Segmental Maxillary Osteotomies in Conjunction With Bimaxillary Orthognathic Surgery: Indications – Safety – Outcome

The biomechanical effects of bimaxillary osteotomies to the patients with mandibular retraction under incisal clenching

The purpose of this study is to investigate the biomechanical effect of bimaxillary osteotomies on patients with mandibular retraction. Mandibular retraction, as a typical maxillofacial deformity, and has great adverse effects on TMJ. Bimaxillary osteotomies are widely used to correct symptoms of mandibular retraction. It is necessary to understand the effect of surgery on temporomandibular disc (TMJ). Five patients with mandibular retraction and 10 asymptomatic subjects were involved in this study. Finite element models of preoperative, postoperative and control group were constructed based on the CT data. Nine sets of concentrated forces were used to simulate the muscle effect and contact method was used to simulate the interaction within the TMJs and dentitions. The results showed that bimaxillary osteotomies could effectively improve the maxillofacial morphology and alleviate the overload in TMJ. The facial asymmetry and right chewing side preference could cause imbalanced stress distributions in the TMJs and interfere the surgical treatment.

The Use of Clear Aligners in Multi-Segmental Maxillary Surgery: A Case-Control Study in Cleft Lip and Palate and Skeletal Class III Patients

Background: Maxillary hypoplasia and mandibular asymmetry may be corrected with orthognathic surgery after growth completion. For most stable results, some cases may require segmental Le Fort I osteotomies. Unfortunately, Invisalign's software (6.0 version) still has some inherent limitations in predicting outcomes for complex surgeries. This study explores the potential of aligners, particularly in multiple-piece maxillary osteotomies in both cleft and non-cleft patients. Method: Thirteen patients who underwent pre-surgical treatment with Invisalign were retrospectively matched in terms of diagnosis, surgical procedure, and orthodontic complexity with thirteen patients treated using fixed appliances. Virtual curves following the lower arch were employed to guide the correct pre-surgical positions of the upper teeth with a simple superimposition technique. The amount of impressions required in both groups to achieve satisfactory pre-surgical alignment of the segmented arches was compared. Results: one or no refinement phases were needed in the Invisalign group to reach an acceptable pre-surgical occlusion, while the amount of pre-surgical impressions needed to reach adequate coordination with fixed appliance treatment was slightly higher (p > 0.05). Conclusions: it appears that clear aligner could serve as an effective treatment for individuals necessitating segmental Le Fort I osteotomies when aided by the suggested simple superimposition approach.

Customized palatal guide and splint for maxillary expansion

Customization in orthognathic surgery allows better precision and a reduced surgical time. In Le Fort I osteotomy surgery, the maxillary segmentation is considered one of the most unstable procedures due to transverse instability. Various different types of palatal device have been proposed to address this instability. This note describes a customized bone-borne palatal guide and splint that may help surgeons shorten the surgical time and achieve better three-dimensional repositioning, with more postoperative comfort for the patient and occlusal control for the surgeon.

Successful rehabilitation after multiple severe complications following orthognathic surgery: a case report

BACKGROUND

Complications of orthognathic surgery are quite rare, but they cause suffering in affected individuals. The range of complications is broad and includes both hard and soft tissue.

CASE PRESENTATION

We here present a case of a fully healthy woman without signs of impaired healing capacity. The patient underwent bimaxillary orthognathic surgery and experienced multiple complications both peri- and post-operatively. During the post operative period, the patient also suffered from soft tissue complications after an orthopaedic injury. Therefore, we referred the patient to her general practitioner for further medical investigation. We also present the result after restorative surgery and endodontic and prosthodontic treatment resulting in a successful rehabilitation.

CONCLUSION

This case report clearly shows the need for a good collaboration between different odontological and medical fields to achieve a good and predictable result. In situations where normal healing processes do not occur, in-depth analysis must be carried out.

HIGHLIGHTS

Orthognathic surgery affects soft and hard tissue which can result in adverse healing and complications. It is of great importance to follow up performed surgery to see late complications. Be restrictive with early re-operations when there are signs of necrosis. Always use a multidisciplinary approach when handling complications after surgery.

