Outcome of facial contour asymmetry after conventional two-dimensional versus computer-assisted three-dimensional planning in cleft orthognathic surgery

Abstract

Computer-assisted 3D planning has overcome the limitations of conventional 2D planning-guided orthognathic surgery (OGS), but difference for facial contour asymmetry outcome has not been verified to date. This comparative study assessed the facial contour asymmetry outcome of consecutive patients with unilateral cleft lip and palate who underwent 2D planning (n = 37)-or 3D simulation (n = 38)-guided OGS treatment for correction of maxillary hypoplasia and skeletal Class III malocclusion between 2010 and 2018. Normal age-, gender-, and ethnicity-matched individuals (n = 60) were enrolled for comparative analyses. 2D (n = 60, with 30 images for each group) and 3D (n = 43, with 18 and 25 images for 2D planning and 3D simulation groups, respectively) photogrammetric-based facial contour asymmetry-related measurements were collected from patients and normal individuals. The facial asymmetry was further verified by using subjective perception of a panel composed of 6 blinded raters. On average, the facial contour asymmetry was significantly (all p < 0.05) reduced after 3D virtual surgery planning for all tested parameters, with no significant differences between post-OGS 3D simulation-related values and normal individuals. No significant differences were observed for pre-and post-OGS values in conventional 2D planning-based treatment, with significant (all p < 0.05) differences for all normal individuals-related comparisons. This study suggests that 3D planning presents superior facial contour asymmetry outcome than 2D planning.Orthognathic surgery (OGS) plays a key role for successful management of a myriad of facial deformities associated with malocclusion, with facial asymmetry feature being most frequently associated with skeletal class III malocclusion 1-3 . Particularly, patients with unilateral cleft lip and palate differ from the noncleft population, because they have a congenital orofacial defect compromising both the bone and soft tissues on the lesion side 4-6 , which may be expressed as facial asymmetry 7-15 . Skeletal mature patients with clefts frequently presents with maxillomandibular disharmony (maxillary hypoplasia and skeletal class III malocclusion) which requires OGS treatment 7-15 . As residual facial asymmetry after OGS treatment may negatively impact patients' perceptions about outcome requiring further revisionary surgical interventions [16][17][18][19] , the significance of preoperative prediction of this deformity should not be underestimated 15,16,20 . Therefore, it is of paramount that an accurate diagnosis of asymmetry is accomplished preoperatively for that a precise surgical planning and execution is performed 7,15,16,20 .In this setting, OGS planning has evolved over the past decades 15-24 . Traditionally, OGS planning has been constructed on two-dimensional (2D) cephalometry, 2D photographic analysis, articulators, and dental models 21,22 . However, this planning modality presents limitations for challenging clinical scenarios such as patients with clefts associated with malocclusion a...

Three-Dimensional Computer-Assisted Single-Splint 2-Jaw Cleft Orthognathic Surgery: Toward Patient-Centered Surgical Rationale

“…Over the past 4 decades, all technical details that could attenuate the surgical burden of care (ie, reduction in the number of revision surgeries, clinical appointments, and overall treatment time) during the development and maturity phases have been combined to compose our current cleft surgical protocol (Denadai and Lo, 2019; Pai et al, 2019; Denadai et al, 2020). The single-splint concept based on patient-centered planning and execution has been consistently reproduced by treating surgeons in our center, resulting in the minimization of cleft stigma (Supplementary Material 7), achieving a maximum benefit–risk equilibrium as required for elective surgery, improved symmetry (overall facial symmetry, midline, and contour), clinically stable results (relapse within the clinically acceptable range), and minimal requirement of revision surgery (Lonic et al, 2016; Chou et al, 2019; Liao et al, 2019; Seo et al, 2019; Hsu et al, 2020). The 3D digital environment of OGS treatment supports the complete integration of functionally and aesthetically rehabilitated patients into society (Supplementary Material 8), which is the goal of long-term cleft care (Denadai and Lo, 2019; Pai et al, 2019; Denadai and Lo, 2020).…”

“…Compared with conventional 2-dimensional imaging-aided stone model surgery, 3D virtual surgery has revolutionized the perioperative workup (ie, laser scanned dentition, 3D cephalometric tracings, digital occlusion set-up, and computer-generated surgical splint) and outcomes (ie, time efficiency, accuracy, facial contour symmetry, and cost-effectiveness) of OGS care (Lonic et al, 2016; Ho et al, 2017; Wu et al, 2017; Hsu et al, 2020). The cone-beam computed tomography-based 3D diagnostic pathway (Supplementary Material 1) provides the opportunity for an orthodontic-surgical collaborative approach (Wu et al, 2017).…”

Current trends in orthognathic surgery

“…Wilson et al [28] reported that there was a high degree of conformity when comparing the virtual surgical planning to the actual postoperative outcomes, except for some incongruent results of maxillary vertical and mandibular sagittal movement. Furthermore, 3D virtual planning also has advantages for soft tissue simulation with facial contouring, and Hsu et al [33] reported that 3D planning presents superior facial contour symmetry outcomes than two-dimensional (2D) planning in unilateral cleft patients. The use of a fabricated osteotomy cutting guide and prebended fixation plates based on virtual surgical planning increases the feasibility of planned osteotomies and repositioning of the maxillomandibular segment, thereby saving time [34].…”

Considerations for virtual surgical planning and simulation in orthognathic surgery—a narrative review

“…Computerized planning in orthognathic surgery allows surgeons to carry out comprehensive evaluation of anatomical structures of the surgical field. In asymmetric patients, VSP can be used to diagnose presurgical problems and can predict the postoperative 3D position of osteotomized segments, thereby predicting redundant asymmetry after surgery (26). At the same time, the need for dental decompensation after surgery can also be visualized and it is possible to reflect the magnitude of overcorrection to VSP in advance (1).…”