Patient-Specific Facial Implants in Polyetheretherketone and Their Stability: A Preliminary Study.

BACKGROUND: Polyetheretherketone (PEEK) is a synthetic material with many favorable characteristics; PEEK implants are increasingly used for a variety of applications ranging from cranioplasty to orthopedic surgery and facial implants. METHODS: This study is a retrospective review of patients who underwent PEEK implant placement in our department over the last 5 years. Polyetheretherketone computer-aided design and manufacture facial implants were designed from high-resolution computed tomography (CT) scans of each patient. The implants placed were onlay implants used for facial rehabilitation purposes to correct malformative and posttraumatic malformations. RESULTS: Twenty-eight consecutive patients (11 males and 17 females) underwent PEEK implant positioning between January 2015 and December 2020. Common indications were anterior plagiocephaly, hemifacial microsomia, and residual facial imbalance after orthognathic surgery. No complications of implant breakdown, exposure, infection, or displacement were noticed during the follow-up period. During routine controls on 3 patients, we requested a craniomaxillofacial CT scan for reasons unrelated to the implanted prostheses. The CT scans were all high resolution (<1-mm slices). The CT images indicated that bone was starting to form around the implant in all 3 patients as well as in the penetrating holes that were planned in the implants. CONCLUSIONS: In our experience, computer-designed, patient-specific PEEK onlay implants are a valid option for the treatment of malformative and posttraumatic malformations. This is, to the best of our knowledge, the first clinical report on bone reaction to PEEK implantation in the maxillofacial field. Moreover, based on the signs of bone regrowth that we observed in CT controls we can presume that the design of this type of prosthesis can probably take advantage of some technical stratagems not yet codified and fully exploited. Despite our preliminary favorable results, further multicentric and comparative studies are necessary to evaluate outcomes and better understand the behavior of this promising material and thus optimize its use in craniomaxillofacial surgery.

Approach to Fronto-Orbital Sequelae in Anterior Synostotic Plagiocephaly: Our Flow Chart Based on Di Rocco Classification.

INTRODUCTION: Anterior synostotic plagiocephaly recognizes the synostosis of one of the hemicoronal sutures as a cause and can manifest itself with varying degrees of severity. Clinically it presents a reduction of the sagittal growth of the affected side and flattening of the frontoparietal complex. MATERIALS AND METHODS: The authors retrospectively examined our case sample dividing it into 3 groups based on the Di Rocco classification. For each category, we assessed the extent of facial alterations at the end of skeletal growth and retrospectively analyzed the surgical options aimed at correcting aesthetic and skeletal deficits. RESULTS: The authors found that predictable results could be obtained by standardizing the surgical procedure based on Di Rocco's classification groups; in particular, the authors achieved satisfactory results by assigning a specific surgical procedure to each class.

Patient First: Surgery First and More.

INTRODUCTION: The success of surgery first approach has been defined by the number of advantages offered and is definitively determined by the satisfaction of the patients themselves. The strength of this protocol resides in its philosophy that puts the patient at the center of the whole diagnostic-therapeutic process. The compliance of the patient, its happiness and comfort are the best guarantee of a good final results. While pursuing this philosophy we have wondered whether there was way to increase the comfort of surgery first approach even more and to make it even more appealing for the patients. For these reasons, we have decided to work on a preliminary protocol in order to reduce or even eliminate the use of orthodontic braces and wires during perioperative stages. Materials and Methods: No orthodontic braces or wires are bonded on the teeth before surgery. Intraoperatory intermaxillary fixation (IMF) is carried out with the use of IMF screws which are positioned at the beginning of the operation on the edge between keratinized and nonkeratinized gingiva. Once the osteotomies are performed IMF with IMF screws is carried out on the planned occlusion with the use of surgical splints.Discussion and Conclusions: In selected cases the postsurgical orthodontic treatment can be carried out with the use of clear aligners, completely eliminating the need of braces and wires with an additional level of comfort.

Virtual Surgical Planning for Reconstruction of Giant Ameloblastoma of the Mandible.

