A finite element analysis of stress distribution with various directions of intermaxillary fixation using orthodontic mini-implants and elastics following mandibular advancement with a bilateral sagittal split ramus osteotomy.

OBJECTIVE: This finite element analysis (FEA) aimed to assess the stress distribution in the mandible and fixation system with various directions of the intermaxillary fixation (IMF) using mini-implants (MIs) and elastics following mandibular advancement with a bilateral sagittal split ramus osteotomy (BSSRO). MATERIALS AND METHODS: A total of nine mandibular advancement models were set according to the position of the MIs (1.6 mm in diameter, 8 mm in length) and direction of the IMF elastics (1/4 inch, 5 oz). Major and minor principal stresses in the cortical and cancellous bones, von Mises stresses in the fixation system (miniplate and monocortical screws), and bending angles of the miniplate were analysed. RESULTS: Compressive and tensile stress distributions in the mandible and von Mises stress distributions in the fixation system were greater in models with a Class III IMF elastic direction and a higher IMF elastic force than in models with a Class II IMF elastic direction and a lower IMF elastic force. The bending angle of the miniplate was negligible. CONCLUSIONS: Stress distributions in the bone and fixation system varied depending on the direction, amount of force, and position of IMF elastics and MIs. Conclusively, IMF elastics in the Class II direction with minimal load in the area close to the osteotomy site should be recommended.

Alternate levels versus all levels mini-plate fixation in C3-6 cervical laminoplasty: a retrospective comparative study.

OBJECTIVE: The purpose of this study is to compare radiological and clinical outcomes between alternate levels (C4 and C6) and all levels mini-plate fixation in C3-6 unilateral open-door laminoplasty. METHODS: Ninety-six patients who underwent C3-6 unilateral open-door laminoplasty with alternate levels mini-plate fixation (54 patients in group A) or all levels mini-plate fixation (42 patients in group B) between September 2014 and September 2019 were reviewed in this study. Radiologic and clinical outcomes were assessed. Clinical results included Visual Analogue Scale (VAS) of axial neck pain and Japanese Orthopedic Association (JOA) score. Radiographic results included cervical range of motion (ROM), cervical curvature index (CCI), and the spinal canal expansive parameters including open angle, anteroposterior diameter (APD), and Pavlov`s ratio. RESULTS: There was no significant difference in VAS, JOA score, ROM, and CCI between two groups. There was no significant difference in canal expansion postoperatively between two groups. However, open angle, APD, and Pavlov`s ratio in group A decreased significantly during the follow-up. In group B, APD, Pavlov`s ratio, and open angle were maintained until the final follow-up. There was no hardware failure or lamina reclosure occurred in both groups during the follow-up. The mean cost of group B was higher than that of group A. CONCLUSIONS: Despite the differences in the maintenance of canal expansion, alternate levels mini-plate fixation can achieve similar clinical outcomes as all levels mini-plate fixation in C3-6 unilateral open-door laminoplasty. As evidenced in this study, we believe C3-6 laminoplasty with alternate levels (C4 and C6) mini-plate fixation is an economical, effective, and safe treatment method.

Highly extensile approach for comminuted ulna coronoid process fractures with mini-plate fixation: a case series of 31 patients.

