Three-Dimensional Computer-Assisted Orthognathic Surgery: Traditional Hybrid Versus Full Digital Planning Models

Virtual surgical plan with custom surgical guide for orthognathic surgery: systematic review and meta-analysis

BACKGROUND

The shift from traditional two-dimensional (2D) planning to three-dimensional (3D) virtual surgical planning (VSP) has revolutionized orthognathic surgery, offering new levels of precision and control. VSP, combined with computer-aided design/computer-aided manufacturing (CAD/CAM) technology, enables the creation of patient-specific surgical guides and implants that translate preoperative plans into more precise surgical outcomes. This review examines the comparative accuracy and operative efficiency of VSP, especially when used with custom surgical guides, against conventional 2D planning in orthognathic surgery.

MAIN TEXT

The study systematically reviewed and analyzed published literature comparing the accuracy and operative time between VSP and conventional planning methods. The meta-analysis included clinical trials, controlled trials, and observational studies on patients undergoing orthognathic surgery, focusing on the degree of alignment between planned and postoperative bone positions and total surgery time. Results indicate that VSP consistently reduces discrepancies between planned and actual surgical outcomes, particularly when integrated with custom surgical guides. Additionally, while VSP demonstrated potential time-saving advantages over conventional planning, these differences were not statistically significant across studies, likely due to high variability among study protocols and designs.

CONCLUSIONS

VSP with custom surgical guides enhances surgical accuracy in orthognathic procedures, marking a significant advancement over traditional methods. However, the reduction in operative time was not conclusively significant, underscoring the need for further studies to evaluate time efficiency. These findings emphasize VSP's role in improving surgical precision, which holds substantial implications for future orthognathic surgical practices.

Treatment of skeletal class III malocclusion using a combined clear aligner and surgery-early approach : Assessment based on the American Board of Orthodontics Objective Grading System

PURPOSE

To evaluate whether clear aligner therapy (CAT) combined with a surgery-early approach can achieve good therapeutic effects in patients with skeletal class III malocclusion.

METHODS

Thirty consecutive skeletal class III malocclusion cases treated with clear aligners combined with early surgery were selected. Treatment time, lateral cephalograms and American Board of Orthodontics Objective Grading System (ABO-OGS) scores of the treatment models were measured to evaluate the treatment efficiency, facial profile, and occlusion.

RESULTS

The results showed that early surgery was achieved after 7.71 months of presurgical orthodontics, on average. ANB decreased by 5.57° (P < 0.001), and STissue N Vert to Pog' decreased by 7.29 mm (P = 0.001), both reaching normal values. The posttreatment ABO-OGS scores were 26.600 on average, meeting its standards.

CONCLUSIONS

With the assistance of CAT, early surgery can be accomplished in patients with skeletal class III malocclusion, improving their facial profile and achieving functional occlusion.

Average Three-Dimensional Skeletofacial Model as a Template for Bone Repositioning during Virtual Orthognathic Surgery

BACKGROUND

Virtual planning has revolutionized orthognathic surgery. This study presents a computer-assisted method for constructing average three-dimensional skeletofacial models that can be applied as templates for surgical planning for maxillomandibular repositioning.

METHODS

The authors used the images of 60 individuals (30 women and 30 men) who had never undergone orthognathic surgery to construct an average three-dimensional skeletofacial model for male participants and one for female participants. The authors validated the accuracy of the newly developed skeletofacial models by comparing their images with 30 surgical simulation images (ie, skulls) that had been created using three-dimensional cephalometric normative data. The comparison was conducted by superimposing surgical simulation images created using the authors' models with the previously created images to analyze their differences, particularly differences in the jawbone position.

RESULTS

For all participants, the authors compared the jaw position in the surgical simulation images created using the authors' average three-dimensional skeletofacial models with that in the images created using three-dimensional cephalometric normative data. The results revealed that the planned maxillary and mandibular positions were similar in both images and that the differences between all facial landmarks were less than 1 mm, except for one dental position. Most studies have reported less than 2 mm to be the success criterion for the distance difference between planned and outcome images; thus, the authors' data indicate high consistency between the images in terms of jawbone position.

CONCLUSION

The authors' average three-dimensional skeletofacial models provide an innovative template-assisted orthognathic surgery planning modality that can enhance the fully digital workflow for virtual orthognathic surgical planning.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Single-Splint, 2-Jaw Orthognathic Surgery for Correction of Facial Asymmetry: 3-Dimensional Planning and Surgical Execution

Three-dimensional (3D) planning of orthognathic surgery (OGS) improves the treatment of facial asymmetry and malocclusion, but no consensus exists among clinicians regarding technical details. This study verified the consistency of authors' workflow and strategies between 3D planning and surgical execution for facial asymmetry. This retrospective study recruited consecutive patients (n=54) with nonsyndromic facial asymmetry associated with malocclusion. The stepwise workflow included orthodontic treatment, 3D imaging-based evaluation, planning, and transferring the virtual of single-splint 2-jaw OGS to actual surgery in all patients. Seven landmark-based measurements were selected for postoperative assessment of facial symmetry. Fifty patients had no anesthetic/surgical-related episode and procedure-related complications. Others experienced wound infection (n=1), transient TMJ discomfort (n=1), and facial numbness (n=3). Two cases had minor residual asymmetry (cheek and chin, respectively), but did not request revisionary bone or soft tissue surgery. Comparisons between the planned and postoperative 3D images with quantitative measurement revealed acceptable outcome data. The results showed a significant increase in facial symmetry at 7 landmark-based postoperative measurements for both male and female. This 3D-assisted pathway of OGS permitted achievement of consistent satisfactory results in managing facial asymmetry, with low rate of complications and secondary management.

