Complications and toxicities of implantable biomaterials used in facial reconstructive and aesthetic surgery: a comprehensive review of the literature

Modern Oncologic Maxillary Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: (1) Have a broad understanding of the oncological principles relating to cancers involving the maxilla. (2) Define anatomically the various types of maxillectomy defects and their associated morbidity. (3) Understand the goals and principles of maxillary reconstruction. (4) Demonstrate an understanding of the strengths, limitations, and alternative reconstructive options for the various types of maxillectomy defects.

SUMMARY

Reconstruction of the maxilla following cancer resection has evolved over the past decade. Underpinned by advances in virtual surgery technology and an increased focus on dental rehabilitation, more sophisticated workflows using free bone flaps have become more commonplace. There are few reconstructions anywhere in the body that require the restoration of similarly intricate bone and soft-tissue relations with implications for both form and function, like the maxilla. Success demands careful anatomical definition of the defect, an understanding of the goals and principles of reconstruction, and the understanding of relative strengths and limitations of the various reconstructive options. Equally, as no one technique is without shortcomings and maxillary surgery can be associated with a significant complication profile, it is just as important to match the patient and oncologic context to the reconstruction. This article is intended to provide the reader with a broad overview of these core factors.

Facial Implants in Male Rejuvenation

Many different methods achieve male facial augmentation. Arranged from shorter- to longer-term results, these methods include filler, fat/tissue grafting, fat/tissue transposition, and alloplastic implants. This study solely reviews allografts, which provide the most predictable hard-tissue augmentation. An array of alloplasts will be discussed in this study including chin, cheek, mandibular angle, frontal, and temporal implants. The most common and severe complications will also be explored with preventative and treatment algorithms.

The Treatment of Alar Base Depression in Rhinoplasty with Diced Autologous Cartilage or Mass Cartilage: A Systematic Review

BACKGROUND

Alar base is the basal part where the two sides of the nose and the upper lip are connected. Alar base depression affects the overall facial contour by making the nasolabial folds deepen, the nasolabial angle smaller, the center of the face flat, etc. Despite the rapid development of rhinoplasty, controversy still exists regarding the treatment of alar base depression. This systematic review aims to evaluate the efficacy and safety of two prevalent techniques-diced autologous cartilage and mass cartilage-for addressing alar base depression.

METHODS

A systematic review was conducted by searching the literature published in PubMed, Embase and Web of Science, Cochrane from January 2000 to April 2023 with the key words 'alar base depression or depressed alar base' and 'alar base augmentation,' and 2 investigators independently screened the retrieved literature according to inclusion and exclusion criteria.

RESULTS

A total of 269 articles were obtained through database search. After removing duplicates, reading titles and abstracts, and finally reviewing the full text, 6 articles were included in the final study, including 165 patients.

CONCLUSIONS

The results demonstrate that both diced autologous cartilage and mass cartilage techniques exhibit favorable outcomes in correcting alar base depression. Diced autologous cartilage offers better malleability, lighter border contours, and a more natural appearance. On the other hand, diced autologous cartilage seems to offer superior long-term effects, while mass cartilage presents certain surgical procedural advantages. Also, compared to diced cartilage, mass cartilage may have a lower rate of long-term resorption and a lower risk of displacement. This review emphasizes the need for personalized treatment selection based on individual patient characteristics.

LEVEL OF EVIDENCE III

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 .

Early outcomes and risk factors for complications after facial alloplastic implant surgery: An ACS-NSQIP study

BACKGROUND

Facial implantology (FI) is a growing field in facial surgery that focuses on harmonizing and balancing facial features. Despite its increasing popularity, larger-scale studies on FI outcomes and risks are scarce.

METHODS

The ACS-NSQIP (2008-2021) was queried to identify patients who underwent combined/isolated alloplastic FI surgery of the malar/mandibular region. Based on CPT codes (21125; 21270), procedures were subdivided into combined or isolated FI surgery of the malar or the mandibular region.

RESULTS

The study population included 84 patients, of which n = 19 (23%), n = 10 (12%), n = 33 (39%), and n = 22 (26%) underwent combined malar, isolated malar, combined mandibular, and isolated mandibular FI surgery, respectively. Isolated malar (total n = 10) and mandibular FI surgery (total n = 22) patients had relatively high comorbidity rates with up to n = 6 (60%) active smokers and n = 9 (41%) with hypertension, respectively. Combined malar (n = 19) and mandibular FI surgeries (n = 33) had the highest complication rates with n = 3 (16%) and n = 5 (15%) patients experiencing any complications. For both isolated malar and mandibular FI procedures, n = 1 (10% and 4.5%) patient reported any complications.

CONCLUSION

In this study, we accessed the ACS-NSQIP database and found alloplastic augmentation for zygoma and mandible to be safe. Patients who underwent combined procedures and mandibular augmentation were more likely to show complications or require inpatient stay. Most alloplastic augmentations of mandible or zygoma were combined with other procedures (62%) which suggests that alloplastic facial implants (in the academic setting) are often used as an adjunct in the treatment of complex craniofacial disorders.

