Correction of Severe Secondary Cleft Lip Nasal Deformity.

BACKGROUND: The lower lateral cartilages (LLCs) are key elements for alar and tip support. Repositioning of both LLCs is an effective procedure for correcting a laterally spreading dome of LLCs and drooping nasal tip in cleft lip nasal deformity (CLND). The alar contour graft has become an essential component of rhinoplasty for correcting the concave or collapsed and retracted alar. Herein, onlay cartilage graft was combined with nasal tip plasty to correct hypoplastic cleft lateral crus or alar rim retraction, and with columella strut to obtain better aesthetic outcomes in patients with severe CLND. METHODS: Seven patients with severe secondary unilateral CLND, including hypoplastic cleft lateral crus or alar rim retraction, underwent rhinoplasty from October 2013 to April 2020. Both LLCs were isolated and repositioned approximated medially using tip suture technique combined with columella strut. A septal cartilage onlay graft was applied on the hypoplastic cleft lateral crus. Cartilage graft on the nasal tip was performed to further project and enhance the nasal tip. Photogrammetric evaluation of the operated patients and statistical analysis of the obtained data were performed. RESULTS: The average age at operation was 23.5 (range: 17-36) years. The follow-up period was 6-36 (mean, 14.3) months. All patients were enrolled by photogrammetric evaluation. Height of the medial nostril and short axis of the nostril on the cleft side were increased with a statistical significance of P < 0.05, indicating that depressed ala on the cleft side, which is a feature of CLND, was corrected similar to that of the noncleft side. CONCLUSIONS: The alar contour cartilage graft, as an effective adjunctive technique, improves the alar margin, prevents the alar rim from collapsing, and provides supports to the cleft-side alar rim. It can be a prophylactic measure to prevent postoperative retraction in patients with weakened LLCs. Lower lateral cartilage repositioning, columellar strut, and nasal tip plasty are useful for correcting severe secondary unilateral CLND.

The Effect of Orthognathic Surgery on Changes in Masticatory Muscle Volume in Patients With Facial Asymmetry.

ABSTRACT: The masseter muscle changes remarkably with orthognathic surgery and has a marked influence on the contours of the lower face. If the postoperative volume change of masticatory muscles, including the masseter muscles, can be predicted, it will facilitate preoperative planning and outcome prediction. This study investigated the association of masticatory muscle volume according to the presence or absence of facial asymmetry, and evaluated whether the volume of masticatory muscles, including that of the masseter muscle, changes after orthognathic surgery in facial asymmetry patients.Twenty patients who underwent LeFort I osteotomy and bilateral sagittal segmentation ramus osteotomy (BSSRO) with facial asymmetry between 2011 and 2017 were assigned to the asymmetric group. Additionally, 207 patients with a simple nasal fracture between 2016 and 2019 were included as the common group. Threedimensional computed tomography images were retrospectively analyzed and compared between the asymmetric group and common group.The volume of both temporal and masseter muscles differed according to facial asymmetry, with the asymmetry in the muscle volume increasing in proportion to the degree of facial asymmetry. The difference in masseter volume on the shortened and lengthened sides was significantly reduced after orthognathic surgery, but a difference of about 1 cm 3 remained. Additionally, the masticatory muscle volume on the lengthened side tended to be decreased more than that on the shortened side.Consideration of the postoperative change in the volume of the masticatory muscles may be helpful in planning orthognathic surgery in facial asymmetry patients.

Influence of Irradiation on Capsules of Silicone Implants Covered with Acellular Dermal Matrix in Mice.

