Patient-specific Implants Research Articles

Comparative Studies Simulation Software for Bone Plate Compression

Medical applications occasionally require PSI (patient-specific implant) designs to match the implant bone’s geometry. To verify and predict failures of the design as well as a treatment before the manufacturing process, FEA (finite element analysis) is employed to simulate when given a specific number of loads. Plenty of studies have done the FEA using a couple of types of software; however, to the best of our knowledge, there is no literature to compare those several FEA results with a comparable experiment. This study further analyzes material stress, particularly to compute the VMS (Von Misses stress) of the Ti6Al4V bone plate. Furthermore, this study proposes to examine and deliver a comprehensive understanding using the four most used software of COMSOL, Ansys, Abaqus, and Autodesk Inventor. The results of those four simulations are then compared with the stress test through the Hardness Vickers test. This study will contribute significantly as a novel comparison between VMS and hardness test as a stress prediction in an implant material.

Innovative Developments in Lumbar Interbody Cage Materials and Design: A Comprehensive Narrative Review.

This review comprehensively examines the evolution and current state of interbody cage technology for lumbar interbody fusion (LIF). This review highlights the biomechanical and clinical implications of the transition from traditional static cage designs to advanced expandable variants for spinal surgery. The review begins by exploring the early developments in cage materials, highlighting the roles of titanium and polyetheretherketone in the advancement of LIF techniques. This review also discusses the strengths and limitations of these materials, leading to innovations in surface modifications and the introduction of novel materials, such as tantalum, as alternative materials. Advancements in three-dimensional printing and surface modification technologies form a significant part of this review, emphasizing the role of these technologies in enhancing the biomechanical compatibility and osseointegration of interbody cages. In addition, this review explores the increase in biodegradable and composite materials such as polylactic acid and polycaprolactone, addressing their potential to mitigate long-term implant-related complications. A critical evaluation of static and expandable cages is presented, including their respective clinical and radiological outcomes. While static cages have been a mainstay of LIF, expandable cages are noted for their adaptability to the patient's anatomy, reducing complications such as cage subsidence. However, this review highlights the ongoing debate and the lack of conclusive evidence regarding the superiority of either cage type in terms of clinical outcomes. Finally, this review proposes future directions for cage technology, focusing on the integration of bioactive substances and multifunctional coatings and the development of patient-specific implants. These advancements aim to further enhance the efficacy, safety, and personalized approach of spinal fusion surgeries. Moreover, this review offers a nuanced understanding of the evolving landscape of cage technology in LIF and provides insights into current practices and future possibilities in spinal surgery.

Maxillofacial Surgery inUkraine During a War: Challenges andPerspectives-A National Survey.

The invasion of Ukraine by Russian troops on February 24, 2022, and the beginning of the full-scale war had huge humanitarian consequences. The major challenges facing the Ukrainian health care system included the disruption of medical infrastructure and logistics, the termination of the supply of expendable materials, significant migration, and a dramatic increase in high-velocity blast and gunshot injuries among combatants and civilians.The aim of the present study was to analyze the challenges and solutions in patient care faced by the Ukrainian system of maxillofacial surgery during the war in different regions of the country. A cross-sectional study was designed and implemented as an online survey to collect national data concerning maxillofacial surgeons' experiences and professional activities. The study was initiated and supported by Bogomolets National Medical University (Kyiv, Ukraine), the Ukrainian representative of AO CMF (Arbeitsgemeinschaft für Osteosynthesefragen Craniomaxillofacial Surgery) and the University of Helsinki (Finland).The questionnaire was developed by specialists in maxillofacial surgery and sociologists and contained 65 close-ended questions. Surgeons who had not worked in this specialty in inpatient departments of hospitals since at least the beginning of the full-scale war were excluded from the study. We received and analyzed 97 responses that met the abovementioned criteria. The geography of respondents covered all the regions and the main cities of Ukraine, expect for the occupied territories. After a year of warfare, the percentage of surgeons who treated patients with blast and gunshot injuries increased from 43.4% to 86.6%. This percentage was higher in military hospitals and in regions located in the vicinity of the front line. We found that, during the war, 78.6% of respondents performed osteosynthesis in cases of high-velocity multifragmented facial bone fractures (in such cases, 58.3% of them strictly followed AO CMF recommendations, while 41.7% performed the fixation based on available hardware, existing technical possibilities and their own preferences). We found that 70.2% of respondents had the opportunity to apply Computer-Aided Design/Computer-Aided Manufacture technology and patient-specific implants for the treatment of gunshot injuries, 38.1% reported that their hospitals were able to perform microsurgical reconstructions for facial defects, 79.4% of respondents reported that their departments received humanitarian aid and support from volunteer organizations (either Ukrainian or international), which significantly facilitated the treatment process. According to this nationwide survey of Ukrainian maxillofacial surgeons during a year of the full-scale war, 86.6% of respondents were involved in the treatment of gunshot and ballistic injuries in civilians and combatants. The main problems reported by the respondents were (1) a lack of experience and knowledge related to the treatment of severe wounds, especially by secondary reconstruction, and (2) a deficit of resources (equipment, materials, and medications) under conditions of disrupted logistics and changes in the numbers and nosological distribution of patients. There were the opportunity to transfer the patients to European clinics (29.9%), online consultations (45.4%), collaboration with foreign surgeons who come to Ukraine asvolunteers (32%).