Ameloblastoma is a histologically benign tumor that behaves aggressively because of its tendency to invade local structures, and it has a high probability of local recurrence. If neglected, ameloblastomas can grow substantially over the course of years, reaching the size of giant ameloblastomas. This large size can lead to deformities in facial appearance and impairments in speaking, swallowing, eating, and breathing.Surgical planning can be challenging because of the extension of the tumor and the consequent reconstructive issues.In this article, we present our experience with the reconstruction of 2 cases of giant ameloblastomas planned on the basis of occlusal casts and acrylic splints. In these patients, computerized planning was rendered complex and potentially inaccurate because of the dimensions of the tumor, the loss of anatomical landmarks, and the loss of occlusal landmarks. The cases were successfully reconstructed, but the technique can be flawed. A 3-dimensional virtual model of the mandible can be used as a template to develop cutting guides for reconstruction with free fibular flaps. This will allow us to overcome limitations, standardize the procedure, and achieve optimal functional and aesthetic results.

Monolithic CAD-CAM lithium disilicate versus monolithic CAD-CAM zirconia for single implant-supported posterior crowns using a digital workflow: A 3-year cross-sectional retrospective study.

STATEMENT OF PROBLEM: Dentistry has evolved significantly with the introduction of digital technologies and materials; however, clinical evidence for the performance of the complete digital workflow for single implant-supported posterior crowns is lacking. PURPOSE: The purpose of this cross-sectional retrospective clinical study was to compare the clinical outcomes of 2 types of implant-supported crown used to replace a single missing posterior tooth in a completely digital workflow: transocclusal screw-retained monolithic lithium disilicate crowns versus transocclusal screw-retained monolithic zirconia crowns. MATERIAL AND METHODS: A total of 38 participants who had been provided with dental implants and transocclusal screw-retained monolithic lithium disilicate or zirconia single crowns were evaluated in the study. Clinical and esthetic outcomes were recorded after a 3-year follow-up. RESULTS: Both groups had comparable clinical outcomes with a survival rate of 100%. In the lithium disilicate group, 89% of the participants were free of technical complications, and 95%, in the zirconia group. Only 1 patient experienced minor chipping affecting a lithium disilicate crown. All complications were considered minor and were easily resolved, and none of the participants required replacement of a crown. No biological complications were recorded in either group. CONCLUSIONS: Within the limitations of this cross-sectional retrospective clinical study, monolithic lithium disilicate and zirconia screw-retained single crowns fabricated using computer-aided design and computer-aided manufacturing (CAD-CAM) and a fully digital workflow were found to be reliable and suitable clinical options for restoring a posterior missing tooth on a dental implant.

Quantification of Residual Perfume by Py-GC-MS in Fragrance Encapsulate Polymeric Materials Intended for Biodegradation Tests.

Perfume encapsulates are widely used in commercial products to control the kinetic release of odorant molecules, increase storage stability and/or improve deposition on different substrates. In most of the cases, they consist of core-shell polymeric microcapsules that contain fragrance molecules. A current challenge is to design and produce polymeric materials for encapsulation that are both resistant and non-persistent. The selection of such eco-friendly formulations is linked to a deep understanding of the polymeric material used for encapsulation and its biodegradation profile. To collect this information, pure samples of capsule shells are needed. In this article we present an innovative quantification method for residual volatiles based on pyrolysis-GC-MS to enable validation of sample quality prior to further testing. The presented analytical method also led to the development of a robust and comprehensive purification protocol for polymers from commercial samples. Standard techniques are not suited for this kind of measurement due to the non-covalent embedding of volatiles in the 3D structure of the polymers. We demonstrated the confounding impact of residual volatiles on the estimated biodegradability of fragrance encapsulates.

Single-Molecule Kinetics of Growth and Degradation of Cell-Penetrating Poly(disulfide)s.

The delivery of therapeutic agents into target cells is a challenging task. Cell penetration and intracellular targeting were recently addressed with biodegradable cell-penetrating poly(disulfide)s (CPDs). Cellular localization is determined by the length of these polymers, emphasizing the significance of initial chain length and the kinetics of intracellular depolymerization for targeted delivery. In the present study, the kinetics of CPD polymer growth and degradation were monitored in a single-molecule nanoreactor. The chain lengths achievable under synthetic conditions with high concentrations of dithiolanes were then predicted by using the rate constants. For example, CPDs comprising 40 units are generated in 1 s at pH 7.4 and 0.3 s at pH 8.4 at dithiolane concentrations of 200 mM. The rate constants for degradation suggest that the main depolymerization pathway in the cell is by monomer removal by self-cyclization, rather than by intrachain cleavage by endogenous thiols.

Use of Navigation System in Craniofacial Surgery.