BACKGROUND: In advanced breast cancer, radiotherapy is recommended as adjuvant therapy following breast reconstructive surgery. This inevitably led to growing concerns over possible complications of radiotherapy on implants. In this experimental animal study, we investigated the utility of acellular dermal matrix (ADM) wraps around implants as preventive management for radiotherapy complications. METHODS: Black mice (C57NL6; n = 32) were assigned to groups that either received radiation or did not: groups A and B underwent surgery using implants without radiotherapy; while groups C and D underwent surgery using implants with radiotherapy for one and three months, respectively. The hemispheric silicone implants with an 0.8-cm-diameter were inserted on the left back of each mouse, and implants wrapped by ADM were inserted on the right back. The Clinic 23EX LINAC model was used for irradiation at 10 Gy. The samples were evaluated by gross assessment, histological analysis, immunohistochemical analysis, and the Western blotting test. RESULTS: The H&E staining analysis showed that membrane thickness is smallest in group A, followed by groups C, D, and B. In a Masson trichrome histological analysis, collagen fibers became less dense and more widespread over time in the groups that received an ADM. Immunohistochemistry findings were similarly constant. However, the expression of TGF-ß1 was increased in the irradiated groups, whereas it was decreased in the non-irradiated groups as observed over time. CONCLUSIONS: Radiotherapy was shown to increase risk factors for capsular contracture, including inflammatory response, pseudoepithelium, thinning of membrane, and TGF-ß1 expression over time; however, the accompanying framework using an ADM as a barrier between implant and tissue was shown to be effective in alleviating these risks. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

Osteogenesis of 3D-Printed PCL/TCP/bdECM Scaffold Using Adipose-Derived Stem Cells Aggregates; An Experimental Study in the Canine Mandible.

Three-dimensional (3D) printing is perceived as an innovative tool for change in tissue engineering and regenerative medicine based on research outcomes on the development of artificial organs and tissues. With advances in such technology, research is underway into 3D-printed artificial scaffolds for tissue recovery and regeneration. In this study, we fabricated artificial scaffolds by coating bone demineralized and decellularized extracellular matrix (bdECM) onto existing 3D-printed polycaprolactone/tricalcium phosphate (PCL/TCP) to enhance osteoconductivity and osteoinductivity. After injecting adipose-derived stem cells (ADSCs) in an aggregate form found to be effective in previous studies, we examined the effects of the scaffold on ossification during mandibular reconstruction in beagle dogs. Ten beagles were divided into two groups: group A (PCL/TCP/bdECM + ADSC injection; n = 5) and group B (PCL/TCP/bdECM; n = 5). The results were analyzed four and eight weeks after intervention. Computed tomography (CT) findings showed that group A had more diffuse osteoblast tissue than group B. Evidence of infection or immune rejection was not detected following histological examination. Goldner trichrome (G/T) staining revealed rich ossification in scaffold pores. ColI, Osteocalcin, and Runx2 gene expressions were determined using real-time polymerase chain reaction. Group A showed greater expression of these genes. Through Western blotting, group A showed a greater expression of genes that encode ColI, Osteocalcin, and Runx2 proteins. In conclusion, intervention group A, in which the beagles received the additional ADSC injection together with the 3D-printed PCL/TCP coated with bdECM, showed improved mandibular ossification in and around the pores of the scaffold.

A rare complication of reduction malarplasty.

UNLABELLED: In this report, the authors introduce a rare complication after reduction malarplasty in a 21-year-old male patient. The patient underwent two-jaw surgery and reduction malarplasty at a local plastic surgery clinic in December 2012. He presented with mass-like swelling of the left temporomandibular joint (TMJ) and a clicking sound with jaw movement that began 5 months after surgery. Physical examination, ultrasonography, and enhanced facial 3-dimensional computed tomography indicated suspicion of TMJ capsule injury. Therefore, mass excisional biopsy was performed with plate and screw removal. Biopsy results of the excised cystic mass revealed bursitis. The patient's symptoms disappeared after surgery. This is the first report of bursitis as a rare complication after reduction malarplasty. LEVEL OF EVIDENCE V: 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.

Prosthodontic rehabilitation after myofascial flap surgery of hemimaxillectomy defects in the edentulous patient: a clinical report.

OBJECTIVE: The aims of this clinical report were to present and discuss the clinical procedure and the treatment considerations of prosthetic rehabilitation after myofascial flap surgery. DESIGN: A 78-year-old edentulous woman with a squamous cell carcinoma underwent hemimaxillectomy. A temporalis myofascial flap surgery combined with implant-supported prosthesis is one successful approach to the restoration of oral function after hemimaxillectomy. CONCLUSIONS: Although the bulky and mobile nature of a temporalis myofascial flap prevented the retention of a tissue-borne denture, an appropriate impression technique and the fabrication of implant-supported prosthesis using an implant attachment system enhanced the overall satisfaction by the patient.