Virtual planning for mandible resection and reconstruction

Abstract In mandibular reconstruction, computer-assisted procedures, including virtual surgical planning (VSP) and additive manufacturing (AM), have become an integral part of routine clinical practice. Especially complex cases with extensive defects after ablative tumor surgery benefit from a computer-assisted approach. Various CAD/CAM-manufactured tools such as surgical guides (guides for osteotomy, resection and predrilling) support the transition from virtual planning to surgery. Patient-specific implants (PSIs) are of particular value as they facilitate both osteosynthesis and the positioning of bone elements. Computer-based approaches may be associated with higher accuracy, efficiency, and superior patient outcomes. However, certain limitations should be considered, such as additional costs or restricted availability. In the future, automation of the planning process and augmented reality techniques, as well as MRI as a non-ionizing imaging modality, have the potential to further improve the digital workflow.

Skeletal stability after mandible bilateral sagittal split osteotomy – comparison of patient-specific implant and mini-plate fixation: A retrospective study

The aim of the study was to compare the stability of the virtual surgical planning (VSP) and computer-aided design accompanied by patient-specific implants (PSIs) and conventional mini-plates in mandible advancement with bilateral sagittal split osteotomy (BSSO).This retrospective study evaluates the clinical and cephalometric records of 53 patients (12 male, 41 female) treated with BSSO in Helsinki University Hospital. Subjects were divided into two groups: VSP–PSI (21 patients: 4 male and 17 female; mean age 38 years, range 25–53 years); and conventional wafer-based repositioning with mini-plate fixation (32 patients: 8 male and 24 female; mean age 39 years, range 21–56 years). The effect of the amount and direction of the advancement on the stability was also analysed individually. The standardized lateral cephalometric radiographs in three time points were analysed to compare the groups.After surgery (T2), there were no differences between groups in cephalometric variables. During follow-up (T2–T3), the cephalometric variables in both Groups A and B were stable, so there was no difference in stability between the VSP–PSI and the conventional mini-plate groups. During follow-up, the mandibles rotated clockwise or counterclockwise, relapsed towards their original direction, and the changes were statistically significant (jaw relationship; p = 0.018, soft tissue profile; p = 0.025); when the advancement of mandible was >6 mm, the increase in gonial angle compared to mandibles advanced ≤6 mm was statistically significant (p = 0.03).VSP–PSI and conventional mini-plate fixation can be considered equally stable. Large advancements with counterclockwise rotation regardless of fixation method are more susceptible to relapse. VSP-PSI alone cannot solve the relapse-related concerns in mandible osteotomy.

