Skeletal stability after maxillary distraction osteogenesis or conventional Le Fort I osteotomy in patients with cleft lip and palate: A superimposition-based cephalometric analysis

PURPOSE

The aim was to assess skeletal stability after maxillary advancement using either distraction osteogenesis (DO) or conventional Le Fort I osteotomy (CO) in patients with cleft lip and palate (CLP) or cleft palate (CP) utilising a new superimposition-based cephalometric method.

METHOD

This retrospective study included patients who were treated with DO (N = 12) or CO (N = 9). Sagittal and vertical changes after surgery, and skeletal stability at 18 months post-operatively were assessed with superimposition-based cephalometry, comparing lateral cephalograms performed pre-operatively (T0), post-operatively after CO or immediately after completed distraction in DO (T1), and at 18 months of follow-up (T2).

RESULTS

The mean sagittal movements from T0 to T2 in the DO and CO groups were 5.9 mm and 2.2 mm, respectively, with a skeletal relapse rate of 16% in the DO group and 15% in the CO group between T1 and T2. The vertical mean movement from T0 to T2 in the DO and CO groups was 2.8 mm and 2.0 mm, respectively, and the skeletal relapse rate between T1 and T2 was 36% in the DO group and 32% in the CO group.

CONCLUSION

Sagittal advancement of the maxilla was stable, in contrast to the vertical downward movement, which showed more-extensive relapse in both groups. Despite more-extensive maxillary advancement in the DO group, the rates of skeletal relapse were similar.

The surgery-first approach for orthognathic correction of maxillary deficiency-is it stable? Three-dimensional assessment of CBCT scans and digital dental models

The aim of this study was to determine the skeletal stability of Le Fort I maxillary advancement following the surgery-first approach, by three-dimensional (3D) assessment of cone beam computed tomography (CBCT) scans and digital dental models. CBCT scans of 25 class III patients obtained 1 week preoperatively (T0) and 1 week (T1) and 6 months (T2) postoperatively were superimposed to measure surgical movements (T0-T1) and skeletal relapse (T1-T2). The distorted dentition of the CBCT scans at T1 was replaced with 3D images of the dental models to assess the postoperative occlusion. Surgical movements of the maxilla (mean ± standard deviation values) were 6.79 ± 2.30 mm advancement, 1.28 ± 1.09 mm vertically, and 0.71 ± 0.79 mm mediolaterally. Horizontal rotation (yaw) was 1.56° ± 1.21°, vertical rotation (pitch) 1.86° ± 1.88°, and tilting (roll) 1.63° ± 1.54°. At T2, the posterior relapse was 0.72 ± 0.43 mm (P = 0.001) and relapse in pitch was 1.56° ± 1.42° (P = 0.007). There was no correlation between the size of the surgical movements and the amount of relapse. A weak correlation was noted between the number of teeth in occlusal contact immediately following surgery and relapse of maxillary roll (r = - 0.434, P = 0.030). The stability of maxillary advancement with the surgery-first approach was satisfactory and was not correlated with the quality of the immediate postoperative occlusion.

Comparative Evaluation of Relapse After LeFort 1 Osteotomy in Cleft Palate and Non-cleft Individuals: A Longitudinal Study

PURPOSE

The aim of this study was to assess and compare the likelihood of relapse one year after LeFort I advancement surgery in patients with and without cleft lip and palate.

METHODS

A retrospective observational study which included two groups of participants who underwent LeFort I maxillary advancement was performed. Group 1 included 10 non-cleft subjects and Group 2 included 21 subjects with cleft palate. These maxillary deficient patients were chosen and operated using a technique where only a sagittal displacement was intended. Patients who underwent additional mandibular surgery, significant vertical or transverse alterations, or both were excluded. Pre-operative (T1), immediately post-operative (T2), and minimum one-year follow-up (T3) lateral cephalograms were studied for each group. Skeletal stability and dental stability after LeFort I surgery at a minimum of one-year follow-up in cleft palate and non-cleft patients were evaluated.

RESULTS

For the given sample size, relapse tendencies showed statistically significant differences between cleft palate patients and non-cleft palate patients after maxillary advancement. The sella nasion angle and horizontal overlap of the maxillary and mandibular incisors (overjet) decreased by 2 degrees and 0.9 mm respectively in the cleft palate group while decreasing by 1.10 degrees and 0.40 mm in the non-cleft group.