Applications of three-dimensional imaging techniques in craniomaxillofacial surgery: A literature review

Three-dimensional (3D) imaging technologies are increasingly used in craniomaxillofacial (CMF) surgery, especially to enable clinicians to get an effective approach and obtain better treatment results during different preoperative and postoperative phases, namely during image acquisition and diagnosis, virtual surgical planning (VSP), actual surgery, and treatment outcome assessment. The article presents an overview of 3D imaging technologies used in the aforementioned phases of the most common CMF surgery. We searched for relevant studies on 3D imaging applications in CMF surgery published over the past 10 years in the PubMed, ProQuest (Medline), Web of Science, Science Direct, Clinical Key, and Embase databases. A total of 2094 articles were found, of which 712 were relevant. An additional 26 manually searched articles were included in the analysis. The findings of the review demonstrated that 3D imaging technology is becoming increasingly popular in clinical practice and an essential tool for plastic surgeons. This review provides information that will help researchers and clinicians consider the use of 3D imaging techniques in CMF surgery to improve the quality of surgical procedures and achieve satisfactory treatment outcomes.

Effectiveness of individualized 3D titanium-printed Orthognathic osteotomy guides and custom plates

BACKGROUND

Computer-aided design/manufacturing (CAD/CAM) technology was developed to improve surgical accuracy and minimize errors in surgical planning and orthognathic surgery. However, its accurate implementation during surgery remains a challenge. Hence, we compared the accuracy and stability of conventional orthognathic surgery and the novel modalities, such as virtual simulation and three-dimensional (3D) titanium-printed customized surgical osteotomy guides and plates.

METHODS

This prospective study included 12 patients who were willing to undergo orthognathic surgery. The study group consisted of patients who underwent orthognathic two-jaw surgery using 3D-printed patient-specific plates processed by selective laser melting and an osteotomy guide; orthognathic surgery was also performed by the surgeon directly bending the ready-made plate in the control group. Based on the preoperative computed tomography images and intraoral 3D scan data, a 3D virtual surgery plan was implemented in the virtual simulation module, and the surgical guide and bone fixation plate were fabricated. The accuracy and stability were evaluated by comparing the results of the preoperative virtual simulation (T0) to those at 7 days (T1) and 6 months (T2) post-surgery.

RESULT

The accuracy (ΔT1‒T0) and stability (ΔT2‒T1) measurements, using 11 anatomical references, both demonstrated more accurate results in the study group. The mean difference of accuracy for the study group (0.485 ± 0.280 mm) was significantly lower than in the control group (1.213 ± 0.716 mm) (P < 0.01). The mean operation time (6.83 ± 0.72 h) in the control group was longer than in the study group (5.76 ± 0.43 h) (P < 0.05).

CONCLUSION

This prospective clinical study demonstrated the accuracy, stability, and effectiveness of using virtual preoperative simulation and patient-customized osteotomy guides and plates for orthognathic surgery.

Artificial Intelligence Splint in Orthognathic Surgery for Skeletal Class III Malocclusion: Design and Application

BACKGROUND

Digital splints are indispensable in orthognathic surgery. However, the present design process of splints is time-consuming and has low reproducibility. To solve these problems, an algorithm for artificial intelligent splints has been developed in this study, making the automatic design of splints accessible.

METHODS

Firstly, the algorithm and program of the artificial intelligence splint were created. Then a total of 54 patients with skeletal class III malocclusion were included in this study from 2018 to 2020. Pre and postoperative radiographic examinations were performed. The cephalometric measurements were recorded and the difference between virtual simulation and postoperative images was measured. The time cost and differences between artificial intelligent splints and digital splints were analyzed through both model surgery and radiographic images.

RESULTS

The results showed that the efficiency of designing splints is significantly improved. And the mean difference between artificial intelligent splints and digital splints was <0.15 mm in model surgery. Meanwhile, there was no significant difference between the artificial intelligent splints and digital splints in radiological image analysis.

CONCLUSIONS

In conclusion, compared with digital splints, artificial intelligent splints could save time for preoperative design while ensuring accuracy. The authors believed that it is conducive to the presurgical design of orthognathic surgery.

Facial Feminization Surgery: A Systematic Review of Perioperative Surgical Planning and Outcomes

Background:

Facial feminization is a critical step in a transfeminine patient’s surgical transition. However, the existing literature on the various types of feminization surgeries suffers from inadequate reporting on perioperative aspects of care, such as preoperative evaluation and postoperative outcomes. The aim of this study is to evaluate facial feminization surgery (FFS), preoperative planning, and patient reported outcomes after various types of procedures.