BACKGROUND: For the treatment of coronoid process fractures, medial, lateral, anterior, anteromedial, and posterior approaches have been increasingly reported; however, there is no general consensus on the method of fixation of coronal fractures. Here, we present a highly-extensile minimally invasive approach to treat coronoid process fractures using a mini-plate that can achieve anatomic reduction, stable fixation, and anterior capsular repair. Further, the study aimed to determine the complication rate of the anterior minimally invasive approach and to evaluate functional and clinical patient-reported outcomes during follow-up. METHODS: Thirty-one patients diagnosed with coronoid fractures accompanied with a "terrible triad" or posteromedial rotational instability between April 2012 and October 2018 were included in the analysis. Anatomical reduction and mini-plate fixation of coronoid fractures were performed using an anterior minimally invasive approach. Patient-reported outcomes were evaluated using the Mayo Elbow Performance Index (MEPI) score, range of motion (ROM), and the visual analog score (VAS). The time of fracture healing and complications were recorded. RESULTS: The mean follow-up time was 26.7 months (range, 14-60 months). The average time to radiological union was 3.6 ± 1.3 months. During the follow-up period, the average elbow extension was 6.8 ± 2.9° while the average flexion was 129.6 ± 4.6°. According to Morrey's criteria, 26 (81%) elbows achieved a normal desired ROM. At the last follow-up, the mean MEPI score was 98 ± 3.3 points. There were no instances of elbow instability, elbow joint stiffness, subluxation or dislocation, infection, blood vessel complications, or nerve palsy. Overall, 10 elbows (31%) experienced heterotopic ossification. CONCLUSION: An anterior minimally invasive approach allows satisfactory fixation of coronoid fractures while reducing incision complications due to over-dissection of soft tissue injuries. In addition, this incision does not compromise the soft tissue stability of the elbow joint and allows the patient a more rapid return to rehabilitation exercises.

Comparison of reconstruction plates and miniplates in mandibular defect reconstruction with free iliac flap.

OBJECTIVE: Given the increasing demand for precise and reliable reconstructive techniques in maxillofacial surgery, we try to offer valuable insights for clinicians in selecting optimal fixation methods. MATERIALS AND METHODS: Patients were categorized into miniplate and reconstruction plate groups for accuracy and bone healing comparison. We measured gonial angle, intercondylar, intergonial and anterior-posterior distance for general accuracy and distance of segmental endpoint to the sagittal plane for partial accuracy. The bone healing rate of the two groups was compared with CT images at 3, 6 and 12 months after operation. RESULT: Considering directional indicators, the miniplate group exhibited a wider intercondylar distance than the reconstruction plate group (p = 0.029). At 6 months postoperatively, the miniplate group demonstrated a higher bone healing rate compared to the reconstruction plate group, with no significant differences at other time points. CONCLUSION: Over a nearly 5-year review, mandibular reconstruction with vascularized iliac bone flaps showed that reconstruction plates better maintained condylar position accuracy, while miniplates had superior bone healing rates at 6 months. No significant differences were found in other accuracy indices between the two plates. CLINICAL RELEVANCE: Clinicians' selection of fixation plates frequently depends on personal preference rather than evidence-based criteria. This study compares the precision and postoperative osseous healing outcomes of miniplates and reconstruction plates to provide a more scientifically grounded basis for clinical decision-making.

The use of miniplates for nontraditional orthodontic treatment: clinical considerations for referring general dentists.

Distalization of mandibular molars comes with significant challenges, especially in adult and young adult patients. In selected cases, third molar extraction procedures offer the opportunity to place miniplates for anchorage to distalize mandibular molars, providing additional solutions to the traditional extraction of premolars or a single incisor. This approach can be of special interest to adult patients, who may have life commitments and time restraints that limit traditional orthodontic and surgical treatment options, and it can improve the efficiency of dental care. This case series describes 3 clinical scenarios in which miniplates were placed with minimal invasiveness during the removal of impacted third molars, offering the patients nontraditional orthodontic treatment options. Awareness of these options is essential for general dentists so that they can explain all treatment possibilities and provide appropriate referrals to patients with impacted third molars.

Z-shaped Miniplates vs Conventional Miniplates for Fixation of Mandibular Parasymphyseal Fractures.

