Assessing the Impact of Transcutaneous Maxillary Distraction Osteogenesis on Pharyngeal Airway Volume in Children with Cleft Lip and Palate: A 3D Evaluation Study.

Cleft lip and cleft palate (CLCP) patients often have a retrusive maxilla and a severe skeletal Class III malocclusion, which can result in velopharyngeal insufficiency (VPI). The aim of this study was to evaluate the changes in the volume of the 3D airway in CLCP children after maxilla distraction using the transcutaneous maxillary distraction osteogenesis (TMDO) method. 15 children with bilateral or unilateral CLCP were included in the study. 3D CBCT images were taken before and after distraction and were segmented and reconstructed to create a 3D airway model. The airway was divided into three regions: the upper, oropharyngeal, and hypopharyngeal airway. Pearson correlation tests were used to assess correlations between volume changes and corresponding skeletal and dental landmark movements (Point N, ANS, A, B, Pog, U1, and L1). The results showed that the ANS point advanced 9.85 ± 3.60 mm, and the A point advanced 14.22 ± 4.57 mm. The total airway volume change increased by 2535.06 ± 2791.80 mm3. However, there was no significant correlation between the A/ANS/U1 and the three different airway regions. Only B/Pog/L1 showed a positive correlation with these airway regions, with a high correlation between B/Pog/L1 and the hypopharyngeal airway region. TMDO can result in greater anterior advancement of the maxilla and an increase in airway volume, but the changes in bony landmarks did not show a strong positive correlation with the increase in airway volume as expected. Further investigation is needed to analyze the influence of surrounding soft tissue on the changes in airway volume.

Approaching patients with panfacial fractures by using an anatomical reference: A novel concept and preliminary study.

Panfacial fractures are challenging for craniofacial surgeons. Aside from involving multiple subunits, they also lack the reliability of a useful landmark of the facial skeleton. Properly, reducing and fixing palatal fracture to re-establish the premorbid maxillary dental arch is important. This was a retrospective study conducted from 2015 to 2020. All patients underwent computed tomography (CT) scan for surgical planning of orthognathic surgery due to either esthetic or occlusion concerns. The classification of occlusion was recorded as class I, II, and III. The parameters measured on CT were the distance between the midpoint of the supra-orbital foramen/notch (IS), mesio-buccal cusp tips (IB), central fossa (IC), palatal cusp tips (IP), and the midpoint of the palatal marginal gingiva (IM) of the bilateral maxillary first molars. The IS was compared with the IB, IC, IP, and IM. The results were analyzed by using one-way repeated measurement analysis of variance. Eighty-seven patients (36 men and 51 women) were included in the study. There were 13 patients of class I malocclusion, 8 of class II malocclusion, and 66 of class III malocclusion. The IS was comparable to the IC in all three groups. The IS can predict the IC, regardless of the patient's occlusion, and can be subsequently used to decide the width of maxillary dental arch in panfacial fracture management. Further studies are necessary to obtain more definite results.

Comparison of the Post-Surgical Position of the Temporomandibular Joint after Orthognathic Surgery in Skeletal Class III Patients and Patients with Cleft Lip and Palate.

OBJECTIVE: The purpose of our research is to compare the post-surgical position of the temporomandibular joint in skeletal Class III patients and patients with cleft lip and palate treated with two-jaw orthognathic surgery using a three-dimensional computer tomography image. MATERIALS AND METHODS: Twenty-three skeletal Class III patients with mandibular prognathism associated with maxillary retrognathism in group 1 and twenty cleft mid-face retrusion skeletal Class III patients in group 2 were enrolled in this study. All subjects were treated with two-jaw orthognathic surgery. Computed tomography scans were taken in all subjects at 3 weeks preoperatively and 6 months postoperatively. Three-dimensional craniofacial skeletal structures were build-up, and assessed the temporomandibular joint position changes before and after surgery. RESULTS: Forty-three selected patients were separated into two groups. The mean age of patients was 22.39 ± 4.8 years in group 1 and 20.25 ± 3.8 years in group 2. The range of mean three-dimensional discrepancy of the selected condylar points was 0.95-1.23 mm in group 1 and 2.37-2.86 mm in group 2. The mean alteration of intercondylar angle was 2.33 ± 1.34° in group 1 and 6.30 ± 2.22° in group 2. The significant differences in the discrepancy of TMJ and changes in intercondylar angle were confirmed within the intra-group and between the two groups. CONCLUSIONS: Significant changes in postoperative TMJ position were present in both groups. Furthermore, the cleft group presented significantly more postoperative discrepancy of TMJ and more changes in intercondylar angle after surgery. This finding may be a reason leading to greater postoperative instability in cleft patients compared with skeletal Class III non-cleft patients. CLINICAL TRIAL REGISTRATION NUMBER: IRB No: 202201108B0.