The use of navigated surgery in the treatment of craniofacial malformations can help obtain optimal results. In this article, the authors will discuss a case of anterior plagiocephaly, corrected with frontorbital bandeau remodeling. Navigation was used during the osteotomy and the reposition phase to ensure the correct positioning of the osteotomy instruments. It was also used to ensure that the bandeau was correctly repositioned in accordance with the surgical plan determined during the virtual simulation phase of the surgery.

Early Surgical Treatment in Anterior Synostotic Plagiocephaly: Is This the Best Choice?

At the end of craniofacial growth, in anterior synostotic plagiocephaly, some aesthetical deficiencies may still be evident. This can depend on an inadequate initial correction or on altered postoperative growth or even on the combination of the 2 factors.Aesthetic alterations can result from various factors that could potentially affect the skeleton, the skin, subcutaneous, and muscular tissues.The pathological changes in the cutaneous and subcutaneous tissues are greater in patients who have undergone multiple surgical treatments of the frontoorbital area. The aim of this observational cohort study is to assess the residual aesthetic and functional impairment at the end of skeletal growth, in patients affected by anterior synostotic plagiocephaly who have undergone surgery at an early age. The purpose is to investigate whether early surgery can still be considered unavoidable in patients with this malformation.Between July 2012 and February 2015, patient's data were retrieved from our archives among the patients referred to our department from 2003 to 2012 for Anterior Synostotic Plagiocephaly at an early age.The authors studied this patient with CT scans and photographic documentation. On CT scans, the authors have assessed skeletal alterations, soft tissues alterations, and muscular tissue alterations. With photographic documentation, the authors have studied the perception of the malformation among external subjects.From this study it was possible to demonstrate that is many esthetical alterations are to still to be found in patients treated with an early surgical approach; for this reason in children without early complications, the authors suggest that surgical treatment should be delayed after the end of craniofacial growth.

Effect of Surgery First Orthognathic Approach on the Temporomandibular Joint.

INTRODUCTION: Correction of severe malocclusions with skeletal discrepancies requires orthodontic treatment in combination with orthognathic surgery. Even though conventional orthognathic surgery (COS) is a common and well-accepted approach its influence on the signs and symptoms of temporomandibular disorders (TMDs) is still debated. Recently with the introduction of surgery first approach, a different timing for the management of dentoskeletal imbalances has been proposed. The present study is aimed at assessing the relationship between surgery first approach and temporomandibular joint (TMJ) disorders. METHODS: The study sample consisted of 24 patients who were selected to be treated with surgery first approach. Clinical follow-ups after surgery were performed every week for the first month, at 3 months, 6 months, and at 1 year. A radiological follow-up was performed at 1 week and at 1 year after the operation with a panorex and a latero-lateral teleradiograph. To assess the effect of surgery first approach on the TMDs signs and symptoms, a clinical assessment was performed 4 days before surgery (T1), 6 months after surgery (T2), and 1 year postoperatively (T3). RESULTS: The results of the authors' study show that pain assessment revealed a general improvement of this symptom in correspondence to TMJ and masticatory muscles except in the masseter and neck region. Also joint noises, TMJ functioning, migraine, and headache underwent a considerable improvement. CONCLUSION: Surgery first approach is an innovative orthognathic procedure and, by undergoing surgery first approach, patients with pre-existing TMJ dysfunction may experience a significant improvement or even resolution of the TMDs signs and symptoms.

The Arterialized Facial Artery Musculo-Mucosal Island Flap for Post-Oncological Tongue Reconstruction.

BACKGROUND: In 1992, Pribaz described the facial artery musculomucosal flap (FAMM), an axial musculomucosal flap based on the facial artery. The FAMM flap, a modification of the nasolabial and buccal mucosal flaps, is widely used in the reconstruction of defects in the oral cavity. Many modifications of this flap have been described in the literature. Here we aimed to explore the use of an arterialized tunnelized FAMM island flap (a-FAMMIF) for the reconstruction tongue defects after tumor resection. METHOD: From January 2015 to December 2016, five cases of tongue cancer were selected for the use of arterialized FAMMIF flap to reconstruct defects after tumor resection. RESULTS: Reconstruction was successful in all cases, except one case of total flap necrosis; partial necrosis of the flap occurred in two patients, which were solved with medications. CONCLUSION: The authors consider the a-FAMMIF an unreliable flap in the reconstruction of tongue defects.The authors recommend avoiding tunneling and island modification when the vein is not included in the pedicle.