Dental Occlusion Characteristics for Treatment Decision-Making Regarding Surgery-First Approach in Orthodontics

The surgery-first approach (SFA) is conducted to decrease the difficulty and duration of orthodontic treatment by correcting the skeletal discrepancy at the initial stage of treatment. However, the indication of the SFA has not been well defined yet. This study explored the dental occlusion characteristics for treatment decision-making regarding the SFA. A total of 200 skeletal Class III patients were consecutively collected and divided into two groups: the orthodontic-first approach (OFA) group and the SFA group. The pretreatment digital dental models and lateral cephalograms were measured. Logistic regression was completed and receiver operating characteristic (ROC) curves were obtained to predict the probability of the SFA. Results showed that the ROC model with L1-MP, upper and lower arch length discrepancy, overbite, and asymmetric tooth number as influencing factors revealed that the sensitivity and specificity for determining SFA were 83.0% and 65.0%, respectively; the accuracy of prediction was 75.0%. In conclusion, our findings indicate that the six measurements from digital dental models and lateral cephalograms can be effectively applied in treatment decision-making for the SFA with satisfactory accuracy.

Accuracy of Patient-Specific Implants in Virtually Planned Segmental Le Fort I Osteotomies

(1) Background: In orthognathic surgery, segmental Le Fort I osteotomies are a valuable method to correct maxillary deformities or transversal discrepancies. However, these procedures are technically challenging, and osteosynthesis can be prone to error. (2) Methods: In this retrospective, monocentric cohort study, patients were enrolled who underwent a virtually planned segmental maxillary osteotomy during their combined treatment. Positioning and osteosynthesis were achieved by either a 3D-printed splint and conventional miniplates or patient-specific implants (PSI). The preoperative CT data, virtual planning data, and postoperative CBCT data were segmented. The deviation of all the segments from the desired virtually planned position was measured using the analysis function of IPS CaseDesigner. (3) Results: 28 Patients in the PSI Group and 22 in the conventional groups were included. The PSI group showed significantly lower deviation from the planned position anteroposteriorly (-0.63 ± 1.62 mm vs. -1.3 ± 2.54 mm) and craniocaudally (-1.39 ± 1.59 mm vs. -2.7 ± 3.1 mm). For rotational deviations, the pitch (0.64 ± 2.59° vs. 2.91 ± 4.08°), as well as the inward rotation of the lateral segments, was positively influenced by PSI. (4). Conclusions: The presented data show that patient-specific osteosynthesis significantly reduces deviations from the preoperative plan in virtually planned cases. Transversal expansions and vertical positioning can be addressed better.

Condylar positional changes and remodeling following bimaxillary anterior segment osteotomy with and without Le Fort I osteotomy: a three-dimensional comparative analysis

OBJECTIVE

To evaluate 3D condylar displacement and long-term remodeling following the correction of bimaxillary protrusion by anterior segment osteotomy (ASO) with and without Le Fort I surgery.

MATERIALS AND METHOD

This retrospective study included 32 adults with bimaxillary protrusion who underwent ASO alone (group 1) or with concomitant Le Fort I osteotomy (group 2). Subject's computed tomography scans at basic (T0), immediate postoperatively (T1), and at 1 year or more follow-up (T2) were collected. The condyle displacement was measured at superior-inferior, lateromedially, and anteroposterior surfaces, while condyle remodeling was measured at the superior, lateral, anterior, medial, and posterior surfaces. All 3D analyses were performed using 3D Slicer software (4.11.2).

RESULTS

At T1, 52.7%, 86.7%, and 94.4% of condyles in group 1 were displaced inferiorly, laterally, and posteriorly, respectively, as well as 75%, 89.2%, and 53.5% of condyles in group 2, which had not fully returned to the original preoperative positions at T2. Condylar remodeling was observed in both groups at T2, and no significant difference was found in the overall condylar volume between T1 and T2 in both groups. Patients in group 2 exhibited significant bone resorption at both lateral and anterior surfaces compared to group 1 (P = 0.000 and 0.01, respectively).

