Maxillary Orthognathic Surgery Research Articles

The Effects of the Maxillary Movements in Angle Class 2 and 3 Malocclusion Treatment on Nose Air Flow Amount, Rate, and Resistance.

Maxillary movements performed during orthognathic surgery affect the external and internal anatomy of the nose. The functional and anatomical effects may change nasal airway parameters after the surgery, and these alterations can be examined objectively by rhinomanometry. In this study, patients who underwent maxillary orthognathic surgery were divided into 3 groups based on their surgical plans: advancement (group 1), impaction and advancement (group 2), and setdown and advancement (group 3). Preoperative and postoperative rhinomanometric data including the average nasal volume, minimum cross-sectional area, average airflow resistance of the right and left nasal passageways, and an average of both nasal passages were collected. The study included 50 patients who underwent orthognathic surgery between October 2021 and October 2022. There were 20 patients each in group 1 and group 2 and 10 patients in group 3. The average nasal passage volume increased in the advancement (group 1) and impaction-advancement (group 2) groups. In addition, the advancement (group 1) group had a decreased average airflow resistance. Setdown-advancement (group 3) group did not show a positive or negative effect on nasal airway parameters. Maxillary movements during orthognathic surgery revealed no adverse effect on nasal parameters. Moreover, advancement and impaction positively affected nasal functional and anatomical parameters.

Novel Difficulty Index for Cleft Maxillary Orthognathic Surgery

Novel Difficulty Index for Cleft Maxillary Orthognathic Surgery

Incidence of Sinusitis Postoperatively in Orthognathic Surgery: A Systematic Review and Meta-Analysis.

Maxillary osteotomies as a component of orthognathic surgery disrupt the normal anatomy and function of the sinus. The osteotomy with advancement of the inferior component of the sinus leaves a bony and mucosal opening in the sinus. Immediately after surgery, nasal drainage is impeded because of intranasal swelling. Acute and chronic maxillary sinusitis would be expected; however, its incidence as an expected complication is not well documented. A systematic review and meta-analysis was completed using PubMed to determine the incidence of sinusitis after maxillary orthognathic surgery. Studies were reviewed by two authors, and incidence data were extracted. Two hundred six articles were identified with 24 meeting the criteria for analysis. The incidence of sinusitis was based on 4213 participants who had undergone orthognathic surgery. Twenty-three studies reported a total number of sinusitis cases, and the results demonstrated a pooled incidence of 3.3% (95% confidence interval: 1.77, 6.06). One study did not report a total number of cases but reported chronic sinusitis survey-duration-based and Lund-Mackay scores. These scores, respectively, worsened from 7.6 to 14.8 and from 1.58 to 2.90 postoperatively. Despite the variability of maxillary surgery, the surgical technique, and the postoperative management, the incidence is low but sinusitis does occur. Prospective studies with validated questionnaires within the context of a specific protocol may further elucidate the causality of sinusitis. Further, patients with sinonasal symptoms postsurgery should be encouraged to consult with an otolaryngologist to ensure prompt treatment.

Comparison of Different Decompensation Approaches on Facial Profile in Orthodontic-Orthognathic Treatment for Skeletal Class III Patients.