AIM: The aim of this study was to evaluate a clinically and radiographically Z-shaped miniplate for the fixation of the parasymphyseal fractures. PATIENTS AND METHODS: Twenty patients (10 patients in each group) who had parasymphseal mandibular fractures were randomly selected for this study. In this study, open reduction and internal fixation were performed for mandibular parasymphyseal region fractures using two miniplates as group I, and open reduction and internal fixation were performed for mandibular parasymphyseal region fractures using a newly designed Z-shaped miniplate as group II. Clinical and radiographic evaluations were made. Each patient was evaluated: (1) clinically evaluated preoperatively and postoperatively for operating time, ease of placement of the miniplate, and occlusion and (2) radiological: postoperative reduction of fracture was evaluated radiologically at 5-day, 1-month, 2-month, and 3-month intervals with orthopantomogram, and lingual splaying was evaluated by cone-beam computed tomography (CBCT) immediately postoperatively and at an interval of 3 months. The collected data were subjected to statistical analysis. Data analysis was performed by SPSS software, version 25 (SPSS Inc., PASW statistics for Windows version 25). Chicago: SPSS Inc. RESULTS: There was a statistically significant difference (p < 0.001) between the mean intraoperative time. This indicates that group I had a longer time for fracture fixation than group II. Group I had a longer time elapsed for plate adaptation and definitive fixation than group II. Occlusion and reduction stability in both groups were similar. There was a statistically significant difference in postoperative lingual display control after 5 days and 3 months between the studied groups. This indicates that lingual display control in group II is better than in group I. CONCLUSION: The Z-shaped miniplate is effective and provides three-dimensional stability for the fixation of parasymphyseal fractures, ease of use, easily adapted in cases of fractures near the mental nerve reduced operative time, and better control of lingual splaying than conventional miniplates. CLINICAL SIGNIFICANCE: The newly designed Z-shaped miniplate is a valuable option for fixation parasymphysis fractures that need open reduction and internal fixation instead of using conventional miniplates, which are less successful in controlling lingual splaying.

[The use of an individualized mini plate for the distalization of teeth]. / Ispol'zovanie individualizirovannoi miniplastiny dlya distalizatsii zubov.

The case of treatment of a 32-year-old patient with complaints about the aesthetics of a smile and the absence of teeth 17 and 46 is presented. During the examination, it was established: the retraction position of the teeth in the frontal part of the upper jaw, the closure of the molars according to the II class of the second subclass of Engl (distal bite), the vestibular position of the teeth 13, 23. To change the spatial position of the lower jaw, the fixation of the bracket system on the upper jaw was performed. and also an individualized mini-plate was installed in the area of the zygomatic alveolar ridge on the right and left, for distalization of the dentition of the upper jaw with the help of orthodontic traction applied from the teeth to the mini-plates. This clinical example demonstrates the possibility of using individualized mini-plates for distalization of the upper dentition, as an alternative and more stable method of treatment in such clinical cases.

Risk factors associated with the stability of mini-implants and mini-plates: systematic review and meta-analysis.

OBJECTIVE: The objective of this systematic review is to assess the risk factors associated with the stability of mini-implants and mini-plates in patients undergoing orthodontic treatment using temporary anchorage devices. MATERIAL AND METHODS: Search strategies were developed for each electronic database (PubMed/Medline, LILACS, Scopus, Web of Science, Embase, and Cochrane Library) and gray literature (Google Scholar, Proquest, and Open Grey). The risk of bias was assessed using the Cochrane Collaboration tool for assessing the risk of bias and Meta-Analysis of Statistics Assessment and Review Instrument. The certainty of the evidence was assessed using the GRADE tool. Meta-analyses and meta-regressions of random effects were performed for the outcomes of interest. RESULTS: A total of 1517 articles were found, of which seven were selected for quantitative synthesis. When comparing the risk of failure between mini-implants and mini-plates, the risk values approached the threshold of statistical significance (p = 0.07) (RR = 1.83; 95% CI = 0.96-3.50; I2 = 69%), showing significance after sensitivity analysis (p < 0.05) and a greater risk for mini-implants. Mandible installation presented a higher risk of failure (RR = 1.85; 95% CI = 1.17-2.91). CONCLUSIONS: The evidence found indicates that failure in the stability is related to the type of device and that there is a greater risk by using isolated mini-implants, especially when positioned in the mandible. CLINICAL RELEVANCE: These findings help the orthodontist and/or the surgeon to stipulate risks, learn about the predictability of techniques, and communicate with the patient in an easier way.