Research progress of metal-based additive manufacturing in medical implants

Abstract Metal-based additive manufacturing has gained significant attention in the field of medical implants over the past decade. The application of 3D-printing technology in medical implants offers several advantages over traditional manufacturing methods, including increased design flexibility for implant customization, reduced lead time for emergency cases, and the ability to create complex geometry shapes for patient-specific implants. In this review study, the working principles and conditions of metal 3D-printing technologies such as selective laser sintering, selective laser melting, and electron beam melting, as well as their applications and advantages in the medical field, are investigated in detail. The application scenarios and research status of non-degradable metals including titanium alloy, medical stainless steel, etc., and degradable metals like magnesium alloy are introduced as printing materials. We discuss the improvement of mechanical properties and biocompatibility of implants through surface modification, porous structure design, and the optimization of molding processes. Finally, the biocompatibility issues and challenges caused by the accuracy of CT imaging, fabrication, implant placement, and other aspects are summarized.

Ankle and Foot Arthroplasty and Prosthesis: A Review on the Current and Upcoming State of Designs and Manufacturing.

The foot and ankle serve vital roles in weight bearing, balance, and flexibility but are susceptible to many diverse ailments, making treatment difficult. More commonly, Total Ankle Arthroplasty (TAA) and Total Talus Replacement (TTR) are used for patients with ankle degeneration and avascular necrosis of the talus, respectively. Ankle prosthesis and orthosis are also indicated for use with lower limb extremity amputations or locomotor disability, leading to the development of powered exoskeletons. However, patient outcomes remain suboptimal, commonly due to the misfitting of implants to the patient-specific anatomy. Additive manufacturing (AM) is being used to create customized, patient-specific implants and porous implant cages that provide structural support while allowing for increased bony ingrowth and to develop customized, lightweight exoskeletons with multifunctional actuators. AM implants and devices have shown success in preserving stability and mobility of the joint and achieving fast recovery, as well as significant improvements in gait rehabilitation, gait assistance, and strength for patients. This review of the literature highlights various devices and technologies currently used for foot and ankle prosthesis and orthosis with deep insight into improvements from historical technologies, manufacturing methods, and future developments in the biomedical space.

Anterior Lumbar Interbody Fusion (ALIF) for Lumbar Hemivertebra in an Adult Using Three-Dimensional-Printed Patient-Specific Implants and Virtual Surgery Planning: A Technical Report

Introduction: Hemivertebrae are a common defect of vertebral formation, potentially resulting in debilitating congenital scoliosis and necessitating highly traumatic surgery. Virtual surgical planning (VSP) and 3D-printed patient-specific implants (PSIs) have increasingly been applied to complex spinal surgery, and offer a range of potential benefits. Research Question: We report the use of 3D-printed PSIs and VSP as part of a two-level anterior lumbar interbody fusion (ALIF) for the management of lateral hemivertebra and congenital scoliosis. Material and Methods: A 53-year-old male with chronic low-back pain, due to L4 hemivertebra and mild congenital scoliosis, presented with new-onset leg pain. CT revealed L4/5 and L5/S1 degeneration and foraminal stenosis. Given the complex anatomy and extensive multi-level osteophytosis, 3D-printed PSIs were designed, manufactured, and implanted as part of a two-level ALIF. Results: Excellent implant fit was achieved intraoperatively, confirmed via postoperative imaging. VSP assisted with navigating challenging bony and vascular anatomy. Three-month postoperative imaging demonstrated construct stability, early signs of bony fusion, with implant placement, spinal curvature, and disc height corrections closely matching the VSP. Clinically, the patient’s pain and functional impairment had effectively resolved by nine-month follow up, as demonstrated through subjective and objective measures. Discussion and Conclusions: Virtual surgical planning and 3D-printed PSIs can be useful surgical aids in the management of the often-complex cases involving hemivertebrae and congenital scoliosis. This case of congenital pathology adds to the growing reports of PSI application to a variety of complex spinal pathologies, with analyses showing a close match of the postoperative construct to the preoperative VSP.

The Utility of 3D Printing for Surgical Planning and Patient-Specific Implant Design in Maxillofacial Surgery: A Narrative Review.

