Multiple-segment osteotomy in maxillofacial surgery

The accuracy of virtual surgical planning in segmental Le Fort I surgery: A comparison of planned and actual outcome

Segmental Le Fort I surgery is an effective technique to correct complicated dentomaxillofacial deformities. This retrospective study evaluated the accuracy of segmental Le Fort I surgery under the guidance of virtual surgical planning (VSP). A total of 129 patients who accepted segmental Le Fort I surgery were investigated in this study. VSP was transferred to segmental surgery with different pieces precisely with the aid of 3D-printed surgical templates and splints. The surgical result was evaluated by postoperative complications, color distance maps, and quantitative accuracy analysis. Outcomes showed that the VSP was successfully transferred to actual surgery with high accuracy. The overall mean linear difference was 1.28 mm, and the overall mean angular difference was 2.4°. Except for one case of root injury, there was no serious complication recorded. The results suggested that VSP was a reliable assistance for segmental Le Fort I surgery.

Computer-Assisted Microvascular Free Flap Reconstruction and Implant Rehabilitation of the Maxilla-Treatment of a Rare Post-orthognathic Complication

Orthognathic surgery is generally a safe and predictable procedure. Major postoperative complications are rare and often non-life threatening. An example of a rare complication associated with the LeFort I osteotomy is avascular necrosis of the maxilla (ANM). While cases of ANM have been described in the literature, the majority involves only a portion or segment of the maxillary complex and is commonly treated with conservative measures such as strict oral hygiene, hyperbaric oxygen therapy and local debridement. Occasionally, larger segments of osteonecrosis may require extensive reconstruction such as bone grafting with local soft tissue flaps. Here, we present a patient that underwent a single-stage microvascular free tissue reconstruction with concomitant placement of dental implants and a patient-specific implant (PSI) for post-orthognathic ANM.

Modified Le Fort I interpositional grafting of the severe atrophied maxilla - a retrospective study of 106 patients over 10 years

OBJECTIVES

The objective of this study was to evaluate a modified Le Fort I interpositional grafting followed by dental implants for the rehabilitation of edentulous atrophied maxillae (Cawood classes IV and V). The surgical modification was a bilateral sinus floor augmentation prior to the osteotomy. This generated a closed recipient bed which allowed the use of particulated bone grafts (xenogenic bone mineral) and a reduced amount of autologous iliac bone grafts.

MATERIALS AND METHODS

106 patients with maxillary interpositional bone grafts were included in this retrospective analysis between 2006 and 2020. The panoramic radiographs and lateral cephalograms were analysed to assess the gain and stability of the maxillary bone and the peri-implant bone loss. In addition, the observational period of up to 14 years implant survival and success was evaluated.

RESULTS

A stable vertical bone height with mean 0.63 ± 1.41mm resorption over 5 years after implant loading was observed. A mean of 0.20 ± 0.37mm marginal bone loss was noted after 5 years. The implant survival was 96.4% after 5 years and implant success can be rated 91.7% in a mean follow-up period of 93 months and 168 months maximal observation time. Perioperative complications included sinus membrane perforation (59.43%), wound healing disturbances (25.47%) and transient primary complications (13.78%). All receded apart from two subtotal graft losses (1.8%).

CONCLUSIONS

The modified Le Fort I osteotomy with interpositional bone grafts is a predictable procedure in terms of bone and implant stability. Patients with atrophic maxillae who are fit for surgery should be informed about risks and benefits of this treatment alternative.

Complications Following One-Stage Versus Two-Stage Surgical Treatment of Transverse Maxillary Hypoplasia

PURPOSE

Contemporary literature suggests a similar transverse stability of a surgical-assisted rapid palatal expansion and a segmented Le Fort I osteotomy. The aim of this study was to compare postoperative complications of 1-stage (segmental maxillary osteotomy) and 2-stage (surgical-assisted rapid palatal expansion followed by Le Fort I osteotomy) treated patients to determine the preferred treatment strategy.