Free Vertical Latissimus Dorsi Flap for Tongue Reconstruction After Total Glossectomy.

BACKGROUND/AIM: The tongue is an important anatomical structure, playing an significant role in natural speech, swallowing, and sense of taste. Immediate reconstruction using autologous tissue must be performed following glossectomy for tongue cancer to improve patient quality of life. This study aimed to demonstrate the usefulness of a surgical technique using the free vertical latissimus dorsi flap (FvLDF) for tongue reconstructions using autologous tissue. PATIENTS AND METHODS: Among patients who underwent total glossectomy for tongue cancer from November 2014 to February 2023, we selected 10 patients who underwent immediate tongue reconstruction with a radial free forearm flap (RFFF) or free anterolateral thigh flap and four patients who underwent FvLDF. The patients were compared regarding postoperative function (width of oropharyngeal space in computed tomography, language-speech evaluation), aesthetic results, and features. RESULTS: All four patients who underwent FvLDF showed successful flap survival, with no severe complications. Because vertical incision was made during flap harvest with primary closure possible with the mid-axillary line, donor morbidity was significantly lower in patients who underwent reconstruction with FvLDF than in those who underwent reconstruction with RFFF, and good aesthetic results were obtained. In comparing the oropharyngeal space of patients on neck CT preoperatively and postoperatively, the width increase rate of patients who underwent reconstruction with FvLDF was significantly smaller. FvLDF patients demonstrated good speech and swallowing functions. CONCLUSION: Considering the advantages of reconstruction with FvLDF in terms of features and aesthetic results, this surgical technique may be a reliable alternative technique for tongue defects after glossectomy.

Effect of surface treatment on shear bond strength of relining material and 3D-printed denture base.

PURPOSE: This study aimed to analyze the shear bond strength between the 3D-printed denture base and the chairside relining material, according to the surface treatment. MATERIALS AND METHODS: Cylindrical specimens were prepared using DENTCA Denture Base II. The experimental groups were divided into 6 (n = 10): no surface treatment (C), Tokuyama Rebase II Normal adhesive (A), sandblasting (P), sandblasting and adhesive (PA), sandblasting and silane (PS), and the Rocatec system (PPS). After bonding the chairside relining material to the center of the specimens in a cylindrical shape, they were stored in distilled water for 24 hours. Shear bond strength was measured using a universal testing machine, and failure mode was analyzed with a scanning electron microscope. Shear bond strength values were analyzed using one-way analysis of variance, and Tukey's honest significant difference test was used for post-hoc analysis (P < .05). RESULTS: Group PPS exhibited significantly higher shear bond strength than all other groups. Groups P and PA displayed significantly higher bond strengths than the control group. There were no significant differences between groups PS and A compared to the control group. Regarding the failure mode, adhesive failure occurred primarily in groups C and A, and mixed failure mainly in groups P, PA, PS, and PPS. CONCLUSION: The shear bond strength between the 3D-printed denture base and the chairside relining material exhibited significant differences according to the surface treatment methods. It is believed that excellent adhesive strength will be obtained when the Rocatec system is applied to 3D-printed dentures in clinical practice.

Effect of Breast Silicone Implant Topography on Bacterial Attachment and Growth: An In Vitro Study.

BACKGROUND/AIM: The mechanisms underlying capsular contracture remain unclear. Emerging evidence supports the inflammation hypothesis, according to which bacteria from an adherent biofilm cause chronic inflammation and collagen deposition on the implant and trigger capsular contracture. Our goal was to evaluate the effect of different types of breast implants on the growth of Staphylococcus aureus, S. epidermidis, and Pseudomonas aeruginosa, which are commonly found in biofilms in infection. MATERIALS AND METHODS: Bacteria were grown in tryptic soy broth at 37°C for 2, 6, and 24 h and subsequently incubated for 24 h on 12 shell sections of smooth, nano-, and macrotextured breast implants. After incubation, the solutions were ultrasonicated and bacterial numbers were determined by serial dilution. S. aureus were fixed, washed with phosphate-buffered saline, dehydrated in ethanol, and coated with a platinum film to visualize the presence of biofilms by scanning electron microscopy. RESULTS: The numbers of S. aureus and S. epidermidis attached to the smooth and nanotextured surface implants were significantly lower than those on the macrotextured surface for all incubation times, whereas the number of P. aeruginosa was non-significantly lowest on the nanotextured surface after 24h incubation. Biofilms on smooth and nanotextured implant surfaces showed patchy patterns on scanning electron microscopy in contrast to the continuous pattern detected on macrotextured implants. CONCLUSION: Nanotextured breast implants may limit bacterial growth and thus prevent capsular contracture.