Maxillofacial reconstructive implants are typically created in standard shapes and have a widespread application in head and neck surgery. During surgical procedures, the implant must be correctly bent according to the architecture of the particular bones. Bending takes practice, especially for untrained surgeons. Furthermore, repeated bending may increase internal stress, resulting in fatigue in vivo under masticatory loading and an array of consequences, including implant failure. There is a risk of fracture, screw loosening, and bone resorption. Resorption, infection, and displacement are usually associated with the use of premade alloplastic implants and autogenous grafts. Recent technological breakthroughs have led to the use of patient-specific implants (PSIs) developed by computer-designed additive manufacturing in reconstructive surgery. The use of computer-designed three-dimensional (3D)-printedPSI allows for more precise restoration of maxillofacial deformities, avoiding the common difficulties associated with premade implants and increasing patient satisfaction. Additive manufacturing is something that refers to a group of additive manufacturing methods. This technique has been quickly used in a variety of surgical procedures. The exponential expansion of this technology can be attributed to its enormous surgical value. Adding 3D printing to a medical practice can be a rewarding experience with stunning results.

The Use of Patient-Specific Implants for the Treatment of Upper Extremity Fractures.

In this article, we discuss the use of three-dimensional (3-D) printed patient-specific implants in the management of upper extremity fractures. Traditional fracture fixation methods involve the use of standard-sized implants, which may not adequately address the needs of every patient, particularly those who have complications related to fracture nonunion or malunion and those who have significant bone loss. The benefits and limitations of this technology are also discussed, along with considerations for implementation in clinical practice. Overall, the use of 3-D printed patient-specific implants holds promise for improving the accuracy and efficacy of upper extremity fracture management.

Patient specific implants versus conventional implants in primary total knee arthroplasty: No significant difference in patient reported outcomes at 5 years

BackgroundPatient specific implants (PSI) represent a novel innovation aimed to improve patient satisfaction and function after total knee arthroplasty (TKA); however, longitudinal patient reported outcome measures (PROMs) for PSI are not well described. We sought to primarily evaluate PROMs of patients undergoing TKA with either PSI or off-the-shelf (OTS) implants at mid-term follow-up. MethodsA retrospective review was performed on a prospectively collected cohort of 43 primary, cruciate-retaining TKAs performed with PSI (n = 23) and OTS implants (n = 20) by a single surgeon. Patient demographics, operative characteristics, range of motion (ROM) return, reoperations, and outcomes [Patient-Reported Outcomes Measurement Information System (PROMIS) T-score, Knee Injury and Osteoarthritis outcome score (KOOS), and Knee Society Score-Function (KSS-F)] were compared. Mean follow-up was 5 years. ResultsTKA performed with either PSI and OTS implants demonstrated no difference in obtaining ROM by 3 months (extension 3° short of full extension vs. 0°, p = 0.16) or flexion (114° vs. 115°, p = 0.99) and final ROM was identical [0° extension to 120° flexion (p = 1)]. Although not significant (p = 0.42), 5 (22%) PSI TKA and 2 (10%) OTS implant patients required manipulation under anesthesia. KSS-F and PROMIS T-scores were higher in the PSI versus OTS TKA patients, respectively (90 vs. 73, p = 0.002; 51.6 vs. 44.5, p = 0.01). However, after multivariable analysis, none of these continuous outcome measures were significantly different (p = 0.28 for KSS and p = 0.45 for PROMIS T-score) between the groups. ConclusionIn a series of TKAs performed with PSI, no difference existed in postoperative ROM, reoperations, or patient-reported outcomes compared to OTS implants at 5 years. Surgeons may utilize the equivocal midterm results during TKA preoperative patient discussion of implant technologies.

Computer-guided cranioplasty using ultra-high molecular weight polyethylene patient-specific implants: a case series