Skeletal and dentoalveolar effects of class II malocclusion treatment using bi-maxillary skeletal anchorage: a systematic review.

BACKGROUND: The goal of this systematic review was to assess the available evidence regarding the skeletal and dentoalveolar effects of bi-maxillary skeletal anchorage devices (BMSADs) used in treating growing class II malocclusion patients. METHODS: A comprehensive search was conducted on PubMed, Scopus, Science Direct, Web of Science, Cochrane, and LILACS up to November 2021, which was augmented by a manual search. The studies included were clinical trials (RCTs) and/or follow-up observational studies (retrospective and prospective). The outcomes of interest were the skeletal, dentoalveolar, and occlusal treatment-induced changes obtained from pre- and post-cephalometric measurements. The risks of bias of the included studies were assessed using an assessment tool from previous publications. RESULTS: Out of 742 screened articles, only 4 were eligible and thus included in the qualitative synthesis. They showed a moderate overall risk of bias. The results are presented as mean changes in both the study and control groups. All studies reported retrusion of the maxillary base and advancement of the mandible (meaning reduced ANB angle). Three of the included studies reported an increase in the vertical jaw relation, which was contrary to what the fourth study reported. Three studies reported an increase in the maxillary incisors' inclination or position, while one study reported their retroclination. Proclination of the mandibular incisors happened in two studies, whereas the other two studies reported retroclination. The overjet was reduced in all included studies. CONCLUSION: Apart from the protrusive effects on the mandible, retrusive effects on the maxilla, and the consequent reduction of the overjet, BMSADs results in inconsistent skeletal and dentoalveolar effects. However, the current evidence is limited due to the variability in the biomechanics of the intermaxillary components, type of anchorage, and comparable groups in the included studies. Further RCTs with more standardized methodologies are highly encouraged. CLINICAL RELEVANCE: BMSADs (using miniscrews or miniplates on both jaws) induces more skeletal than dentoalveolar effects. However, this must be practiced with caution, based on the benefit to risk (surgical insertion) ratio, and the limited evidence available in hand so far. Registration The protocol for this systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO, No.: CRD42020199601).

Reconstruction and repair, using mini-plate and bone graft for persons living with HIV with giant cell tumor of long bone: retrospective analysis of a single-center experience.

BACKGROUND: To evaluate the effect of reconstruction and repair, using a mini-plate and bone graft for HIV -positive patients with giant cell tumor of long bone. METHODS: We conducted a retrospective analysis of 12 HIV positive patients with giant cell tumor of long bone. A non-HIV-positive cohort of patients, matched for age, sex, and disease type, was selected as the control group. From June 2012 to August 2020, curettage by ultrasonic scalpel was performed in all patients, combined with min- plate and bone graft treatment. All patients were followed- up for 18 to 60 months. Limb function was evaluated, using the MSTS93 scoring system, and any examples of postoperative recurrence, distant metastasis, complications, MSTS93 score, and fracture prognosis were recorded. RESULTS: The mean age of HIV group was 43.5 years. The ratio of men to women was 11: 1. In all cases the histopathological diagnosis was clear, except the patients with primary malignant giant cell tumor of bone, including five, three, two, and two cases in the proximal tibia, distal femur, distal tibia, and talus, respectively. Following their surgery, all patients were followed up with an average of 31.24 ± 11.84 months. No local recurrence or pulmonary metastases were observed. Post-surgery, all the 12 patients showed good bone morphologic repair and reconstruction, good bone healing, good joint function, and no pathological fractures around their lesion. In the HIV group, one case of giant cell tumor in the proximal tibia showed mild articular surface collapse and mild valgus deformity of the knee joint but retained good joint function. The MSTS scores of excellent or good in the two groups comprised 83.3%, thus, there was no significant difference between them (P > 0.05). Compared with preoperatively, the MSTS scores in the HIV group were significantly improved, ranging from 7 to 11 points preoperatively to 24 to 27 points postoperatively; this difference was statistically significant (P < 0.05). CONCLUSION: Reconstruction and repair, using a mini-plate and bone graft for HIV -positive patients with giant cell tumor of long bone can achieve satisfactory results. The mini- plate requires little space and is flexible during reconstruction and fixation, significantly reducing complications such as surgical site infection, as well as preserving joint function and avoiding amputation; therefore, it is a safe and effective treatment method.