CONCLUSIONS

After maxillary advancement with LeFort I osteotomy and miniplate fixation in patients with cleft palate and non-cleft patients, some degree of relapse was detected in both groups for the given sample size after one year post-operatively. The cleft palate group displayed additional relapse tendencies when compared to the non-cleft group.

A 3D dynamic finite element analysis of biomechanical behaviour of maxilla and fixative appliances following advancement Le Fort I surgery applied in different lengths

OBJECTIVES

Dynamic analysis of chewing impact on the stability of rigid fixation techniques following Le Fort I osteotomy has not been investigated in the previous literature. The aim of the present study was to evaluate segmental displacement and von Mises (VM) stress values on the fixation devices following different amounts of Le Fort I advancements under dynamic loading conditions.

MATERIALS AND METHODS

The 3D finite element models simulating 3, 5 and 8 mm advancement of maxilla at the Le Fort I level were generated using CBCT scan data. The models included two anterior L plates and two posterior I plates fixations bilaterally. Dynamic finite element analysis was performed to evaluate their biomechanical behavior against chewing cornflakes bio. Von Mises stresses and displacement values on three points were calculated.

RESULTS

Calculations were made in a time of 38, 40 and 40.5 ms for 3, 5 and 8 mm advancement models, respectively. As the advancement increased, stress values on the plates and displacement values in the D1 (intersection of the apex of the canine tooth with the osteotomy line), D2 (the most prominent point of zygomatic buttress on the osteotomy line), and D3 (intersection of the midline of the second molar tooth with the osteotomy line) points increased. The lowest stress and displacement values were found in the 3 mm advancement model. As advancement increased, the highest values were found in the I plates. The stress levels on the plates and screws remained within safe limits.

CONCLUSIONS

The von Mises stresses and displacement values tend to increase in according with the amount of advancement. More stress is transferred to posterior I plates and screws under dynamic forces.

Factors affecting the relapse of maxilla and soft tissues of nose, upper lip and velopharyngeal structures after maxillary advancement in cleft patients

The objectives of this study were to find the factors affecting the relapses after maxillary advancement in cleft patients. This retrospective study included 25 cleft patients. The serial lateral cephalograms were used for the evaluation of the maxilla and the soft tissue relapses in 1-year post-operative period. The skeletal relapse rate correlated with the amount of skeletal movement only in horizontal direction (r = 0.483, p = 0.015). The patients with significant skeletal relapse did not have different amount of soft tissue relapses when compared to the patients without significant skeletal relapse, except for the A' point. Relapses of the soft tissue parameters of the upper lip and nose were correlated with the upper incisor tip position horizontally and vertically. When comparing the patients who underwent maxillary distraction (DO) with the patients who underwent conventional orthognathic surgery (CO), the DO group had greater NLA relapse and increase of pharyngeal depth than the CO group.

Orthognathic Surgery and Relapse: A Systematic Review

BACKGROUND

This review aimed to analyze the relapse in orthognathic surgery.

METHODS

PubMed, Scopus, and Web of Science databases were used to find papers that matched our topic dating from 1 January 2012 up to November 2022. Inclusion criteria were (1) human studies, (2) open access studies, (3) studies concerning the correlation between orthognathic surgery and relapse. Exclusion criteria were: (1) in vitro or animal studies, (2) off-topic studies, (3) reviews, (4) other languages than English.

RESULTS

A total of 482 results were obtained resulting in 323 publications after duplicate removal (158). After screening and eligibility phases 247 records were excluded: 47 reviews, 5 in animals, 35 in vitro, 180 off-topic. The authors successfully retrieved the remaining 78 papers and evaluated their eligibility. A total of 14 studies from these were ultimately included in the review.

CONCLUSION

Using cephalometric examinations and digital study models, these studies reveal that the relapse after orthognathic surgery is an event that occurs in most of the cases. The limitation of our research is that most of the studies are retrospective and use small sample sizes. A future research goal should be to conduct long-term clinical trials with larger numbers of samples.