MATERIALS AND METHODS

This retrospective study included 74 consecutive patients (age range: 14 - 57 years; 36 males, 38 females) with a moderate transverse maxillary hypoplasia: 32 patients were treated in a 1-stage protocol and 42 in a 2-stage protocol with a postoperative follow-up of at least 1 year. Dental complications such as loss of teeth, gingival dehiscence, periodontal bone loss, apical root resorption, and surgical complications such as pain, hemorrhage, altered neurosensitivity, wound infection, aseptic necrosis were analyzed. Univariate analysis consisted of a generalized linear model with logit link or Fisher exact test.

RESULTS

No significant difference was found for group characteristics except for longer orthodontic treatment time in the 2-stage group. Incidence and severity of complications were comparable for the 1-stage and 2-stage patients. Only overall pain was significantly greater in the 2-stage patient group (P = .038).

CONCLUSIONS

Considering a similar complication rate and transversal stability, the choice between 1-stage and 2-stage approach for patients with a moderate transverse maxillary hypoplasia should be patient specific.

Orthodontic Clockwise Rotation of Maxillomandibular Complex for Improving Facial Profile in Late Teenagers with Class III Malocclusion: A Preliminary Report

Objective

Orthodontic camouflage treatments improve occlusion but might worsen facial profile in patients with Class III malocclusion. It has been reported that surgical clockwise rotation of maxillomandibular complex (MMc) improves facial profile by reducing chin prominence and chin throat length in patients with Class III malocclusion. The purpose of this report was to illustrate two orthodontic techniques for clockwise rotation of the MMc in late teenagers with Class III malocclusion and preliminarily evaluate their clinical effects.

Patients and Methods

Six patients in late teenage with Class III malocclusion were included in this preliminary report. Bite raisers were first placed on the upper molars to open the bite and clockwise rotate the mandible. Intermaxillary elastics were then applied vertically between the upper and lower dentitions in 3 patients for bimaxillary extrusion (Technique-1) or between the upper dentition and the lower temporary anchorage devices (TADs) in another 3 patients (Technique-2) for upper dentition extrusion and closure of the anterior open bite. The three-dimensional cone-beam computed tomography images taken before and after orthodontic treatment were superimposed to evaluate the treatment effects of MMc clockwise rotation for both techniques.

Results

The Technique-1 extruded the upper and lower dentitions, rotated the mandible clockwise 2.01°, moved chin down 2.98 mm, and back −1.64 mm, although the mandible grew 2.47 mm during the treatment period. The Technique-2 extruded the upper dentition, rotated the mandible clockwise 0.90°, moved chin down 1.78 mm, but slightly forward 0.47 mm due to the mandible grew 2.50 mm and lower dentition was not extruded.

Conclusions

The orthodontic clockwise rotation of MMc is an effective technique for orthognathic camouflage. The applications of bite raisers and bimaxillary dentition extrusion could be more effective than single dentition extrusion with TADs in the mandible for clockwise rotation of MMc and improvement of occlusion and facial profile in late teenagers with Class III malocclusion. However, the comprehensive clinical effects and long-term stability need further clinical studies.

Application of 4-Meta Adhesive Resin to the Occlusal Surface During Surgery Facilitates Postoperative Occlusal Management

PURPOSE

Orthognathic surgery is generally used to correct facial deformities and establish functional occlusion. Preoperative orthodontic treatment is important for stabilizing and establishing the postoperative occlusion. However, sufficient preoperative surgical orthodontic treatment might be sometimes difficult in patients with an abnormally shaped maxilla or mandible or severe jaw deformity.

METHODS

We performed this technique over 10 patients with jaw deformities after insufficient presurgical orthodontic treatment. Adhesive resins are attached to the maxillary palatal cusps to during surgery for disclusion of the premolars and molars.

RESULTS

The resins which are interfered during the postoperative orthodontic treatment can be removed gradually with a bur. Postoperative orthodontic treatment can be subsequently facilitated with a stable occlusion.

CONCLUSION

This technique should be applied for surgery-first orthognathic surgery and avoidance of multi-piece Le Fort I osteotomy, and can facilitate postoperative orthodontic treatment following gradually removal of cusp interferences.