Study on Synergistic Effects of Nanohydroxyapatite/High-Viscosity Carboxymethyl Cellulose Scaffolds Stimulated by LIPUS for Bone Defect Repair of Rats

Despite the self-healing capacity of bone, the regeneration of critical-size bone defects remains a major clinical challenge. In this study, nanohydroxyapatite (nHAP)/high-viscosity carboxymethyl cellulose (hvCMC, 6500 mPa·s) scaffolds and low-intensity pulsed ultrasound (HA-LIPUS) were employed to repair bone defects. First, hvCMC was prepared from ramie fiber, and the degree of substitution (DS), purity, and content of NaCl of hvCMC samples were 0.91, 99.93, and 0.017%, respectively. Besides, toxic metal contents were below the permissible limits for pharmaceutically used materials. Our results demonstrated that the hvCMC is suitable for pharmaceutical use. Second, nHAP and hvCMC were employed to prepare scaffolds by freeze-drying. The results indicated that the scaffolds were porous, and the porosity was 35.63 ± 3.52%. Subsequently, the rats were divided into four groups (n = 8) randomly: normal control (NC), bone defect (BD), bone defect treated with nHAP/hvCMC scaffolds (HA), and bone defect treated with nHAP/hvCMC scaffolds and stimulated by LIPUS (HA-LIPUS). After drilling surgery, nHAP/hvCMC scaffolds were implanted in the defect region of HA and HA-LIPUS rats. Meanwhile, HA-LIPUS rats were treated by LIPUS (1.5 MHz, 80 mW cm-2) irradiation for 2 weeks. Compared with BD rats, the maximum load and bone mineral density of HA-LIPUS rats were increased by 20.85 and 51.97%, respectively. The gene and protein results indicated that nHAP/hvCMC scaffolds and LIPUS promoted the bone defect repair and regeneration of rats significantly by activating Wnt/β-catenin and inhibiting OPG/RANKL signaling pathways. Overall, compared with BD rats, nHAP/hvCMC scaffolds and LIPUS promoted bone defect repair significantly. Furthermore, the research results also indicated that there are synergistic effects for bone defect repair between the nHAP/hvCMC scaffolds and LIPUS.

Balancing beauty and science: a review of facial implant materials in craniofacial surgery

Facial reconstruction and augmentation, integral in facial plastic surgery, address defects related to trauma, tumors infections, and congenital skeletal deficiencies. Aesthetic considerations, including age-related facial changes, involve volume loss and diminished projection, often associated with predictable changes in the facial skeleton. Autologous, allogeneic, and alloplastic implants are used to address these concerns. Autologous materials such as bone, cartilage, and fat, while longstanding options, have limitations, including unpredictability and resorption rates. Alloplastic materials, including metals, polymers, and ceramics, offer alternatives. Metals like titanium are biocompatible and used primarily in fracture fixation. Polymers, such as silicone and polyethylene, are widely used, with silicone presenting migration, bony resorption, and visibility issues. Polyethylene, particularly porous polyethylene (MedPor), was reported to have one of the lowest infection rates while it becomes incorporated into the host. Polyether-ether-ketone (PEEK) exhibits mechanical strength and compatibility with imaging modalities, with custom PEEK implants providing stable results. Acrylic materials, like poly-methylmethacrylate (PMMA), offer strength and is thus mostly used in the case of cranioplasty. Bioceramics, notably hydroxyapatite (HaP), offer osteoconductive and inductive properties, and HaP granules demonstrate stable volume retention in facial aesthetic augmentation. Combining HaP with other materials, such as PLA, may enhance mechanical stability. 3D bioprinting with HaP-based bioinks presents a promising avenue for customizable and biocompatible implants. In conclusion, various materials have been used for craniofacial augmentation, but none have definitively demonstrated superiority. Larger randomized controlled trials are essential to evaluate short- and long-term complications comprehensively, potentially revolutionizing facial balancing surgery.

Current Guidelines and Opinions in the Management of Orbital Floor Fractures

Orbital floor fractures are a common manifestation of facial trauma that is encountered by ophthalmology, otolaryngology, and oral maxillofacial specialists. Surgical intervention is required emergently in cases of tissue entrapment and less urgently in cases of presenting with persistent diplopia, enophthalmos greater than 2 mm, and/or fractures involving greater than 50% of the orbital floor. Surgical management is a debated topic with differing opinions among surgeons regarding timing of repair, type of implant, and surgical approach.

Transoral endoscopic thyroid surgery via vestibular approach with silastic chin augmentation genioplasty

From July 2020 to March 2022, 3 patients with papillary thyroid cancer (PTC) and microgenia underwent transoral endoscopic thyroid surgery via a vestibular approach or a endoscopic lateral neck dissection via the breast and transoral approaches with chin silastic augmentation genioplasty performed concurrently. Image documentation, patient satisfaction, complications and other factors such as demographics and clinicopathologic details were recorded. None of the patients developed major complications and there were no complications such as infection or displacement of the implant. All patients were satisfied with the cosmetic outcomes. Despite the study being limited to these 3 selected patients with PTC and microgenia, the follow-up to our initial description of the new technique established its safety and efficacy.

Application of Paranasal Augmentation Rhinoplasty in Asians With Midfacial Concavity

BACKGROUND

For Asian rhinoplasty patients with midfacial concavity, the conventional method is to solve the problem by using structural rhinoplasty to increase the nasal height and length. However, the results are not satisfying, and many complications are caused.Paranasal augmentation as an adjunct to rhinoplasty can improve surgical results and increase satisfaction. However, there are limited studies focusing on the details and evaluation of this technique.

OBJECTIVES

To investigate a minimally invasive method to correct midfacial concavity simultaneously with rhinoplasty, as well as improve satisfaction and reduce complications.

MATERIALS AND METHODS

Between January 2010 and December 2019, we reviewed all rhinoplasty patient records from patients who had midfacial concavity and underwent simultaneous paranasal augmentation with our technique. The patient demographics, surgical characteristics, and outcomes were reviewed retrospectively. Satisfaction was evaluated by an independent medical staff who reviewed the preoperative and postoperative photos.

RESULTS

Sixty-seven patients were included in the study. The mean age of the patients was 28.7 ± 8.0 years, and the median follow-up time was 26 months (range, 2-60 months). Overall satisfaction was high (90%). Eight (12%) patients had complications, including 5 (7.4%) cases of implant displacement and 3 (4.4%) cases of infection. All patients healed uneventfully after revision surgery.