A Comparative Study of Skeletal and Dental Outcome between Transcutaneous External Maxillary Distraction Osteogenesis and Conventional Rigid External Device in Treating Cleft Lip and Palate Patients.

BACKGROUND: Traditional distraction osteogenesis (DO) with the tooth-borne rigid external device (RED) system was regularly used in treating patients with cleft-related maxillary hypoplasia. However, the bone-borne RED system with miniplates and bone screws has currently become an effective treatment. This retrospective study was to compare bone-borne RED with traditional tooth-borne RED in distraction effectiveness, blood loss, operative time, and long-term stability. METHODS: Twenty-two growing patients who underwent RED therapy were divided into two groups: eleven patients utilizing the bone-borne RED system with the transcutaneous wire attached with skeletal anchorage; another eleven patients using the traditional tooth-borne RED system with the intra-oral device attached with dental anchorage. Serial lateral cephalograms were analyzed for comparing treatment outcomes and stability in 1 month, 6 months, and 1.5 years after distraction. RESULTS: In bone-borne RED group, the maxilla was advanced by 19.98 mm with slight clockwise rotation of 0.40° and minimal palatal inclination change of incisor by -3.94°. In traditional tooth-borne RED group, the maxilla showed less advancement by 14.52 mm, with significant counter-clockwise rotation of -11.23° and excessive palatal inclination change of incisor by -10.86°. Although operative time was longer in the bone-borne RED group by 38.4 min, this did not bring about greater blood loss. CONCLUSIONS: the bone-borne RED via transcutaneous wire system provides an easy, simple, and comfortable procedure as well as favorable long-term stability in maxillary distraction.

One-Year Treatment Outcome of Profile Changes After Transcutaneous Maxillary Distraction Osteogenesis in Growing Children With Cleft Lip and Palate.

OBJECTIVE: To evaluate the long-term stability of LeFort I osteotomy followed by distraction osteogenesis with a transcutaneous rigid external device for the treatment of severe maxillary hypoplasia in patients with cleft lip and palate. PATIENTS AND METHODS: Nine patients with cleft lip and palate underwent rigid external distraction after a LeFort I osteotomy for maxillary advancement. Lateral cephalometric films were analyzed for assessment of treatment outcome and stability in 1 month, 6 months, and 1 year after distraction. RESULTS: Significant maxillary advancement was observed in the horizontal direction, with the anterior nasal spine (ANS) distance of the maxilla increasing by an average of 20.5 ± 5.1 mm after distraction. The ANS relapse rates in 6 months and 1 year were 8.7% and 12.8%, respectively. The mean inclination of upper incisors to the palatal plane was almost unchanged (before: 109.8° ± 6.6°; after: 108.9° ± 7.5°). The movement ratios at the nasal tip/ANS, soft tissue A point/A point, and the upper vermilion border/upper incisor edge were 0.36:1, 0.72:1, and 0.83:1, respectively. CONCLUSION: Considerable maxillary advancement was achieved with less change of incisors inclination after distraction. Moreover, the relapse rate after 1 year was minimal. The concave facial profile was improved as well as the facial balance and aesthetics.

Postsurgical Stability of Temporomandibular Joint of Skeletal Class III Patients Treated with 2-Jaw Orthognathic Surgery via Computer-Aided Three-Dimensional Simulation and Navigation in Orthognathic Surgery (CASNOS).

