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Sequencing in orthognathic bimaxillary surgery: which jaw should be operated first? A scoping review

Bimaxillary orthognathic surgery is widely used for the correction of dentoskeletal deformities. Surgery sequencing (maxilla or mandible first) remains debated, and guidelines and consensus are lacking. This scoping review summarizes the state of the art and compares the advantages and disadvantages of both approaches. The review was conducted following PRISMA-ScR guidelines. Three electronic databases (PubMed, Scopus, Web of Science) were searched using the PICO protocol and key words in orthognathic surgical sequencing. Four reviewers screened the records independently, and disagreement was resolved by consensus. A total of 23 records met the inclusion criteria. The advantages and disadvantages of the two approaches were compared and assessed for accuracy of reporting. Within the limitations of the present study, available evidence for the intrinsic advantages and the accuracy of the mandible-first sequence supports the choice of this approach in most cases. Nevertheless, each clinical case needs to be evaluated individually, as no dogmatic recommendations can be given for sequencing in bimaxillary orthognathic surger

Combined orthodontic and surgical open bite correction: Principles for success. Part 2

Objectives: To present a clinical description of the team's treatment techniques. Materials and Methods: In Part 1, 30 patients underwent segmental maxillary orthodontics, multisegment Le Fort I, and bilateral sagittal osteotomies of the mandible. Part 1 reported excellent occlusal stability at a mean follow-up of 49.43 months (range, 36-92 months). Cases presented in Part 2 were selected based on availability of excellent technique photographs. The same techniques described in Part 2 cases were used on all Part 1 patients. Results: The coordination of arch widths and forms, overbite, overjet, and maxillary curve of Spee corrections were stable using the team protocols for orthodontic and surgical treatment. Conclusions: In the study group, long-term three-dimensionally stable occlusal results were achieved. To duplicate these results, specific orthodontic preparation, intraoperative surgical steps, and postsurgical steps must be carefully planned and executed. These steps are described in this article, Part 2. (Angle Orthod. 2022;92:431-445.

The effect of subspinal Le Fort I osteotomy and alar cinch suture on nasal widening

The aim of this retrospective study was to evaluate the relationships between upper jaw movements and nasal soft-tissue changes in patients who have undergone subspinal Le Fort I osteotomy combined with alar cinch suture.Single and multivariate linear regression analyses were used to examine the relationships between greatest inter-alar width (GAW) and maxillary advancement, maxillary impaction, and rotational movements. The database of our referral hospital was searched for patients who had undergone upper jaw surgery with a subspinal LFI osteotomy to correct dentoskeletal deformities between April 2012 and June 2016.Thirty-eight of the patients (15 men and 23 women) who were identified were eligible for inclusion. The average change in inter-alar width (Delta GAW) was +1.7 +/- 1.2 mm. GAW increased by 0.3 mm (p < 0.0001) for each millimetre of maxillary advancement, and increased by 0.5 mm (p < 0.0001) for each millimetre of maxillary impaction. GAW increased by 0.2 mm for each degree of counterclockwise rotation of the occlusal plane (p < 0.0001).An analysis of our data compared with the current literature confirmed that subspinal Le Fort I combined with alar cinch suture reduced alar base widening. (C) 2020 Published by Elsevier Ltd on behalf of European Association for Cranio-Maxillo-Facial Surgery

Transconjunctival and Subciliary Approach in the Treatment of Orbital Fractures: A Study on Oculoplastic Complication

The aim of the present study was to compare lower eyelid post-operative complications, such as ectropion, entropion, and scleral show of orbital floor fractures, associated to the subciliary vs transconjunctival approaches

ZYGOMA IMPLANT-SUPPORTED PROSTHETIC REHABILITATION OF A PATIENT AFTER SUBTOTAL BILATERAL MAXILLECTOMY

This clinical report describes the successful implant-supported prosthetic rehabilitation of a patient who underwent subtotal bilateral maxillectomy for an oral squamous cell carcinoma with a consequent wide defect interesting the whole hard palate and most of the soft palate, causing a large opening that directly connects the oral cavity to the nasal fosse bilaterally. The innovative aspect of this case is represented by the realization of a obturator prosthesis supported by just three zygoma implants. The maxillary bone had been largely excised by radical surgery. Despite the resection had a complete oncological success and the patient was free of disease after 24 months follow up, the patient experienced severe speech and deglutition deficit due to the iatrogenic large oro-antral communication. Three zygoma implants have been positioned, two trough the right maxillary bone and, owing the wide lack of bone, just one on the left side. No mucogengival surgery was necessary around the zygoma implants. The obturator prosthesis was stabilized by the three implants and the patient\u2019s oral function as well as quality of life widely improved. The results show that zygoma implants could represent a viable surgical option to obtain a satisfactory oral function rehabilitation even in case of extensive maxillary defect

Stem Cell Fate and Immunomodulation Promote Bone Regeneration via Composite Bio-Oss®/AviteneTM Biomaterial