IntroductionCranioplasty is the surgical correction of a cranial defect. Three-dimensional software designs have allowed patient-specific single-step cranial reconstruction for neuroprotection and cosmesis. Ultra-high molecular weight polyethylene for partial or total bone replacement has been recently introduced as a promising material for cranioplasty. The objectives of this study are to evaluate the complications and esthetic results concerning the use of ultra-high molecular weight polyethylene patient-specific implants in craniectomy patients.MethodsWe report a series of nine patients with cranial defects from a previous craniectomy, or patients eligible for simultaneous craniectomy and cranioplasty via computer designed ultra-high molecular weight polyethylene patient-specific implants. We have analyzed the complications and cosmetic outcomes over a course of six months.ResultsNone of the cases developed infection, extra/subdural hematoma, cerebrospinal fluid leak, or implant failure. Three cases had postoperative sequalae: The first patient had mild postoperative seroma which subsided after medical therapy and compression, the second showed wound breakdown due to tumor metastasis and recurrence but did not necessitate implant removal, while the third sequela was a subgaleal hematoma which was aspirated, and the patient healed uneventfully afterward. Esthetic results were highly satisfactory in 75% of the patients (good patient acceptance without touch-ups).ConclusionUltra-high molecular weight polyethylene is in all respects suitable for primary and secondary cranioplasty, combined with computer-aided manufacturing–computer-aided design techniques, excellent esthetic and functional results were achieved. However, proper preoperative planning is important, and we recommend further prospective studies with larger number of patients followed up for longer periods for better assessment.

Surgical accuracy of CAD/CAM splints using virtual surgical planning in orthognathic surgery: policy implications for healthcare in Australia.

This study examines post-surgical outcomes of maxillary position using virtual surgical planning (VSP) with computer designed and manufactured surgical splints, without the use of costly patient specific implants (PSI), in the treatment of routine nonsyndromic orthognathic patients. The cost of these personalized medical devices and their impact in the setting of cranio-maxillofacial surgery is currently under review by The Department of Health and Aged Care in Australia. This is a single-centre retrospective analysis of 49 patients who underwent bimaxillary orthognathic surgery by a single surgeon at Epworth Richmond Hospital (Victoria, Australia) over a period spanning 2016 to 2020. Patients were included in the study provided their surgery was facilitated using VSP with manufacture of computer designed occlusal splints. Use of computer designed and manufactured splints were highly reliable in reproducing the virtual surgical plan, when using palatal plane, upper incisor angulation, and anterior upper facial height. Use of computer designed and manufactured splints provide a method of leveraging the accuracy of VSP methods, without the additional costs associated with PSI. These findings may assist in appropriate resource allocation and case stratification in patients undergoing orthognathic surgery.

Biomechanical comparison of titanium alloy additively manufactured and conventionally manufactured plate-screw constructs

ABSTRACTAimTo biomechanically compare the bending stiffness, strength, and cyclic fatigue of titanium additively manufactured (AM) and conventionally manufactured (CM) limited contact plates (LCP) of equivalent dimensions using plate-screw constructs.MethodsTwenty-four 1.5/2.0-mm plate constructs (CM: n = 12; AM: n = 12) were placed under 4-point bending conditions. Data were collected during quasi-static single cycle to failure and cyclic fatigue testing until implants plastically deformed or failed. Bending stiffness, bending structural stiffness, and bending strength were determined from load–displacement curves. Fatigue life was determined as number of cycles to failure. Median test variables for each method were compared using the Wilcoxon rank sum test within each group. Fatigue data was also analysed by the Kaplan–Meier estimator of survival function.ResultsThere was no evidence for a difference in bending stiffness and bending structural stiffness between AM and CM constructs. However, AM constructs exhibited greater bending strength (median 3.07 (min 3.0, max 3.4) Nm) under quasi-static 4-point bending than the CM constructs (median 2.57 (min 2.5, max 2.6) Nm, p = 0.006). Number of cycles to failure under dynamic 4-point bending was higher for the CM constructs (median 164,272 (min 73,557, max 250,000) cycles) than the AM constructs (median 18,704 (min 14,427, max 33,228) cycles; p = 0.02). Survival analysis showed that 50% of AM plates failed by 18,842 cycles, while 50% CM plates failed by 78,543 cycles.Conclusion and clinical relevanceAdditively manufactured titanium implants, printed to replicate a conventional titanium orthopaedic plate, were more prone to failure in a shorter fatigue period despite being stronger in single cycle to failure. Patient-specific implants made using this process may be brittle and therefore not comparable to CM orthopaedic implants. Careful selection of their use on a case/patient-specific basis is recommended.