Skeleton first in surgical treatment of facial disharmony

PURPOSE

The aim of this study was to correct facial disharmony with or without occlusal dysfunction.

METHODS

Based on computed tomography and presurgical design, restoration of normal skeleton relationship is a priority for selected facial deformities. Combination of different osteotomies for facial skeleton was chosen in 1-stage operation such as orthognathic surgery, zygomatic reduction, and mandibular angle reduction. Supplementary surgeries was considered in some cases as substitute implantation or autologous fat graft.

RESULTS

All the 50 patients (hemifacial microsomia, Romberg syndrome, mandibular condyle hyperplasia, secondary cleft palate, and Crouzon syndrome) received surgeries, and their facial appearance improved significantly. Yearly follow-up shows that the symmetry and balance of the facial proportion approach normal, whereas most of their occlusal relationship has been significantly improved after the first stage of surgery.

CONCLUSIONS

For most facial disharmony with or without occlusal dysfunction, skeleton-first surgery is a feasible strategy.

Surgery-first accelerated orthognathic surgery: orthodontic guidelines and setup for model surgery

The surgery-first approach indicates that the orthognathic surgery precedes the orthodontic treatment, whereas the orthodontics-first approach indicates that the orthodontic treatment precedes the orthognathic surgery. The conventional approach is an orthodontics-first approach. The purposes of this article are to introduce the concept of the surgery-first approach and to report the guidelines for orthodontic management and model surgery without presurgical orthodontic decompensation. The surgery-first approach treats facial esthetics first and then occlusion, whereas the conventional approach treats occlusion first and then facial esthetics. The surgery-first approach uses osteotomy to solve both skeletal problems and dental compensation, and a "transitional" occlusion is set up postoperatively. Orthodontics in the surgery-first approach is a postoperatively adjunctive treatment to transfigure the transitional occlusion into the solid final occlusion. The advantages of the surgery-first approach are that 1) the patient's chief complaint, dental function, and facial esthetics are achieved and improved in the beginning of the treatment; 2) the entire treatment period is shortened to 1 to 1.5 years or fewer depending on the complexity of orthodontic treatment; and 3) the phenomenon of postoperatively accelerated orthodontic tooth movement reduces the difficulty and treatment time of orthodontic management in the surgery-first approach.

Comparison of progressive cephalometric changes and postsurgical stability of skeletal Class III correction with and without presurgical orthodontic treatment

PURPOSE

This study compares 1) progressive dental and skeletal changes, 2) postsurgical stability, and 3) treatment efficacy of patients with skeletal Class III correction with and without presurgical orthodontic treatment.

PATIENTS AND METHODS

The study includes 53 patients who underwent orthognathic surgery (OGS) to correct skeletal Class III malocclusion. The patient grouping is based on presurgical orthodontics: surgical-first (SF) approach (n = 18) and modified-conventional (MC) approach (n = 35). This study divides the MC group into 2 groups based on whether patients underwent tooth extraction in the presurgical phase (Ext group) (n = 10) or not (Nxt group) (n = 25). Serial lateral cephalometric film measurements identify skeletal and dental changes before treatment (T1), before OGS (T2), 1 month after OGS (T3), and at completion of treatment (T4). This investigation reviews the medical charts for treatment progress and duration.

RESULTS

In the presurgical phase, the Ext group showed mild retraction of the upper incisors and more proclination of the lower incisors than the Nxt group. The skeletal sagittal parameters were similar from T1 to T4 in both the SF and MC groups. In the SF group, SN/U1 decreased 6.2° after surgery and was mildly proclined at T4; in the MC group, upper incisor inclination (SN/U1) increased 1.8° from T1 to T4, being 9.4° greater than that in the SF group at T4. The lower incisor inclination (MP/L1) was similar at T4 in both groups. In the MC group, the MP/L1 was shown to be proclined 4.5° before surgery, retroclined 1.9° after surgery, and further retroclined 4.5° until T4. The relapse rate of the mandibular setback was 14.3% in the SF group and 15.7% in the MC group without significant differences. The percentage of sagittal relapse less than 2 mm was 50% in the SF group and 54% in the MC group. The ratio was greater in the MC group with a relapse between 2 and 4 mm but lesser with a relapse greater than 4 mm. The Ext group showed a 3-month longer treatment duration than the Nxt group.