Clinical Stability of Bespoke Snowman Plates for Fixation following Sagittal Split Ramus Osteotomy of the Mandible

Maxillofacial skeletal surgery often involves the use of patient-specific implants. However, errors in obtaining patient data and designing and manufacturing patient-specific plates and guides can occur even with accurate virtual surgery. To address these errors, bespoke Snowman plates were designed to allow movement of the mandible. This study aimed to compare the stability of bespoke four-hole miniplates with that of a bespoke Snowman plate for bilateral sagittal split ramus osteotomy (SSRO), and to present a method to investigate joint cavity changes, as well as superimpose virtual and actual surgical images of the mandible. This retrospective study included 22 patients who met the inclusion criteria and underwent orthognathic surgery at a university hospital between 2015 and 2018. Two groups were formed on the basis of the plates used: a control group with four-hole bespoke plates and a study group with bespoke Snowman plates. Stability was assessed by measuring the condyle-fossa space and superimposing three-dimensional virtual surgery images on postoperative cone-beam computed tomography (CBCT) scans. No significant differences were observed in the condyle-fossa space preoperatively and 1 year postoperatively between the control and study groups. Superimposing virtual surgery and CBCT scans revealed minimal differences in the landmark points, with no variation between groups or timepoints. The use of bespoke Snowman plates for stabilizing the mandible following SSRO exhibited clinical stability and reliability similar to those with bespoke four-hole plates. Additionally, a novel method was introduced to evaluate skeletal stability by separately analyzing the condyle-fossa gap changes and assessing the mandibular position.

Differences in the stability of the lesser and greater maxillary segments after cleft orthognathic surgery: A retrospective study using 3D analysis

The aim of this study was to determine whether significant differences in postoperative stability exist between the lesser and the greater maxillary segments after cleft orthognathic surgery in patients with and without residual alveolar cleft. A retrospective study of orthognathic patients with unilateral cleft was conducted. The patients were divided into two groups according to maxillary status before surgery, with group 1 comprising single-piece maxilla and group 2 comprising two-piece maxilla. Four maxillary points were used for intra- and intergroup comparisons of movements and relapses between the two maxillary segments. In total, 24 patients were included. The intragroup comparison showed significant differences in vertical relapses between lesser and greater segments in both group 1 (anterior, p = 0.004 and posterior, p = 0.01) and group 2 (posterior, p = 0.013). With regard to intergroup comparison, the lesser segments in the two groups differed in transverse movements (anterior, p = 0.048) and relapses (posterior; p = 0.04), while the greater segments differed in transverse movements (anterior, p = 0.014 and posterior, p = 0.019), with significant differences in relapses anteriorly (vertical, p = 0.031 and sagittal, p = 0.036) and posteriorly (transverse, p = 0.022). Maxillary changes following cleft orthognathic surgery showed significant differences between the lesser and the greater segments. These findings imply that 3D images should be used to assess each maxillary segment separately with regard to planning and outcome evaluation.

Stability of Le Fort 1 osteotomy in patients with bilateral cleft lip and palate: A retrospective study of 71 patients

The aim of this study was to evaluate the sagittal and vertical relapses after Le Fort 1 osteotomy in bilateral cleft lip and palate (BCLP) patients. Lateral cephalograms before surgery, immediately after the procedure, at one year, and at least two years (when available) after surgery were superimposed. The positions of five landmarks were studied in a coordinate system. Uni- and multivariate analyses investigated the effect of various factors on the relapse. Of the 71 patients included for a BCLP, 54 presented complete data at one year, and 30 patients were included for the long follow-up study (mean of 55 months). The mean maxillary advancement was 6.2 mm on the sub-spinal point (A). Sagittal relapse occurred at one year (mean of 1.1 mm on point A, 0.7 mm on point prosthion (P); p < 0.0001) and progressed by 0.5 mm and 1.0 mm, respectively, on the same points at the last follow-up. The mean vertical relapse was 0.5 mm on point A (p = 0.044), 0.6 mm on point P (p = 0.16) and 0.5 mm on incisor (I) (p = 0.056). The vertical relapse was correlated to the degree of vertical movement. Three factors were associated to the recurrence including a prior pharyngeal flap, an associated mandibular osteotomy and smoking habits.