CONCLUSION

This study's results demonstrated that ASO is associated with a degree of condylar changes even if the posterior mandible is not osteomized. The positional changes vary between bimaxillary ASO alone and those with simultaneous Le Fort I osteotomy. However, both groups' condyle volume remained stable at the long-term follow-up.

Association Between Maxillary Segmentation and Perioperative Complications in Le Fort I Osteotomy

The Le Fort I osteotomy is used to reposition the maxilla to correct numerous maxillofacial and occlusal deformities. The aim of this study was to delineate perioperative complication rates associated with Le Fort I osteotomy and determine whether the number of maxillary segments or bone grafting yielded increased complication rates. Patients undergoing Le Fort I osteotomy from 2012 to 2019 were identified from the multi-institution "National Surgical Quality Improvement Program" database using Current Procedure Terminology codes. The predictor variables of interest included maxillary segmentation defined as 1, 2, or 2 pieces and the presence or absence of bone graft. Perioperative complications were collected as the primary outcome variable, including superficial and deep space infections, wound dehiscence, airway complication, peripheral nerve injury, and hemorrhage. The secondary outcome variables included readmission and reoperation rate within the 30-day postoperative period. Complication rates were compared using multivariate analysis across groups stratified by the number of maxillary segments and inclusion of bone grafting. Of the 532 patients that met the inclusion criteria, 333 (63%) underwent 1-piece, 114 (21%) 2-piece, and 85 (16%) 2-piece Le Fort I osteotomy procedures. A total of 48 patients exhibited complications (9%), with hemorrhage (2.3%) being the most common complication observed. The number of maxillary segments was not a significant predictor of perioperative complications ( P = 0.948) nor was the use of bone grafting ( P = 0.279).

The role of anterior segmental osteotomies in orthognathic surgery for protrusive faces in a Southeast Asian population: 10-year retrospective data of 51 patients treated in a single centre

Bimaxillary protrusion is a dentofacial deformity common in the East Asian population. It is often difficult to decide between orthodontic and surgical retraction to treat patients with bimaxillary protrusion, especially if surgery to correct skeletal base discrepancies is also required. The objective of this study was to investigate the treatment outcomes of surgical versus orthodontic retraction in patients with bimaxillary protrusion undergoing orthognathic surgery. A retrospective cohort study was conducted, where the medical records and radiographs of 51 patients with bimaxillary protrusion who had an anterior segmental osteotomy concomitant with orthognathic surgery were examined. Patients who had bimaxillary anterior segmental osteotomies were more likely to achieve an inter-incisal angle of 135 ± 5° at the end of treatment, when compared to patients who had orthodontic retraction (P < 0.01). The total treatment duration of patients who had bimaxillary anterior segmental osteotomies was significantly shorter as compared to that of the patients who only had these osteotomies in the maxilla (P < 0.001) or mandible (P = 0.012). Complications and permanent long-term sequelae following anterior segmental osteotomies were uncommon. It is concluded that bimaxillary anterior segmental osteotomies are a viable alternative for patients with concomitant bimaxillary protrusion and skeletal base discrepancies. This allows for a significantly shorter treatment time and greater correction of inter-incisal angles, without a significant increase in complications.

Early Outcomes and Risk Factors in Orthognathic Surgery for Mandibular and Maxillary Hypo- and Hyperplasia: A 13-Year Analysis of a Multi-Institutional Database

BACKGROUND

Orthognathic surgery (OS) is a frequently performed procedure for the correction of dentofacial deformities and malocclusion. Research on OS is mostly limited to single-surgeon experience or single-institutional reports. We, therefore, retrospectively analyzed a multi-institutional database to investigate outcomes of OS and identify risk factors for peri- and postoperative complications.

METHODS

We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2008-2020) to identify patients who underwent OS for mandibular and maxillary hypo- and hyperplasia. The postoperative outcomes of interest included 30-day surgical and medical complications, reoperation, readmission, and mortality. We also evaluated risk factors for complications.