The objective of the present study was to assess the hard and soft tissue differences of skeletal Class III malocclusion patients treated with orthodontic-orthognathic surgery treatment between two decompensation approaches including extraction of maxillary premolars in preoperative orthodontics and clockwise rotation of the maxilla in orthognathic surgery. 22 skeletal Class III patients with the crowding of maxillary dental arch less than 3mm were included in this study. These patients were divided into two groups: extraction group and non-extraction group. Lateral cephalograms taken before preoperative orthodontic treatment and after postoperative orthodontic treatment were used to analyze the differences of hard and soft tissues between two groups. Independent t test was used to evaluate the differences of variables between extraction group and non-extraction group. After treatment, there was significant difference of Wits between extraction group and non-extraction group (- 4.34 mm vs - 2.82 mm, respectively, P <0.05). Co-Gn was significantly greater in non-extraction group than in extraction group (77.18 mm vs 71.58 mm, P <0.05). U1-SN and L1-MP in extraction group were significantly closer to the normal values than non-extraction group (P <0.05). Regarding the change of variables before and after orthodontic-orthognathic treatment, NLA (7.25° vs 1.46°, P <0.01) and G-Sn-Pog' (8.06° vs 4.62°, P <0.05) were significantly greater in extraction group than in non-extraction group. For patients with skeletal Class III malocclusion, extraction of maxillary premolars in preoperative orthodontic treatment can more effectively eliminate the dental compensation and achieve a more harmonious facial profile compared to clockwise rotation of the maxilla in orthognathic surgery. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Long-term Stability Over 2 Years After Isolated Maxillary Orthognathic Surgery Combined With Mandibular Autorotation in Risk Patients for Condylar Resorption.

Counterclockwise rotation of mandible can cause condylar resorption and condylar displacement posteroinferiorly after maxillary orthognathic surgery with mandibular in patients with high-angle mandibular retrognathism. This study was aimed to evaluate long-term stability >2 years and postoperative changes of condylar displacement. In 15 patients who underwent Le Fort I osteotomy with mandibular autorotation, postoperative stability was cephalometrically investigated until 2 years. Condylar changes were analyzed with transcranial temporomandibular joint projection. Correlation between condylar displacement and surgical movement was analyzed. Significant clockwise relapse of mandible ( P <0.01 for SNB reduction and backward movement of point B) was observed between 6 months and >2 years after surgery, even though the values were small (0.5±0.1 degrees and 1.14±0.13mm, respectively). The condyle was displaced posteroinferiorly immediately after surgery; however, it achieved a stable position at postoperative 6 weeks. The amount of vertical condylar displacement was significantly correlated with surgical change in mandibular posterior border sagittal angle, palatal plane angle, facial height ratio, and point B in the horizontal dimension. Greater mandibular rotation prompted more vertical condylar displacement. Small mandibular relapse in long term should be considered after maxillary orthognathic surgery with mandibular autorotation, although it is regarded as a surgical maneuver to minimize mandibular instability in patients susceptible to postoperative condylar resorption.

Custom made cutting guides and osteosynthesis plates versus CAD/CAM occlusal splints in positioning and fixation of the maxilla in orthognathic surgery: A prospective randomized study

The aim of this study is to compare the accuracy of maxilla positioning in orthognathic surgery with the use of custom-made devices (cutting guides and patient-fitted osteosynthesis plates) comparing to CAD/CAM splints.A prospective randomized study was performed. Patients with dentofacial deformities undergoing orthognathic surgery were compared, using customized guides (experimental group) vs. CAD/CAM surgical splints (control group) for the repositioning of the upper maxilla. Preoperative and postoperative CT scans were used to compare positioning and fixation of the maxilla in the three planes of space.A total of 30 patients were included in the study (15 patients in each study group). The mean error obtained with customized guides was 0.8 mm (range 0.1–1.9) in the anterior-posterior axis, 0.4 mm (range 0–1.4) in the vertical axis and 0.2 mm (range 0–1.1) in the horizontal axis. There were statistically significant differences in the anterior-posterior and vertical axes in favour of the customized implants, whereas there were no differences in the horizontal plane. Furthermore, there was a mean reduction of the operative time of 36.5 min in the experimental group.Within the limitations of the study it seems that patient specific surgical guides should be preferred when accuracy of repositioning of the maxilla and saving operative time are the priority.

