Modified tragus edge approach for mid-level or low condylar fractures

Abstract

The aim of this study was to evaluate and report a modified tragus edge approach (MTEA) for surgical access to mid-level or low condylar fractures. The MTEA was used on 45 patients (59 sides). All of the patients were reviewed for scarring, parotid fistula, facial nerve function, occlusion, deviation, and limitation of mouth opening (MO). Forty-one patients (64 sides) with middle or low level condylar fractures who underwent surgery by retromandibular approach during the same period were selected for comparison. In the MTEA group, scars were not obvious and there was no parotid fistula. The occlusion of four cases (8.9%) was not ideal, but returned to normal after 2 weeks of intermaxillary traction. Temporary facial nerve damage was present on two sides (3.4%). MO was not deviated in any patient, but was limited in the first 2 weeks after operation in three cases (6.7%). The risks of facial nerve dysfunction and parotid fistula were much higher in the retromandibular approach group than in the MTEA group, while the risks of malocclusion and limitation of MO were similar. MTEA is safe and has good aesthetic outcomes. MTEA represents an appropriate surgical access to mid-level and low condylar fractures.

The condylar process is frequently involved in oral–facial fractures, and condylar process fractures account for 25–50% of fractures of the mandible. The treatment of fractures of the condylar process remains controversial. Although it is widely accepted that the treatment outcomes of open reduction and internal fixation are superior to those of conservative treatment for grossly displaced condylar fractures, a discussion of the surgical access for the treatment of condylar fractures is warranted. Several approaches have been advocated for condylar fractures in previous publications. A novel surgical approach–the modified tragus edge approach (MTEA)–used on 45 patients suffering from mid-level or low condylar fractures was assessed in this study. The purpose of this retrospective study was to evaluate this novel surgical approach to mid-level or low condylar fractures in terms of cosmesis, operability, and complication rates.

Materials and methods

Ethical approval for this study was obtained from the university hospital research ethics board. This study was performed in accordance with the ethical standards of the responsible committee on human experimentation and the Declaration of Helsinki of 1975, as revised in 2013.

Clinical data

This retrospective study covered the period October 2007 to February 2015. During this period, 45 patients with mid-level or low condylar fractures underwent surgical treatment via MTEA in the oral and maxillofacial surgery department of the study university hospital in Hangzhou, China. All patients suffered from displaced fractures with functional impairment. There were 26 males and 19 females, ranging in age from 19 to 54 years. Thirty-one patients had unilateral condylar fractures and 14 had bilateral condylar fractures, for a total of 59 sides. Thirty-three patients had their surgical intervention within a week of injury, while 12 patients had a delay of 1 to 3 weeks before surgery. Thirty-six of the fractures were classified as mid-level and 23 as low condylar neck fractures.

Forty-one patients with middle or low level condylar fractures who underwent surgery by retromandibular approach during the same period were selected as a control group. Twenty-three of these patients had bilateral condylar fractures and 18 had unilateral fractures, for a total of 64 sides. There were 35 mid-level and 29 low condylar neck fractures in the control group.

Surgical methods

Modified tragus edge incision

The incision is made along the tragus edge, extending downward to the inferior margin of the ear lobe, and then curving upwards behind the auricle for 2–3 cm. The upper limit of the tragus edge incision extends only to the mid-tragus and does not need to be extended any further.

Fracture exposure

The incision is cut open and then the skin flap is raised forward along the superficial temporal fascia. After raising the skin flap anterior to the parotid over the parotid fascia, a large space is exposed between the parotid duct and the lower buccal branch of the facial nerve ( Fig. 1 ). Dissection is performed in layers between the anterior edge of the parotid and the posterior edge of the masseter muscle, to expose the posterolateral mandibular ramus. The condylar neck and sigmoid notch of the mandible can then be exposed after the parotid is retracted back and the masseter is retracted anteriorly, without disrupting the parotid gland ( Fig. 2 ). If more space is required at the fracture site to facilitate the reduction of the fractured segment, the ascending ramus can be distracted inferiorly by applying an artery forceps at the mandibular angle and pulling it inferiorly. A better exposure can also be achieved by pushing the ramus inferiorly and anteriorly with an instrument on the sigmoid notch.

Fig. 1
Exposure of the fracture. Reflecting the skin flap to the front of the parotid, over the parotid fascia, and exposing the space between the parotid duct and the lower buccal branch of the facial nerve.

Fig. 2
Diagrammatic drawing of fracture exposure. Exposure of the fractured condyle intraoperatively by retracting the parotid posteriorly and superiorly, retracting the masseter anteriorly, and entering the fracture site between the parotid duct and the lower buccal branch of the facial nerve.

Fixation

All of the condylar neck fractures were fixed with two titanium miniplates ( Fig. 3 ), one placed on the posterolateral edge of the fracture line to resist compressive stresses and the other placed on the anteromedial edge to resist tensile stresses. The attachment of the lateral pterygoid muscle to the condylar process was carefully preserved as best as possible in every patient.

Fig. 3
Fixation and postoperative computed tomography scan. Left: The condylar neck fracture is fixated with two titanium miniplates through this modified approach. Right: Three-dimensional computed tomography scan showing reduction and fixation of the condylar fracture with two titanium plates.

Postoperative therapy

Intermaxillary traction (IMT) was used for 2 weeks in four patients to correct slight malocclusion. Mouth opening physiotherapy was adopted at 1 week post-surgery for the 41 patients who did not receive IMT, and was also performed on the four patients post IMT.

Study indices and evaluation criteria

Patients were followed-up for 6–12 months, with postoperative assessments performed at each follow-up visit. The following were assessed: cosmetic result (scar formation), occlusion, deviation and limitation of mouth opening (MO), facial nerve dysfunction, and the occurrence of salivary fistulae.

Results

Surgical scars were unnoticeable and not prominent in the MTEA group ( Fig. 4 ). All the wounds healed well without abscesses or salivary fistulae. Symptoms of facial nerve paralysis were noted for two sides (3.4%), in which shallower nasolabial folds were presented. However, the complication resolved within 2 months in both sides. Slight malocclusion was found in four patients (8.9%). MO was not deviated in any patient, but was limited in the first 2 weeks after the operation in three patients (6.7%). Ideal occlusion and normal MO were achieved eventually (6 months later) for all of these patients following 2 weeks of IMT.

Fig. 4
Unnoticeable surgical scar. Surgical scarring of the tragus incision was minor and cosmetically acceptable.

For the 41 patients suffering from middle or low level condylar fractures who underwent reduction and fixation via retromandibular approach, the scar was found to be more prominent and the patient self-evaluation score for scarring was lower than in the MTEA group. Parotid fistulae were identified in four sides (6.3%), and seven sides (10.9%) were affected by temporary facial nerve paralysis. A limitation of MO was found in three patients (7.3%), but MO was not deviated in any patient. Slight malocclusion was found in three patients (7.3%); this recovered to normal in all cases after 2 weeks of IMT.

The risks of facial nerve dysfunction and parotid fistula were much higher in the retromandibular approach group than in the MTEA group, while the risks of malocclusion and limitation of MO were similar. Details of the comparisons between the two groups are found in Tables 1 and 2 .

Dec 15, 2017 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Modified tragus edge approach for mid-level or low condylar fractures
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