CONCLUSIONS

Paranasal augmentation can improve the outcome and increase satisfaction in Asian rhinoplasty patients who have midfacial concavity. Preoperative patient evaluation, surgery planning, and surgery details are crucial to ensure a favorable result. The expanded polytetrafluoroethylene implant has advantages over other materials and therefore is recommended in paranasal augmentation surgery.

Reliability and Validity Evaluation of the Chin Augmentation With Medpor Using FACE-Q Scales Effectiveness

BACKGROUND

Chin augmentation (CA) is important treatment modality for microgenia. The use of implantable alloplastic biomaterials in CA grows in popularity, and there is no verifiable documentation of patients' satisfaction about CA with Medpor (CAWM) exists in the literature, this study examined effectiveness of CAWM by analyzing patient satisfaction.

METHODS

Patients had undergone CAWM were followed up postoperatively. Occurrence of complications was collected, patients' satisfactions with chin shape and surgical decision were analyzed using FACE-Q scales, the reliability of operation was studied through analyzing the statistics, and the influences of sex and follow-up time on satisfaction were compared.

RESULTS

One hundred ten patients who had undergone CAWM received FACE-Q scales and 64 valid questionnaires were collected. 61 (95.3%) showed high satisfaction with chin shape after CAWM (Cronbach α coefficients were all above 0.8), the median values of satisfaction of chin shape and decision making were 85 (67, 100) and 100 (75,100), respectively. The median chin satisfactions of females and males were 87 (67, 100), 79 (61,100). The median chin satisfactions of patients had surgery before 2 years ago and within 2 years were 81 (67, 100), 87 (64,100), respectively. During the follow-up, among 110, 1 (0.91%) developed graft-related infection and 1 (0.91%) developed an allergic reaction, 1 (0.91%) underwent prosthesis removal because dissatisfaction with chin shape.

CONCLUSIONS

Chin augmentation with prothesis is a safe and efficacious way to improve microgenia. Medpor is the desired implant material with less infection, displacement and bone absorption, which is worthy of promotion and further study in CA surgery.

Silicone Facial Implants, to Fixate or Not to Fixate: A Narrative Review

Silicone implants are one of the most widely used implants for facial augmentation, especially in the chin, mandibular angle, and malar area, utilizing different surgical approaches. Despite their various advantages, many complications have also been reported, including hematoma, infection, bone resorption, numbness, displacement, and asymmetry. This study aims to evaluate the need for facial-implant fixation and compare and contrast fixated and nonfixated facial silicone implants in different facial sites. A narrative review of the topic of facial-implant stabilization using the PubMed database inclusion criteria included articles that discussed the topic of facial implants, were published in English, and included critical information such as the location of the implant, type of stabilization, follow-up periods, and complications. A total of 11 studies were included. Of these, two were prospective clinical studies, three were case series, and the remaining six were retrospective clinical studies. The studies were published between 1995 and 2018. The sample size varied from 2 to 601 cases. Stabilization includes suturing, monocortical screws, or no stabilization. Complications were reported in most of these studies, including asymmetry, bone resorption or erosion, displacement, dissatisfaction, edema, hematoma, infection, mucosal irritation, pain, and paresthesia. The follow-up period ranged from one month to 17 years. Despite the varied settings of these studies, silicone facial implant complications were reported in both fixated and nonfixated implants, with a lack of significant differences between fixated and nonfixated facial silicone implants regarding the method of fixation.

Partial nasal bone reconstruction with acrylic bone cement: experimental study

Background

The aim of this study was to evaluate the effectiveness of acrylic bone cement in partial nasal bone reconstruction.

Methods

This study was conducted using nine New Zealand rabbits. The left nasal bones of the rabbits were included in the experimental group, and the right nasal bones were evaluated as the control group. The partial bone segments on the bilateral nasal bones were marked and removed symmetrically. A synthetic graft material made of acrylic bone cement was placed in experimental group, and the partial bone segment removed from the right side was placed in control group as an autograft. All rabbits were sacrificed at the end of the 28th day. Samples were taken from the grafts and from the surrounding soft tissues for histopathological examination. Acute inflammation, chronic inflammation, vascularization, fibrosis, foreign body reaction, bone proliferation, and the presence of empty lacunae were evaluated under a light microscope for both groups.

Results

Surrounding soft tissue on synthetic and autograft were the same in terms of chronic inflammation. There was no statistically significant difference for vascularization, fibrosis, and foreign body reaction. Synthetic graft and autograft were the same in terms of chronic inflammation, fibrosis, and bone proliferation. There was no statistically significant difference for vascularization, foreign body reaction, and presence of empty lacunae (p > 0.05).

Conclusion

This study showed no significant differences between the use of acrylic bone and the use of an autograft for partial nasal bone reconstruction in terms of graft or tissue healing. Acrylic bone cement may therefore serve as a good alternative for nasal bone reconstruction.

Comparison of the Results of Suture and Resorbable Plate-Screw Fixation in Craniosynostosis

BACKGROUND

Although many fixation methods are used alone or in combination for craniosynostosis, only few studies have compared the effectiveness and long-term results of these methods.

METHOD

In this study, patients in whom suture or resorbable plate-screw system was used for fixation were evaluated in terms of postoperative results and complications. The data of patients who underwent surgery for craniosynostosis between 2002 and 2019 were retrospectively reviewed and evaluated.

RESULTS

A total of 70 patients, 41 in the suture group and 29 in the resorbable plate-screw group, were included in the study. Whitaker classification was used for head shape evaluation, and anthropometric head circumference measurements were performed in all patients in the preoperative and postoperative periods. In the postoperative period, all patients were compared in terms of the operation time, transfusion requirement, discharge, follow-up period, and complications according to the chosen fixation method.The mean age, postoperative complication rates, anthropometric head circumference measurements, and Whitaker scores of both groups were found to be statistically similar. Although the resorbable plate-screw group had a longer follow-up period, the operation time was longer in the suture group. Furthermore, the suture group had lower transfusion requirement and earlier discharge from the hospital than the resorbable plate-screw group.