Miniplate-anchored maxillary protraction in adolescent patients with cleft lip and palate: A literature review of study design, type and protocol, and treatment outcomes.

OBJECTIVE: To review the study design, type, protocol, and treatment outcomes of miniplate-anchored maxillary protraction (MAMP) in adolescent patients with unilateral or bilateral cleft lip and palate. SETTING/SAMPLE POPULATION: Five retrospective and two prospective studies (n = 138 patients) were selected as per the inclusion criteria. MATERIALS AND METHODS: The study design, type, protocol of MAMP and the amount of skeletodental change were investigated. RESULTS: Two studies adopted type 1 (two miniplates at the infrazygomatic crest with a facemask), four studies adopted type 2 (four miniplates at the infrazygomatic crest and mandibular symphysis and use of intermaxillary elastics), and one study compared the two types. The mean start age was older than 10 years except one study. The mean duration was less than 1 year in two studies, between 1 and 2 years in three studies, and more than 2 years in two studies. The type 1 used 500 g/side for 12-14 h/d, and the type 2 used three increase methods (100, 200, 250 g/side; 75, 150, 250 g/side; 150, 200, and 250 g/side) for 24 h/d. The ranges of A point advancement were 0.5°-4.2° in ΔSNA and 1.7-5.6 mm in ΔA-vertical reference plane, respectively. The ranges of rotation of the palatal plane, occlusal plane, and mandibular plane were -1.5° to 2.0°, -2.0° to 2.0°, -1.5° to 3.2°, respectively. The increase of overjet was ranged from 2.3 to 5.8 mm. CONCLUSION: The MAMP therapy is effective for the correction of maxillary hypoplasia in adolescent cleft patients despite different types and protocols.

APPLIANCE OF CAD / CAM MODELING IN PROSTHETICS OF BONE DEFECTS OF FACIAL BONES.

OBJECTIVE: The aim: Improving the ability to restore the shape and function of the bones of the maxillofacial area through the use of their own techniques. PATIENTS AND METHODS: Materials and methods: Materials and methods: This research was carry out on the basis of the Department of Surgical Dentistry and Maxillofacial Surgery of Kharkov National Medical University in the Department of Head and Neck Surgery, Kharkov "Regional Clinical Hospital" (2018-2020 years). Examination and treatment of 26 patients, aged from 19 to 55 years, who needed reconstructive surgery to restore the anatomical shape, integrity and function of the maxilla or mandibular jaw. RESULTS: Results: All patients were treated according to the developed method (utility model patent № 145754 "Method of treating traumatic fractures of the maxillofacial area in adults using bone osteosynthesis 3D modeled titanium mini plates"), which consists in 3D modeling, based on previously performed computed tomography, and exploitation individually modeled titanium mini grids and titanium endoprostheses. The experience of this technique shown the advantage of the proposed method not only in the correction of traumatic defects, but also defects of the jaw bones that occur due to the removal of bulky neoplasms. CONCLUSION: Conclusions: Individual 3D simulated mini grids / plates and endoprostheses, according to the study provide maximum adaptation and restoration of anatomical shape, relief of jaws, their integrity and contour, provide prevention of pathological fractures by stabilizing residual bone tissue (titanium mini grids) serves as a carcass , provide prevention of prolapse (germination) of soft tissues in the area of postoperative bone defect (mini grid does not allow soft tissues to germinate in the area of postoperative bone defect on the outside), which improves functional and cosmetic results. Thus, our proposed method of osteosynthesis using 3D simulated titanium miniplates can be recommended for use in clinical practice.

Comparison of Maximum Mouth Opening Following Mandibular Bilateral Sagittal Splitting Ramus osteotomies in Class III Females Using Two Different Osteosynthesis Methods.

