Long-term follow upStabilitySkeletal stability Orthognathic surgery
Many surgeons and orthodontists are very curious about the long-term outcomes, including stability, following the surgery-first approach (SFA). I explained and described SFA-related stability issues in the previous chapter; this chapter focuses on long-term surgical outcomes, including facial aesthetics and occlusion, in clinical cases. Many surgeons suggested the method how the relapse is minimized and the skeletal stability is maintained [1, 2, 5–7].
The surgery-first orthognathic concept was introduced in our practice to address the above-mentioned issues. Since its initial 2001 presentation, titled “functional orthognathic surgery,” we have actively applied SFA. We understand that there are numerous concerns regarding this approach; however, many surgeons have recently published outcomes on this topic. Nonetheless, different authors have widely varying philosophies and methodologies.
Our application of SFA does not simply omit presurgical orthodontic treatment. Rather, it begins with a functional concept that is based on presurgical orthodontic treatment simulated on a dental model (Fig. 14.1). Based on the results of these analyses, we determine whether SFA should be performed. Among recently published articles, there are very few reports of large-scale, long-term stability outcomes. We analyzed our SFA data, based on cephalometric analyses, and compared the traditional and surgery-first approaches (Figs. 14.2, 14.3).
14.1 Results
In total, 104 patients (66 females) with Class III deformities were enrolled in the SFA group and 51 similar patients (35 females) were enrolled in the traditional approach group. The patients in both groups were ethnic Asians and had average ages of 23.3 years (SFA group) and 23.1 years (traditional group). The follow-up period ranged from 17.3 to 121.2 months (average, 74.0 months). Satisfactory results were achieved in all 155 patients with dentofacial deformities, in this study and none required additional surgeries to resolve occlusal instability. There were no major complications, such as serious infections, malocclusions, or fixation failures; two patients experienced mild wound infections, which resolved after 10 days of antibiotic treatment. The baseline cephalometric landmarks are shown (Table 14.1). Overall, the analyses revealed that anteroposterior skeletal stability in the SFA group was statistically similar to that in the traditional group. Initially, we investigated whether the two groups had preoperative differences in their cephalometric landmarks. The presurgical cephalometric analysis failed to reveal any significant differences in preoperative horizontal skeletal landmarks, except for the angle of lines connecting the sella, nasion, and point B (SNB), vertical reference plane (VRP) to point B, and VRP to the anterior nasal spine (ANS) and point A. The differences meant that more severe Class III dentofacial deformities were present in the SFA group than in the traditional group [1–4].
Table 14.1
Preoperative comparison between the orthodontic- and surgery-first groups at T0 for initial evaluation of cephalometric differences
Orthodontics-first (n = 51)
Surgery-first (n = 104)
P
Mean
SD
Mean
SD
Horizontal skeletal pattern
A to N perp
−2.46
5.79
−0.9
4.53
0.0989
Pog to N perp
−3.72
10.13
1.28
9.2
0.0026*
SNA
77.98
5.57
79.52
4.43
0.0656
SNB
77.79
5.45
80.17
4.85
0.0069*
ANB difference
0.2
4.45
−0.64
3.79
0.2252
APDI
90.24
9.97
90.86
7.76
0.7006
Combination factor
154.86
9.86
152.27
9.16
0.112
Wits
−5.45
4.74
−6.6
4.6
0.1525
Facial convexity
−0.98
10.35
−2.73
8.45
0.2658
Ramus height
52.51
7.12
52.72
6.22
0.8527
Body length
76.26
6.26
79.74
7.53
0.0052*
Body to ant cranial base ratio
1.15
0.09
1.17
0.1
0.191
FABA
87.68
9.7
90.67
8.09
0.0458*
FH to OP
10.71
6.15
9.13
4.9
0.0864
VRP to ANS
65.45
7.7
68.84
7.42
0.0098*
VRP to PNS
17.09
4.78
18.5
4.15
0.0617
VRP to A
60.37
8.12
63.89
7.38
0.008*
VRP to B
56.03
11.79
62.29
10.67
0.0012*
A point A, ANB angle of lines connecting point A, the nasion, and point B, ANS anterior nasal spine, APDI anteroposterior dysplasia indicator, FABA Frankfort horizontal line to AB plane angle, FH Frankfort horizontal line, N nasion, per perpendicular, PNS posterior nasal spine, Pog pogonion, SNA angle of lines connecting the sella, nasion, and point A, SNB angle of lines connecting the sella, nasion, and point B, VRP vertical reference plane
*P < 0.05
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