Pediatrics, Craniofacial and Orthognathic Surgery Track: Juvenile Active Ossifying Fibroma of the Frontal Sinus: A Case Report of Single-Stage Resection and Reconstruction Using Virtual Surgical Planning and Patient-Specific Implants

Pediatrics, Craniofacial and Orthognathic Surgery Track: Juvenile Active Ossifying Fibroma of the Frontal Sinus: A Case Report of Single-Stage Resection and Reconstruction Using Virtual Surgical Planning and Patient-Specific Implants

An insertability constraint for shape optimization

Patient-specific implants offer a host of benefits over their generic counterparts. Nonetheless, the design and optimization of these components present several technical challenges, among them being the need to ensure their insertability into the host bone tissue. This presents a significant challenge due to the tight-fitting nature of the bone-implant interface. This paper presents a novel insertability metric designed to efficiently assess whether a rigid body can be inserted into a tight-fitting cavity, without interference. In contrast to existing solutions, the metric is fully differentiable and can be incorporated as a design constraint into shape optimization routines. By exploiting the tight-fitting condition, the problem of planning an interference-free insertion path is reformulated as the search for a single interference-free movement, starting from the inserted configuration. We prove that if there exists any outward movement for which no interference is indicated, then the body can be fully extracted from or, equivalently, inserted into the cavity. This formulation is extremely efficient and highly robust with respect to the complexity of the geometry. We demonstrate the effectiveness and efficiency of our method by applying it to the optimization of two-dimensional (2D) and three-dimensional (3D) designs for insertability, subject to various design requirements. We then incorporate the proposed metric into the optimization of an acetabular cup used in total hip replacement (THR) surgery where geometric and structural requirements are considered.

Accuracy of Patient-Specific Implants in Virtually Planned Segmental Le Fort I Osteotomies.

(1) Background: In orthognathic surgery, segmental Le Fort I osteotomies are a valuable method to correct maxillary deformities or transversal discrepancies. However, these procedures are technically challenging, and osteosynthesis can be prone to error. (2) Methods: In this retrospective, monocentric cohort study, patients were enrolled who underwent a virtually planned segmental maxillary osteotomy during their combined treatment. Positioning and osteosynthesis were achieved by either a 3D-printed splint and conventional miniplates or patient-specific implants (PSI). The preoperative CT data, virtual planning data, and postoperative CBCT data were segmented. The deviation of all the segments from the desired virtually planned position was measured using the analysis function of IPS CaseDesigner. (3) Results: 28 Patients in the PSI Group and 22 in the conventional groups were included. The PSI group showed significantly lower deviation from the planned position anteroposteriorly (-0.63 ± 1.62 mm vs. -1.3 ± 2.54 mm) and craniocaudally (-1.39 ± 1.59 mm vs. -2.7 ± 3.1 mm). For rotational deviations, the pitch (0.64 ± 2.59° vs. 2.91 ± 4.08°), as well as the inward rotation of the lateral segments, was positively influenced by PSI. (4). Conclusions: The presented data show that patient-specific osteosynthesis significantly reduces deviations from the preoperative plan in virtually planned cases. Transversal expansions and vertical positioning can be addressed better.

Extrusion-based 3D printing of osteoinductive scaffolds with a spongiosa-inspired structure.