A Case of Nasolabial Cyst After Orthognathic Surgery

Nasolabial cyst is a rare, non-odontogenic cyst that occurs in the submucosa of the anterior nasal floor. Its most likely origin is known to be remnants of the nasolacrimal duct. The patient usually comes to the hospital for swelling or pain in the nasolabial area, and the diagnosis is made by combining clinical features, radiologic imaging, and histological test. The most commonly used treatment is surgical excision via sublabial approach. A 40-year-old male, who had undergone maxillary orthognathic surgery for malocclusion 11 years ago, visited our hospital for pain and swelling of the nasolabial folds that had persisted for a year. A large nasolabial cyst with a size of 4.8×3.3×3.1 cm was confirmed on paranasal sinus CT, and surgical excision was performed via sublabial approach. The pathologic finding was a cyst lining consisting of ciliated pseudostratified columnal epithelium and goblet cells, consistent with the characterization of a nasolabial cyst. No recurrence was observed during follow-up for 3 months.

Effects of orthognathic surgery with maxillary impaction plus septoplasty and total turbinectomy on breathing

Complete removal of hypertrophied inferior nasal turbinates may favour the occurrence of the empty nose syndrome (ENS). Some surgeons recommend partial turbinectomy in order to minimize the occurrence of ENS. However, little is known about whether total removal of the inferior nasal turbinate is associated with ENS. The aim of the present study was to evaluate the effects of total turbinectomy and septoplasty on the breathing of individuals undergoing orthognathic surgery with maxillary impaction. A total of 20 individuals participated in this cross-sectional study, in which the relationship between exposure (maxillary orthognathic surgery) and outcome (nasal respiratory function) was investigated. The Empty Nose Syndrome 6-Item questionnaire and Nasal Obstruction Symptom evaluation scale were applied to investigate the ENS. A three-dimensional assessment of the piriform opening was performed pre- and postoperatively by computed tomography in order to measure the volume of the nasal cavities using the Dolphin Imaging software. ENS was detected in 35% of patients, while 13 reported improved breathing. Symptoms of ENS such as dryness, suffocation, nose feels too open and nasal crusting were mentioned. The mean nasal cavity volume was 7477.15 mm³ greater in the initial evaluation (p&lt;0.05). In summary, the occurrence of ENS does not constitute an absolute contraindication of total turbinectomy, a procedure that contributed to the improvement of airway permeability.

Clinical feasibility evaluation of digital dental articulation for three-piece maxillary orthognathic surgery: a proof-of-concept study

Digital dental articulation for three-piece maxillary orthognathic surgery is challenging. The purpose of this proof-of-concept study was to evaluate the clinical feasibility of a newly developed mathematical algorithm to digitally establish the final occlusion for three-piece maxillary surgery. Five patients with jaw deformities who had undergone a three-piece double-jaw surgery that was planned virtually were randomly selected for this study. The final occlusion had been hand-articulated using stone casts, scanned into the computer and used in the surgery. These hand-articulated occlusions served as the control group. To form the experimental group, the three-piece maxillary dental arch was articulated again automatically from the patient’s original occlusion using the mathematical algorithm. The hand- and algorithm-articulated occlusions were then evaluated qualitatively by two experienced orthodontists. A quantitative evaluation was also performed. The results of the qualitative evaluation showed that all of the three-piece occlusions, hand- and algorithm-articulated, were clinically acceptable based on the American Board of Orthodontics grading system. When compared, two of the algorithm-articulated occlusions were clearly better (40%), one was the same (20%), and two were slightly worse (40%) than the hand-articulated occlusions. All of the quantitative measurements were comparable between the two articulation methods. In conclusion, the results of this study demonstrate that it is clinically feasible to digitally articulate the three-piece maxillary arch to the intact mandibular dental arch.

Evaluation of using Piezoelectric device versus Conventional Saw for Osteotomy in Maxillary Orthognathic Surgery

Evaluation of using Piezoelectric device versus Conventional Saw for Osteotomy in Maxillary Orthognathic Surgery

Does Combined Temporomandibular Joint Reconstruction With Patient-Fitted Total Joint Prosthesis and Orthognathic Surgery Provide Stable Skeletal and Occlusal Outcomes in Juvenile Idiopathic Arthritis Patients?