CONCLUSIONS

If fixation with suture is chosen in suitable patients, in addition to the low patient cost, this method can be safely applied in centers with limited logistical possibilities, because of the results and complication rates being similar to fixation with resorbable plate-screws.

Portable hand-held bioprinters promote in situ tissue regeneration

Three-dimensional bioprinting, as a novel technique of fabricating engineered tissues, is positively correlated with the ultimate goal of regenerative medicine, which is the restoration, reconstruction, and repair of lost and/or damaged tissue function. The progressive trend of this technology resulted in developing the portable hand-held bioprinters, which could be used quite easily by surgeons and physicians. With the advent of portable hand-held bioprinters, the obstacles and challenges of utilizing statistical bioprinters could be resolved. This review attempts to discuss the advantages and challenges of portable hand-held bioprinters via in situ tissue regeneration. All the tissues that have been investigated by this approach were reviewed, including skin, cartilage, bone, dental, and skeletal muscle regeneration, while the tissues that could be regenerated via this approach are targeted in the authors' perspective. The design and applications of hand-held bioprinters were discussed widely, and the marketed printers were introduced. It has been prospected that these facilities could ameliorate translating the regenerative medicine science from the bench to the bedside actively.

Lip Lift

The perioral area can be an important feature to convey femininity, particularly when speaking and smiling. A feminine lip has a shorter distance between the nasal sill and the vermillion border, fullness of the vermillion, and a few millimeters of tooth show with the mouth slightly open. The keys to a good outcome are incision design that respects the natural anatomy, placing the tension of the lift deep to the dermis to take tension off of the skin incision, determining the appropriate amount of lift for the patient's anatomy, and not violating the orbicularis oris.

Cheek Augmentation in Gender-Affirming Facial Surgery

The cheek area is an important area in facial beauty. High cheekbones and full malar area is considered a desired feminine feature and therefore an essential component of gender-affirming facial surgery. The most common treatment options are injectable fillers, autologous fat grafting, and alloplastic cheek implants. Fillers are customizable and reversible and have minimal recovery but are not preferred because of need for maintenance and cost. Fat grafting has many desirable characteristics, such as abundance, customizability, biocompatibility, and relative low cost. However, evidence for its long-term longevity is lacking. Alloplastic implants are a reliable augmentation method but associated with implant related complications such as infection, migration, and visibility.

Mandibular recontouring with polyetheretherketone (PEEK) patient-specific implants

The definition of the mandibular angle profile is a common challenge for oral and maxillofacial surgeons. Accurate diagnosis and treatment planning are mandatory in order to properly manage soft and hard tissues. The use of several biomaterials is described in the literature. The present paper reports the treatment of a defect in the right mandibular angle in otomandibular syndrome sequelae by positioning polyetheretherketone (PEEK) patient-specific implants (PSI) in a 25-year-old patient who previously underwent orthognathic surgery. Satisfactory aesthetic results were achieved with no complications 12 months after surgery. Considering its advantageous physical properties and the low rate of postoperative complications reported in the literature, PEEK can increase the treatment options for recontouring not only the upper third and the middle third of the face, but also of the lower third, in particular in cases of large three-dimensional defects.

Aesthetic Enhancement of the Brow using Hydroxyapatite

Background

An aesthetically pleasing appearance of the ‘eyes’ usually includes good projection of the outer brow. Weak bony projection of the superolateral periorbital region tends to be not only less attractive, but also predisposes to hooding over the temporal part of the upper lid. Congenital lack of skeletal volume is exacerbated by ageing due to lipoatrophy and soft tissue laxity. The rationale and technique for performing skeletal augmentation of the superolateral orbital rim is described, along with long-term results from a series of cases.

Material and Methods

A series of patients having augmentation of the superolateral orbital rim, using the technique described, were evaluated. A forehead crease incision was used, then a precise subperiosteal pocket developed in the lateral brow region between the supraorbital foramen and the superior temporal septum. The hydroxyapatite granule mixture was incrementally placed using modified syringes. The patients were followed to assess the long-term results.

Results

Two hundred and fifty patients, 80% women, mean age = 53 years [range 23–78] underwent supraorbital rim augmentation using subperiosteal hydroxyapatite granules, during a 12-year period, commencing in 2007. The mean follow-up was 41 months (range 1–12 years). The mean volume used for augmentation was 1.0 mL per side (range 0.4–2.3 mL). Projection of the upper lateral periorbital prominence was effectively increased, resulting in enhancement of the brow position and shape. Twenty-seven patients (11%) had an undercorrection, requiring additional volume augmentation, all during the first three years of the experience. Twelve patients (5%) required correction of contour irregularities. There were no infections and no long-term complications. Resorption of the hydroxyapatite volume over time was not noted.

Conclusion

The aesthetic significance of superolateral orbital rim projection is introduced. Patients who have a degree of skeletal deficiency of the zygomatic process of the frontal bone should be considered for hydroxyapatite augmentation of the bone as a complement to upper lid blepharoplasty and brow elevation. This procedure should be considered in the spectrum of upper periorbital aesthetic procedures.

Level of Evidence IV

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.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00266-022-02793-y.