Methods:

An electronic database search of Ovid MEDLINE was completed according to PRISMA guidelines for articles pertaining to FFS. Study characteristics, operative information, and patient demographics were collected. Data concerning preoperative imaging, virtual simulation, postoperative complications, and patient-reported outcome measures (PROMs) were collected and analyzed for patterns.

Results:

A total of 22 papers representing 1302 patients were included for analysis. The most commonly discussed operations included upper face procedures, particularly of the forehead (17 studies, 77%). When discussed, preoperative planning for FFS included standard photography in 19 (86%) studies, advanced imaging, such as cephalometry or computed tomography, in 12 (55%) studies, and virtual simulation of surgical outcomes in four (18%) studies. Patient-centered outcomes, such as postoperative satisfaction, were described in 17 (77%) studies. Standardized PROMs were heterogenous across included studies with only 11 (50%) including at least one PROM.

Conclusions:

FFS is common, safe, and highly satisfying for transfeminine patients seeking surgical intervention for identity actualization. Future research concerning transgender care must evaluate advanced surgical planning and 3D simulation combined with more standardized assessment of PROMs to ensure high-quality analysis of patient satisfaction.

Outcome of full digital workflow for orthognathic surgery planning in the treatment of asymmetric skeletal class III deformity

BACKGROUND/PURPOSE

Studies have reported the advantages of digital imaging-assisted orthognathic surgery planning, but there is scarce information about a full digital planning modality. This study evaluated the 3D cephalometric-based and patient-reported outcomes of a full digital workflow for orthognathic surgery planning in the treatment of asymmetric maxillomandibular disharmony.

METHODS

A postoperative 3D image dataset of 30 Taiwanese Chinese patients with asymmetric skeletal Class III deformities who underwent full digital planning for two-jaw surgery were retrieved from the authors' database. The 3D cephalometric data (dental, skeletal, and soft tissue evaluations) were compared to the ethnicity-matched 3D cephalometric normative values. Patient-reported outcome measure tools regarding postoperative overall appearance and satisfaction with facial areas (ranging from 0 to 100 and 0 to 10, respectively) were administered. The number of needed or requested revisionary surgery was collected.

RESULTS

No difference (all p > 0.05) was observed between the orthognathic-surgery-treated patients and the normative value for most of the tested 3D cephalometric parameters, with the exception (p < 0.05) of three mandible and occlusal-plane-related parameters. Both patient-reported outcome measure tools showed that patients' satisfaction with their postoperative appearance was high for overall face (89.7 ± 4.5) and specific facial regions (nose, 7.1 ± 1.3; lip, 8.3 ± 1.6; upper gum, 8.5 ± 1.2; cheek, 8.8 ± 1.1; chin, 9.2 ± 1.2; and teeth, 9.3 ± 0.8), with no need for revisionary surgery.

CONCLUSION

The patients treated with a full 3D digital planning-assisted two-jaw surgery had a similar 3D dental relation, facial convexity, and symmetry compared to healthy ethnicity-matched individuals, and they reported higher satisfaction levels with their postoperative facial appearance results.

Cheek soft tissue prediction in cleft orthognathic surgery: A 3D computer-assisted investigation with comparative analysis

BACKGROUND

The Le Fort I maxillary advancement and rotational movement have been adopted to treat patients with cleft-related skeletal Class III pattern and anteromedial cheek soft tissue deficiency, but cleft-specific cheek soft tissue prediction data are insufficient. This 3D imaging-based study addressed the issue.

METHODS

3D craniofacial soft tissue and bone models were created from 32 consecutive patients who received computer-aided two-jaw orthognathic surgery for the correction of cleft-related Class III deformity and cheek soft tissue deficiency. Using superimposed 3D models, the cheek volumetric change, the cheek sagittal movement, and the 3D cheek mass position were calculated. 3D data from orthognathic surgery-treated patients with no cleft (noncleft cohort) and individuals with no facial deformity (3D norm value) were retrieved for comparative analysis.

RESULTS

Surgical maxillary advancement (p < 0.001) but not maxillary clockwise rotation (p > 0.05) had a significant impact on the cheek soft tissue change, with prediction models showing that maxillary advancement elucidated 77 and 79% of this change on the cleft and noncleft sides, respectively. Cleft cohort (0.46±0.12) had a significantly (p < 0.001) smaller cheek soft-to-hard tissue ratio than that of the noncleft cohort (0.73±0.13). Cleft maxillary advancements >4 mm resulted in a 3D cheek mass position (2.1±1.1 mm) similar (p > 0.05) to the 3D norm value (2.2±1.2 mm), but different (p = 0.037) from the noncleft cohort (2.38±0.7 mm).

CONCLUSION

This study showed that maxillary advancement but not the maxillary rotation affects the cheek soft tissue change, and the predictive values and comparative data could assist the orthodontist-surgeon interaction during preoperative planning and patient counseling.