Current trends in orthognathic surgery

Virtual surgical planning in orthognathic surgery: a dental hospital's 10-year experience

PURPOSE

The primary objective of this study was to evaluate how the utilization of virtual surgical planning (VSP) and the epidemiological profile of patients undergoing orthognathic surgery (OGS) have changed in the past decade.

METHODS

The records of patients who had undergone orthognathic surgery at a national dental hospital were reviewed. Trends in VSP, epidemiological data, presentation of dentofacial deformity, and management details were recorded.

RESULTS

A total of 1184 patients were included in this study. The majority of the patients seeking treatment in this dental hospital were young Chinese adults with dentofacial deformities requiring bimaxillary surgeries. Most patients presented with a skeletal Class III pattern (79.0%), and asymmetry was diagnosed in 80.8% of all cases.

CONCLUSION

There was an initial slow pick-up rate for VSP, but this rapidly increased to a high adoption rate of 98.7-100% between 2019 and 2021. Together with an increasing body of evidence suggesting greater accuracy in VSP, utilization in this technology can be enhanced with greater familiarity with the technology and improvements in the VSP services.

Predicting optimal patient-specific postoperative facial landmarks for patients with craniomaxillofacial deformities

Orthognathic surgery primarily corrects skeletal anomalies and malocclusion to enhance facial aesthetics, aiming for an improved facial appearance. However, this traditional skeletal-driven approach may result in undesirable residual asymmetry. To address this issue, a soft tissue-driven planning methodology has been proposed. This technique estimates bone movements based on the envisioned optimal facial appearance, thereby enhancing surgical accuracy and effectiveness. This study investigates the initial implementation phase of the soft tissue-driven approach, simulating the patient's ideal appearance by realigning distorted facial landmarks to an ideal state. The algorithm employs symmetrization and weighted optimization strategies, aligning projected optimal landmarks with standard cephalometric values for both facial symmetry and form, which are essential in orthognathic surgery for facial aesthetics. It also incorporates regularization to preserve the patient's facial characteristics. Validation through retrospective analysis of preoperative patients and normal subjects demonstrates this method's efficacy in achieving facial symmetry, particularly in the lower face, and promoting a natural, harmonious contour. Adhering to soft tissue-driven principles, this novel approach shows promise in surpassing traditional methods, potentially leading to enhanced facial outcomes and patient satisfaction in orthognathic surgery.

Lefort 1 Osteotomy Study of Maxillary Bone in Caprine Skull Model: Comparison of Different Osteotomy Techniques (Piezo Versus Lindemann Bur Versus Manual Chisel)

OBJECTIVE

In this study, we aimed to compare the efficiency of different osteotomy techniques for Lefort 1 osteotomy in an experimental caprine skull model.

METHODS

Twelve caprine skulls were used for the study. Skulls were divided into 3 groups: (1) manual chisel group, (2) Lindemann bur group, and (3) piezo osteotomy group. Bilateral osteotomies were performed on each skull. Results were evaluated with three-dimensional computerized tomography scans and macroscopic observations of the mucosal tears and soft tissue.

RESULTS

The mean length of the bone gap in the manual, Lindemann, and piezo groups was 4.8 (±0.7), 3.38 (±1.49), and 1.39 (±0.3) mm, respectively (P < 0.05). The mean number of comminuted fractures in the manual, Lindemann, and piezo groups was 5.5 (±1.4), 1.6 (±0.3), and 0.6 (±0.5), respectively (P < 0.05). Mucosal tearing and soft tissue damage based on subjective inspection observations were negligible in the piezo technique. Soft tissue and mucosal damage were observed significantly more in the manual chisel osteotomy method compared with the other 2 techniques.

CONCLUSION

We anticipate that piezo, which has started to be used in new application areas besides rhinoplasty, will continue to be used more widely, especially in reconstructive orthognathic surgery, due to the minimal damage it causes to tissues. With the long-term results, much healthier interpretations can be made.

