights. Pathological process.
Condylar fracture could be Intracapsular fracture Extracapsular fracture High condyle neck fracture Low condylar fracture Unilateralor bilateral fracture Condylar fracture with concomitant mandibular fracture. Condylar fracture with pan-facial fracture.
Line A. A perpendicular line through the sigmoid notch to the ascending ramus1) Diacapitular (through the head of the condyle) fracture; the fracture starts in the articular surface and may extend outside the capsule.2) Fracture of the condylar neck. The fracture line starts above line A, and in more than half (the fracture distance) runs above line A. High condylar fracture.3) Fracture of the condylar base. The fracture line runs behind the mandibular foramen and in more than half the distance below line A. Low condylar fracture.
The clinical examination should consist of inspection and palpation. It is best to proceed in an orderly fashion and to perform this evaluation as a component part of the entire head and neck examination of the trauma patient. The skin of the face and, in particular, the area around the mandible should be inspected for swelling, hematomas, and lacerations. A common site for a laceration is under the chin, and this should alert the clinician to the possi- bility of an associated subcondylar or symphysis fracture
The best routine to evaluate facial fractures is to start at the top and work down, assessing the stability of the anatomic structures in a mediolateral fashion. Failure to detect the translation of the condyle, especially when associated with pain on palpation, is highly indicative of a fracture in this area.
If bilateral condylar fractures are pre-sent, the occlusion may not be deviated. The midlines are often coincident, and premature contact is present bilaterally on the posterior dentition with an anterior open bite. Any significant deviation on opening may be indicative of subcondylar fracture on the side to which the mandible deviates.
Swelling, pain, tenderness and restriction of movement Deviation of mandible towards the side of fracture Gagging of occlusion (premature contact on the posterior teeth) with bilateral condylar displaced or over-riding fractures Displacement of mandible toward the affected side Anterior open bite on opposite side of fracture Laceration of EAM Retroauricular ecchymosis Cerebrospinal leak and otorrhea in association with skull base fracture
The typical radiographic findings when a condylar fracture is present are the following: a shortened condylar-ramus length; the presence of a radiolucent fracture line or, in the case of overlapped segments, the presence of a radiopaque double density and evidence of premature contact on the side of fracture.
1. Significant displacement or dislocation, particularly if open reduction is contemplated 2. Limited range of motion with a suspicion of mechanical obstruction caused By the position of the condylar segment 3. Alteration of the surrounding osseous anatomy by other processes, such as previous internal derangement or temporomandibular joint surgery, to the degree that a pretreatment base-line is necessary 4. Inability to position the multiple-trauma patient for conventional radiographs (CT scans may be the only useful radiograph that can be obtained)
Noroutine laboratory testing is indicated unless dictated by the medical history.
Goals of Therapy 1. Obtain stable occlusion. 2. Restore interincisal opening and mandibular excursive movements. 3. Establish a full range of mandibular excursive movements. 4. Minimize deviation of the mandible. 5. Produce a pain-free articular apparatus at rest and during function. 6. Avoid internal derangement of the TMJ on the injured or the contralateral side. 7. Avoid the long-term complication of growth disturbance.
No treatment. closed reduction (management). open reduction. endoscopically assisted. free plating and grafting.
1) No Treatment: No treatment is considered when no occlusal discrepancy or functional impairment exists.2) Closed Reduction: Condylar neck fractures in children <15 years Very high condylar neck fractures without dislocation Intra-capsular fractures. Grossly comminuted fractures and gun shot.
3) Open Reduction: 1. Absolute indications A. Limitation of function secondary to the following: 1. Fracture into middle cranial fossa 2. Foreign body within the joint capsule 3. Lateral extracapsular dislocation of condylar head. 4. Other fracture dislocations in which a mechanical stop is present on opening,which is confirmed radiographically B. Inability to bring the teeth into occlusion for closed reduction
2. Relative indications: A. Bilateral condylar fractures with comminuted midface fractures in which rigid internal fixation of the midface is not possible B. Situations when intermaxillary fixation is not feasible as a result of the following: 1. Medical restrictions a. Poorly controlled seizure disorder b. Psychiatric disorders c. Severe mental retardation d. Concomitant injuries such as head injury or chest injury (unless tracheostomy is planned) 2. Displaced fractures where dentures or splints are not feasible because of severe mandibular atrophy C. Bilateral fractures in which it is impossible to determine what the proper occlusion is as a result of loss of posterior teeth or the presence of a preinjury skeletal malocclusion D .In fracture dislocation in adults to restore the position and function of the meniscus (controversial)
4) endoscopically assisted. it reduces the risk to the facial nerve and minimizes scarring. Condylar neck fractures may be treatable by EAORIF as long as there is sufficient bone stock to place at least two bicortical screws in the proximal fragment. Subcondylar fractures are generally suitable for EAORIF as long as significant comminution is not present. Using the intraoral approach, a ramus incision similar to one for a mandibular osteotomy is made and the masseter muscle stripped to create the optical cavity. A 4-mm 30° endoscope with an adapted retractor provides direct vision and this is aided by a Freer elevator with built in suction. Under vision and with special instruments the fracture is manipulated and reduced
5) Free plating and grafting: This is used with severe extensive fractures/lesions in which a large portion of bone is lost
The mandible is manipulated so that the teeth are in normal occlusion, followed by mandibulo-maxillary fixation. This is achieved by the use of Arch bars Jelenko Erich pattern German silver notched Cap splints
Gunning’s splintBonded bracketsIMF screwsDental wiring: Direct wiring Eyelet wiring Local anesthesia or sedation Treatment can be performed under GA or LA and when surgery is contraindicated
Differences in the length of IMF depend on 1) the age of the patient. 2) the type of fracture. 3) the presence of other fractures.Ranging from 2-8 weeks until re-establishing a preinjury occlusion.