RESULTS

The study population included 674 patients, 48% of whom underwent single jaw surgery, 40% double jaw surgery, and 5.5% triple jaw surgery. The average age was 29 ± 11 years, with an equal gender distribution (females: n = 336; 50%, males: n = 338; 50%). Adverse events were relatively rare, with a total of 29 (4.3%) complications reported. The most common surgical complication was superficial incisional infection (n = 14; 2.1%). While the multivariable analysis revealed isolated single lower jaw surgery (p = 0.03) to be independently associated with surgical complication occurrence, it also identified an association between the outpatient setting and the frequency of surgical complications (p = 0.03) and readmissions (p = 0.02). In addition, Asian ethnicity was identified as a risk factor for bleeding (p = 0.003) and readmission (p = 0.0009).

CONCLUSION

Based on the information recorded by the ACS-NSQIP database, our analysis underscored the positive (short-term) safety profile of OS. We found OS of the mandible to be associated with higher complication rates. The calculated risk role of OS in the outpatient setting warrants further investigation. A significant correlation between Asian OS patients and postoperative adverse events was found. Implementation of these novel risk factors into the surgical workflow may help facial surgeons refine their patient selection and improve patient outcomes. Future studies are needed to investigate the causal relationships of the observed statistical correlations.

Combined orthodontic and surgical open bite correction

OBJECTIVES

To examine the stability of combined surgical and orthodontic bite correction with emphasis on open-bite closure. All study patients were treated with strict and consistent orthodontic and surgical protocols.

MATERIALS AND METHODS

Study inclusion required all patients to have anterior open bites, maxillary accentuated curve of Spee, 36-month minimum follow-up, and no temporomandibular joint pathology. Thirty patients met the inclusion/exclusion criteria. Importantly, segmental upper arch orthodontic preparation (performed by EG) was used. Surgery consisted of a multisegment Le Fort I (MSLFI) combined with a bilateral sagittal osteotomies (BSSO). Surgery was performed (by ADA and LT) at the Department of Dentistry and Maxillofacial Surgery of the University of Verona, Italy.

RESULTS

The long-term open bite and overjet relapse were not statistically significant. The mean transverse relapse of the upper and lower molars was statistically significant. Of great importance, the upper and lower arch widths narrowed together, maintaining intercuspation of the posterior dentition which prevented anterior open bites from developing.

CONCLUSIONS

This study revealed stability of three-dimensional occlusal correction including anterior open bite. Stable open bite closure was achieved by using rigid protocols for orthodontic preparation, surgical techniques, surgical follow-up, and orthodontic finishing.

Orthognathic Surgery-LeFort I Osteotomy

Orthognathic surgery is a complex type of facial surgery that can have a profound impact on a patient's occlusal function and facial aesthetics. Close collaboration between the maxillofacial surgeon and an orthodontist is required, and the surgical team must have a strong foundation in facial analysis and firm understanding of the maxillofacial skeleton to achieve surgical success. Herein, we review the maxillary LeFort I osteotomy as it pertains to orthognathic surgery, with particular attention to the indications, contraindications, preoperative assessment, surgical technique, and possible complications encountered.

Transmucosal posterior segmentation in the context of minimally invasive Le Fort I osteotomy: Technical note

In patients in which posterior segmentation of the maxilla is planned in the context of a minimally invasive Le Fort I osteotomy, accessing the posterior segmentation may tear the soft tissues, causing the minimally invasive approach to become lost, and tissue vascularization may be jeopardized. A technical note is presented for maintaining the original incision length when posterior osteotomies are required in the context of a minimally invasive Le Fort I osteotomy. Two vertical incisions are performed at the level of the premolars, a subperiosteal tunnel is made to access the bone with the piezoelectric device, and then an osteotome is used to complete the osteotomy. It thus may be concluded that this simple and safe additional limited approach can be reproduced in all cases where reaching an anatomical structure in the posterior maxillary region is required in the context of a minimally invasive Le Fort I osteotomy. The described technique offers easy and direct access to the posterior region of the maxilla while maintaining the initial incision length and preserving vascularization through the buccal corridors.

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.