Bone defects in maxillofacial regions lead to noticeable deformity and dysfunctions. Therefore, the use of biomaterials/scaffolds for maxillofacial bone regrowth has been attracting great interest from many surgical specialties and experts. Many approaches have been devised in order to create an optimal bone scaffold capable of achieving desirable degrees of bone integration and osteogenesis. Osteogenesis represents a complex physiological process involving multiple cooperating systems. A tight relationship between the immune and skeletal systems has lately been established using the concept of “osteoimmunology,” since various molecules, particularly those regulating immunological and inflammatory processes, are shared. Inflammatory mediators are now being implicated in bone remodeling, according to new scientific data. In this study, a profiler PCR array was employed to evaluate the expression of cytokines and chemokines in human adipose derived-mesenchymal stem cells (hASCs) cultured on porous hydroxylapatite (HA)/Collagen derived Bio-Oss® /Avitene scaffolds, up to day 21. In hASCs grown on the Bio-Oss® /Avitene biomaterial, 12 differentially expressed genes (DEGs) were found to be up-regulated, together with 12 DEG downregulated. Chemokine CCL2, which affects bone metabolism, tested down-regulated. Interestingly, the Bio-Oss® /Avitene induced the down-regulation of pro-inflammatory interleukin IL-6. In conclusion, our investigation carried out on the Bio-Oss® /Avitene scaffold indicates that it could be successfully employed in maxillofacial surgery. Indeed, this composite material has the advantage of being customized on the basis of the individual patients favoring a novel personalized medicine approach

Combined orthodontic and surgical open bite correction: Principles for success. Part 1

Objectives: To examine the stability of combined surgical and orthodontic bite correction with emphasis on open-bite closure. All study patients were treated with strict and consistent orthodontic and surgical protocols. Materials and Methods: Study inclusion required all patients to have anterior open bites, maxillary accentuated curve of Spee, 36-month minimum follow-up, and no temporomandibular joint pathology. Thirty patients met the inclusion/exclusion criteria. Importantly, segmental upper arch orthodontic preparation (performed by EG) was used. Surgery consisted of a multisegment Le Fort I (MSLFI) combined with a bilateral sagittal osteotomies (BSSO). Surgery was performed (by ADA and LT) at the Department of Dentistry and Maxillofacial Surgery of the University of Verona, Italy. Results: The long-term open bite and overjet relapse were not statistically significant. The mean transverse relapse of the upper and lower molars was statistically significant. Of great importance, the upper and lower arch widths narrowed together, maintaining intercuspation of the posterior dentition which prevented anterior open bites from developing. Conclusions: This study revealed stability of three-dimensional occlusal correction including anterior open bite. Stable open bite closure was achieved by using rigid protocols for orthodontic preparation, surgical techniques, surgical follow-up, and orthodontic finishing. (Angle Orthod. 2022;92:161-172.

Genetics and Epigenetics of Bone Remodeling and Metabolic Bone Diseases

Bone metabolism consists of a balance between bone formation and bone resorption, which is mediated by osteoblast and osteoclast activity, respectively. In order to ensure bone plasticity, the bone remodeling process needs to function properly. Mesenchymal stem cells differentiate into the osteoblast lineage by activating different signaling pathways, including transforming growth factor β (TGF-β)/bone morphogenic protein (BMP) and the Wingless/Int-1 (Wnt)/β-catenin pathways. Recent data indicate that bone remodeling processes are also epigenetically regulated by DNA methylation, histone post-translational modifications, and non-coding RNA expressions, such as micro-RNAs, long non-coding RNAs, and circular RNAs. Mutations and dysfunctions in pathways regulating the osteoblast differentiation might influence the bone remodeling process, ultimately leading to a large variety of metabolic bone diseases. In this review, we aim to summarize and describe the genetics and epigenetics of the bone remodeling process. Moreover, the current findings behind the genetics of metabolic bone diseases are also reporte

Hydroxylapatite-collagen hybrid scaffold induces human adipose-derived mesenchymal stem cells to osteogenic differentiation in vitro and bone regrowth in patients

Tissue engineering-based bone graft is an emerging viable treatment modality to repair and regenerate tissues damaged as a result of diseases or injuries. The structure and composition of scaffolds should modulate the classical osteogenic pathways in human stem cells. The osteoinductivity properties of the hydroxylapatite-collagen hybrid scaffold named Coll/Pro Osteon 200 were investigated in an in vitro model of human adipose mesenchymal stem cells (hASCs), whereas the clinical evaluation was carried out in maxillofacial patients. Differentially expressed genes (DEGs) induced by the scaffold were analyzed using the Osteogenesis RT2 PCR Array. The osteoinductivity potential of the scaffold was also investigated by studying the alkaline phosphatase (ALP) activity, matrix mineralization, osteocalcin (OCN), and CLEC3B expression protein. Fifty patients who underwent zygomatic augmentation and bimaxillary osteotomy were evaluated clinically, radiologically, and histologically during a 3-year follow-up. Among DEGs, osteogenesis-related genes, including BMP1/2, ALP, BGLAP, SP7, RUNX2, SPP1, and EGFR, which play important roles in osteogenesis, were found to be upregulated. The genes to cartilage condensation SOX9, BMPR1B, and osteoclast cells TNFSF11 were detected upregulated at every time point of the investigation. This scaffold has a high osteoinductivity revealed by the matrix mineralization, ALP activity, OCN, and CLEC3B expression proteins. Clinical evaluation evidences that the biomaterial promotes bone regrowth. Histological results of biopsy specimens from patients showed prominent ossification. Experimental data using the Coll/Pro Osteon 200 indicate that clinical evaluation of bone regrowth in patients, after scaffold implantation, was supported by DEGs implicated in skeletal development as shown in "in vitro" experiments with hASCs