CONCLUSION

The amount of skeletal correction and postsurgical relapse, as well as treatment duration, were no different in Class III OGS patients with or without presurgical orthodontic treatment. The presurgical work of lower incisor proclination returned to an inclination similar to the initial status after completing treatment. The final outcome of patients evidenced no difference in lower incisor inclination, with or without presurgical orthodontics.

Transverse stability of 3-piece Le Fort I osteotomies

PURPOSE

The transverse dentoalveolar and skeletal stability of multipiece Le Fort I osteotomies with 3 different techniques was investigated.

MATERIALS AND METHODS

The records of 87 patients undergoing bimaxillary osteotomies with 3-piece Le Fort I osteotomy were evaluated. According to the surgical technique of maxillary expansion, the subjects were divided into 3 groups: unilateral palatal osteotomy (group A), bilateral palatal osteotomy (group B), and unilateral palatal osteotomy with fixation of the palatal vault with a resorbable plate (group C). In group A palatal bone grafts were used in 9 patients. Posterior-anterior cephalograms and dental casts were taken before surgery (T1), immediately after surgery (T2), and after a follow-up of 12 to 15 months (T3). The skeletal base was measured between the intersections of the lateral contour of the maxillary alveolar process and the lower contour of the maxillo-zygomatic process. Dentoalveolar width was measured between the first premolars and the first molars. According to the magnitude of expansion, the groups were divided into the following subgroups: negative (constriction), 0 to 2 mm, greater than 2 mm to 4 mm, and greater than 4 mm. An analysis of variance with Bonferroni correction was used to compare the demographic and treatment characteristics and the surgical and postsurgical transverse movements of the 3 study groups. The paired t test was run to evaluate the surgical changes (T2 - T1) and the postsurgical stability (T3 - T2). The influence of palatal bone grafts and downgrafting of the maxilla on the amount of relapse was investigated with the unpaired t test.

RESULTS

The study variables (T1), the surgical changes (T2 - T1), and the postsurgical changes (T3 - T2) showed no significant differences between the 3 study groups. However, a tendency for less relapse in cases with major expansion was seen in group C. The mean expansion of the entire sample was 2.13 mm at the skeletal base, 1.11 mm in the premolar region, and 1.99 mm in the molar region. Mean relapses of 0.20 mm (9%) at the skeletal base, 0.76 mm (68%) in the premolar region, and 1.20 mm (60%) in the molar region were seen. Palatal bone grafts had no significant effect on the postsurgical changes in group A. Anterior and posterior downgrafting did not result in significantly more relapse.

CONCLUSIONS

Surgical expansion of the maxilla provides stable results at the maxillary skeletal base but high relapse rates in the dentoalveolar area. Preoperative orthodontic expansion is one of the main sources of transverse relapse. Fixation of the palatal vault with resorbable plates is a possible technique to improve transverse stability. Larger samples are necessary to provide statistical significance.

Surgical complications of segmental Le Fort I osteotomy

Segmental maxillary osteotomy is a useful adjunct in orthognathic surgery for the correction of vertical and transverse maxillary deformities, but we know of few published reports that document complications. We evaluated the complication rates associated with segmental maxillary surgery in our unit by retrospective review of medical records, radiographs, and study models of 85 consecutive patients (mean age 23.3 years, range 14-51; male:female ratio 1:2) treated from 1995 to 2009. Types of deformity were anterior open bite (n=30, 35%), transverse maxillary deficiency (n=24, 28%), anterior open bite with transverse maxillary deficiency (n=28, 33%), and anterior vertical maxillary excess (n=3, 4%). There were 70 tripartite (82%), 13 bipartite (15%), and two quadripartite (2%) maxillas. Twenty-one patients (25%) had bone grafts. Fixation was done using titanium miniplates in 80 patients (94%), and titanium miniplates and resorbable plates in five (6%). The overall complication rate was 27%. Three patients (4%) had devitalisation of teeth, three (4%) developed minor periodontal defects, and one had tooth loss. Eight patients (9%) had plates removed, and two patients developed persistent postoperative palatal fistula. There was no segmental loss of bone or teeth. Our results show that complications in this cohort were relatively low, and that segmental maxillary surgery is safe as an adjunct in carefully selected cases.