To determine skeletal and occlusal surgical changes and long-term stability outcomes for patients diagnosed with juvenile idiopathic arthritis (JIA) after TMJ reconstruction with TMJ Concepts patient-fitted total joint prostheses (TJP) and concomitant maxillary orthognathic surgery. A retrospective cohort study was conducted of all patients diagnosed with JIA, receiving TJP, and concomitant maxillary orthognathic surgery between 1991 and 2019, at Baylor University Medical Center treated by 1 surgeon. Patient evaluations presurgery (T1), immediate postsurgery (T2), and at longest follow-up (LFU) (T3) were analyzed using 20 cephalometric landmarks to compute 29 linear and angular measurements to determine surgical changes, long-term skeletal and occlusal stability, as well as oropharyngeal airway changes. Comparative data were tested for significance (α=0.05) using paired and unpaired t tests. Forty-two patients met the JIA inclusion criteria, with a median age of 17.5 years and median postsurgical follow-up of 26 months. There were significant surgical changes (T1-T2) (P ≤ .05) for all parameters associated with mandibular linear and angular surgical changes, except for the horizontal position of posterior nasal spine and the vertical/horizontal position of gonion, indicating highly stable surgical outcomes. There were significant improvements in the oropharyngeal airway dimensions. This study suggests that TMJ Concepts patient-fitted TJP for TMJ reconstruction in conjunction with maxillary orthognathic surgery for counterclockwise rotation of the maxillo-mandibular complex for the JIA patients provides long-term skeletal and occlusal stability as well as dimensional improvement in the oropharyngeal airway.

Changes in the facial soft tissue profile after maxillary orthognathic surgery.

ObjectivesTo compare the changes of the soft tissue profile in relation to the displacement of the underlying hard structures in maxillary orthognathic surgery and to contribute to the esthetic prediction of the facial profile after surgical procedures.Materials and methodsWe analyzed the sagittal changes in the facial soft tissue profile related to surgical changes in skeletal structures after maxillary osteotomy in a retrospective study. The study sample comprised 115 adult patients between the ages of 18–50 years who had undergone maxillary orthognathic surgery and interdisciplinary orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. LeFort I osteotomy cases in both maxillary monognathic and bignathic osteotomy procedures were included. All subjects had received rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed and the correlations between hard tissue and soft tissue change ratios were evaluated using a bivariate linear regression analysis. A vertical line through the landmark sella (S) perpendicular to the nasion-sella line (NSL) served as the reference plane.ResultsThe subnasale (Sn) followed the A point (A) by 57%, the soft tissue A point (A′) followed the A point (A) by 73% and the upper lip, represented by the landmark labrale superius (Ls) followed the upper incisor (Is) by 73%; all three in a linear correlation with a mean prediction error of nearly 2 mm.ConclusionThe scatterplots show a linear correlation with a wide spread for all three pairs of reference points. The wide spread and the high prediction error of almost 2 mm indicate low predictability of the expected lip position and Sn.

Surgical correction of the severe jaw deformity in teenagers with juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) can create severe jaw deformities affecting function, esthetics and psychosocial health of teenagers afflicted with this disease. The aim of this chapter is to present the dentofacial manifestations of this disease and the proven surgical protocol to correct these debilitating deformities. Clinical and imaging characteristics of JIA patients with temporomandibular joint (TMJ) involvement and severe jaw deformities are presented as well as the surgical protocol to produce predictable stable outcomes. Clinical research studies documenting the efficacy of this surgical protocol will be reviewed. The most predictable, successful, and stable surgical protocol to treat JIA patients with severe dentofacial deformities includes: bilateral TMJ reconstruction and mandibular counterclockwise rotation-advancement with patient-fitted TMJ total joint prostheses (TJP) and concomitant maxillary osteotomies, as well as adjunctive procedures, performed in a single operation. This protocol provides improvement in jaw function, facial esthetics, pain, and airway. Research studies document the predictability of the treatment protocol. Case presentations illustrate the deformity and the expected outcomes with this surgical protocol. Patient-fitted TJP for TMJ and mandibular reconstruction in conjunction with maxillary orthognathic surgery provides long-term skeletal and occlusal stability in the JIA patient as well as improvement in jaw function, pain, esthetics and airway.