Bio-inspired strategy for on-surface synthesis of silver nanoparticles for metal/organic hybrid nanomaterials and LDI-MS substrates.

A strategy for the on-surface synthesis of silver nanoparticles (AgNPs) on a variety of two- to three-dimensional material surfaces, utilizing polydopamine, an emerging surface modifying agent, is reported in this paper. This material-independent platform for AgNP synthesis is useful for fabricating organic/inorganic hybrid nanomaterials and for preparing substrates for laser desorption-ionization time-of-flight mass spectrometry (LDI-ToF MS).

Comparison of surface topography and roughness in different yttrium oxide compositions of dental zirconia after grinding and polishing.

PURPOSE: The purpose of this study was to compare the surface roughness, phase transformation, and surface topography of dental zirconia with three different yttrium oxide compositions under same grinding and polishing conditions. MATERIALS AND METHODS: Three zirconia disks (IPS e.max ZirCAD LT, MT, MT multi, Ivoclar Vivadent AG, Schaan, Liechtenstein) were selected for experimental materials. Sixty-nine bar-shaped specimens were fabricated as 12.0 × 6.0 × 4.0 mm using a milling machine and glazing was conducted on 12.0 × 6.0 mm surface by same operator. With a custom polishing device, 12.0 × 6.0 mm surfaces were polished under same condition. Surface roughness (Ra[µm]) was measured before grinding (C), after grinding (G), and at every 3 steps of polishing (P1, P2, P3). X-ray diffraction and FE-SEM observation was conducted before grinding, after grinding, and after fine polishing (P3). Statistical analysis of surface roughness was performed using Kruskal-Wallis test and Mann-Whitney-U test was used as a post hoc test (α = .05). RESULTS: There were no significant differences of surface roughness between LT, MT, and MM groups. In LT, MT, and MM groups, P3 groups showed significantly lower surface roughness than C groups. X-ray diffraction showed grinding and polishing didn't lead to phase transformation on zirconia surface. In FE-SEM images, growths in grain size of zirconia were observed as yttrium oxide composition increases. CONCLUSION: Polished zirconia surface showed clinically acceptable surface roughness, but difference in yttrium oxide composition had no significant influence on the surface roughness. Therefore, in clinical situation, zirconia polishing burs could be used regardless of yttrium oxide composition.

A nationwide cohort study on growth impairment by cleft lip with or without palate.

There are very few nationwide studies discussing the height, weight, head circumference, and dental screening of children with cleft lip with or without palate (CL/P), with most reports on this subject based on a 1900s cohort. This study aimed to characterize CL/P children in the 2000s in terms of height, weight, head circumference, and dental screening. This nationwide population-based study evaluated the National Health Insurance Service-Infants and Children's Health Screening (NHIS-INCHS), specifically the height, weight, and head circumference of millions of children. Dental screening data, including the status of each tooth and comprehensive dental judgment, were also evaluated. Syndromic and nonsyndromic CL/P children had lower height, weight, and head circumference than no CL/P children until the age of 66-71 months. Children with cleft palate only or both cleft lip and palate showed similar results. Regarding dental screening, the primary teeth of CL/P children erupted later and fell out faster than no CL/P children. Dental caries was also more common in CL/P children. Children with CL/P had inferior general growth, regardless of palatoplasty surgery. More aggressive dental treatment was required for CL/P children due to the instability of primary teeth and tendency for caries.

Stability of lingual plate osteotomy in orthognathic surgery for patients with severe facial asymmetry: A retrospective analysis with 1-year follow-up.