The Dilemma of Reconstructive Material Choice for Orbital Floor Fracture: A Narrative Review

The aim of this study is to present a narrative review of the properties of materials currently used for orbital floor reconstruction. Orbital floor fractures, due to their complex anatomy, physiology, and aesthetic concerns, pose complexities regarding management. Since the 1950s, a myriad of materials has been used to reconstruct orbital floor fractures. This narrative review synthesises the findings of literature retrieved from search of PubMed, Web of Science, and Google Scholar databases. This narrative review was conducted of 66 studies on reconstructive materials. Ideal material properties are that they are resorbable, osteoconductive, resistant to infection, minimally reactive, do not induce capsule formation, allow for bony ingrowth, are cheap, and readily available. Autologous implants provide reliable, lifelong, and biocompatible material choices. Allogenic materials pose a threat of catastrophic disease transmission. Newer alloplastic materials have gained popularity. Consideration must be made when deliberating the use of permanent alloplastic materials that are a foreign body with potential body interactions, or the use of resorbable alloplastic materials failing to provide adequate support for orbital contents. It is vital that surgeons have an appropriate knowledge of materials so that they are used appropriately and reduce the risks of complications.

Preparation of the bioglass/chitosan-alginate composite scaffolds with high bioactivity and mechanical properties as bone graft materials

Bioglass/chitosan-alginate (BCA) composite scaffolds with remarkable performance for bone tissue engineering are successfully prepared by freeze-drying method. The influence of the addition amount of sodium alginate (SA) on the microstructure, porosity, pore size, swelling ratio, degradation ratio, mechanical properties and mineralization ability of BCA composite scaffolds is studied and characterized by various techniques of the scanning electron microscopy, X-ray diffraction, infrared absorption spectrometer and so on. The results show that the BCA composite scaffolds have the three-dimensional interconnected network structure with the high porosity of 82%-87% and a suitable average pore size of 140-200 μm. With the increase of SA addition, the porosity and pore size of BCA gradually reduced and the thickness of pore wall increased. The swelling and degradation ratios decreased gradually with the raising SA and increased with the prolongation of soaking time in PBS. The mechanical strength of BCA was also significantly enhanced, and the mineralization ability of bioglass was effectively deployed with the adding SA of BCA. The improved performance of BCA may be attributed to the formed 3D network structure, activated bioavailability and crosslinking ability between chitosan and SA. It indicates that BCA composite scaffolds have potential applications in bone issues engineering.

Tear Trough Malar Implant Penetrating Lacrimal Sac Causing Lacrimal Obstruction and Epiphora: Case Report and Review

Tear trough implantation may be associated with a number of well-reported complications. To our knowledge, penetration of the lacrimal sac has never been reported as a complication of malar or tear trough implants. We report a case of lacrimal sac penetration discovered at the time of endoscopic dacryocystorhinostomy surgery in a patient who developed epiphora soon after the tear trough implant was placed.

Approach to Orbital Fractures After Athletic Injuries

The bony orbit is commonly involved in athletic injuries. Evaluation should include a comprehensive history and ocular examination. Computed tomography imaging is the gold standard for diagnostic testing. Urgent surgical intervention for orbital floor fractures should occur after "white eye" trapdoor fractures or if oculocardiac response occurs. Most orbital fractures do not require urgent intervention and repair can be completed within 2 weeks of injury. There are many approaches to repair orbital fractures, and consideration of techniques depends on the unique fracture pattern. Intraoperative computed tomography has become frequently used and can lead to increased identification of plate malpositioning intraoperatively.

Donor variability alters differentiation and mechanical cohesion of tissue-engineered constructs with human endothelial/MSC co-culture

To move towards clinical applications, tissue engineering (TE) should be validated with human primary cells and offer easy connection to the native vascularisation. Based on a sheet-like bone substitute developed previously, we investigated a mesenchymal stem cells/endothelial cells (MSCs/ECs) coculture to enhance pre-vascularisation. Using MSCs from six independent donors whose differentiation potential was assessed towards two lineages, we focused on donor variability and cell crosstalk regarding bone differentiation. Coculture was performed on calcium phosphate granules in a specific chamber during 1 month. MSCs were seeded first then ECs were added after 2 weeks, with respective monocultures as control groups. Cell viability and organisation (fluorescence, electronic microscopy), differentiation (ALP staining/activity, RT-qPCR) and mechanical cohesion were analysed. Adaptation of the protocol to coculture was validated (high cell viability and proliferation). Activity and differentiation showed strong trends towards synergistic effects between cell types. MSCs reached early mineralisation stage of maturation. The delayed addition of ECs allowed for their attachment on developed MSCs' matrix. The main impact of donor variability could be here the lack of cell proliferation potential with some donors, leading to low differentiation and mechanical cohesion and therefore absence of sheet-like shape successfully obtained with others. We suggest therefore adapting protocols to cell proliferation potentials from one batch of cells to the other in a patient-specific approach.

3D printed gelatin-genipin scaffolds for temporomandibular joint cartilage regeneration

Gelatin has emerged as a biocompatible polymer with high printability in scaffold-based tissue engineering. The aim of the current study was to investigate the potential of genipin-crosslinked 3D printed gelatin scaffolds for temporomandibular joint (TMJ) cartilage regeneration. Crosslinking with genipin increased the stability and mechanical properties, without any cytotoxic effects. Chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSC) on the scaffolds were compared to cell pellets and spheres. Although hBMSC seeded scaffolds showed a lower expression of chondrogenesis-related genes compared to cell pellets and spheres, they demonstrated a significantly reduced expression of collagen (COL) 10, suggesting a decreased hypertrophic tendency. After 21 days, staining with Alcian blue and immunofluorescence for SOX9 and COL1 confirmed the chondrogenic differentiation of hBMSC on genipin-crosslinked gelatin scaffolds. In summary, 3D printed gelatin-genipin scaffolds supported the viability, attachment and chondrogenic differentiation of hBMSC, thus, demonstrating potential for TMJ cartilage regeneration applications.

