Proteome analysis reveals that de novo regenerated mucosa over fibula flap-reconstructed mandibles resembles mature keratinized oral mucosa

One-stage prosthodontically driven jaw reconstruction in patients with benign and malignant pathologies: A 7- to 11-year cohort study

OBJECTIVES

One stage functional jaw reconstruction is defined as the resection and reconstruction of segmental defects in conjunction with the placement of dental implants in an ideal prosthetic position and loaded with a provisional restoration, during one surgical procedure. The aim of the study is to describe clinical outcomes of patients who underwent one stage functional jaw reconstruction.

METHODS

Patients who underwent one-stage functional jaw reconstruction, from January 2013 to March 2016 were recalled in 2022 and 2023. Planning and execution for the reconstruction utilized either analogue or digital techniques. Outcome parameters recorded were treatment-related outcomes at patient level, implant-related outcomes and patient-reported outcome measures.

RESULTS

Eighteen patients underwent one-stage jaw reconstruction with a total of 57 implants. Four patients had maxillary and 14 had mandibular reconstructions. Ten patients underwent postoperative radiotherapy. Ten patients were planned using analogue and eight by digital planning. Three patients had partial flap necrosis, three patients had plate fractures, implant loss was seen in one patient and four patients died during the period. A functional prosthesis was provided in 16 out of the 18 patients.

CONCLUSION

One-stage functional jaw reconstruction is a predictable method for providing rehabilitation with successful outcomes at 7-11 years. However, caution should be exercised when the treatment modality is carried out in patients with malignant pathologies who have undergone radiotherapy.

Rehabilitation of Reconstructed Maxilla Using Denture-Guided Epithelial Regeneration in DCIA Flap: 10-Year Follow-Up

This 10-year follow-up report describes the interdisciplinary comprehensive management of a patient with aneurysmal bone cyst of the maxilla in a 24-year-old patient. The treatment included resection and primary reconstruction with vascularized deep circumflex iliac artery-based composite free flap, implant placement, and peri-implant soft tissue management using denture-guided epithelial regeneration with interim dentures. Definitive management was done using implant-supported cast partial dentures, and the patient followed up for 10 years.

Mass spectrometry-based proteomic applications in dental implants research

Dental implants have been established as successful treatment options for missing teeth with steadily increasing demands. Today, the primary areas of research in dental implantology revolve around osseointegration, soft and hard tissue grafting as well as peri-implantitis diagnostics, prevention, and treatment. This review provides a comprehensive overview of the current literature on the application of MS-based proteomics in dental implant research, highlights how explorative proteomics provided insights into the biology of peri-implant soft and hard tissues and how proteomics facilitated the stratification between healthy and diseased implants, enabling the identification of potential new diagnostic markers. Additionally, this review illuminates technical aspects, and provides recommendations for future study designs based on the current evidence.

Vestibuloplasty and its impact on the long-term survival and success of dental implants in irradiated and non-irradiated patients after head and neck tumor therapy: a retrospective study

OBJECTIVES

This study aimed to evaluate the influence of vestibuloplasty on the clinical success and survival of dental implants in head and neck tumor patients.

MATERIALS AND METHODS

A retrospective single-center study was conducted. All patients received surgical therapy of a tumor in the head or neck and underwent surgical therapy and, if necessary, radiotherapy/radiochemotherapy. Patients with compromised soft tissue conditions received vestibuloplasty using a split thickness skin graft and an implant-retained splint. Implant survival and success and the influence of vestibuloplasty, gender, radiotherapy, and localizations were evaluated.

RESULTS

A total of 247 dental implants in 49 patients (18 women and 31 men; mean age of 63.6 years) were evaluated. During the observation period, 6 implants were lost. The cumulative survival rate was 99.1% after 1 year and 3 years and 93.1% after 5 years for patients without vestibuloplasty, compared to a survival and success rate of 100% after 5 years in patients with vestibuloplasty. Additionally, patients with vestibuloplasty showed significantly lower peri-implant bone resorption rates after 5 years (mesial: p = 0.003; distal: p = 0.001).

CONCLUSION

This study demonstrates a high cumulative survival and success rate of dental implants after 5 years in head and neck tumor patients, irrespective of irradiation. Patients with vestibuloplasty showed a significantly higher rate of implant survival and significantly lower peri-implant bone resorption after 5 years.

CLINICAL RELEVANCE

Vestibuloplasty should always be considered and applied if required by the anatomical situations to achieve high implant survival/success rates in head and neck tumor patients.

Cell wall channels of Rhodococcus species: identification and characterization of the cell wall channels of Rhodococcus corynebacteroides and Rhodococcus ruber

The cell wall of Rhodococcus corynebacteroides formerly known as Nocardia corynebacteroides contains cell wall channels that are responsible for the cell wall permeability of this bacterium. Based on partial sequencing of the polypeptide subunits and a BLAST search, we identified one polypeptide of R. corynebacteroides (PorARc) and two polypeptides (PorARr and PorBRr) from the closely related bacterium Rhodococcus ruber. The corresponding genes, porARc (606 bp), porARr (702 bp), and porBRr (540 bp) are constituents of the known genome of R. corynebacteroides DSM-20151 and R. ruber DSM-43338, respectively. porARr and porBRr of R. ruber are possibly forming a common operon coding for the polypeptide subunits of the cell wall channel. The genes coding for PorARc and for PorARr and PorBRr without signal peptide were separately expressed in the porin-deficient Escherichia coli BL21DE3Omp8 strain and the proteins were purified to homogeneity. All proteins were checked for channel formation in lipid bilayers. PorARc formed channels with characteristics that were very similar to those of a previous study. The proteins PorARr and PorBRr expressed in E. coli could alone create channels in lipid bilayer membranes, despite the possibility that the two corresponding genes form a porin operon and that both subunits possibly form the cell wall channels in vivo. Based on amino acid sequence comparison of a variety of proteins forming cell wall channels in bacteria of the suborder Corynebacterineae, it seems very likely that PorARc, PorARr, and PorBRr are members of a huge family of proteins (PF09203) that form MspA-like cell wall channels.

