Stability of orthognathic surgery and distraction osteogenesis: options and alternatives

Does the Implementation of Virtual Planning has a Significant Impact on Reducing the Revision Rate in Orthognathic Surgery?

PURPOSE

Conventional orthognathic surgical planning has limitations in accurately transferring the relationship between soft tissue and bone. Virtual planning offers enhanced accuracy and visualization through computer simulation. This study aimed to compare the need for reoperation between patients who underwent conventional and virtual surgical planning for orthognathic surgery.

MATERIAL AND METHODS

The study included 352 patients who underwent orthognathic surgery. Reoperation rates and reasons for reoperation were evaluated in patients with conventional model surgery planning (143 patients) and virtual planning (209 patients).

RESULTS

The reoperation rate was 7.69% for conventional surgery patients and 3.82% for virtual planning patients. Malocclusion was the most common reason for reoperation in both groups. Bilateral sagittal split ramus osteotomies (BSSO) and genioplasty were the most frequently performed revision procedures.

CONCLUSION

Virtual planning in orthognathic surgery may lead to a reduced reoperation rate compared with conventional planning methods. The accuracy, visualization, and interdisciplinary collaboration offered by virtual planning can improve surgical outcomes.

Stability of box genioplasty: a retrospective study

In box genioplasty it is possible to advance, retrude, impact, and elongate, as well as to correct asymmetry. The aim of this study was to analyse the stability of box genioplasty as part of orthognathic correction. Twenty-five consecutive patients who had gone through the multidisciplinary pathway were selected. Menton and pogonion positions on radiographs taken just prior to surgery, and actual surgical movement on three-week and 12-month postoperative cephalograms, were compared. A one-sample Wilcoxon test was applied to assess whether the distributional change in advancement and vertical measurements was equal to zero. After treatment, anteroposterior changes in pogonion and vertical changes in menton were statistically insignificant (p>0.05). Our study demonstrated statistically significant stability of menton and pogonion positions after box genioplasty when surgical movement was only in the symphysis.

Orthodontic-surgical treatment of an Angle Class II malocclusion patient with mandibular hypoplasia and missing maxillary first molars: A case report

BACKGROUND

Adult patients presenting with Angle Class II division 1 malocclusions that have a strong skeletal etiology can be challenging for clinicians, particularly if accompanied by retrognathia of the mandible and a dolichofacial growth pattern.

CASE SUMMARY

In this case report, we describe the successful orthodontic and surgical management of a 20-year-old woman with an Angle Class II malocclusion with a severe anteroposterior skeletal discrepancy characterized by mandibular deficiency. She had incompetent lips, dental and skeletal Class II malocclusion, high mandibular plane angle, mild mandibular crowding, and two missing maxillary first molars. The treatment plan comprised: (1) Extraction of two mandibular second premolars to decompensate and retract mandibular incisors; (2) pre-surgical alignment, leveling, and space closure of the teeth in both arches, and protraction of the second maxillary molars to close the maxillary space; (3) surgical treatment including a LeFort I osteotomy for maxillary retraction and rotation, a bilateral sagittal split osteotomy for mandibular advancement and rotation, and a genioplasty for correctting the skeletal deformities; and (4) post-surgical correction of the malocclusion.

CONCLUSION

The patient’s facial esthetics was significantly improved and a desirable occlusion was achieved after 16 mo treatment. Follow-up records after 2 years showed stable esthetics and function.

Virtual Planning and 3D Printing in Contemporary Orthognathic Surgery

Orthognathic surgery is a powerful tool to improve facial balance, form, and function. Virtual planning and three-dimensional printing has improved our ability to visualize complex anatomy, consider various iterations and execute complex movements, and create accurate splints, plates, and cutting guides. This article will outline the distinct advantages of the use of virtual surgical planning over traditional planning, and it will explore the utility of computer-aided design and technology within contemporary orthognathic surgery, including its expanded applications and limitations.

Operative time, length of stay and reoperation rates for orthognathic surgery

Orthognathic surgery improves quality of life in terms of oral function and facial aesthetics. Our aim was to establish and compare operative time and length of inpatient stay for orthognathic procedures, and to assess the reoperation rate. Departmental electronic data base was used to identify all patients undergoing orthognathic surgery in a single unit between the 01/01/2016 and the 01/08/2018. 251 patients were identified who underwent 409 orthognathic surgery procedures. The mean operating time for a bimaxillary osteotomy (n=107) was 139.3 min. For single jaw procedures, the mean operating time for a Le Fort I osteotomy (n= 42) was 82.2 min and for a bilateral sagittal split osteotomy (BSSO) (n= 102) was 80.3min. Bimaxillary osteotomy combined with genioplasty (n=17) this increased the operating time on average by 31 min. and of a BSSO combined with a genioplasty (n=14) by 27 mins. The mean postoperative hospital stay was 1.2 ± 0.2 days. 96.4% patients spent only one postoperative night in hospital. 6/251 (2.4%) patients required re-operation. In regression analysis, age was the only significant factor in increasing length of stay (p<0.008), 95% CI 0.03-0.2). Our review shows short operating times and postoperative inpatient stays in a large cohort of patients undergoing orthognathic surgery. This is combined with a low reoperation rate. This may point to a patient benefit from high volume orthognathic centres.