OBJECTIVE: The aim of this study is to clarify the postsurgical stability of temporomandibular joints in skeletal class III patients treated with 2-jaw orthognathic surgery which was performed utilizing computer-aided three-dimensional simulation and navigation in orthognathic surgery (CASNOS) protocol. MATERIALS AND METHODS: 23 consecutive nongrowing skeletal class III patients with mandibular prognathism associated with maxillary retrognathism treated with 2-jaw orthognathic surgery between 2018 and 2019 were enrolled in this study. The surgery was planned according to the standardized protocol of CASNOS (computer-aided three-dimensional simulation and navigation in orthognathic surgery). Computed tomography (CT) scans were performed in all patients 3 weeks presurgically and 6 months postsurgically. ITKSNAP and 3D Slicer software were used to reconstruct three-dimensional facial skeletal images, to carry out image segmentation, and to superimpose and quantify the TMJ position changes before and after surgery. Amount of displacement of the most medial and lateral points of the condyles and the change of intercondylar angles were measured to evaluate the postsurgical stability of TMJ. RESULTS: A total amount of 23 skeletal class III patients (female : male = 12 : 11) with age ranged from 20.3 to 33.5 years (mean: 24.39 ± 4.8 years old) underwent Le Fort I maxillary advancement and BSSO setback of the mandible. The surgical outcome revealed the satisfactory correction of their skeletal deformities. The mean displacement of the right most lateral condylar point (RL-RL') was 1.04 ± 0.42 mm and the mean displacement of the left most lateral condylar point (LL-LL') was 1.19 ± 0.41 mm. The mean displacement of the right most medial condylar point (RM-RM') was 1.03 ± 0.39 mm and the left most medial condylar point (LM-LM') was 0.96 ± 0.39 mm. The mean intercondylar angle was 161.61 ± 5.08° presurgically and 159.28 ± 4.92° postsurgically. CONCLUSION: The postsurgical position of TM joint condyles in our study only presented a mild change with all the landmark displacement within a range of 1.2 mm. This indicates the bimaxillary orthognathic surgery via 3D CASNOS protocol can achieve a desired and stable result of TMJ position in treating skeletal class III adult patients with retrognathic maxilla and prognathic mandible.

Three-Dimensional Outcome Assessments of Surgical Correction in Cleft and Noncleft Patients with Class III Skeletal Relation: A Case-Control Study.

BACKGROUND: The orthognathic strategies to treat patients with a concave profile but different tissue conditions remain controversial. The aim of this case-control study was to investigate the outcome predictability of orthognathic surgery in cleft lip and palate (CLP) patients and matched controls. METHODS: Fifty consecutive CLP and 45 matched non-CLP patients who received whole-piece Le Fort I and bilateral sagittal split osteotomy to correct class III skeletal relations were enrolled. The outcome discrepancies (ODs) from simulations among all groups were evaluated with consideration of the possible influences from planned surgical movements (PSM). Receiver operating characteristic curves were used to determine threshold values of PSMs that yielded clinically relevant OD. RESULTS: Unilateral CLP (UCLP) patients had comparable postsurgical OD to non-CLP patients in both jaws, whereas bilateral CLP (BCLP) patients had greater deviations from predicted results. Vertical movement of the A - point > 1.33 mm and yaw correction > 1.65° in the BCLP patients was associated with clinically relevant maxillary OD. CONCLUSIONS: The OGS outcomes of BCLP patients were less predictable than those of the UCLP and noncleft patients. Vertical movements of the A - point > 1.33 mm and yaw correction > 1.65° in BCLP patients increased OD to a clinically relevant extent.

Intraoperative Blood Loss and Postoperative Pain in the Sagittal Split Ramus Osteotomy and Intraoral Vertical Ramus Osteotomy: A Literature Review.

PURPOSE: The purpose of the present study was to review the literature regarding the blood loss and postoperative pain in the isolated sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO). MATERIALS AND METHODS: Investigating the intraoperative blood loss and postoperative pain, articles were selected from 1970 to 2021 in the English published databases (PubMed, Web of Science, and Cochrane Library). Article retrieval and selection were performed by two authors, and they independently evaluated them based on the eligibility criteria. The articles meeting the search criteria had especially at least 30 patients. RESULTS: In the review of intraoperative blood loss, a total of 139 articles were retrieved and restricted to 6 articles (SSRO: 4; IVRO: 2). In the review of postoperative pain, a total of 174 articles were retrieved and restricted to 4 articles (SSRO: 3; IVRO: 1). The mean blood loss of SSRO and IVRO was ranged from 55 to 167 mL and 82 to 104 mL, respectively. The mean visual analog scale (VAS) scores of the first postoperative day were 2 to 5.3 in SSRO and 2.93 to 3.13 in IVRO. The mean VAS scores of the second postoperative day were 1 to 3 in SSRO and 1.1 to 1.8 in IVRO. CONCLUSION: Compared to traditional SSRO, IVRO had a significantly lower amount of blood loss. However, the blood transfusion is not necessary in a single-jaw operation (SSRO or IVRO). Postoperative pain was similar between SSRO and IVRO.

Temperature Effect of van der Waals Epitaxial GaN Films on Pulse-Laser-Deposited 2D MoS2 Layer.

