Treatment of low subcondylar fractures—a 5-year retrospective study

Abstract

The aim of the present study was to retrospectively review the treatment outcome of low subcondylar temporomandibular joint fractures. The retrospective analysis was performed on all patients treated for low subcondylar fractures (below the sigmoid notch) between 2006 and 2011. Patients were divided into two groups: the closed reduction group (maxillomandibular fixation, MMF) and the open reduction group (anteroparotid transmasseteric (APTM) approach). Out of 129 condylar fractures, a total of 37 patients met the inclusion criterion of a fracture below the sigmoid notch (low subcondylar). Ten patients (seven males and three females) were treated using the APTM approach, and 27 patients were treated conservatively by MMF. In the open reduction group, two patients (20%) had limited mouth opening that resolved following physiotherapy; the closed reduction group had a similar percentage (18.5%) of mouth opening limitation (below 35 mm). No facial nerve damage was noted. Adult patients suffering from low subcondylar fractures can be treated by open reduction and internal fixation using the APTM approach, which was found to be a safe and reproducible procedure with no facial nerve damage; however this is a surgical procedure with a shallow learning curve.

The frequency of condylar fractures accounts for more than a third of all mandibular fractures. If these fractures are left undiagnosed or incorrectly treated, the result can be severe functional impairment, including malocclusion, limited mouth opening with or without deviation, and mandibular lateral movement impairment. The surgical treatment of condylar fractures can be divided into two major treatment modalities: closed reduction (CR) and open reduction with internal fixation (ORIF). Growing evidence in recent publications has shown that surgically treated condylar fractures have better results compared to non-surgical closed reduction methods in terms of occlusion, masticatory function, mouth opening, and bone morphology. ORIF was found to provide better functional reconstruction of mandibular condyle fractures than CR and maxillomandibular fixation (MMF). A significantly higher percentage of malocclusion (22–28%), decreased mandibular motion, and reduced posterior facial/ramus height was found in patients who were treated by closed reduction compared to patients treated using the ORIF approach. In a prospective randomized multicenter trial comparing the methods used for the treatment of displaced condylar fractures, the results were clearly in favor of the operative approach.

Two major approaches are known for ORIF of condylar fractures. The first is the intraoral approach (endoral access), which greatly reduces the risks of facial nerve damage and visible postoperative scarring, but is also technically difficult, requiring special training and specialized instruments; this approach is also associated with a high risk of postoperative complications. The second approach is the extraoral approach, which allows straightforward fracture reduction and healing, but with a risk of facial nerve injury; this approach sometimes results in a visible facial scar. In a prospective, randomized controlled multicenter trial involving patients with condylar neck fractures who were randomized to receive ORIF using an extraoral (submandibular, preauricular, or retromandibular) or a transoral endoscopic procedure, comparable functional results were achieved after reduction and internal fixation using either technique.

The aim of the present study was to evaluate the treatment modalities for low subcondylar fractures in the last 5 years. A comparison was made between closed reductions of low subcondylar fractures (below the sigmoid notch) versus open reduction using the anteroparotid transmasseteric (APTM) approach.

Materials and methods

From 2006 to 2011, 129 patients suffered subcondylar fractures that required some type of surgical treatment (either closed or open reduction). However only 37 Caucasian patients met the inclusion criterion of a low (below the sigmoid notch) subcondylar fracture (uni/bilateral). These patients were treated using either conservative, mainly closed reduction (27 patients: four females and 23 males; average age 27.1 years, range 12–66 years), or open reduction using the APTM (extraoral) approach (10 patients: three females and seven males; average age 30.2 years, range 19–42 years). There were 11 low subcondylar fractures in the open reduction group (one patient had bilateral condylar fractures). The criteria for ORIF of low subcondylar fractures were: (1) patient cannot withstand mouth closure for a minimum of 2 weeks; (2) patient is suffering from a systemic illness for which mouth closure could risk his/her life, such as uncontrolled epilepsy, anorexia/bulimia, uncontrolled diabetes mellitus (mainly type 1), and severe chronic obstructive pulmonary disease; (3) inability to perform MMF, for example in an edentulous patient. Following the surgical procedure, all patients underwent vigorous physiotherapy and 4 weeks of liquid and semi-liquid feeding.

Inclusion criteria were: low subcondylar fractures (subsigmoid) with no need for further reduction of associated facial bone fractures and a minimum follow-up period of 1 year.