Combined Orthodontic-Orthognathic Approach for Dentofacial Deformities as a Risk Factor for Gingival Recession: A Systematic Review

PURPOSE

The objective of this systematic review was to evaluate the risk of development of gingival recession (GR) as a result of the combined orthodontic-orthognathic approach.

MATERIALS AND METHODS

The PubMed, Google Scholar, ClinicalTrials.gov, and Cochrane Library databases were searched. Included articles mentioned gingival parameters in their materials and methods sections; specifically, they evaluated GR, which was measured before and after the surgical procedure. Study parameters such as methodology, evaluation period, sample characteristics, and follow-up were extracted by 2 authors independently.

RESULTS

In total, 133 relevant articles were identified from the databases; after screening and full-text analysis, 9 studies were included in this systematic review. Meta-analysis could not be conducted because of considerable heterogeneity in methods. The incidence of GR in the range of 0.5 to 3.0 mm as a significant clinical finding after orthognathic surgery showed statistically significant differences in all included articles. Among patients with GR, the mean age was 23.0 to 29.5 years and the mandibular incisors were the most common site. However, no case of recession greater than 3.0 mm was associated with surgery.

CONCLUSIONS

On the basis of the findings of this review, GR of approximately 0.5 to 3.0 mm is a common finding after the combined orthodontic-orthognathic approach. Although periodontal damage up to 3 mm can be observed as an isolated finding in mainly the incisors, true recession is not associated with orthognathic surgery in general.

Is a Final Splint Necessary in Bimaxillary Orthognathic Surgery?

For bimaxillary orthognathic surgery, a splint is commonly used to achieve the final occlusion and is then maintained through initial skeletal healing. The purpose of this study is to document how often a final splint is used to achieve the planned intraoperative occlusion, and how often is the final splint retained after surgery to maintain the occlusion during the initial skeletal healing phase.The investigators developed a retrospective case series. The study variables were demographic and operative. The outcome variables were the use of a final splint to achieve the desired intraoperative occlusion; the frequency and clinical indication for maintaining the final splint during the 5-weeks of initial skeletal healing; and the occlusion achieved after initial healing (5 weeks) compared to that planned from model surgery. Descriptive statistics were reported.The study sample was composed of 41 consecutive subjects. The mean age at operation was 26.9 ± 11.8 years and 51% of the subjects were male. Twenty-five subjects required segmental maxillary surgery. The final splint was used in 39% of subjects to achieve final occlusion and maintained postoperatively in only 10%. No subjects developed transverse relapse during the initial healing phase (5-weeks). All subjects with planned immediate mid-arch open-bites (n = 8) showed vertical improvement or closure during the initial healing when the splint was not maintained.The use of a final occlusal splint and then maintenance of the splint through initial skeletal healing is not required in the majority of bimaxillary orthognathic surgery cases to achieve the planned occlusion.

Interproximal bone in maxillary anterior teeth in subjects with Class III facial deformity: Are there options for segmental maxillary osteotomy in "surgery first"?

Our aim was to give a morphometric description of the interproximal bone between the anterior maxillary teeth of subjects with class III facial deformity, who were candidates for segmented Le Fort I osteotomy. We measured the width of the interproximal bone from the upper right canine to the upper left canine in cone-beam computed tomographic images of 35 subjects, and identified five interproximal areas of measurement. The lower and upper measurements were established 5mm and 10mm from the cervical crest of the interproximal bone. A paired samples t test and Pearson's correlation coefficient were applied and probabilities of less than 0.05 were accepted as significant. In all the scans of interproximal bone, the apical zone was significantly wider than the inferior zone (p<0.001). The area between the central incisors was the widest, with a mean (SD) of 2.42 (0.68) mm in the lower, and 4.27 (0.99) mm in the upper, region followed by the space between the canines and lateral incisors. The minimum interproximal spaces in the lowest area were between 1.1 and 1.5mm, which suggested the potential for damage to the teeth during segmental osteotomy. The interproximal spaces were at potential risk of dental and periodontal injuries, and the area between the central incisors seemed to be most suited to interproximal osteotomies in "surgery first".