Van der Waals epitaxial GaN thin films on c-sapphire substrates with a sp2-bonded two-dimensional (2D) MoS2 buffer layer, prepared by pulse laser deposition, were investigated. Low temperature plasma-assisted molecular beam epitaxy (MBE) was successfully employed for the deposition of uniform and ~5 nm GaN thin films on layered 2D MoS2 at different substrate temperatures of 500, 600 and 700 °C, respectively. The surface morphology, surface chemical composition, crystal microstructure, and optical properties of the GaN thin films were identified experimentally by using both in situ and ex situ characterizations. During the MBE growth with a higher substrate temperature, the increased surface migration of atoms contributed to a better formation of the GaN/MoS2 heteroepitaxial structure. Therefore, the crystallinity and optical properties of GaN thin films can obviously be enhanced via the high temperature growth. Likewise, the surface morphology of GaN films can achieve a smoother and more stable chemical composition. Finally, due to the van der Waals bonding, the exfoliation of the heterostructure GaN/MoS2 can also be conducted and investigated by transmission electron microscopy. The largest granular structure with good crystallinity of the GaN thin films can be observed in the case of the high-temperature growth at 700 °C.

Accuracy assessment of computer-aided three-dimensional simulation and navigation in orthognathic surgery (CASNOS).

PURPOSE: This study is aimed for measuring the accuracy of simulation and prediction of our CASNOS protocol in adult patients treated with 2-jaw orthognathic surgery. METHODS: Adult patients with skeletal Class III malocclusions requiring 2-jaw orthognathic surgery were enrolled in the study. Three-dimensional imaging data of 1-month pre-surgical (T1) and 6-month post-surgical (T2) CT were compared to assess accuracy of CASNOS planning. The accuracy of CASNOS protocol was evaluated by calculating the differences in the positions of selected landmarks between simulated surgical and post-surgical 3D images parameters, including ANB, A-Nv, Pog-Nv, and the positions of selected landmarks (ANS, Point A, Point B, Pog) changes in horizontal (x-axis) and vertical (y-axis) directions. Overall geographical discrepancy of planning was assessed by superimposing the color mapping of T1 and T2 imaging. RESULTS: Thirty adult patients with a mean age of 20.6 ± 1.5 years (female/male = 18/12) were enrolled. The geographical changes of overall superimposition between the planned and post-surgical imaging was 0.60 ± 0.19 mm (range: 0.42-1.08 mm). The discrepancies between simulated and post-surgical ANB, A-Nv, Pog-Nv were 1.16 ± 0.36°, 1.25 ± 0.33 mm, 1.19 ± 0.35 mm, respectively. The deviations between simulated and post-surgical Point A and Point B positions were within 1 mm in horizontal and vertical directions. CONCLUSION: The application of the pre-designed bony guiding splints of CASNOS protocol can allow surgeons to treat patients with craniofacial deformities precisely. CASNOS provides a novel approach for orthodontists and surgeons accurately remedying the patients with complex craniofacial discrepancies.

Blood loss and operative time associated with orthognathic surgery utilizing a novel navigation system in cleft lip and palate patients.

PURPOSE: This retrospective study evaluated the volume of blood loss and operative time associated with management of nongrowing patients with cleft lip and palate (CLP) using bimaxillary orthognathic surgery (OGS) designed by a three-dimensional (3D) computer-assisted simulation and navigation for orthognathic surgery (CASNOS) system. METHODS: This study included 53 skeletal Class III nongrowing patients with unilateral CLP who underwent bimaxillary OGS using either the CASNOS protocol (n = 30) or the traditional two-dimensional (2D) method (n = 23). The skeletal parameters of jaw-bone components, the levels of hemoglobin (Hb) and hematocrit (Hct) were measured before and after surgery. The estimated blood loss and actual blood loss (ABL) were also calculated. RESULTS: The two groups did not differ significantly with regard to the demographic parameters (age, gender, and body mass index), the preoperative skeletal parameters and surgical changes of jaw-bone components. The mean ABL of the CASNOS group was significantly lower than that of the control group (915.6 ± 280.5 vs. 1204.9 ± 201.0 ml, p < 0.001), and the changes in Hb and Hct level also followed a similar pattern in both groups. The mean operative time was significantly shorter in the CASNOS group compared with the control group (384.2 ± 48.5 vs. 469.0 ± 94.9 min, p < 0.001). CONCLUSION: This study demonstrated that the application of the 3D CASNOS approach in OGS for the management of complicated Class III nongrowing patients with CLP significantly shortened the operative time and reduced ABL in comparison with the traditional 2D methods.