The Rules of Attractiveness: A Study on the Lower Facial Third.

What is considered attractive may not fall into the "norm," and it can vary from culture to culture and depending on the historical time, for this reason the standard cephalometric and antropometric references may not be sufficient in these cases.Lately some techniques have arose to popularity that are aimed to changing the frontal and lateral aspect of the facial lower third, such as V-line or the Chin-Wing Osteotomy technique, but no reference system exists at the moment to define to which extent a modification of the lower third falls within what is considered beautiful, and everything is left to the patient's will or to the surgeon's sensitivity.The aim of this article is to study which antropometric value is considered attractive by the most for what concerns the frontal shape of the lower third of the face.Twenty-four female models were enrolled in this study and the angle taken into consideration was the one at the intersection between the 2 lines connecting the cutaneous gonial angle of each side of the face and the most external part of the chin on the same side. Measures were made on pictures in frontal view.Two hundred two random examiners were asked to see the pictures and rate them as attractive or nonattractive.Results were then paired with the angles values.Among the models the higher angle measured was 107.5° (found in 1 individual) while the lower angle was 76° (found in 1 individual), the average measure calculated was 88.3° while the median angle was 89.5°.According to the result the subjects considered more attractive were those with an angle between 84.5 and 91.5 (92 for male examiners).This could be an important starting point for studies who can evaluate attractiveness from a numerical point of view.

In-Site Monocyte Implantation in Bone Grafting for Maxillary Atrophy Reconstruction: A Preliminary Observational Proof of Concept Study.

PURPOSE: The main objective of this study, involving 11 patients, is to share our experience on an integrated treatment modality, namely, the use of cellular therapy simultaneously with surgical reconstruction. Published works show that the implantation of monocytes in ischemic tissue enhances healing by providing neo-angiogenesis, a key mechanism in tissue regenerative processes. MATERIALS AND METHODS: Our approach included the utilization of autologous monocytes and endothelial precursor cells in the bone graft itself to improve the success rate of the integration of the bone graft and its long-term viability/survival by promoting angiogenesis. We compared the standard regenerative procedures, namely sinus lift grafting performed with xenogeneic particle bone graft and posterior mandible grafting performed with on-lay or in-lay autologous cortical/medullary bone-block graft harvested from the iliac crest, with and without the use of cellular implementation. We evaluated results by both radiological and histological assessment. RESULTS: Autologous cortical/medullary bone-block graft had a different response to implementation with monocytes, showing a better osteointegration than expected conversely to the xenogeneic particle bone graft. CONCLUSIONS: Monocytes seem to improve autologous bone-block graft according to the "Therapeutic Angiogenesis" concept. Implementation with monocytes does not always improve xenogeneic particle bone graft.

Strained Cyclic Disulfides Enable Cellular Uptake by Reacting with the Transferrin Receptor.

In this study, we demonstrate that appendage of a single asparagusic acid residue (AspA tag) is sufficient to ensure efficient cellular uptake and intracellular distribution of fully unprotected peptides. We apply this new delivery method to induce apoptotic response in cancer cells using long (up to 20mer) BH3 domain peptides. Moreover, to understand the molecular mechanism of the cellular uptake, we perform chemical proteomics experiments and identify the direct molecular targets of the asparagusic acid tag. Our findings document covalent bond formation between the asparagusic acid moiety and the cysteines 556 and 558 on the surface of the transferrin receptor resulting in subsequent endocytic uptake of the payload. We believe that the small size, low cellular toxicity and the efficient transferrin receptor-mediated uptake render the AspA tag highly attractive for various life science applications.

Navigation System Approach in Zygomatic Implant Technique.

In some patients, the resolution of severe maxillary atrophies can be hardly achieved without the use of zygomatic implants. Although many scientific studies have already demonstrated the excellent immediate stability in long term, the use of zygomatic implants is not yet widespread. Among the complications of this technique, the most threatening is the risk of damaging the eyeball or the maxillary nerve.The use of the navigator system as a surgical aid for implant placement allows to control, at any time, the position of the drill in the bone, avoiding any injury to ocular and nervous structures. The authors present a clinical report which shows a patient affected by a very severe form of post-traumatic maxillary atrophy that has been solved through the of zygomatic implants placement using the "Implant Bone Navigation" system. This procedure allows both to cut down the risks on ocular and nervous structures of the maxilla and also to reach excellent rehabilitation results in such severely compromised patients.