Study of soft tissue changes in the upper lip and nose after backward movement of the maxilla in orthognathic surgery.

ObjectivesThis study evaluates soft tissue changes of the upper lip and nose after maxillary setback with orthognathic surgery such as Le Fort I or anterior segmental osteotomy.Materials and MethodsAll 50 patients with bimaxillary protrusion and skeletal Class II malocclusion underwent Le Fort I or anterior segmental osteotomy with backward movement. Soft and hard tissue changes were analyzed using cephalograms collected preoperatively and 6 months postoperatively.ResultsCluster analysis on the ratios shows that 2 lines intersected at 4 mm point. Based on this point, we divided the subjects into 2 groups Group A (less than 4 mm, 27 subjects) and Group B (more than 4 mm, 23 subjects). Also, each group was divided according to changes of upper incisor angle (≥4°=A1, B1 or <4°=A2, B2). The correlation between A and B groups for Aʼ/ANS and Ls/Is (P<0.001) was significant; Aʼ/A (P=0.002), PRN/A (P=0.043), PRN/ANS (P=0.032), and St/Is (P=0.010). Variation of nasolabial angle between the two groups was not significant. There was no significant correlation of vertical movement and angle variation.ConclusionThe ratio of soft tissue to hard tissue movement depends on the amount of posterior movement in the maxilla, showing approximately two times higher rates in most of the midface when posterior movement was greater than 4 mm. The soft tissue changes caused by posterior movement of the maxilla were little affected by angular changes of upper incisors. Interestingly, nasolabial angle showed a different tendency between A and B groups and was more affected by incisal angular changes when horizontal posterior movement was less than 4 mm.

Three-Dimensional Repositioning of the Maxilla in Orthognathic Surgery Using Patient-Specific Titanium Plates: A Case Series

Successful orthognathic surgery is fundamentally based on accurately carrying out the intended surgical plan intraoperatively. The purpose of this study was to evaluate the accuracy of bone-borne patient-specific maxillary cutting guides and 3-dimensional (3D)-printed plates in repositioning the maxilla during bimaxillary orthognathic surgery. This was a retrospective case series consisting of patients who had undergone Le Fort I osteotomy with a patient-specific cutting guide and 3D-printed plate as well as a bilateral sagittal split osteotomy and had 6-week postoperative cone-beam computed tomography studies. The primary outcome variable was the difference between the position of the postoperative maxilla and the virtually planned maxilla measured at 10 landmarks in 3 dimensions. Other study variables included the preoperative diagnosis and planned surgical movement at each landmark. Descriptive statistics were tabulated, and bivariate analyses were performed. A total of 10 patients were included in this study. The mean age was 25.7±8.1years, and there were 5 female patients. The median planned surgical movement was 0.350mm on the x-axis (right-left), 3.750mm on the y-axis (anterior-posterior), and 1.704mm on the z-axis (superior-inferior). The median absolute discrepancy between the postoperative position and the planned position on the x-axis, y-axis, and z-axis was 0.638, 0.798, and 0.481mm, respectively. There was no significant difference in the discrepancies between the x-axis and y-axis (P=.575), x-axis and z-axis (P=.332), and y-axis and z-axis (P=.114). Using a patient-specific cutting guide and 3D-printed plate when performing Le Fort I osteotomy allows for accurate 3-dimensional positioning of the maxilla in accordance with the surgical plan.

Effectiveness of Selegiline Hydrochlorate in Treating Neurosensory Disorders of the Lower Alveolar Nerve Resulting From Mandibular Sagittal Osteotomy: Preliminary Study.