Modified Le Fort I Arc Osteotomy Combined With Autologous Bone Grafts to Improve Midface Hypoplasia Combined With Skeletal Class III Malocclusion: A Technical Note

Midface hypoplasia sometimes appears in patients with skeletal class III malocclusion in the Asian population, often requires additional surgical treatments. The technical note is intended to introduce a modified Le Fort I arc osteotomy combined with autologous bone grafts harvested from proximal segments after bilateral sagittal split ramus osteotomy to improve the profile for skeletal class III malocclusion patients with midface hypoplasia. The benefit of the modified technology is that the size and position of the arc can be adjusted according to the severity of the deformity to suit different patients. In addition, the application of autologous bone grafts increased the extra height of osteotomy line and enhanced the surgical effect, and maintained bone consolidation. More importantly, the osteotomy line of the modified Le Fort I arc osteotomy can be easily designed and this modification will not cause additional injuries. Therefore, we believe that for skeletal class III malocclusion patients with midface hypoplasia in Asia modified Le Fort I arc osteotomy combined with autologous bone grafts will be an efficient surgical method to improve midface hypoplasia.

Postoperative skeletal stability at the one-year follow-up after splintless Le Fort I osteotomy using patient-specific osteosynthesis versus conventional osteosynthesis: a randomized controlled trial

The purpose of this study was to assess the 1-year skeletal stability of the osteotomized maxilla after Le Fort I surgery, comparing conventional osteosynthesis with patient-specific osteosynthesis. Patients were assigned to a conventional or patient-specific osteosynthesis group using prospective randomization. The primary outcome was the three-dimensional change in postoperative skeletal position of the maxilla between the 2-week and 1-year follow-up cone beam computed tomography scans. Fifty-eight patients completed the protocol for the 2-week postoperative analysis, and 27 patients completed the 1-year follow-up study protocol. Of the 27 patients completing the entire protocol, 13 were in the conventional group and 14 in the patient-specific osteosynthesis group. The three-dimensional translation analysis showed that the use of the patient-specific osteosynthesis resulted in a skeletally stable result, comparable to that of conventional miniplate fixation. For both the patient-specific osteosynthesis and conventional miniplate fixation groups, median translations of less than 1 mm and median rotations of less than 1° were observed, indicating that both methods of fixation resulted in a stable result for the 27 patients examined. For the Le Fort I osteotomy, the choice between patient-specific osteosynthesis and conventional osteosynthesis did not affect the postoperative skeletal stability after 1 year of follow-up.

One-Jaw versus Two-Jaw Orthognathic Surgery for Patients with Cleft: A Comparative Study Using 3D Imaging Virtual Surgical Planning

Whether a one-jaw or two-jaw design is used in orthognathic surgery for patients with cleft remains varied and controversial. This study aimed to compare the two approaches using 3-dimensional imaging surgical simulation. This study was conducted on 41 consecutive patients with complete unilateral cleft lip and palate treated in the craniofacial center. All patients had original two-jaw virtual planning and orthognathic surgery. Simulation of one-jaw LeFort I surgery was performed using the same final dental occlusion on 3-dimensional images. Cephalometric data and asymmetry index were collected and compared among the designs. Average advancement of the maxilla was 7.46 mm in one-jaw and 4.80 mm in two-jaw design. SNA, SNB, and A-N perpendicular were significantly greater and close to normative data in the one-jaw design. ANB angles were similar in both designs. The anterior and posterior occlusal plane cants, the deviation of midline landmarks, and the asymmetry index were more improved in the two-jaw approach. It is concluded that the two-jaw cleft orthognathic surgery could significantly improve facial midline and symmetry compared with the one-jaw approach. However, the two-jaw surgery with mandibular setback produced less protrusive facial contour although a harmonious relationship between the maxilla and mandible was achieved.

Is Le Fort I Distraction Enough to Treat Severe Midface Hypoplasia?

BACKGROUND

In severe cases of maxillary hypoplasia, Le Fort I distraction may be required for treatment. This study describes our experience with internal distraction devices and assesses our outcomes in patients with a negative overjet on average >15 mm.

METHODS

A retrospective review of patients with a history of cleft lip and/or palate who underwent Le Fort I distraction at our institution from 11/2007-11/2017 was performed. Data regarding demographics, procedural details and outcomes were collected and analyzed.