Criticism of the disadvantages of prolonged immobilization of the jaws has included patient complaints of panic, insomnia, social inconvenience, pho- netic disturbance, loss of effective work time, physical discomfort, weight loss, histo- logic changes in the condylar head, and dif- ficulty recovering a normal range of jaw movement. This has led some clinicians to seek alternative methods of treatment, including the use of rigid internal fixation.
A variety of surgical approaches to the fractured condyle have been suggested, including:- intraoral. submandibular. retro-mandibular. preauricular. more recently, endoscopic. The most important factor in determining the approach used is the level at which the fracture has occurred. Modifying factors such as the degree of displacement or dislocation and the planned method of fixation may also have a bearing on the approach selected.
Traditionallyfractures in the condylar neck and above were best approached through a preauricular incision. Subcondylar fractures and fractures extending into the upper ramus region are best approached using a retro-mandibular or Hinds approach.
The incision begins approximately 1 cm below the lobe of the ear and 1 cm posterior to the ramus of the mandible. The dissection is carried down to the parotid gland, which is retracted anteriorly, providing access to the vertical fibers of the masseter muscle overlying the ramus. These fibers are not stripped but instead are separated bluntly along their vertical course, allowing access to the underlying ramus.
Low sub-condylar fractures, especially those with-out a significant degree of displacement, may be easily approached from an intra-oral incision. In severe anteromedial fracture dislocations in which the condylar head is not retrievable despite the choice of approach, a vertical ramus osteotomy, followed by removal of the osteotomized segment, has been recommended.
Transosseous wiring Circumferential wiring External pin fixation Bone clamps Trans-fixation with Kirschner wires
Non-compression small plates Compression plates Miniplates Lag screws Resorbable plates and screws
In cases in which open reduction internal fixation is employed without the use of postoperative IMF, follow-up visits should be used as reinforcement sessions to remind the patient about proper diet (soft mechanical diet) and progressive increase in function. In most cases some form of IMF will have been employed. The length of the fixation period, as previously discussed, varies between 2 to 8 weeks depending on many factors. At the end of this period, a systematic approach for removal of the fixation is desirable.
Children of less than 12 years of age rarely require more fixation, but patients over the age of 12 years show extreme variability, regardless of fracture type. If the occlusion is stable and reproducible at the time of IMF release, then jaw-opening exercises are begun. after release of IMF the patient should 1) be evaluated in 24 hours to confirm the presence of a stable occlusion.
2) The arch bars are left in place and training elastics are used to permit function while maintaining the occlusion. 3) the elastics are used for 24 hours a day in the 1st week where it is lightly applied during daytime and more tightly at night. 4) in 2nd to 3rd week, day time elastics may be completely abandoned and used only at night.
5) the patient should be allowed to function without any guiding elastic fixation for approximately 1 week. If, at that time, there continues to be a stable occlusion, further evaluation should continue for other problems, such as limited mouth opening or pain, and the arch bars may be removed. 6) Throughout the post-IMF period, aggressive maintenance of range of motion is necessary. In some patients this may be as simple as instructing them to open their mouths as wide as possible in a symmetrical manner.
7) in other patients, Manually forcing the teeth apart, use of a ratchet, mouth props, progressive wedging of tongue blades between the teeth.
Delayed Union and Nonunion Infection Malunion Nerve injury Growth alteration Temporomandibular Joint Dysfunction
1)Internal Derangement: A correlation exists between previous condylar fracture and the development of internal derangement of the TMJ. There is a greater incidence of temporomandibular joint pain, deviation on opening and joint noise in patients with previous condylar fractures.
2) Ankylosis: It is more likely to occur in children and is associated with intracapsular fractures and immobilization of the mandible. The most commonly accepted etiology is of intra-articular hemorrhage, leading to abnormal fibrosis and ultimately ankylosis.
site and type of fracture. the age of the patient at the time of injury. the duration of IMF. the extent of damage to the disk.
Intracapsular fractures are best treated closed. Fractures in children are best treated closed except when the fracture itself anatomically prohibits jaw function. Most fractures in adults can be treated closed. Physical therapy that is goal-directed and specific to each patient is integral to good patient care and is the primary factor influencing successful outcomes, whether the patient is treated open or closed. When open reduction is indicated, the procedure must be performed well, with an appreciation for the patients occlusal relationships, and it must be supported by an appropriate physical therapy and follow-up regimen.