Contemporary Review on Craniectomy and Cranioplasty; Part 2: Material Selection and Plate Manufacture

ABSTRACT

Cranioplasty materials include metals (ie, titanium); ceramics (ie, hydroxyapatite); polymers (ie, poly-methyl-metha-acrylate [PMMA]); and plastics (ie, polyether ether ketone). This paper aims to review their advantages and drawbacks. No ideal material currently exist, however, titanium implants are universally agreed to have lower infection rates than those reported for hydroxyapatite and PMMA implants; thus justifying their current wide use. These implants can be manufactured conventionally from medical grade titanium alloy Ti64 (titanium-aluminum-vanadium) in the form of plates ranging in thickness from 0.5 to 0.7 mm thick, or following the computer-aided design/manufacture principle. Surface finish of these implants is best achieved by electroplating.

A Staged Approach for Contouring of Temporal Deformities Using Porous Polyethylene and Lipofilling

ABSTRACT

Many studies evaluated the effectiveness of a single reconstructive material during temporal cranioplasty, or in comparison to the outcome of another material. To our knowledge, no previous study evaluated a staged combination of reconstruction modalities during temporal cranioplasty. In a prospective interventional study, the authors combined high-density porous polyethylene (HDPP) implant insertion (stage I) with a following lipofilling session (stage II) in 8 patients scheduled for temporal cranioplasties. This two-staged approach was evaluated 6 months after each stage independently. The patients' satisfaction as regards the aesthetic outcome was evaluated through a 5-points Likert scale by the patients themselves. For every individual patient, this psychometric analysis was repeated by medical staff from other departments. Statistical analysis of the patients and medical staff satisfaction scores showed a statistically significant increase after the addition of lipofilling session (stage II) if compared to implant insertion only (stage I). Clinically, this outcome was maintained in a long-term follow-up ranged from 1 - 8 years. Nevertheless, 2 patients needed one more lipofilling session to obtain their satisfaction as regards the final aesthetic outcome. No other complications were recorded in this study. In conclusion, combining alloplastic and autogenous reconstruction modalities in a staged approach can suffice the reconstruction requirements for such temporal defects. After a long follow-up period, the insertion of high-density porous polyethylene implant with the addition of a following lipofilling session showed more evaluators' satisfaction in terms of the final aesthetic outcome.

Application of Diced Autologous Rib Cartilage for Paranasal Augmentation in Cleft Nose

OBJECTIVE

This study aimed to investigate the clinical effect of diced cartilage on correcting nasal alar base depression in Asian cleft rhinoplasty.

METHODS

A retrospective study was conducted on 25 patients with nasal deformity, who underwent the second cleft rhinoplasty between January 2018 and January 2020. Autologous costal cartilage was harvested in all the patients to reconstruct the contour of the nose, while the remaining cartilage from the surgery was cut into 1.0×1.0 mm pieces and filled into the nasal alar base. The preoperative and postoperative effects of visual images were compared and analyzed using Adobe Photoshop CS6 software. The patients were followed up for 8-18 months (mean 12 months) to investigate the satisfaction and complication rate.

RESULTS

The nasal alar base depression was corrected, and the profile of malformed noses was significantly improved in 25 patients after the surgery. The postoperative effect was satisfactory, and no obvious graft shift or other complications were observed in the follow-up.

CONCLUSIONS

The application of diced cartilage to correct nasal alar base depression after cleft lip surgery is a feasible method. Its advantages include mainly the crafty use of the remaining cartilage and the presentation of a more natural appearance than mass cartilage.

LEVEL OF EVIDENCE IV

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 .

Human Histology and Persistence of Various Injectable Filler Substances for Soft Tissue Augmentation

An increasing number of soft tissue filler substances have been introduced to the beauty market outside the U.S. which lackexperimental and clinical data in support of their claim. Ten commercially available filler substances were examined for biocompatibility and durability: 0.1 cc of each substance was injected deep intradermally into the volar forearm of one of the authors and observed for clinical reaction and permanence. At 1, 3, 6, and 9 months the test sites were excised, histologically examined, and graded according to foreign body reactions classification. Collagen (Zyplast) was phagocytosed at 6 months and hyaluronic acid (Restylane) at 9 months. PMMA microspheres (Artecoll) had encapsulated with connective tissue, macrophages, and sporadic giant cells. Silicone oil (PMS 350) was clinically inconspicuous but dissipated into the tissue, causing a chronic foreign body reaction. Polylactic acid microspheres (New-Fill) induced a mild inflammatory response and had disappeared clinically at 4 months. Dextran microspheres (Reviderm intra) induced a pronounced foreign body reaction and had disappeared at 6 months. Polymethylacrylate particles (Dermalive) induced the lowest cellular reaction but had disappeared clinically at 6 months. Polyacrylamide (Aquamid) was well tolerated and remained palpable to a lessening degree over the entire testing period. Histologically, it dissipated more slowly and was kept in place through fine fibrous capsules. Polyvinylhydroxide microspheres suspended in acrylamide (Evolution) were well tolerated, slowly diminishing over 9 months. Calcium hydroxylapatite microspheres (Radiance FN) induced almost no foreign body reaction but were absorbed by the skin at 12 months.Host defense mechanisms react differently to the various filler materials, but all substances- resorbable or nonresorbable-appeared to be clinically and histologically safe, although all exhibit undesirable side effects. Since the mechanism of late inflammation or granuloma formation is still unknown, early histological findings are not useful in predicting possible late reactions to filler substances.