RESULTS

Twenty patients, 13 (65.0%) male and 7 (30.0%) female, were included. All (100%) patients had a history of cleft lip and/or palate and 2 (10.0%) of them had associated syndromes. All 20 patients underwent internal distraction. The average age at surgery was 17.8 years (range 15.2-20.7, SD 1.6 years). The average preoperative negative overjet was 19.27 mm (range 10-30, SD 5.63 mm). The mean total distraction length was 15.3 mm (range 0-30, SD 6.72 mm). There were no intraoperative complications, however, there were a total of 4 (20.0%) postoperative complications, 2 of which required reoperation due to device malfunction or displacement. 14 (70.0%) patients had repeat procedures to complete occlusal correction or correct relapse.

CONCLUSIONS

Maxillary distraction alone was insufficient for correction of maxillary discrepancies averaging >15 mm. Instead, it's utility may be in positioning the maxilla for a more viable final advancement and fixation procedure, rather than being solely responsible for achieving normal occlusion during distraction.

One-Year Stability of LeFort I Advancement in Patients With Complete Cleft Lip and Palate Using a Standardized Clinical and Surgical Protocol

AIM

To assess treatment outcome and 1-year stability of LeFort I advancement in patients with complete cleft lip and palate.

METHODS

Thirty-five patients (age 20.65 ± 2.20 years) with unilateral (n = 25) or bilateral (n = 10) complete cleft lip and palate who underwent LeFort I advancement were included.Lateral cephalograms before surgery (T1), immediately postsurgery (T2), and at 1-year follow-up (T3) were superimposed, and the position of anterior nasal spine (ANS), A-point, and U1 Tip assessed using an x, y coordinate system. Differences between landmark positions at the 3-time points were analyzed using paired sample t-tests, with a significance defined as α ≤ 0.05.

RESULTS

The mean surgical advancement in the horizontal direction (T2-T1) was 6.50 ± 2.62 mm at ANS (P < 0.001) and 7.05 ± 2.51 mm at A-point (P < 0.001). At a 1-year follow-up (T3-T2), the mean horizontal relapse at ANS was -1.41 ± 1.89 mm (P < 0.001) and -0.79 ± 1.48 mm at A-point (P 0.003). Mean horizontal relapse was 21.7% and 11% of surgical advancement when assessed at ANS and A-point, respectively. The central incisor tip position remained stable during the postsurgical period (0.12 ± 2.11 mm, P 0.732). At A-point, the mean vertical surgical change (T2-T1) was -0.96 ± 2.57 mm (P < 0.001). No significant post-treatment (T3-T2) vertical changes were detected at ANS or A-point. Phenotypic stability was excellent, with all patients maintaining positive overjet at 1-year follow-up.

CONCLUSIONS

LeFort I advancement in complete cleft lip and palate is stable, with less than a 2 mm relapse after 1-year. Surgical overcorrection by 10% to 20% is recommended to compensate for the expected skeletal relapse.

Cleft Lip and Palate: Le Fort I Distraction Using an Internal Device

Maxillary hypoplasia is a commonly seen dentofacial anomaly in patients with cleft lip and palate after surgical repair of the cleft anomaly. To facilitate large horizontal movements of the maxilla, distraction osteogenesis is used to slowly stretch the soft tissue envelope with the skeletal advancement preventing tissue recoil and skeletal relapse. Internal distraction devices have the advantage of reducing the amount of physical and psychological stress placed on patients, families, and caregivers. The technique has been successful in producing stable results for large advancements of the facial skeleton when compared with conventional Le Fort I advancement and fixation of the maxilla.

Variables associated with stability after Le Fort I osteotomy for skeletal class III malocclusion

The purpose of this study was to assess skeletal stability and predictors of relapse in patients undergoing an isolated Le Fort I osteotomy. A retrospective cohort study of 92 subjects undergoing Le Fort I osteotomy for Class III malocclusion was implemented. Predictor variables were demographic and perioperative factors. The primary outcome variable was postoperative skeletal position with relapse defined as >2mm sagittal and/or vertical change at A-point on serial lateral cephalograms at immediate postoperative, 1 year, and latest follow-up time points. Mean advancement at A-point was 6.28±2.63mm and mean lengthening was 0.92±1.76mm. Eight subjects (8.70%) had relapse (>2mm) in the sagittal plane, and two subjects (2.17%) in the vertical plane. No subjects required reoperation for relapse as overbite and overjet remained in an acceptable range due to dental compensation. In regression analysis, magnitude of maxillary advancement was an independent predictor of relapse in the sagittal plane (P=0.008). There were no significant predictors of relapse in the vertical plane. This study suggests that isolated Le Fort I osteotomy for correction of skeletal Class III malocclusion is a stable procedure and that greater advancement is an independent risk factor for sagittal relapse.