Current Orthognathic Practice in India: Do We Need to Change?

The last decade or so has seen paradigm shifts in the various aspects of orthognathic surgery. A lot of these changes are to do with digitalization of the orthodontic-surgical workflow, optimization of surgery-first protocols, virtual surgical planning-based 3D printing solutions and changing patient-health-care dynamics. The aim of this article is to provide evidence-based recommendations that are both practical and economically viable for the current orthognathic practice in India.

Complete Reoperation in Orthognathic Surgery

BACKGROUND

Complete reoperation is defined as undergoing reoperative/repeated jaw osteotomies, in a patient who previously underwent orthognathic surgery. The purpose of this study is to (1) describe jaw positions at three time-points (before primary and before and after reoperative surgery), (2) investigate factors necessitating reoperation, and (3) outline the technical challenges.

METHODS

Repeated orthognathic surgery cases >1-year out were included. Demographic, radiologic, and perioperative data were compiled. Repeated osteotomies (Le-Fort and/or bilateral split sagittal osteotomy, with or without genioplasty), were compared to their respective primary procedures. Statistical analysis was performed using t tests and z-scores.

RESULTS

Fifteen patients were included (28.1 years; 71 percent female). Reoperative/repeated surgery was most often needed to address iatrogenic bony malposition and asymmetry. Relapse was a less common indication. Time between reoperative and primary surgery was 14 months. Sagittal discrepancies (p = 0.029) were the most frequent reason for primary orthognathic surgery (e.g., mandibular hypoplasia (p = 0.023). Reoperative/repeated orthognathic was performed for asymmetry (p = 0.014). Repeated procedures used more 3-dimensional planning (p < 0.001), required all three osteotomies (p = 0.034), had longer operative times (p = 0.078), and all required hardware removal (p < 0.001). Anatomical outcomes were good with 100% patient satisfaction at long-term follow-up.

CONCLUSIONS

Reoperative/repeated orthognathic surgery is challenging and underreported in the literature. Whereas primary orthognathic typically addressed sagittal discrepancies, reoperative/repeated osteotomies were needed to correct iatrogenic bone malposition and asymmetries. Challenges include: re-planning, scar burden, need to remove integrated hardware, and repeated osteotomy/fixation. Despite these difficulties, outcomes and patient acceptance were good.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Osteotomy Site Grafting in Bilateral Sagittal Split Surgery With Bioactive Glass S53P4 for Skeletal Stability

In orthognathic surgery, the aim of the treatment is to achieve a good occlusion and a satisfying aesthetic outcome. In large mandibular advancements insufficient healing at the mandibular inferior border may lead to loss of support for the overlaying tissue at the osteotomy site. Augmentation can be performed to improve stability, bone regeneration, and the aesthetic outcome. The purpose of this prospective clinical study was to evaluate the use of a novel material for this indication; granules of the antibacterial, osteoconductive, and slowly resorbing bioactive glass S53P4 as filling material in large mandibular advancement in bilateral sagittal split osteotomies. The authors treated 25 patients who underwent bilateral sagittal split osteotomies due to class II dentoskeletal deformities. The mandibular osteotomy site defects (8-15 mm) were augmented with bioactive glass S53P4. The average clinical follow-up was 33 months and the average radiological follow-up with cone beam computerized tomography was 24 months. The clinical and radiological results were good with regard to healing, bone regeneration, and stability of the osteotomy sites. The recontouring of the inferior mandibular border provided a good soft tissue support followed by an excellent aesthetic outcome in 96% of the osteotomy sites. The occlusion was stable in 88% of the patients. The authors' results show that bioactive glass S53P4 is a safe grafting material for osteotomy site defects in significant mandibular advancements with reliable bone regeneration, providing long-term stability at the osteotomy site and at the inferior mandibular border.

Stability of Le Fort I Osteotomy With Propeller Graft for Canting Correction in Facial Asymmetry

The aim of this study was to evaluate the maxillary stability in patients who had undergone Le Fort I osteotomy with propeller graft and mandibular sagittal split ramus osteotomy for correction of maxillary asymmetry. This was a retrospective study on 15 facial asymmetry patients (7 men, 8 women: 22.2 years) requiring surgical correction at the preoperative (T0), immediately postoperative (T1) and 6 months after surgery (T2) stages. To evaluate the skeletal stability, computed tomography (CT) superimposition was used, and skeletal landmarks were measured and compared from the superimposed images according to an x, y, z coordinate system. The skeletal changes at each stage (ΔT1-T0 and ΔT2-T1) were compared by paired t-test (P<0.05). The obtained data on the skeletal changes immediately postoperatively to 6-month follow-up (ΔT2-T1) showed that the Le Fort I osteotomy with propeller graft had effected stable maxillary skeletal stability at the maxillary measurement points (posterior nasal spine (PNS ), nasopalatine canal, U3 crown tip, U3 root apex, and U6 furcation). These results suggested that in cases of facial asymmetry where the upper tooth exposure is proper and anterior-posterior movement of the maxilla is not much required, Le Fort I osteotomy with propeller graft is an effective method for stable canting correction.