Biocompatible implant mimicking cartilage: A new horizon for reconstructive facial field

Cartilage is avascular with limited to no regenerative capacity, so its loss could be a challenge for reconstructive surgery. Current treatment options for damaged cartilage are also limited. In this aspect there is a tremendous need to develop an ideal cartilage-mimicking biomaterial that could repair maxillofacial defects. Considering this fact in this study we have prepared twelve silicone-based materials (using Silicone 40, 60, and 80) reinforced with hydroxyapatite, tri-calcium phosphate, and titanium dioxide which itself has proven their efficacy in several studies and able to complement the shortcomings of using silicones. Among the mechanical properties (Young's modulus, tensile strength, percent elongation, and hardness), hardness of Silicone-40 showed similarities with goat ear (P > .05). Silicone peaks have been detected in FTIR. Both AFM morphology and SEM images of the samples confirmed more roughed surfaces. All the materials were nonhemolytic in hemocompatibility tests, but among the twelve materials S2, S3, S5, and S6 showed the least hemolysis. For all tested bacterial strains, adherence was lower on each material than that grown on the plain industrial silicone material which was used as a positive control. S2, S3, S5, and S6 samples were selected as the best based on mechanical characterizations, surface characterizations, in vitro hemocompatibility tests and bacterial adherence activity. So, outcomes of this present study would be promising when developing ideal cartilage-mimicking biocomposites and their emerging applications to treat maxillofacial defects due to cartilage damage.

In situ bioprinting - Bioprinting from benchside to bedside?

Bioprinting technologies have been advancing at the convergence of automation, digitalization, and new tissue engineering (TE) approaches. In situ bioprinting may be favored during certain situations when compared with the conventional in vitro bioprinting when de novo tissues are to be printed directly on the intended anatomical location in the living body. To date, few attempts have been made to fabricate in situ tissues, which can be safely arrested and immobilized while printing in preclinical living models. In this review, we have explained the need and utility for in situ bioprinting with regard to the conventional bioprinting approach. The two main in situ bioprinting approaches, namely, robotic arm and handheld approaches, have been defined and differentiated. The various studies involving in situ fabrication of skin, bone, and cartilage tissues have been elucidated. Finally, we have also discussed the advantages, challenges, and the prospects in the field of in situ bioprinting modalities in line with parallel technological advancements. STATEMENT OF SIGNIFICANCE: In situ bioprinting may be favored during certain situations when compared with the conventional in vitro bioprinting when tissues are to be fabricated or repaired directly on the intended anatomical location in the living body, using the body as a bioreactor. However, the technology requires a lot more improvement to fabricate complex tissues in situ, which could eventually be possible through the multi-disciplinary innovations in tissue engineering. This review explains the need and utility and current approaches by handheld and robotic modes for in situ bioprinting. The latest studies involving in situ fabrication of skin, bone, and cartilage tissues have been elucidated. The review also covers the background studies, advantages, technical and ethical challenges, and possible suggestions for future improvements.

Paranasal Augmentation Using Multi-Folded Expanded Polytetrafluorethylene (ePTFE) in the East Asian Nose

BACKGROUND

Paranasal augmentation has commonly been performed utilizing alloplastic materials such as silicone or porous polyethylene. However, there are problems such as bone absorption, implant migration, and infection risk attributable to intraoral approaches.

OBJECTIVES

The authors attempted anterior positioning of the alar crease junction as an adjunct method of rhinoplasty. The authors aimed to determine the long-term results of the intranasal approach for placement of multi-folded expanded polytetrafluorethylene (ePTFE).

METHODS

A retrospective review was conducted of patients who underwent intranasal surgical approach for paranasal augmentation employing multi-folded ePTFE implants in 19 septorhinoplasties who were followed-up for 3 to 10 years. Patient charts were reviewed for demographic information, concomitant operations, and complications. Preoperative and postoperative photographs were utilized to evaluate operative outcomes. The photographs were reformatted to 2-dimensional images employing standard photographic methods.

RESULTS

Of the 19 patients treated, 17 were female and 2 were male; ages ranged from 18 to 58 years. All patients reported improvement in their lateral profiles and were pleased at follow-up. There were no major complications, no nerve or vascular supply compromise, and no cases of implant malposition. The average increase in soft tissue outline near the alar crease junction was more than 3.2 mm (P < 0.001), but the alar base did not became wider.

CONCLUSIONS

Paranasal augmentation with multi-folded ePTFE is a simple, safe, and effective method that can readily improve the lateral profile. In particular, the intranasal approach combined with rhinoplasty can synergistically improve outcomes and lead to greater patient satisfaction.

LEVEL OF EVIDENCE: 4

Extrusion of Alloplastic Septal Silicone Implant: 25 Years After Rhinoplasty

Multiple techniques and a variety of materials used for grafting have been described and applied over the years. Silicone implants are one of the most widely used alloplastic materials in Asian rhinoplasty, however, there are several complications. The authors report a case of an Asian woman who presented with implant rejection after 25 years later as a late complication of rhinoplasty. The patient was underwent revision augmentation rhinoplasty and stayed uneventful for 6 months as she was satisfied with aesthetic results and nasal airflow. The silicone implants are still going to be the most popular grafts in Asian augmentation rhinoplasty even so the long term complications must be kept in mind.

Alloplastic Facial Implants: A Systematic Review and Meta-Analysis on Outcomes and Uses in Aesthetic and Reconstructive Plastic Surgery

BACKGROUND

Alloplastic materials in facial surgery have been used successfully for various applications in the reconstructive restoration or aesthetic augmentation of the facial skeleton. The objective of this study was to conduct a comprehensive systematic review of alloplastic implant materials utilized to augment the facial skeleton stratified by anatomical distribution, indication, specific material used, and respective outcomes.

METHODS

A comprehensive systematic review on alloplastic facial implant data was conducted utilizing Medline/PubMed database. Articles were stratified by (1) anatomic localization in the face, as well as (2) alloplastic material.

RESULTS

A total of 17 studies (n = 2100 patients, follow-up range = 1 month-27 years) were included. Overall, mersilene mesh implants were associated with the highest risk of infection (3.38%). Methyl methacrylate implants were associated with the highest rate of hematoma (5.98%). Implants placed in the malar region (2.67%) and frontal bones (2.50%) were associated with the highest rates of infection. Implants placed in the periorbital region were associated with the highest rate of inflammation (8.0%), explantation (8.0%), and poor cosmetic outcome (17.0%). Porous implants were shown to be more likely to potentiate infection than non-porous implant types.