Critical-sized bone defects resulting from trauma, inflammation, and tumor resections are individual in their size and shape. Implants for the treatment of such defects have to consider biomechanical and biomedical factors, as well as the individual conditions within the implantation site. In this context, 3D printing technologies offer new possibilities to design and produce patient-specific implants reflecting the outer shape and internal structure of the replaced bone tissue. The selection or modification of materials used in 3D printing enables the adaption of the implant, by enhancing the osteoinductive or biomechanical properties. In this study, scaffolds with bone spongiosa-inspired structure for extrusion-based 3D printing were generated. The computer aided design process resulted in an up scaled and simplified version of the bone spongiosa. To enhance the osteoinductive properties of the 3D printed construct, polycaprolactone (PCL) was combined with 20% (wt) calcium phosphate nano powder (CaP). The implants were designed in form of a ring structure and revealed an irregular and interconnected porous structure with a calculated porosity of 35.2% and a compression strength within the range of the natural cancellous bone. The implants were assessed in terms of biocompatibility and osteoinductivity using the osteosarcoma cell line MG63 and patient-derived mesenchymal stem cells in selected experiments. Cell growth and differentiation over 14days were monitored using confocal laser scanning microscopy, scanning electron microscopy, deoxyribonucleic acid (DNA) quantification, gene expression analysis, and quantitative assessment of calcification. MG63 cells and human mesenchymal stem cells (hMSC) adhered to the printed implants and revealed a typical elongated morphology as indicated by microscopy. Using DNA quantification, no differences for PCL or PCL-CaP in the initial adhesion of MG63 cells were observed, while the PCL-based scaffolds favored cell proliferation in the early phases of culture up to 7days. In contrast, on PCL-CaP, cell proliferation for MG63 cells was not evident, while data from PCR and the levels of calcification, or alkaline phosphatase activity, indicated osteogenic differentiation within the PCL-CaP constructs over time. For hMSC, the highest levels in the total calcium content were observed for the PCL-CaP constructs, thus underlining the osteoinductive properties.

Reconstruction of Maxillary Defects Using Virtual Surgical Planning and Additive Manufacturing Technology: A Tertiary Care Centre Experience

IntroductionMaxillary reconstruction is often a challenging task for the surgeons because of the complex anatomy. However, with the advances in virtual surgical planning (VSP) and 3D printing technology there is a new avenue for the surgeons which offers a suitable alternative to conventional flap-based reconstructions.Patients and MethodsIn this article, we have described 4 case scenarios which were managed with the help of VSP and additive manufacturing technology for complex maxillary reconstruction procedures. Use of the technologies aided the clinician in achieving optimal outcomes with regards to form, function and esthetics.DiscussionVirtual surgical planning (VSP) has gained a lot of impetus in past 1 decade. These aides the surgeon in determining the extent of disease and also carry out the treatment planning. In addition to VSP, the concept of additive manufacturing provides a viable alternative to the conventional reconstruction modalities for maxillary defect rehabilitation. Increased accuracy, rehabilitation of normal anatomical configuration, appropriate dental rehabilitation, decreased intra-operative time and post-operative complications are some of the advantages. In addition, patient-specific implants eliminate the need for a separate donor site. Apart from the treatment of pathologies, they also can be used for reconstruction of post-traumatic defect, where endosteal implant placement is not possible.ConclusionThese modalities show promising results for reconstruction of complex maxillary defects.

Treatment of Facial Asymmetry Using Distraction Osteogenesis in a Mandible First Approach.

Facial asymmetry includes several etiologies, among them trauma to the condylar area during early childhood and congenital malformations such as hemifacial microsomia. This article describes the management of facial asymmetry in adolescents and young adults using a mandible first approach by distraction osteogenesis, followed by maxillary Le-Fort I as a second stage. Eighteen patients 14-25 years of age presented with unilateral hypoplasia of the jaws which manifested clinically by deviation of the chin and canting of the occlusal plane. Etiology included hemifacial microsomia and trauma injuries at early childhood.All patients underwent orthodontic treatment and two phases of surgical treatment. Surgical treatment included unilateral mandibular distraction followed by Le-Fort I osteotomy for alignment of the maxilla. Additional bone graft in the affected side and sliding genioplasty were done as required. Marked ramal elongation of 18.94 mm concomitant with mandibular forward traction of 12.5 mm was noted while achieving symmetry. In all cases, the maxilla was centered to the midline in proper occlusion. Post distraction, posteroanterior cephalometric radiographs demonstrated elongation of the affected ramus, improvement in facial symmetry, and correction of the occlusal canting. Relapse was minimal based on long-term follow-ups of 47.4 months. The two-stage surgical approach that includes elongation of the mandible as a first stage followed by adaptation of the maxilla is useful in correcting facial asymmetry. Using this protocol at the correct age (14-18) is very stable, as demonstrated by our results, yet one should always remember the transverse deficiency in the gonial angle requires additional bone grafting or patient specific implants.