Challenges in the Successful Reconstruction of Cleft Lip and Palate: Managing the Nasomaxillary Deformity in Adolescence

The surgical techniques and execution of primary cleft lip and palate repair are no longer the greatest challenge to achieving successful rehabilitation for those born with facial clefting (i.e., bilateral and unilateral cleft lip and palate). Despite a surgeon's best efforts, when cleft palate repair is carried out during infancy, by the mixed dentition, a majority will demonstrate nasomaxillary deficiency. The cleft team's commitment to a family under their care is to ensure that the newborn reaches adulthood reconstructed without need for special regard to their original birth malformation. Guiding principles are provided for the accurate diagnosis and reliable reconstruction of the bilateral and unilateral cleft lip and palate adolescent/adult who presents with nasomaxillary deficiency and any residual oronasal fistula, bony defects, cleft dental gap(s), nasal obstructions, and associated facial dysmorphology. Successful orthognathic surgery provides a stable foundation on which any remaining soft-tissue cleft lip or cleft nasal deformities can be accurately assessed and then reconstructed.

Maxillomandibular Advancement for Obstructive Sleep Apnea Produces Long-Term Horizontal Advancement of the Maxilla and Mandible

PURPOSE

Because limited data have been reported, the purpose of the present study was to evaluate the long-term craniofacial cephalometric skeletal changes associated with maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA).

MATERIALS AND METHODS

We performed a retrospective cephalometric cohort study of craniofacial skeletal changes in patients who had undergone MMA for OSA. The primary predictor and outcome variables were time and the change in SNB over time, respectively. Digitized cephalometric radiographs were analyzed by an independent third-party cloud-based tracing software for 6 skeletal landmarks at 3 points-preoperatively, within 1 month postoperatively, and at the last follow-up evaluation. Post hoc stratification bidimensional analyses by gender and preoperative age and body mass index (BMI) were performed. Clinically significant results were determined as a greater than 2% change from baseline. Univariate and bivariate statistics were computed, and the statistical significance level was set at P < .05.

RESULTS

Thirty consecutive subjects with an even gender distribution were included in the present study. The average preoperative age, apnea hypopnea index, and BMI were 43.7 years, 59.8, and 39.3 kg/m². The average follow-up duration was 10.7 years (range, 5.6 to 18.8). Statistically and clinically significant long-term postoperative changes were found only for SNA (+4.9° or +6.0%; P < .001) and SNB (+3.8° or +4.9%; P < .001). Stratification by gender and median preoperative age and BMI did not find any statistically or clinically significant results.

CONCLUSIONS

Within the limitations of the present study, MMA for OSA produced statistically and clinically significant long-term cephalometric skeletal horizontal angular advancement of the maxilla and mandible of 6 and 4.9%, respectively, independently of gender, age, or BMI.

Update on complications in cleft orthognathic surgery

PURPOSE OF REVIEW

To give an update on recent publications and tendencies concerning complications in cleft orthognathic surgery.

RECENT FINDINGS

Cleft-specific changes after orthognathic surgery and their impact on surgical outcomes are discussed. Focus lays on the causes and mechanisms of cleft-related surgical complications and strategies to prevent or minimize these complications. Bimaxillary surgery is seen as a safe procedure for cleft patients. Maxillary distraction, total or segmental, is pointed out as an alternative method to improve outcomes. Different techniques for osteotomies and maxillary mobilization could decrease adverse events.

SUMMARY

Cleft patients are more susceptible to the occurrence of complications because of peculiar presurgical conditions. Different surgical approaches and techniques are presented to overcome these difficulties, to achieve better results and to increase patient safety. The importance of communication between patient, family and cleft team members is emphasized.