Predicting Optimal Patient-Specific Postoperative Facial Landmarks for Patients with Craniomaxillofacial Deformities

Orthognathic surgery traditionally focuses on correcting skeletal abnormalities and malocclusion, with the expectation that an optimal facial appearance will naturally follow. However, this skeletal-driven approach can lead to undesirable facial aesthetics and residual asymmetry. To address these issues, a soft-tissue-driven planning method has been proposed. This innovative method bases bone movement estimates on the targeted ideal facial appearance, thus increasing the surgical plan's accuracy and effectiveness. This study explores the initial phase of implementing a soft-tissue-driven approach, simulating the patient's optimal facial look by repositioning deformed facial landmarks to an ideal state. The algorithm incorporates symmetrization and weighted optimization strategies, aligning projected optimal landmarks with standard cephalometric values for both facial symmetry and form, which are integral to facial aesthetics in orthognathic surgery. It also includes regularization to preserve the patient's original facial characteristics. Validated using retrospective analysis of data from both preoperative patients and normal subjects, this approach effectively achieves not only facial symmetry, particularly in the lower face, but also a more natural and normalized facial form. This novel approach, aligning with soft-tissue-driven planning principles, shows promise in surpassing traditional methods, potentially leading to enhanced facial outcomes and patient satisfaction in orthognathic surgery.

Male and Female Discrepancies in Anxiety, Depressive Symptoms, and Coping Strategies among Orthognathic Patients: A Cross-Sectional Analysis

With an increasing understanding of the differences between men and women's psychological experiences, this study aimed to probe the sex-based differences in anxiety, depressive symptoms, and coping strategies among orthognathic patients. The study hypothesis was that female patients would show higher levels of anxiety and depressive symptoms than males, and that coping mechanisms would differ between male and female sexes. A cross-sectional design was adopted, examining orthognathic patients from the Department of Oral and Maxillo-Facial Surgery at the Emergency Clinical Municipal Hospital in Timisoara, Romania, from 2020 to 2023. Eligible participants (18+ years with no prior orthognathic treatment) completed a comprehensive online questionnaire 6 weeks before scheduled surgery. This was composed of validated self-report instruments comprising the SF-36, GAD-7, and the PHQ-9, and the COPE-60, along with additional sociodemographic data. Of the 127 orthognathic patients analyzed (68 men and 59 women, aged 18 to 65 years, mean age 32), men rated their physical health status slightly better on the SF-36 scale. However, the most notable difference was in mental health, with females scoring higher on both the PHQ-9 (indicative of depression) and the GAD-7 (indicative of anxiety) scales. Specifically, female participants exhibited average PHQ-9 scores 1.8 points higher and GAD-7 scores 1.5 points higher than their male counterparts. Coping mechanisms also varied: 42% of male patients primarily employed "Disengagement" strategies, while 58% of females predominantly used "Engagement" and "Emotion Focused" strategies. Emotion-focused coping was associated with a 1.6-fold increased risk of depressive symptoms. Sex differences play a crucial role in the psychological experiences of orthognathic patients, evident in anxiety and depression levels, perceived health status, and coping strategies. This underlines the importance of sex-tailored psychological support in the preoperative phase for orthognathic surgery patients.

Occlusal Plane Angle as a Key Factor for Chin Protrusion After Mandibular Osteotomy in Skeletal Class III

There is no treatment algorithm to decide whether maxillomandibular or mandibular osteotomy alone should be performed in borderline cases. This study assessed the factors that affect the changes in soft tissue after mandibular setback. Patients who underwent mandibular osteotomy alone to correct mandibular protrusion were included in this study. Hard and soft tissue analyses were performed on lateral cephalograms before and 12±3 months after surgery. The popular points were set for referencing hard and soft tissues on the lateral cephalogram. Nasolabial, labiomental, and soft tissue facial plane angles were measured for the soft tissue assessment. To assess the mandibular setback amount, SNB was calculated. Twenty-one patients were included in this study. The nasolabial angle was increased after surgery and its change significantly correlated with the change in SNB ( P =0.00815). The change in soft tissue facial plane angle after surgery per change in SNB significantly correlated with the occlusal plane angle ( P =0.0009). An occlusal plane angle of at least 15.45 degrees was required for the SNB and soft tissue facial plane angle to change to the same degree. The occlusal plane angle (whether or not it was ≥15.45 degrees) may help in determining the surgical approach in borderline cases, specifically on whether maxillomandibular or mandibular osteotomy alone should be performed if the mandibular setback is simple.

Role of Three-Dimensional Printing in Treatment Planning for Orthognathic Surgery: A Systematic Review

Three-dimensional (3D) printing refers to a wide range of additive manufacturing processes that enable the construction of structures and models. It has been rapidly adopted for a variety of surgical applications, including the printing of patient-specific anatomical models, implants and prostheses, external fixators and splints, as well as surgical instrumentation and cutting guides. In comparison to traditional methods, 3D-printed models and surgical guides offer a deeper understanding of intricate maxillofacial structures and spatial relationships. This review article examines the utilization of 3D printing in orthognathic surgery, particularly in the context of treatment planning. It discusses how 3D printing has revolutionized this sector by providing enhanced visualization, precise surgical planning, reduction in operating time, and improved patient communication. Various databases, including PubMed, Google Scholar, ScienceDirect, and Medline, were searched with relevant keywords. A total of 410 articles were retrieved, of which 71 were included in this study. This article concludes that the utilization of 3D printing in the treatment planning of orthognathic surgery offers a wide range of advantages, such as increased patient satisfaction and improved functional and aesthetic outcomes.