BACKGROUND: Limitation of mouth opening is a common complaint following orthognathic surgery. OBJECTIVES: This investigation reports on the progress of maximum incisal opening following orthognathic surgery and compares the impact of two different osteosynthesis methods on mouth opening in female patients with Class III dentofacial deformities. METHODS: Forty cases of skeletal class III malocclusion were divided into twenty cases treated using the conventional single miniplate osteosynthesis method (P1) and twenty cases using the additional L-shaped miniplate osteosynthesis method (P2). No significant differences in pre-operative clinical status were detected between the P1 and P2 group, and all patients were managed with elastics in the post-operative period. Independent mouth opening exercises were initiated seven days after surgery, and inter-incisal distance was measured as maximum mouth opening (MMO) at 1 week, 2 weeks, and 1, 2, 3, 6 months. Statistical analysis was performed in order to analyse differences in MMO between the P1 and P2 groups (Prism 7 GraphPad software, San Diego, CA). Values of P < .05 were considered to be significant. RESULTS: MMO significantly increased from 2 weeks after surgery in both groups. The MMO of P2 was significantly larger than that of P1 in all experimental periods after surgery. MMO was statistically improved in P2 at 2 months after surgery, while MMO in P1 was significantly smaller than the pre-operative MMO, even at 6 months post-operative. A minimum MMO of 40 mm was achieved by all patients. CONCLUSION: L-shaped miniplate osteosynthesis was more useful for early limitation of mandibular opening improvement than conventional single miniplate osteosynthesis.

Posterior wall acetabular fracture in a 13-year-old boy treated by open reduction and mini-plate internal fixation: long-term follow-up of 17 years.

BACKGROUND: Acetabular fractures are uncommon in children and adolescents, mainly because of predominant cartilaginous component and strong surrounding ligaments. Although acetabular fractures at this age can lead to significant disability, there is no consensus regarding management, which continues to be controversial. Particularly, long-term outcome after operative management has not been evaluated. CASE PRESENTATION: We report a case of a 13-year-old boy skeletally immature who presented with an isolated acetabular fracture involving the posterior wall secondary to a traumatic hip dislocation. A Kocher-Langenbeck approach with a surgical luxation of the hip was used for reduction and mini-plate internal fixation of the fracture. Long-term (17-year) follow-up showed a good clinical outcome and a good congruence of the. The patient has bilateral beginning osteoarthritis due to a cam configuration of both hips CONCLUSION: We describe a case of successful operative management of an acetabulum fracture in a skelettaly immature child with a long-term follow-up. Aggressive management of this rare type of fractures may lead to durable positive outcome.

O'nil Anteversa® mini-plate for stable hip fracture: first experience considerations and outcomes.

Hip fractures are associated with a 20% one-year mortality and a 50% loss of function. Over 700,000 deaths are estimated to occur annually worldwide following hip fractures. Concern exist regarding which is the best implant for extracapsular fractures fixation. For a correct positioning of the cephalic screw, a new plate (O'Nil Anteversa® mini-plate, Intrauma, Torino, Italy) with a fixed 8°of anteversion in the axial plane was developed. A total of 22 patients with an intertrochanteric fracture underwent surgery with Anteversa® mini-plate between October 2016 and April 2017. Data collected included patients' age at surgery, gender, fracture type, operative side, surgeon, type of implant, TAD, CalTAD and TADCalTAD. All patients underwent clinical and radiographic evaluations according to the AO Surgery Reference classification. The mean TAD, CalTAD and TADcalTAD for the entire population of study were, respectively, 20.18±7.5 mm, 20.45±7.25 mm, and 40.62±14.44 mm. The mean TAD, CalTAD and TADcalTAD of those patients who experienced mobilisation of the cephalic screw were, respectively, 20.26±5.87 mm, 19.53±5.47 mm, and 39.8±11.16 mm. Three patients experienced mobilisation of the cephalic screw, and none of these had a TAD greater than 25 mm, a CalTAD greater of 25mm or a TADcalTAD greater than 50 mm. This type of device meets the essential requirements for a correct treatment of intertrochanteric fractures in elderly patients. However, the excessive need of attention in each step, and the consequent increased time of surgery, could be seen as a limitation for its use.

