In this final blog in our orthognathic series, we will explore Surgery First Approach. The ‘re-staging’ of the conventional orthognathic stages offers potential advantages over conventional orthognathic stages, this blog will explore what the advantages are and what the research has indicated. However, re-staging also creates greater potentially uncertainty, which we will also as part of the disadvantages of Surgery First.
Surgery First is the re-staging of orthognathic surgery, moving surgery to the first stage of combined orthodontic-orthognathic treatment, followed by the second stage of orthodontics to decompensate, align and level and coordinate. By contrast, conventional staging involves delaying surgery, with a first stage of orthodontics to (in general) decompensate, align and level, and coordinate, followed by the second stage of surgery (as discussed in our first blog).
Surgery is carried out at the very beginning of treatment or shortly after placement of orthodontic appliances (within 1 to 2 months) Baek 2010.
Planning. Similarly to conventional orthognathic planning, the surgical planning involves calculation of the planned skeletal changes, however the due to the dentition being compensated, most occlusal parameters cannot be used to aid surgical planning. The molar relationships are therefore used as an estimate guide with 1 mm to 2 mm of overcorrection Liao, 2018. In the vertical plane the planning for deep bite correction is similar to conventional planning, however anterior-open bite planning can be unpredictable due to the lack of levelling or coordination. Transverse planning involves planning around the skeletal base ‘midlines’, and not the dental midlines, which may not be aligned with the skeletal bases.
Intermaxillary fixation. Fixation is achieved through surgical arch bars, orthodontic miniscrews or plates where surgery is carried out first. When surgery is carried out at 1 to 2 months later, the additional options of a passive steel archwire (with custom bends to ensure passive) or an archwire with hooks can be used, however in the case of the latter, the archwire will lack rigidity with the potential to distort during intermaxillary fixation creating interferences post operatively.
Retention of surgical splint. The surgical splint is retained for 1 week to 4 weeks after surgery to help maintain the corrected position for stability (Sugawara, 2010). This stage is uncommonly used in conventional planning due to occlusal stability, however in Surgery First cases, there is a likelihood of occlusal instability.
The proposed advantages are listed below:
The two main advantages are explored below, reduced treatment times and avoiding decompensation of appearance.
The duration of treatment for conventional orthodontic-orthognathic surgery is extended, with an average duration of 30 months Paunonen 2017, with the average treatment time of pre-surgical orthodontics of 18-24 months, followed by approximately 6 months of post-surgical orthodontics. The duration of Surgery First is significantly shorter, on average 10.2-11.7 months, with no or little pre-surgical orthodontics, followed by the post-surgical orthodontics (Anwar 2022, unpublished research Ashraf Ayoub).
The difference between both groups is stark, with Surgery First 1/3rd of the duration of conventional orthodontic-orthognathic surgery. The number of appointment are also reduced, with Surgery First taking on average 14 appointments, and 24 appointments with conventional orthognathic treatment Anwar 2022.
There are two reasons suggested for the difference in duration:
Quality of Life: Overall no difference was present between Surgery First and conventional surgery at the end of treatment (Surgery First 22 SD 3 Vs conventional treatment 29 SD 9). However there is a significant differences of patient’s quality of life during orthodontic treatment, with contrasting findings. Surgery First patients in treatment had a score 22, however by contrast conventional surgery patients have a worsening of scores during treatment by 8 points to 60 Pelo 2017. The worsening of quality of life measures for conventional orthognathic cases is attributed to the visual effects of decompensation, which typically worsen facial appearance, with an associated impact on the patient’s quality of life. Although this increase in worsening quality of life scores occurs in treatment, it is important to note the differences between the groups disappears at the end of both treatment modalities.
The lack of stability has been proposed as a major limitation of Surgery First, attributed to the lack of occlusal stability immediately post-surgery. A systematic review found no difference overall in horizontal relapse between Surgery First and conventional surgery of either the Maxilla or Mandible for a variety of malocclusions (Maxilla MD-0.60 95% Ci -1.44-0.25, Mandible MD 0.02 95% Ci -1.12,1.15) Yang 2017. However two studies did find relapse of 1.5 to 2mm of the mandible in Class III cases 1 year following surgery, and attributed the relapse to mandibular autorotation which occurs after settling of the mandible after the surgery and the removal of occlusal interferences. (Ko 2013, Kim 2014)
Cases with require less orthodontic decompensation lend themselves to a Surgery first approach, with less orthodontic movements required post surgically with more accurate skeletal and soft tissue planning. However, patients with significant compensation, or compensation in three planes of space, can require considerable orthodontic movement to decompensate, which can create uncertainty with Surgery first in terms of planning the skeletal and soft tissue ideas, resulting in under correction of the dento-facial discrepancy. Conventional orthognathic planning is well established with standardized treatment protocols, with predictability discussed in our previous blog, with planning based on the presentation of decompensated arches, which require predicting (and therefore potential error) in Surgery First cases. As a result, Surgery First does not have the same well established protocols in terms of planning. One must also consider with Surgery First the use of orthodontic miniscrews in order to aid control of post-surgical decompensation, which can increase the orthodontic complexity Sugawara, 2010.
Conventional orthognathic surgery has it’s drawbacks, mainly the time in treatment, and worsening of the patients Quality of Life during treatment, both are addressed with the Surgery First Approach, however Surgery First is limited to selected case types and with potentially complex orthodontics required to manage the case post-surgery. For the advantages the technique offers, Surgery First is likely to remain limited to select malocclusions.
Contents: Kerolos AlHakeem 
Contents: James Andrews
Edited/contents: Farooq Ahmed
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