Single-splint technique in orthognathic surgery: intraoperative checkpoints to control facial symmetry

BACKGROUND

Despite the most meticulous preoperative planning and execution, intraoperative soft-tissue response to dentoskeletal changes is often different from those statistically predicted, especially when midline asymmetry is present. A "single-splint" technique for bimaxillary surgery, with intraoperative adjustments and checkpoints, was developed in an attempt to overcome these limitations. The purpose of this study was therefore to determine whether this technique can improve the midline symmetry of facial soft tissues.

METHODS

Forty-five patients who underwent at least a Le Fort I and a bilateral sagittal split osteotomy of the mandible were identified in the authors' patient database. Standardized frontal photographs were used to measure the change in midfacial, intercommissural, chin to midface, and chin to ideal facial midline angles. The facial midline symmetry index, an overall score of facial symmetry, was also calculated.

RESULTS

This study demonstrates that there is a statistically significant improvement of the four angles measured and of the facial midline symmetry index.

CONCLUSIONS

These findings demonstrate that the single-splint technique with its intraoperative checkpoints can successfully maintain or improve facial midline symmetry. Thus, the single-splint technique is a useful alternative to the classic two-splint technique for bimaxillary surgery.

Complications associated with segmentation of the maxilla: a retrospective radiographic follow up of 82 patients

The aim of the present study was to retrospectively examine the clinical and radiographic incidence and frequency of injuries to teeth and their surrounding tissues adjacent to interdental osteotomies in conjunction with segmentation of the maxilla. Vertical interdental osteotomies have been performed in combination with Le Fort I osteotomy for correction of various dento-facial deformities. All our orthognathic patients are followed prospectively in a standardized manner. Eighty-two consecutive patients who underwent dento-facial correction by segmented maxillary osteotomy alone or in combination with simultaneous mandibular surgery between 1992 and 1998 were included in the study. They were followed for up to 30 months postoperatively. A total of 158 interdental osteotomies were performed, involving a total of 316 teeth. Only a small number of complications such as osteolytic processes, marginal bone destruction, root resorption or mechanical injuries to the teeth were seen.

Intra- and perioperative complications of the LeFort I osteotomy: a prospective evaluation of 1000 patients

The LeFort I osteotomy has become a routine procedure in elective orthognathic surgery. The authors report the occurrence of intra- or perioperative complications in a series of 1000 consecutive LeFort I osteotomies performed within a 20-year period. In total, 64 (6.4%) patients experienced complications. Anatomical complications affected 26 (2.6%), patients, including 16 (1.6%) with a deviation of the nasal septum and 10 (1.0%) with non-union of the osteotomy gap. Extensive bleeding that required blood transfusion occurred in 11 (1.1%) patients exclusively after bimaxillary corrections; in 1 patient a ligation of the external carotid artery became necessary. Significant infections such as abscesses or maxillary sinusitis occurred in 11 (1.1%) patients. No patient experienced an osteomyelitis. Ischemic complications affected 10 (1.0%) patients, including 2 (0.2%) who experienced an aseptic necrosis of the alveolar process and 8 (0.8%) who, under critical revision, were affected by retractions of the gingiva. Five (0.5%) patients experienced an insufficient fixation of the osteosynthesis material. The risk and the extent of complications was enhanced in patients with anatomical irregularities (eg, in patients with craniofacial dysplasias, orofacial clefts, or vascular anomalies). The risk of ischemic complications was enhanced in extensive dislocations or transversal segmentation of the maxilla. The authors conclude that patients with major anatomical irregularities should be informed about an enhanced risk of Le-Fort I osteotomies. Preoperative planning avoiding transversal segmentation or extensive dislocations of the maxilla should reduce the occurrence of complications. For healthy individuals, the risk of complications with the LeFort I osteotomy is considered low.