Primary Mandibular Deficiency Dentofacial Deformities: Occlusion and Facial Aesthetic Surgical Outcomes

PURPOSE

The purpose of the present study was to document the malocclusion and facial dysmorphology in primary mandibular deficiency (PMD) subjects with chronic obstructive nasal breathing before treatment and the outcomes after bimaxillary orthognathic, genioplasty, and intranasal surgery.

PATIENTS AND METHODS

A retrospective cohort study of PMD subjects undergoing bimaxillary, chin, and intranasal surgery was implemented. The predictor variables were grouped into demographic, anatomic, operative, and longitudinal categories. The primary outcome variables were the initial postoperative occlusion achieved at 5 weeks postoperatively (T₂) and that maintained long-term more than 2 years after surgery (T₄). Six occlusion parameters were assessed: overjet, overbite, coincidence of dental midlines, Angle classification, molar vertical, and transverse positions. A second outcome variable was the facial esthetic results. Photographs were analyzed to document 7 facial contour characteristics.

RESULTS

Forty subjects met the inclusion criteria. Their age at surgery averaged 32 years (range 13 to 63). The study included 25 females (63%). The findings confirmed that the occlusion after initial surgical healing (T₂) met the objectives for all parameters in 39 of the 40 patients (98%). Most patients (35 of 40; 88%) achieved and maintained a favorable occlusion for each parameter in the long-term (mean 5 years, 3 months). Subjects requiring counterclockwise rotation of the maxillomandibular complex were more likely to a have recurrent anterior open bite in the long-term. Facial contour deformities on presentation included weak chin (80%), deep labiomental fold (90%), everted lower lip (100%), short neck-to-chin length (88%), obtuse neck-to-chin angle (85%), weak mandible angles (93%), and "bunching" of the neck soft tissues (85%). Before surgery, 88% of the subjects exhibited a minimum of 5 of the 7 facial deformities. Correction of all 7 facial deformities was confirmed in 86% of the subjects in the long-term.

CONCLUSIONS

Most PMD subjects achieved and maintained a corrected occlusion in the long-term. In the untreated subjects, a "facial type" was identified. Orthognathic surgery proved effective in correcting the associated facial dysmorphology in most patients.

Cone beam computed tomography evaluation of tooth injury after segmental Le Fort I osteotomy

The purpose of this study was to explore the incidence of injuries to the teeth at the vertical osteotomy line after segmental Le Fort I osteotomy by examination of postoperative cone beam computed tomography (CBCT) images. Data for this retrospective case study were collected using CBCT images of 132 patients with an indication for Le Fort I osteotomy with three-piece segmentation of the maxilla. Twenty-two patients (17%, 95% confidence interval 10-23%) had dental injuries. No patient had more than one dental injury. Thirty-three patients (25%, 95% confidence interval 18-32%) had bone dehiscence of the teeth (defined as the osteotomy line passing through the periodontal ligament). Six patients had bone dehiscence involving two teeth and one patient had bone dehiscence involving three teeth. In the group in which dental injuries occurred, the preoperative interdental distance at the vertical osteotomy line was significantly shorter than the interdental distance in the group without dental injuries. In conclusion, this study demonstrated that a preoperative interdental distance of more than 2.5mm significantly reduced the possibility of tooth injuries adjacent to the vertical osteotomy line during Le Fort I osteotomy with three-piece segmentation of the maxilla.

Primary Maxillary Deficiency Dentofacial Deformities: Occlusion and Facial Esthetic Surgical Outcomes

PURPOSE

The purpose of this study was to document the malocclusion and facial dysmorphology in patients with primary maxillary deficiency (PMD) and chronic obstructive nasal breathing before treatment and the outcomes after bimaxillary orthognathic, genioplasty, and intranasal surgery.