Evaluation of labial versus labio-inferior lines of osteosynthesis using 3D miniplate for fractures of anterior mandible: A finite element analysis with a pilot clinical trial.

PURPOSE: The fractures of anterior mandible are subject to severe torsional forces due to muscles acting in opposite directions. 3D miniplate has been suggested as a good alternative by some researchers. However, finite element model (FEM) studies indicate that labio-inferior positioning of two miniplates perpendicular to each other offers better stability as compared to labial positioning. This study aims at combining the advantages of a single 3D miniplate and labio-inferior positioning of two conventional miniplates, which was assessed by finite element analysis along with a pilot clinical trial. METHODS: Two FEM models were created using CT data of a 24-year-old patient with Angle class I occlusion: control model with labial plating and study model with labio-inferior plating. The models were processed with MIMICS® (materialise, Leuven, Belgium), CATIA® (Dassault Systemes) and finite element analysis softwares. Parameters adopted for analysis were (1) displacement (mm) of fracture fragments during each screw fixation, (2) lingual splay and post fixation stability of fracture fragments with masticatory load, and (3) stress distribution (MPa) across fracture fragments. Moreover, a pilot clinical trial including five patients with anterior mandible fracture was conducted. The fractures were managed by intraoral open reduction and 3D miniplate fixation in labio-inferior position. Intraoperative interfragmentary gap, post fixation lingual splay and radiographic fracture union and complications were assessed clinically. RESULTS: Labio-inferior plating demonstrated less displacement (mm) of fracture fragments during screw fixation (0.059 vs. 0.079) as well as after application of masticatory load (1.805 vs. 1.860). Negligible lingual splay and less stress distribution (MPa) across fracture fragments (1.860 vs. 1.847) were appreciated in the study group as compared to control group. Clinical trial support the favorable outcome related to intraoperative and postoperative assessment parameters. CONCLUSION: FEM analysis and clinical trial reveal better results with labio-inferior positioning of 3D miniplate when compared to labial positioning.

The accuracy and stability of the maxillary position after orthognathic surgery using a novel computer-aided surgical simulation system.

BACKGROUND: Many reports have been published on orthognathic surgery (OGS) using computer-aided surgical simulation (CASS). The purpose of this study was to evaluate the accuracy of the maxillary repositioning and the stability of the maxilla in patients who underwent OGS using a newly developed CASS program, a customized osteotomy guide, and a customized miniplate. METHODS: Thirteen patients who underwent OGS from 2015 to 2017 were included. All patients underwent a bimaxillary operation. First, a skull-dentition hybrid 3D image was rendered by merging the cone beam computed tomography (CBCT) images with the dentition scan file. After virtual surgery (VS) using the FaceGide® program, patient-customized osteotomy guides and miniplates were then fabricated and used in the actual operation. To compare the VS with the actual surgery and postoperative skeletal changes, each reference point marked on the image was compared before the operation (T0) and three days (T1), four months (T2), and a year (T3) after the operation, and with the VS (Tv). The differences between ΔTv (Tv-T0) and ΔT1 (T1-T0) were statistically compared using tooth-based reference points. The superimposed images of Tv and T1 were also investigated at eight bone-based reference points. The differences between the reference points of the bone surface were examined to evaluate the stability of the miniplate on the maxilla over time. RESULTS: None of the patients experienced complications. There were no significant differences between the reference points based on the cusp tip between ΔTv and ΔT1 (p > 0.01). Additionally, there were no significant differences between the Tv and T1 values of the bone surface (p > 0.01). The mean difference in the bone surface between Tv and T1 was 1.01 ± 0.3 mm. Regarding the stability of the miniplate, there were no significant differences between the groups. The difference in the bone surface between T1 and T3 was - 0.37 ± 0.29 mm. CONCLUSIONS: VS was performed using the FaceGide® program, and customized materials produced based on the VS were applied in actual OGS. The maxilla was repositioned in almost the same manner as in the VSP plan, and the maxillary position remained stable for a year.