Peripheral nerves transmit nerve signals between periphery and the spinal cord or brain stem. Its function can be compromised by trauma to the nerve, such as those that occur in surgical procedures such as orthognathic surgery. Depending on the type of injury, treatment may be proposed, but this is still a controversial point in literature. Alternative methods that assist in the treatment of paresthesia should be studied, and in this context, selegiline hydrochloride seems to be a promising drug. Based on the above, the aim of this study was to evaluate the effectiveness of selegiline hydrochloride in the treatment of facial sensory changes resulting from nerve injuries in patients undergoing maxillary orthognathic surgery. This was a double-blind randomized clinical trial with the voluntary participation of individuals who underwent orthognathic surgery. The facial sensitivity of these patients was evaluated by 2-point discrimination tests and directional perception in the region related to the lower alveolar nerve. Tests were comparatively applied at times T0 (before surgery), T8 (8 days after surgery), T15 (15 days after surgery), T30 (30 days after surgery), T60 (60 days after surgery), and T90 (90 days after surgery). The mean age of patients was 31.14 years. With the comparative analysis of the 2-point static test on the chin, difference was observed between groups at times T15 (P = 0.007), T30 (P = 0.010), and T90 (P = 0.027) in the intergroup evaluation. Regarding results of the comparative analysis of the 2-point static test on the lip, difference was observed between groups at times T30 (P = 0.023), T60 (P < 0.001), and T90 (P = 0.005) in the intergroup evaluation. In the direction test on the chin, difference was observed between groups at times T30 (P = 0.015), T60 (P = 0.001), and T90 (P < 0.001) in the intergroup evaluation. Selegiline hydrochloride has shown promising results in the treatment of neurosensory disorders resulting from maxillary orthognathic surgery.

An automatic approach to establish clinically desired final dental occlusion for one-piece maxillary orthognathic surgery.

One critical step in routine orthognathic surgery is to reestablish a desired final dental occlusion. Traditionally, the final occlusion is established by hand articulating stone dental models. To date, there are still no effective solutions to establish the final occlusion in computer-aided surgical simulation. In this study, we consider the most common one-piece maxillary orthognathic surgery and propose a three-stage approach to digitally and automatically establish the desired final dental occlusion. The process includes three stages: (1) extraction of points of interest and teeth landmarks from a pair of upper and lower dental models; (2) establishment of Midline-Canine-Molar (M-C-M) relationship following the clinical criteria on these three regions; and (3) fine alignment of upper and lower teeth with maximum contacts without breaking the established M-C-M relationship. Our method has been quantitatively and qualitatively validated using 18 pairs of dental models. Qualitatively, experienced orthodontists assess the algorithm-articulated and hand-articulated occlusions while being blind to the methods used. They agreed that occlusion results of the two methods are equally good. Quantitatively, we measure and compare the distances between selected landmarks on upper and lower teeth for both algorithm-articulated and hand-articulated occlusions. The results showed that there was no statistically significant difference between the algorithm-articulated and hand-articulated occlusions. The proposed three-stage automatic dental articulation method is able to articulate the digital dental model to the clinically desired final occlusion accurately and efficiently. It allows doctors to completely eliminate the use of stone dental models in the future.

A Robot Arm and Image-Guided Navigation Assisted Surgical System for Maxillary Repositioning in Orthognathic Surgery: A Phantom Skull-Based Trial

This study aimed to present a simplified and safe method to reposition the bone segment with easy identification and removing bone interference using a robot arm and image-guided navigation and to assess the accuracy for maxillary orthognathic surgery on phantom skulls. A surgical system consists of a robot arm with specialized end-effector, and image-guided navigation including the optical tracking system. The end-effector was designed to reflect the surgical procedures including identification and removal of bone interference and repositioning of the bone segment. To evaluate the handling and accuracy of this system, 10 phantom-based experiments were conducted according to four surgical plans. Mean absolute deviations at the upper central incisor were 0.10 ± 0.15 mm medio-laterally, 0.05 ± 0.07 mm antero-posteriorly, and 0.12 ± 0.15 mm supero-inferiorly. There was no significant difference in deviations between anterior and posterior regions of the maxilla. The mean root mean square deviation was 0.18 ± 0.16 mm, and ranged from 0.05 mm to 0.54 mm. The robot arm and image-guided navigation assisted surgical system would be helpful to manage bone interferences and reposition bone segments with improved accuracy. Though further technological advances are necessary, this study may provide a basis for developing clinically applicable robot assisted system for orthognathic surgery.