Clostridium perfringens Beta2 toxin forms highly cation-selective channels in lipid bilayers

Clostridium perfringens is a potent producer of a variety of toxins. Well studied from these are five toxins (alpha, Beta (CPB), epsilon, iota and CPE) that are produced by seven toxinotype strains (A–G) of C. perfringens. Besides these toxins, C. perfringens produces also another toxin that causes necrotizing enterocolitis in piglets. This toxin termed consensus Beta2 toxin (cCPB2) has a molecular mass of 27,620 Da and shows only little homology to CPB and no one to the other toxins of C. perfringens. Its primary action on cells remained unknown to date. cCPB2 was heterogeneously expressed as fusion protein with GST in Escherichia coli and purified to homogeneity. Although cCPB2 does not exhibit the typical structure of beta-stranded pore-forming proteins and contains no indication for the presence of amphipathic alpha-helices we could demonstrate that cCPB2 is a pore-forming component with an extremely high activity in lipid bilayers. The channels have a single-channel conductance of about 700 pS in 1 M KCl and are highly cation-selective as judged from selectivity measurements in the presence of salt gradients. The high cation selectivity is caused by the presence of net negative charges in or near the channel that allowed an estimate of the channel size being about 1.4 nm wide. Our measurements suggest that the primary effect of cCPB2 is the formation of cation-selective channels followed by necrotic enteritis in humans and animals. We searched in databases for homologs of cCPB2 and constructed a cladogram representing the phylogenetic relationship to the next relatives of cCPB2.

Memory-Enhancing Effects of Origanum majorana Essential Oil in an Alzheimer's Amyloid beta1-42 Rat Model: A Molecular and Behavioral Study

Origanum L. (Lamiaceae) is an important genus of medicinal and aromatic plants used in traditional medicine since ancient times as culinary herbs and remedies. The aim of the present study was to evaluate the chemical composition, as well as the biochemical and cellular activities of freshly prepared Origanum majorana L. essential oil (OmEO) in an Alzheimer’s disease (AD) amyloid beta1-42 (Aβ1-42) rat model. OmEO (1% and 3%) was inhaled for 21 consecutive days, while Aβ1-42 was administered intracerebroventricularly to induce AD-like symptoms. Our data demonstrate that OmEO increased antioxidant activity and enhanced brain-derived neurotrophic factor (BDNF) expression, which in concert contributed to the improvement of cognitive function of animals. Moreover, OmEO presented beneficial effects on memory performance in Y-maze and radial arm-maze tests in the Aβ1-42 rat AD model.

Comparison of blood serum protein analysis by MALDI-MS from either conventional frozen samples or storage disc-deposited samples: A study with human serum from pregnant donors and from patients with intrauterine growth restriction

Mass spectrometric profiling of intact serum proteins, i.e. determination of relative protein abundance differences, was performed using two different serum sample preparation methods: one with frozen and thawed serum, the other with at room temperature deposited and dried serum. Since in a typical clinical setting freezing of serum is difficult to achieve, sampling at room temperature is preferred and can be met when using the Noviplex™ card system. Once deposited and dried, serum proteins can be stored and shipped at room temperature. After resolubilization of serum proteins from "dried serum spots", mass spectra of high quality have been recorded comparable to those that were obtained using fresh-frozen and subsequently thawed serum samples. Differentiation between patients with intrauterine growth restriction and control individuals was achievable, independent from the sample work-up procedure. Having at hand a reliable and robust method for serum storage and shipment which works at room temperature bridges the gap between the clinics and the protein analysis laboratory. Our novel serum handling protocol reduces costs for both, storage and shipping, and ultimately enables clinical risk assessment based on mass spectrometric determination of intact protein abundance profiles.

Masticatory efficiency of implant-supported removable partial dental prostheses in patients with free fibula flap reconstructed mandibles: A split-mouth, observational study

OBJECTIVES

The aim of this split-mouth study was to evaluate the masticatory efficiency in patients with segmentally reconstructed mandibles using free fibula flaps, with and without stabilizing osteosynthesis material in-situ during implant placement for rehabilitation with implant-supported removable partial dental prostheses (ISRPDPs).

METHODS

Ten participants (n = 10; ♀ = 2, ♂ = 8; mean age = 38.1 years) consented to participate in this study. The participants' normal side (Side N) of the mandible served as the control side, for comparing the masticatory efficiency of the segmentally reconstructed and rehabilitated side (Side R). Masticatory efficiency was evaluated using the two-colored chewing gum test, measured as subjective assessment (SA) and electronically evaluated variance of hue (VOH). Data were checked for normal distribution and statistically analyzed with the level of significance set to p < 0.05.

RESULTS

Thirty-four tissue-level implants were placed in reconstructed mandibles of 10 participants. There was no significant difference observed in the masticatory efficiencies between Side N and Side R, in both subjective and electronic assessments. No implant loss was observed after a post-rehabilitated mean follow-up period of 42.7 months, revealing an implant survival rate of 100%.

CONCLUSIONS

In patients with surgically reconstructed mandibles, a normal masticatory function can be successfully achieved with a rehabilitation of the reconstructed side with implant-supported removable partial dental prostheses. Implant-supported prostheses should be actively advocated in patients with reconstructive surgeries to restore their masticatory function, extend their food choices, and improve their overall oral health-related quality of life.