Does Social Media Affect a Patient's Decision to Undergo Orthognathic Surgery?

Orthognathic surgery, also known as corrective jaw surgery, is a procedure that corrects abnormalities of the jaw and face. It is used to treat malocclusions, where the teeth and jaws are misaligned. This surgery can improve the function and appearance of the jaw and face, leading to improved mastication, speech, and quality of life for the patients. To assess if social media had any effect on the patients' decision to undergo orthognathic surgery, a self-administered online questionnaire was distributed to patients who had undergone orthognathic surgery at the Oral and Maxillofacial department through the health information system (BESTCare, 2.0A) to participate in the study. In total, 111 responses were recorded from the patients, with 107 agreeing to answer the questionnaire and 4 refusing to answer. Twitter was a source of information about orthognathic surgery for 61 patients (57%). When using a social media platform, 3 patients (2.8%) were influenced by an advertisement or an educational post on social media that presented the surgical correction of the jaws, while 15 (14%) believed that they had been somewhat influenced, and 25 (23.4%) picked their surgeon through social media. Fifty-six patients (52.3%) took the neutral position regarding whether information on social media had answered their questions and concerns regarding the surgical procedure. Social media did not influence patients' decision to undergo the procedure. Surgeons and specialists must utilize their platforms to answer any concerns or questions from any patient undergoing or having undergone this corrective jaw surgery.

Current concepts of craniofacial fibrous dysplasia: pathophysiology and treatment

Fibrous dysplasia is an uncommon genetic disorder in which bone is replaced by immature bone and fibrous tissue, manifesting as slowgrowing lesions. Sporadic post-zygotic activating mutations in GNAS gene result in dysregulated GαS-protein signaling and elevation of cyclic adenosine monophosphate in affected tissues. This condition has a broad clinical spectrum, ranging from insignificant solitary lesions to severe disease. The craniofacial area is the most common site of fibrous dysplasia, and nine out of 10 patients with fibrous dysplasia affecting the craniofacial bones present before the age of 5. Surgery is the mainstay of treatment, but the technique varies according to the location and severity of the lesion and associated symptoms. The timing and indications of surgery should be carefully chosen with multidisciplinary consultations and a patient-specific approach.

Causes of Reoperation Consultation and Clinical Review of Actual Reoperation After Previous Orthognathic Surgery

OBJECTIVE

To investigate the causes of reoperation consultation, and the actual percentage and procedures of reoperation after previous orthognathic surgery.

METHODS

The samples consisted of 30 patients who visited our clinic for reoperation consultation from October 2015 to September 2021 (6 males and 24 females; mean age at reoperation consultation, 28.4 y). Patient's causes of reoperation consultation were divided into "esthetic dissatisfaction," "airway changes," "temporomandibular disorders," "uncomfortable occlusion," and "other complications". In terms of esthetic dissatisfaction, the more detailed esthetic problem was evaluated by the clinical chart, facial photographs, and radiographs. In patients who actually underwent reoperation, the actual percentage and procedures of reoperation were investigated.

RESULTS

The most prevalent causes for reoperation consultation were "esthetic dissatisfaction" (n = 21, 70.0%), followed by "airway changes" (n = 11, 36.7%), "uncomfortable occlusion" (n = 8, 26.7%), "other complications" (n = 5, 16.7%), and "temporomandibular disorder" (n = 4, 13.3%). Less than half of patients actually underwent reoperation (n = 13, 43.3%). Actual reoperation procedures included minor revision surgery, reconstruction surgery, or complete reoperation according to the patient's need. In case of complete reoperation, more accurate and predictable results were obtained by using virtual surgical planning, customized surgical guides, titanium surgical plates made with computer-aided design and computer-aided manufacturing technique, and a 3-dimensional printing method.

CONCLUSION

It is important to communicate with patients about expectations for facial esthetic improvement by orthognathic surgery for obtaining the patient's postoperative satisfaction.