MATERIALS AND METHODS

A retrospective cohort study of patients with PMD undergoing bimaxillary orthognathic, chin, and intranasal surgery was implemented. The predictor variables were grouped into demographic, anatomic, operative, and longitudinal follow-up categories. The primary outcome variables were the initial postoperative occlusion achieved (T₂; 5 weeks postoperatively) and that maintained long-term (T₃ or T₄; >2 years after surgery). Six occlusion parameters were assessed: overjet, overbite, coincidence of dental midlines, Angle classification, and molar vertical and transverse positions. A second outcome variable was facial esthetic results. Photographs were analyzed to document 7 facial contour characteristics.

RESULTS

Sixty-six patients met the inclusion criteria. Age at operation averaged 22 years (15 to 55 yr). The study included 18 women (27%). Most patients (57 of 66; 86%) achieved and maintained a favorable occlusion for each parameter studied long-term (mean, 5 yr). The need for a 3-segment Le Fort I was strongly associated with long-term posterior malocclusion. Facial dysmorphology before surgery included the appearance of a prominent chin (56%), flat labiomental fold (61%), prominent lower lip (88%), prominent nose (77%), sunken midface (100%), flat cheekbones (82%), and recessed upper lip (73%). Before surgery, 82% of patients exhibited at least 5 of the 7 key facial contour deformities. Correction of all 7 facial contour deformities was confirmed in 92% of patients in the long-term. In 8% of patients, an overly prominent-appearing chin persisted.

CONCLUSION

Using orthognathic techniques, most patients with PMD achieved and maintained a corrected occlusion long-term. In unoperated patients, a "facial esthetic type" was identified. Bimaxillary orthognathic and chin surgery proved effective in correcting associated facial dysmorphology in most patients.

Corrective outcome and transverse stability after orthognathic surgery using a surgery-first approach in mandibular prognathism with and without facial asymmetry

OBJECTIVES

The aim of this study was to evaluate corrective outcome and transverse stability after orthognathic surgery via a surgery-first approach (SFA) in mandibular prognathism with and without facial asymmetry using 3-dimensional analysis.

STUDY DESIGN

Twenty-nine patients who received mandibular setback surgery using SFA were divided into 2 groups according to the menton deviation (4 mm): symmetry group (n = 17) and asymmetry group (n = 12). Using computed tomography images obtained before (T0), immediately after (T1), and 6 months after (T2) surgery, time-dependent changes in variables related to facial asymmetry, including maxillary height, ramal length, frontal and lateral ramal inclination, mandibular body length, and mandibular body height, were evaluated.

RESULTS

Immediately after surgery, the asymmetry group showed significantly decreased discrepancies between the longer and non-longer sides for all variables (P < .05); there were no significant differences in discrepancies between the 2 groups. During the postoperative period, no significant changes in discrepancies were found in any variable in either group. Compared with T0, the asymmetry group showed significantly decreased discrepancies in ramal length, frontal and lateral ramal inclination, and mandibular body length at T2.

CONCLUSIONS

Variables related to facial asymmetry showed significant improvement after surgical-orthodontic treatment using SFA, and corrected outcomes showed good postoperative stability in both the symmetry and asymmetry groups.

Evaluation of the stability of maxillary expansion using cone-beam computed tomography after segmental Le Fort I osteotomy in adult patients with skeletal Class III malocclusion

Objective

The aim of this study is to quantitatively evaluate the stability of the skeletal and dental widths using cone-beam computed tomography (CBCT) after segmental Le Fort I osteotomy in adult patients with skeletal Class III malocclusion requiring maxillary expansion.

Methods

In total, 25 and 36 patients with skeletal Class III malocclusion underwent Le Fort I osteotomy (control group) and segmental Le Fort I osteotomy (experimental group), respectively. Coronal CBCT images were used to measure the dental and skeletal widths before (T1) and after (T2) surgery and at the end of treatment (T3). The correlation between the extent of surgery and the amount of relapse in the experimental group was also determined.

Results

In the control group, the dental width exhibited a significant decrease of 0.70 ± 1.28 mm between T3 and T2. In the experimental group, dental and skeletal expansion of 1.83 ± 1.66 and 2.55 ± 1.94 mm, respectively, was observed between T2 and T1. The mean changes in the dental and skeletal widths between T3 and T2 were -1.41 ± 1.98 and -0.67 ± 0.72 mm, respectively. There was a weak correlation between the amount of skeletal expansion during segmental Le Fort I osteotomy and the amount of postoperative skeletal relapse in the experimental group.