A comparative study between traditional fixation with miniplates and modified lag screws for the treatment of mandibular fractures.

OBJECTIVES: The objective of this study is to investigate two internal fixation surgical techniques for mandibular fractures in order to compare modified lag screw techniques with standard miniplates. MATERIALS AND METHODS: This is an observational prospective study. Three hundred eighteen patients were operated on for mandibular fractures. The patients were divided into two groups according to the type of surgical technique used: modified lag screws (155 patients) and traditional miniplates (163 patients). Analyses were made of sociodemographic and preoperative variables, the parameters related to the fracture type and postoperative data. RESULTS: There were no differences between the two groups regarding their sociodemographic characteristics. The modified lag screws were primarily used with double fractures, while conventional miniplates were more often used with simple fractures. The number of complications was higher with the miniplate technique. The unfavorable fractures had an OR of 5.75 due to postoperative complications; double fractures had an OR of 8.87 and simple fractures an OR of 19.53, which, in both cases, were lower with conventional miniplates than with modified lag screws. CONCLUSION: Modified lag screws provide a rigid fixation system that is as secure as miniplates, but with greater compression between the fragments, less postsurgical gap, faster ossification, and fewer postoperative complications. CLINICAL RELEVANCE: The modified screw technique is a safe tool that does not require any specific osteosynthesis materials not found in a basic traumatology kit and has a lower cost, due to the reduced amount of material used.

Anterior Open Bite Treated by Maxillary Posterior Teeth Intrusion Using Zygomatic Miniplates: A Case Report.

AIM: This case report aims to demonstrate the successful utilization of zygomatic miniplates in the treatment of an adult patient with anterior open bite (AOB). BACKGROUND: During treatment of anterior open bite, incisor extrusion may compromise facial esthetics in cases with long facial height and/or sufficient incisor exposure at rest and smile.The intrusion of posterior teeth has the advantage of correcting vertical dimension and maintaining proper incisors show. CASE DESCRIPTION: The patient, a 22-year-old boy, had an anterior open bite of 4.5 mm with increased lower facial height, bilateral posterior crossbite, and two different occlusal planes in the upper arch. Titanium miniplates were used to intrude maxillary posterior teeth with a transpalatal arch appliance to limit buccal tipping.The intrusive force was then applied through elastomeric chains placed bilaterally in the maxillary arch between the miniplate and posterior teeth.The anterior open bite was corrected within 7 months of intrusion with decreased lower facial heightand significant improvement in anteroposterior jaw relationship. CONCLUSION: This report emphasizes the significant role of facial appearance and smile. CLINICAL SIGNIFICANCE: Most of the non-surgical approaches are not suitable for open bite correction in cases with long facial height and/or sufficient incisor exposure at rest and smile because of their extrusive mechanics which compromise the facial and smile esthetics. The intrusion of posterior teeth using min iplates allowing a counterclockwise rotation of the mandible to correct anterior open bite without compromising facial esthetic and smile.

An accurate bimaxillary repositioning technique using straight locking miniplates for the mandible-first approach in bimaxillary orthognathic surgery.

Bimaxillary orthognathic surgery has been widely performed to achieve optimal functional and esthetic outcomes in patients with dentofacial deformity. Although Le Fort I osteotomy is generally performed before bilateral sagittal split osteotomy (BSSO) in the surgery, in several situations BSSO should be performed first. However, it is very difficult during bimaxillary orthognathic surgery to maintain an accurate centric relation of the condyle and decide the ideal vertical dimension from the skull base to the mandible. We have previously applied a straight locking miniplate (SLM) technique that permits accurate superior maxillary repositioning without the need for intraoperative measurements in bimaxillary orthognathic surgery. Here we describe the application of this technique for accurate bimaxillary repositioning in a mandible-first approach where the SLMs also serve as a condylar positioning device in bimaxillary orthognathic surgery.