This study aimed to evaluate the stability of lingual plate osteotomy after sagittal split ramus osteotomy (SSRO) in patients with severe facial asymmetry. It included 20 patients undergoing lingual plate osteotomy between January 2011 and January 2017. Cephalometric X-ray imaging and three-dimensional computed tomography (3DCT) were performed before the operation and then 1 day and 1 year after the operation. The relapse rate and postoperative complications were assessed. The operation time was compared between lingual plate osteotomy and transoral angle osteotomy. Specific values measured on cephalometric X-ray and 3DCT images showed significant changes 1 day after the operation, with 47.9% correction occurring in the occlusal plane angle (mean ± SD = 1.74 ± 0.84°, p < 0.05). However, no significant differences were found between measurements taken 1 day and 1 year after the operation, with a 5% change seen in the occlusal plane angle (mean ± SD = 0.1 ± 0.24°, p = 0.61), suggesting that the surgical outcomes can be well maintained for at least 1 year after surgery. Three patients experienced numbness postoperatively but recovered within 1 year. The operation time for lingual plate osteotomy was shorter than that for transoral angle osteotomy. Our findings indicate that lingual plate osteotomy after SSRO is stable, effective, and safe in patients with severe facial asymmetry.

Surgical approach for venous malformation in the head and neck.

BACKGROUND: Treatment for venous malformations of the head and neck includes sclerotherapy, surgical resection, or a combination of both. Surgical resection can remove or reduce the volume of vascular lesions; however, surgery can cause postoperative scarring and potential surgical complications. This study sought to determine the effectiveness of surgery for the treatment of venous malformations of the head and neck. METHODS: A retrospective review of the medical records of patients who received surgeries for venous malformations of the head and neck from January 2011 to July 2019 was performed. Using clinical photographs, preoperative and postoperative Doppler ultrasonography, outpatient clinic records, and operation records, the postoperative result and complications were evaluated for each case. RESULTS: Among patients who visited our vascular anomalies clinic, 43 patients (ratio of male to female= 24:19) received surgeries for venous malformations of the head and neck. Twenty-nine patients had undergone surgery only, five patients received sclerotherapy after surgery, and nine patients received surgery after preoperative sclerotherapy. In postoperative evaluations, the result was excellent in 24 patients, good in 18 patients, and poor in one patient. Four patients experienced a recurrence of lesions with lagophthalmos, drooping of the corner of the mouth, partial wound necrosis, and scar widening found in one patient each. CONCLUSION: Because the head and neck region is the most exposed area in the body, more active implementation of surgical treatments with or without sclerotherapy is essential to reduce the functional and cosmetic impairments associated with venous malformations.

Usefulness of the LigaSure™ small jaw sealing device for breast reconstruction with a latissimus dorsi flap.

Background: Seromas are the most common complication of latissimus dorsi flap breast reconstruction. Electrocautery for flap elevation can cause seromas and injure the lymph or vessels of the surrounding tissues. Positive effects of the LigaSure Small Jaw (Medtronic [formerly Covidien], Minneapolis, MN, USA) sealing device were examined. Methods: Forty-three latissimus dorsi flap breast reconstruction patients were included. Twenty-three underwent surgery with electrocautery and 21 underwent surgery with LigaSure. The seroma formation rate, total drain volume, drainage indwelling periods at the breast site and donor site, operative time, and hospital stay duration were retrospectively compared. Associations between patient characteristics and these variables were analyzed. Results: Seroma incidence rates were 9/23 (39.1%) and 3/21 (14.3%) for the control and experimental groups. One control group patient underwent surgical treatment; the rest underwent conservative treatment. A significant difference in latissimus dorsi flap elevation time was found between the control and experimental groups (105.6 minutes and 77.1 minutes; p = .026). A significant difference in the drainage indwelling periods of the latissimus dorsi donor site was found (13.1 days and 11 days; p = .006). Excised breast mass weight, latissimus dorsi flap weight, breast drain total volume/indwelling period, and latissimus dorsi drain volume/indwelling period showed statistically significant associations. Radiation and chemotherapy were not significantly associated with any variables. Conclusion: The LigaSure device for latissimus dorsi flap breast reconstruction can reduce seromas, operative time, and hospital stay. It is a reliable and useful surgical sealing device that does not cause injury to the surrounding tissues.

