2017-18 HSC Section 3 Green Book

H.-T. Liao et al. / Journal of Cranio-Maxillo-Facial Surgery 43 (2015) 1595 e 1601

Fig. 5. The preoperative 90 angulation of a condylar neck fracture in three-dimensional CT (mini-preauricular incision group).

Fig. 4. Illustration of how to measure the displacement (left side of the image) and angulation (right side of the image).

3.3. Postoperative jaw function comparison

3.2. Preoperative and postoperative comparison in angulation and displacement of condylar fractures

The mean maximal mouth opening was 39.8 mm in mini- preauricular incision group and 39.9 mm in other approach group ( Table 1 ). No signi fi cant difference was noted between the two groups. Twenty-six of Twenty-nine patients achieved Grade I acceptable occlusion after surgery in both groups ( Table 1 ). Three patients in each group showed mild malocclusion which could be corrected by orthodontists. No patient suffered from major malocclusion which needed further surgical management in either group. Fig. 7 demonstrates good mouth opening 6 months after operation in the mini-preauricular incision group.

Medial displacement with overlapping and shortening of pos- terior ramus height in the mini-preauricular and the other- approach groups was displayed in 23 and 20 condylar fractures, respectively. The mean shortening distance was 6.8 mm and 7.8 mm in the mini-preauricular and other-approach groups, respectively ( Table 2 ). Angulation of the fracture site in the mini- preauricular and other approach groups resulted in 13 and 12 condylar fractures, respectively. The mean angulation was 65.9 and 25.1 mm in the mini-preauricular and other-approach groups, respectively ( Table 2 ). Postoperatively the outcome of anatomical reduction was achieved in 34 of the condylar fractures (94.4%) of the mini- preauricular group, and 29 (90.6%) of the other approach group ( Table 2 ). Two of mini-incision group and three of other approach group showed mild angulation after operation. This mild angula- tion did not cause any malfunction of the TMJ joint or malocclu- sion that needed further surgical correction. Fig. 5 shows the angulation of the condylar fracture preoperatively and Fig. 6 demonstrates the anatomical reduction of the fracture with in- ternal fi xation postoperatively by 3D CT in the mini-preauricular incision group.

3.4. Postoperative complications

The patients in both groups underwent uneventful post- operative courses without infection, hemorrhage, Frey's syndrome, salivary fi stula or sialocele. No major facial palsies were found in either group, expect for one patient who experienced frontal branch paresis after a face-lift approach. Fig. 8 shows the scar over the preauricular area 6 months after operation in the mini- preauricular incision group.

Table 2 Preoperative and postoperative function comparison for each group.

Mini-preauricular Other approaches

Preoperative fracture evaluation Displacement, mean (SD) (mm) Angulation, mean (SD) (degrees)

6.8 (4.6) n ¼ 23 7.8 (5.7) n ¼ 20 65.9 (18.7) n ¼ 13 25.1 (23.1) n ¼ 12

Postoperative fracture evaluation Reduction to anatomical position 34 (94.4%)

29 (90.6%)

Mild angulation

2 (5.6%)

3 (9.4%)

Condylar vertical height shortening 0 Postoperative jaw function Recovery to previous occlusion (Grade I) Mild malocclusion (Grade II) Malocclusion needing re-operation (Grade III) Maximal mouth opening (MMO), mean (SD) (mm) 0

0

26 (89.7%)

26

3 (10.3%)

3 0

39.8 (SD 2.9)

39.9 (SD 4.8)

Fig. 6. Postoperative three-dimensional CT showing the anatomical reduction and internal fi xation of a condylar neck fracture (mini-preauricular incision group).

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