Surgery-first orthognathic approach vs traditional orthognathic approach: Oral health-related quality of life assessed with 2 questionnaires.

INTRODUCTION: The purposes of the study were to investigate and evaluate the differences detected by the patients between the traditional orthognathic approach and the surgery-first one in terms of level of satisfaction and quality of life. METHODS: A total of 30 patients who underwent orthognathic surgery for correction of malocclusions were selected and included in this study. Fifteen patients were treated with the conventional orthognathic surgery approach, and 15 patients with the surgery-first approach. Variables were assessed through the Orthognathic Quality of Life Questionnaire and the Oral Health Impact Profile questionnaire and analyzed with 2-way repeated-measures analysis of variance. RESULTS: The results showed significant differences in terms of the Orthognathic Quality of Life Questionnaire (P <0.001) and the Oral Health Impact Profile (P <0.001) scores within groups between the first and last administrations of both questionnaires. Differences in the control group between first and second administrations were also significant. Questionnaire scores showed an immediate increase of quality of life after surgery in the surgery-first group and an initial worsening during orthodontic treatment in the traditional approach group followed by postoperative improvement. CONCLUSIONS: This study showed that the worsening of the facial profile during the traditional orthognathic surgery approach decompensation phase has a negative impact on the perception of patients' quality of life. Surgeons should consider the possibility of a surgery-first approach to prevent this occurrence.

Strain-Promoted Thiol-Mediated Cellular Uptake of Giant Substrates: Liposomes and Polymersomes.

Simple cyclic disulfides under high tension mediate the uptake of giant substrates, that is, liposomes and polymersomes with diameters of up to 400 nm, into HeLa Kyoto cells. To place them at the surface of the vesicles, the strained disulfides were attached to the head-group of cationic amphiphiles. Bell-shaped dose response curves revealed self-activation of the strained amphiphiles by self-assembly into microdomains at low concentrations and self-inhibition by micelle formation at high concentrations. Poor colocalization of internalized vesicles with endosomes, lysosomes, and mitochondria indicate substantial release into the cytosol. The increasing activity with disulfide ring tension, inhibition with Ellman's reagent, and inactivity of maleimide and guanidinium controls outline a distinct mode of action that deserves further investigation and is promising for practical applications.

The Medical Legal Aspects of Surgery First and a New Model of Consent Form.

The introduction of "surgery first" has resulted in a new requirement to compare and resolve medical legal problems which previously did not exist in traditional orthognathic surgery. The first issue relates to the relationship between the doctor and the patient and, in particular, the need to create a new informed consent form for surgery first. The second problem that has arisen with the arrival of surgery first concerns the relationship between health workers, namely the surgeon, and the orthodontist. The authors of this article propose a new template for informed consent specifically created for surgery first and also a model for the new working relationship between surgeons and orthodontists which will facilitate and improve co-operation between them. This will improve results, and guarantee a greater level of protection for the surgeon. It will also enable the identification the individual responsibilities of each person.

J-Graft for Correction of Vertical and Horizontal Maxillary Bone Defects.

INTRODUCTION: This prospective study aims to evaluate the reliability of a reconstructive technique, which uses autologous J-shaped graft (J-graft) harvested from the mandibular ramus. MATERIALS AND METHODS: Thirty-six maxillary defects among 32 patients (20 women and 12 men) were treated. All patients presented enough bone volume at the donor site to perform the harvesting procedures needed for the autologous reconstruction. All patients underwent clinical and radiographical evaluations through standardized radiographs taken before the intervention, immediately after the bone grafting, 6 to 7 months, and 1 year later. The loss of tooth vitality, the alterations of skin and mucosa sensibility, and the patients' subjective perception of discomfort related to the surgical procedure were investigated. RESULTS: We found an overall success rate of 91.66% with a mean bone gain of 4.8 mm vertically and 5.6 mm horizontally, assessed through computed tomography. According to clinical examinations, 35 sites completely recovered with proper incorporation of the graft, whereas 33 sites reached enough bone volume to allow the implant placement. CONCLUSION: The described technique explains how to harvest and shape a J-graft. It achieves the simultaneous restoration of the horizontal and vertical bone loss with a single bone block.