A computed tomography-based analysis of the structure of the mandible according to age and sex

Background

The primary objectives of mandibular surgery are to achieve optimal occlusion, low sensory disturbance, and adequate fixation with early movement. In-depth knowledge of the mandibular structure is required to achieve these goals. This study used computed tomography (CT) to evaluate the mandibular cortical thickness and cancellous space according to age and sex.

Methods

We enrolled 230 consecutive patients, aged 20 to 50 years, who underwent CT scanning. The cortex and cancellous space centered around the inferior alveolar nerve (IAN) canal were measured at two specific locations: the lingula and second molar region. Statistical analysis of differences according to increasing age and sex was performed.

Results

The t-test revealed that the cancellous space and cortical thickness differed significantly with respect to the threshold of 35 years of age. Both cortical thickness and cancellous space in the molar region were negatively correlated with age. Meanwhile, both cortical thickness and cancellous space in the lingula region showed a positive correlation with age. With respect to sex, significant differences in the cancellous space at the molar region and the cortical thickness at the lingula were observed. However, no further statistically significant differences were observed in other variables with respect to sex. The sum of each measurement on the mandibular body reflected the safe distance from the surface of the outer cortex to the IAN canal. The safe distances also showed statistically significant differences between those above and below 35 years of age.

Conclusion

Knowledge of the anatomical structure of the mandible and of changes in bone structure is crucial to ensure optimal surgical outcomes and avoid damage to the IAN. CT examination is useful to identify changes in the bone structure, and these should be taken into account in the planning of surgery for older patients.

Orthognathic correction and corticobasal implant-supported prostheses as a treatment modality for partial edentulism with mandibular prognathism: A case report and review of literature

Introduction

Mandibular prognathism manifests as elongation of the mandible in the anteroposterior direction, resulting in a sunken appearance of the middle third of the face and sad look of the eyes. It adversely affects esthetics, function, and oral health, reducing the patients' self-esteem. It therefore presents a significant challenge.

Presentation of case

A 23-year-old woman presented with prognathic features characterized by mandibular protrusion, maxillary retrusion, a prominent chin, and reduce self-esteem. Intraoral examination revealed multiple extracted teeth, severe fracture of the crown at 23, mobility of the fixed prosthesis on 13, 14, 15, and 16, a root stump of 18, and periodontally compromised teeth (31, 32, 33, 41, and 42).

A multidisciplinary team formulated the following treatment plan: stage 1, orthognathic osteotomy to retrude the mandible at 34 and 44; stage II, fabrication of transitional acrylic partial dentures; and stage III: fabrication of definitive corticobasal implant-supported prostheses. The patient was delighted with the treatment and complied with the oral hygiene instructions and follow-up program. After 7 years of function, the patient presented without complaints and exhibited significant improvement in oral health, self-esteem, and quality of life.

Discussion

The management of mandibular prognathism requires a multidisciplinary approach. The treatment implemented was considered the optimal option that aligned with the recommendations of several researchers to reduce facial disfigurement and rehabilitate the edentulous state.

Conclusion

The use of corticobasal implant-supported prostheses for the rehabilitation of patients with partial edentulism can significantly improve the treatment outcome following orthognathic surgery in cases with mandibular prognathism.

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Mandibular prognathism may adversely affect the patient’s esthetic and function and quality of life.

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Orthodontic surgery can improve the patient esthetic without replacing the missing dentition

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The patient was rehabilitated using corticobasal implant-supported prostheses.

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The esthetics, function, and oral hygiene improved significantly.

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This treatment modality enhances the patient’s self-esteem and improves the patient’s quality of life.

Evaluation of the Predictability and Accuracy of Orthognathic Surgery in the Era of Virtual Surgical Planning

Virtual surgical planning allows orthognathic surgeons to design a surgical plan preoperatively and establish a personalized surgical protocol. This study aims to validate the predictability and accuracy of orthognathic surgery through a comparison of the three-dimensional (3D) models of the virtual planning and postoperative CBCT using free software (3D Slicer) on 40 patients who underwent bimaxillary orthognathic surgery. The distances of point A, point B, pogonion (Pog), and the first upper and lower molars, both in each axis (x, y, and z) and in the 3D space, were analyzed. The median of the distances in the mediolateral direction was the lowest, while the highest differences were found at point A and Pog in the anteroposterior direction (0.83 mm and 0.78 mm, respectively). Vertical differences were higher in the maxilla than in the mandible. In conclusion, we found that orthognathic bimaxillary surgery using virtual surgical planning was more accurate when positioning the bone segments in the mediolateral direction, using the information provided by the splint, as well as when positioning the mandible compared to the maxilla.