Surgical techniques

Closed reduction was performed under general anaesthesia using arch-bars for MMF, with 4.0 and 5.0 stainless steel wires, for 14 days. For open reduction, the APTM approach was used during the study period (2006–2011). The open reduction was performed under general anaesthesia. In brief, after preparing a sterile surgical field, the articular fossa and mandibular ramus until the angle are identified and marked on the skin. A standard 3-cm skin incision in the retromandibular region is planned and marked. The area of the incision and the fracture site are infiltrated with local anesthetic containing adrenaline. At this point the skin is incised and the subcutaneous tissues are dissected superficial to the superficial muscular aponeurotic system (SMAS) in an antero-superior direction (face-lift approach), using blunt dissection until the fibers of the masseter muscle are visible adjacent to the antero-inferior edge of the parotid gland, just below the parotid duct. Facial nerve fibers should be preserved carefully and protected with a retractor when they are detected; the buccal branch is usually the only branch seen in the area of dissection. The deeper muscle fibers lying underneath the facial nerve can be transected safely if necessary. When the bone surface is reached, the periosteum is elevated and the fracture is identified. For reduction, we expose the fracture as widely as possible to facilitate the reduction, the first plate is fixed to the fractured condylar segment and after securing two screws only on the condylar segment, the plate is used as a retractor to guide the fractured segment into the right anatomy for reduction. Then the drilling is finalized on the ramus fractured segment. If applicable a second plate is fixed to the sigmoid area of the fracture ( Fig. 1 A) . Finally, the wound is well irrigated before it is closed in layers. A suction drain is left in place for 24 h.

Fig. 1
(A) Panoramic radiograph of the postoperative reduction of the right subcondylar fracture using two perpendicular miniplates. (B) Preoperative three-dimensional computed tomography (CT) image of the same patient. (C) Preoperative coronal CT. (D) Patient’s occlusion at postoperative follow-up; no abnormal occlusion disturbances were noted. (E) Postoperative mouth opening; no clicks or disturbances were noted. (F) Photograph of the barely visible 2-cm surgical scar in the right retromandibular area.

Surgical techniques

Closed reduction was performed under general anaesthesia using arch-bars for MMF, with 4.0 and 5.0 stainless steel wires, for 14 days. For open reduction, the APTM approach was used during the study period (2006–2011). The open reduction was performed under general anaesthesia. In brief, after preparing a sterile surgical field, the articular fossa and mandibular ramus until the angle are identified and marked on the skin. A standard 3-cm skin incision in the retromandibular region is planned and marked. The area of the incision and the fracture site are infiltrated with local anesthetic containing adrenaline. At this point the skin is incised and the subcutaneous tissues are dissected superficial to the superficial muscular aponeurotic system (SMAS) in an antero-superior direction (face-lift approach), using blunt dissection until the fibers of the masseter muscle are visible adjacent to the antero-inferior edge of the parotid gland, just below the parotid duct. Facial nerve fibers should be preserved carefully and protected with a retractor when they are detected; the buccal branch is usually the only branch seen in the area of dissection. The deeper muscle fibers lying underneath the facial nerve can be transected safely if necessary. When the bone surface is reached, the periosteum is elevated and the fracture is identified. For reduction, we expose the fracture as widely as possible to facilitate the reduction, the first plate is fixed to the fractured condylar segment and after securing two screws only on the condylar segment, the plate is used as a retractor to guide the fractured segment into the right anatomy for reduction. Then the drilling is finalized on the ramus fractured segment. If applicable a second plate is fixed to the sigmoid area of the fracture ( Fig. 1 A) . Finally, the wound is well irrigated before it is closed in layers. A suction drain is left in place for 24 h.

Fig. 1
(A) Panoramic radiograph of the postoperative reduction of the right subcondylar fracture using two perpendicular miniplates. (B) Preoperative three-dimensional computed tomography (CT) image of the same patient. (C) Preoperative coronal CT. (D) Patient’s occlusion at postoperative follow-up; no abnormal occlusion disturbances were noted. (E) Postoperative mouth opening; no clicks or disturbances were noted. (F) Photograph of the barely visible 2-cm surgical scar in the right retromandibular area.

Results

A diagnosis of low subcondylar fracture (unilateral or bilateral) was made in all the cases examined in the open reduction group ( Fig. 1 B and C). A total of 10 patients (seven males and three females) were examined with a mean follow-up of 49.2 months ( Table 1 ). Occlusion was preserved in all patients ( Fig. 1 D and Table 1 ). The postoperative mouth opening was over 35 mm in all but two patients, corresponding to 20% dysfunction; the limited mouth opening resolved during the physiotherapy period and patients did not require additional physiotherapy ( Fig. 1 E). No facial nerve injury was noted in the open reduction patient group.

Table 1
Open reduction group: patient data and postoperative follow-up complications.
Patient Gender Age, years Location Etiology Occlusion Opening a Chronic pain Dysfunction VII damage Follow-up, months
1 M 42 Right IPV Normal Good No No No 60
2 F 19 Left RTA Normal Good Yes No No 52
3 M 26 Right FFH Normal Good No No No 46
4 M 30 Left FFH Normal Good No No No 46
5 F 25 Right RTA Normal Limited Yes Right TMJ click No 56
6 M 28 Left IPV Normal Good No No No 56
7 M 37 Bilateral FFH Normal Good No No No 58
8 F 27 Right RTA Normal Good Yes No No 43
9 M 38 Left RTA Normal Limited Yes Opening deviation No 43
10 b M 42 Left IPV Normal Good No No No 32
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Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Treatment of low subcondylar fractures—a 5-year retrospective study
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