Feasibility of Delaire cephalometric analysis to predict the ideal sagittal position of the maxilla and chin for surgery-first patients in orthognathic surgery

There is no universally accepted method for determining the ideal sagittal position of the maxilla in orthognathic surgery. The purpose of this study was to compare how well the Delaire's cephalometric analysis correlated with postoperatively findings in patients who underwent orthognathic surgery planned using other cephalometric analyses, as well as to evaluate the feasibility of the Delaire's cephalometric analysis in predicting the ideal sagittal position of the maxilla and chin. In the study, 35 patients with skeletal Class III malocclusion were involved and met the criteria. Treatment plans were developed using photographs, 3-D photographs, radiographs, and standard cephalometric measurements. The Delaire's cephalometric analysis data, like the phase measurements (∠C1-L1 and ∠C1-L2) of the sagittal positions of the maxillary and the chin separating the reference line (L1) of NP point and the reference line (L2) of Me point, were analyzed using Dolphin Imaging software. At the same time, the analyses on standard measurements were also performed. Four orthognathic doctors, 4 orthodontic doctors and 4 college students from non-medical majors were selected as aesthetic evaluators to assess the patients' profile aesthetic by visual analogue scale (VAS). The results through the Delaire's cephalometric analysis were statistically compared with that through standard methods. The mean of ∠C1-L1 was 83.93°±2.99° and∠C1-L2 was 89.08° ±2.48° for males postoperatively, and 85.67° ±3.60° and 88.30° ±4.20° for females postoperatively. Compared with the reference values of Chinese goodlooking people, there was no significant difference of NP point, whereas there was a significant difference of Me point. The postoperative aesthetic scores were: the mean was 6.71±0.25 of upper jaws, 6.81±0.30 of chins and 6.90±0.29 of the overall for males; and 7.19±0.22, 7.26±0.34 and 7.39±0.29 for females. Compared with preoperative scores, there was a significant improvement. Furthermore, the scores of chins and the overall scores were related to the sagittal position of the chins. Compared with standard cephalometric analysis, the Deliare's cephalometric analysis well unravel the preoperative deformity and the final esthetic sagittal positions of maxillary and chin in the present sample, and could be a useful tool for the planning of surgery-first approach in orthognathic surgery.

Surface Topography-Based Positioning Accuracy of Maxillary Templates Fabricated by the CAD/CAM Technique for Orthognathic Surgery without an Intermediate Splint

Computer-aided design/computer-aided manufacturing (CAD/CAM)-based maxillary templates can transfer a surgical plan accurately only when the template is positioned correctly. Our study aimed to evaluate the positioning accuracy of the CAD/CAM-based template for maxillary orthognathic surgery using dry skulls. After reconstruction of a three-dimensional (3D) virtual skull model, a surface-based surgical template for Le Fort I osteotomy was designed and fabricated using CAD/CAM and 3D printing technology. To determine accuracy, the deviation of the template between the planned and the actual position and the fitness of the template were evaluated. The mean deviation was 0.41 ± 0.30 mm in the medio-lateral direction, 0.55 ± 0.59 mm in the antero-posterior direction, and 0.69 ± 0.59 mm in the supero-inferior direction. The root mean square deviation between the planned and the actual position of the template was 1.21 ± 0.54 mm. With respect to the fitness of the template, the mean distance between the inner surface of the template and the underlying bone surface was 0.76 ± 0.24 mm. CAD/CAM-based templates showed precise positioning and good fitness. These results suggest that surface topography-based CAD-CAM templates can be considered as an alternative solution in replacing the traditional intermediate splints for the transfer of surgical plans.