CONCLUSIONS

Alloplastic facial implants are a reliable means of restoring facial symmetry and achieving facial skeletal augmentation with a relatively low complication profile. It is important for plastic surgeons to understand the relative risks for each type of implant to develop postoperative complications or poor long-term cosmetic results. Interestingly, porous implants were shown to be more likely to potentiate infection than non-porous implant types.

LEVEL OF EVIDENCE III

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 .

Enhancing Facelift With Simultaneous Submalar Implant Augmentation

BACKGROUND

The midface is particularly prone to the senescent changes of soft tissue ptosis and volume loss, which in individuals with aging or low adiposity can manifest as submalar hollowing. Facelift alone in those with submalar hollowing inadequately addresses the volume loss and may result in a gaunt appearance postoperatively. Submalar implant augmentation is a powerful tool for permanent midface volume restoration for a more youthful and natural contour, as opposed to soft tissue fillers that diminish over time. When performed together, submalar augmentation and facelift synergistically enhance facial rejuvenation results.

OBJECTIVES

Determine the long-term safety and efficacy of submalar implant augmentation as an adjunct to facelift.

METHODS

Retrospective review evaluating results and complications in all consecutive patients who had submalar implant augmentation with SMAS-plication facelift in a single surgeon private practice setting from January 1, 1991, to December 31, 2017.

RESULTS

Forty-eight patients underwent submalar augmentation with simultaneous facelift with an overall satisfaction rate of 95.7%. Complications included 2.1%transient infraorbital hypoesthesia, 1.1% prolonged swelling, and 1.1% capsular contraction that required a minor adjustment under local anesthesia. No infection, implant migration, or extrusion or facial nerve injury occurred.

CONCLUSIONS

Submalar implant augmentation is a safe and effective means of enhancing facelift results through midface volume restoration, subperiosteal release, and improved soft tissue suspension in a more favorable vector. Submalar implant augmentation performed simultaneously with facelift may be an attractive alternative to repeated soft tissue filler or fat injections for patients with submalar hollowing who are interested in facial rejuvenation surgery.

Facial Implants: Controversies and Criticism. A Comprehensive Review of the Current Literature

BACKGROUND

Polyethylene (Medpor) and silicone are two of the most popular materials used today for facial skeleton implantation. Previous studies have identified common complications with the use of these implants, but patient follow-up has been short. This review of the literature examines complications and patient follow-up in cases using Medpor and silicone implants for reconstructive and aesthetic operations of the mid and lower face over the past 20 years.

METHODS

A literature search was conducted through the PubMed database. Keywords used were as follows: ("mandible implants" or "malar implants" or "chin implants") AND ("reconstruction" or "augmentation") AND ("Medpor" or "silicone").

RESULTS

There were nine studies with 626 patients in the Medpor group and five studies with 365 patients in the silicone group. The silicone group had a higher incidence of infections and displacements. The Medpor group showed a higher incidence of prominence problems. Exposure/extrusion rates were low for both implant types. Chin and mandibular implants were the safest, whereas malar implants had a high incidence of prominence problems. The average follow-up for Medpor was 36.6 months and 24 months for silicone. There were wide ranges of follow-up times, from 2 weeks up to 15 years. A limited number of articles included an averaged time within their ranges. Reported follow-up times were not linked to specific complications.

CONCLUSIONS

Medpor implantation is more common than silicone. Complication rates are low with the use of both materials. Patient follow-up is deficient and has not improved in the past 20 years, raising questions on the reliability of complication rates.

Refining Post-Orthognathic Surgery Facial Contour with Computer-Designed/Computer-Manufactured Alloplastic Implants

BACKGROUND

Le Fort I maxillary osteotomies and sagittal split mandibular osteotomies are performed to correct significant dentofacial deformities. The multidimensional skeletal movements, particularly those of large magnitude, may result in contour irregularities and facial imbalances.

METHODS

Three-dimensional images were reconstructed from computed tomographic scans in patients unhappy with their appearances after Le Fort I advancement and/or bilateral sagittal split osteotomies. The data from these scans were used to produce alloplastic implants using computer-aided design/computer-aided manufacturing for surgical correction of contour irregularities and imbalances. These implants were surgically placed through intraoral and submental incisions and fixed using titanium screws.

RESULTS

A total of 21 patients underwent implant placement with implants produced using computer-design/computer manufacturing. One patient required removal of implants secondary to infection. All other patients were satisfied with their result.

CONCLUSION

The use and surgical placement of implants produced by means of computer-aided design/computer-aided manufacturing has been shown to be effective in refining appearance in 21 patients over a 7-year period with minimal morbidity.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Maxillofacial reconstruction with Medpor porous polyethylene implant: a case series study

Objectives

The role of alloplastic materials in maxillofacial reconstruction is still controversial. Determining the utility of porous, high-density, polyethylene implants as a highly stable and flexible, porous alloplast, with properties such as rapid vascularization and tissue ingrowth, is crucial in cases of maxillofacial deformities and aesthetic surgery.

Materials and Methods

Thirty high-density porous polyethylene implants were implanted in 16 patients that had been referred to a private office over a three-year period. These implants were used for correcting congenital deformities, posttraumatic defects and improving the aesthetic in nasal, paranasal, malar, chin, mandibular angle, body and orbital areas.

Results

The outcomes of the cases in this study showed good aesthetic and functional results. The majority of patients had no signs of discomfort, rejection or exposure. Two implants suffered complications: a complicated malar implant was managed by antibiotic therapy, and an infected mandibular angle implant was removed despite antibiotic therapy.

Conclusion

Based on the results, the Medpor implant seems to be an excellent biomaterial for correcting various facial deformities. Advantages include its versatility and relatively ideal pore size that allows for excellent soft tissue ingrowth and coverage. It is strong, flexible and easy to shape.