Comparisons among four types of absorbable plates used for internal fixation of zygomaticomaxillary complex fractures.

IMPORTANCE: Conventional plating systems include titanium plates for the fixation of facial bone fractures. However, titanium plates result in artifacts on computed tomography images and appear unstable on magnetic resonance images. Therefore, absorbable plates have been widely used for the fixation of facial bone fractures of late in Asia. OBJECTIVE: To compare stability and symmetry among four different absorbable plates used for internal fixation of zygomaticomaxillary complex fractures. PARTICIPANTS: The subjects were patients with zygomaticomaxillary complex fractures that were diagnosed and treated by internal fixation with absorbable plates between January 2012 and April 2018. Patients aged ≤14 years and ≥76 years were excluded. Patients with other fracture types were also excluded. All patients underwent surgery within 2 weeks of the injury. INTERVENTION: Internal fixation was performed with one of four types of absorbable plates, namely Inion®, Polymax®, Osteotrans®, and Biosorb®. MAIN OUTCOME MEASURES: The stability of the four plates was investigated by evaluation of the orbital height ratio (A'/A), zygoma angle (a'/a), distance (b'/b) from the midline, and gap (c) of the temporal process on three-dimensional facial computed tomography images obtained before, 3 weeks after, and 3-6 months after surgery. Any plate-associated complications were recorded. RESULTS: In total, 400 patients were enrolled, and there were 100 patients in each of the four groups. There were no significant differences with regard to postoperative stability and relapse among the four plates. Moreover, facial symmetry showed no changes over time in any group. Complications such as infection and sensory disturbance were not frequent. All plates except Biosorb® were palpable for more than 6 months after surgery, with Osteotrans® remaining palpable for several years. CONCLUSIONS AND RELEVANCE: Our findings suggest that all four types of absorbable plates are useful for treating isolated zygomaticomaxillary complex fractures. While Biosorb® is unsuitable for severe comminuted fractures. Polymax® and Inion® are not bendable at room temperature. It is important to select an appropriate absorbable plate according to each patient's condition and the fracture severity.

Three dimensional deformation of dry-stored complete denture base at room temperature.

PURPOSE: The aim of this study was to evaluate whether there is any typical deformation pattern existing in complete denture when it was dried by using the 3D scanner and surface matching program. MATERIALS AND METHODS: A total of 28 denture bases were fabricated with heat curing acrylic resin (each 14 upper and lower denture bases), and 14 denture bases (each 7 upper and lower denture bases) were stored in the water bottle (water stored), and another 14 denture bases were stored in the air (dry stored). Each specimen was scanned at 1(st) day after deflasking, 14(th) day after deflasking, and 28(th) day after deflasking, and digitalized. Three dimensional deformation patterns were acquired by comparison of the data within storage group using surface matching program. For evaluating differences between groups, these data were compared statisticallyusing Kruskal Wallis and Mann Whitney-U test (α=.05). RESULTS: When evaluating 3D deformation of denture base, obvious deformations were not found in maxillary and mandibular water storage group. However, in dry stored group, typical deformation pattern was detected as storage time passes. It occurred mostly in first two weeks. Major deformations were found in the bilateral posterior area in both maxillary and mandibular group. In maxillary dry stored group, a statistical significance was found. CONCLUSION: It was proved that in both upper and lower denture bases, dry storage caused more dimensional deformation than water storage with typical pattern.

Factors prognostic for phonetic development after cleft palate repair.