Conclusions

Maxillary expansion via segmental Le Fort I osteotomy showed good stability, with a skeletal relapse rate of 26.3% over approximately 12 months. Our results suggest that a greater amount of expansion requires greater efforts for the prevention of relapse.

Long-Face Dentofacial Deformities: Occlusion and Facial Esthetic Surgical Outcomes

PURPOSE

The purpose of this study was to document malocclusion and facial dysmorphology in a series of patients with long face (LF) and chronic obstructive nasal breathing before treatment and the outcomes after bimaxillary orthognathic, osseous genioplasty, and intranasal surgery.

MATERIALS AND METHODS

A retrospective cohort study of patients with LF undergoing bimaxillary, chin, and intranasal (septoplasty and inferior turbinate reduction) surgery was implemented. Predictor variables were grouped into demographic, anatomic, operative, and longitudinal follow-up categories. Primary outcome variables were the initial postoperative occlusion achieved (T₂; 5 weeks after surgery) and the occulsion maintained long-term (>2 years after surgery). Six key occlusion parameters were assessed: overjet, overbite, coincidence of dental midlines, canine Angle classification, and molar vertical and transverse positions. The second outcome variable was the facial esthetic results. Photographs in 6 views were analyzed to document 7 facial contour characteristics.

RESULTS

Seventy-eight patients met the inclusion criteria. Average age at surgery was 24 years (range, 13 to 54 yr). The study included 53 female patients (68%). Findings confirmed that occlusion after initial surgical healing (T₂) met the objectives for all parameters in 97% of patients (76 of 78). Most (68 of 78; 87%) maintained a favorable anterior and posterior occlusion for each parameter studied long-term (mean, 5 years 5 months). Facial contour deformities at presentation included prominent nose (63%), flat cheekbones (96%), flat midface (96%), weak chin (91%), obtuse neck-to-chin angle (56%), wide lip separation (95%), and excess maxillary dental show (99%). Correction of all pretreatment facial contour deformities was confirmed in 92% of patients after surgery. Long face patients with higher preoperative body mass index levels were more likely to have residual facial dysmorphology after surgery (P = .0009).

CONCLUSION

Using orthognathic surgery techniques, patients with LF dentofacial deformity achieved the planned occlusion and most maintained the corrected occlusion long-term. In unoperated patients with LF, a "facial esthetic type" was identified. Orthognathic surgery proved effective in correcting associated facial dysmorphology in most patients.

Method of osteotomy fixation and need for removal following bimaxillary orthognathic, osseous genioplasty, and intranasal surgery: a retrospective cohort study

The purpose of this study was to determine the incidence and causes of fixation hardware removal after bimaxillary orthognathic, osseous genioplasty, and intranasal surgery. A retrospective study was performed, involving subjects with a bimaxillary developmental dentofacial deformity (DFD) and symptomatic chronic obstructive nasal breathing. At a minimum, subjects underwent Le Fort I osteotomy, bilateral sagittal ramus osteotomies (SROs), septoplasty, inferior turbinate reduction, and osseous genioplasty. The primary outcome variable studied was fixation hardware removal. Demographic, anatomical, and surgical predictor variables were assessed. Two hundred sixty-two subjects met the inclusion criteria. Their mean age at operation was 25 years (range 13-63 years); 134 were female (51.1%). Simultaneous removal of a third molar was performed in 39.9% of SROs. Three of 262 Le Fort I procedures (1.1%) and two of 524 SROs (0.4%) required hardware removal. There were four cases of ramus wound dehiscence, four of ramus surgical site infection (SSI), one of chin SSI, two of maxillary sinusitis, and one of lingual nerve injury; none of these subjects underwent hardware removal. A limited need for fixation hardware removal after orthognathic procedures was confirmed. There was no statistical correlation between hardware removal and patient sex, age, pattern of DFD, simultaneous removal of a third molar, or occurrence of wound dehiscence, SSI, or lingual nerve injury.