BACKGROUND: Palatoplasty is aimed to achieve normal speech, improve food intake, and ensure successful maxillary growth. However, the velopharyngeal function is harder to control than other functions. Therefore, many studies on the prognostic factor of velopharyngeal insufficiency have been conducted. This study aimed to evaluate the relationships between speech outcomes and multimodality based on intraoral and preoperative three-dimensional computerized tomographic (CT) findings. METHODS: Among 73 children with cleft palate who underwent palatoplasty between April 2011 and August 2014 at Kyungpook National University Hospital (KNUH), 27 were retrospectively evaluated. The 27 cases were non-syndromic, for which successful speech evaluation was conducted by a single speech-language pathologist (Table 1). Successful speech evaluation was defined as performing the test three times in 6-month intervals. Three intraoral parameters were measured before and immediately after operation (Fig. 1). On axial- and coronal-view preoperative facial CT, 5 and 2 different parameters were analyzed, respectively (Figs. 2 and 3). Regression analysis (SPSS IBM 22.0) was used in the statistical analysis. RESULTS: Two-flap palatoplasty and Furlow's double opposing Z-plasty were performed in 15 and 12 patients, respectively. The operation was performed 11 months after birth on average. Children with a higher palatal arch and wider maxillary tuberosity distance showed hypernasality (p < 0.05; Table 2). CONCLUSIONS: The useful prognostic factors of velopharyngeal function after palatoplasty were palate width and height, rather than initial diagnosis, treatment method, or palate length. Therefore, a more active intervention is needed, such as orthopedic appliance, posterior pharyngeal wall augmentation, or early speech training.

Three-dimensional numerical simulation of stress induced by different lengths of osseointegrated implants in the anterior maxilla.

Lower survival rates were observed for the implant placed in the anterior maxilla. The purpose of this study was to investigate the influence of different implant lengths on the stress distribution around osseointegrated implants under a static loading condition in the anterior maxilla using a three-dimensional finite element analysis. The diameter of 4.0 mm external type implants of different lengths (8.5 mm, 10.0 mm, 11.5 mm, 13.0 mm, 15.0 mm) was used in this study. The anterior maxilla was assumed to be D3 bone quality. All the material was assumed to be homogenous, isotropic and linearly elastic. The implant-bone interface was constructed using a rigid element for simulating the osseointegrated condition. Then, 176 N of static force was applied on the middle of the palatoincisal line angle of the abutment at a 120°angle to the long axis of abutment. The von Mises stress value was measured with an interval of 0.25 mm along the bone-implant interface. Incremental increase in implant length causes a gradual reduction of maximum and average von Mises stress at the labial portion within the implant. In the bone, higher stress was concentrated within cortical bone area and more distributed at the labial cortex, while cancellous bone showed relatively low stress concentration and even distribution. An increase in implant length reduced stress gradients at the cortical peri-implant region. Implant length affects the mechanisms of load transmission to the osseointegrated implant. On the basis of this study the biomechanical stress-based performance of implants placed in the anterior maxilla improves when using longer implants.

Bone-implant interface with simulated insertion stress around an immediately loaded dental implant in the anterior maxilla: a three-dimensional finite element analysis.

PURPOSE: The purpose of the present study was to investigate the stress distribution around the bone-implant interface and the effect of the length of an immediately loaded implant in the anterior maxilla using a finite element model with simulated loading stresses. MATERIALS AND METHODS: Four-mm-diameter external-hex implants with different lengths (8.5, 10.0, 11.5, 13.0, and 15.0 mm) were used in this study. The anterior maxilla was assumed to be D3 bone quality. All of the material was assumed to be homogenous, isotropic, and linearly elastic. Average bone deformation during implant placement was calculated through the simulation process, and using this, insertion stress was created. The bone-implant interface was constructed using a contact element to simulate a nonosseointegrated condition. Then, 176 N of static force was applied at the middle of the palatoincisal line angle of the abutment at a 120-degree angle to the long axis of the abutment. The von Mises stresses were measured at intervals of 0.25 mm along the bone-implant interface. RESULTS: Prior to loading, the stresses were evenly distributed around the implant and highly concentrated in the cortical area. When the load was applied, von Mises stresses were concentrated in the cortical bone of the implant neck area. More favorable stress distribution was seen with increasing implant length. However, when the implant length reached 15.0 mm, the stresses increased. CONCLUSIONS: In the maxilla, when immediate loading is applied after implant placement, 11.5- and 13.0-mm-long single implants showed more favorable stress patterns than the others analyzed. If implants longer than 15.0 mm are used in immediate loading, sufficient bone volume in the recipient site should be considered an important factor.