Surgical Resection and Reconstruction of Ameloblastoma: A 13-Year Retrospective Review.

BACKGROUND: Ameloblastoma is a locally aggressive, benign tumor presenting in the maxilla and mandible prone to recurrence. Resection greatly limits recurrence; however, reconstruction becomes critical to preserve patients' functionality and esthetics. PURPOSE: The aim of this study was to describe surgical resection and reconstructive approaches in the treatment of ameloblastoma and compare clinical outcomes to conservative methods of treatment. STUDY DESIGN, SETTING, SAMPLE: A retrospective case series was completed through analysis of patient records. The study population was composed of patients treated for ameloblastoma at the Royal Brisbane Hospital (Queensland, Australia) in the Oral and Maxillofacial Surgery Unit from January 1, 2008, to December 31, 2020. Patients without histological confirmation of intraosseous ameloblastoma were excluded from the study sample. PREDICTOR VARIABLE: Not applicable. MAIN OUTCOME VARIABLE(S): The primary outcome variable was time to recurrence. Secondary outcome variables included any surgical complications incurred. COVARIATES: The covariate variables collected included age at diagnosis/treatment, gender, ethnicity, location of lesion and site(s) of involvement, tumor extent, alveolar expansion, histopathological growth pattern, and soft tissue involvement. ANALYSES: Descriptive statistics were computed for each study variable. RESULTS: A total of 48 cases of histologically confirmed ameloblastoma were identified (41 mandibular, 7 maxillary) involving 50 excisional operations (44 resections, 6 enucleations). Of these cases, 44 were followed up > 12 months, with a mean length of follow-up time of 65.6 months. No recurrence was detected for resected lesions. One enucleated lesion recurred at 25 months. Thirty-seven reconstructive procedures were undertaken, including 32 immediate free flaps. All reconstructive flaps and grafts survived, and no major complications were recorded. CONCLUSION AND RELEVANCE: Resection of ameloblastoma limits recurrence and should be considered curative. Immediate microvascular free flap reconstruction of maxillary and mandibular defects from resection of ameloblastoma is safe and predictable.

Effects of periodontal cells-derived extracellular vesicles on mesenchymal stromal cell function.

OBJECTIVE: To enrich and compare three extracellular vesicles-EV subtypes (apoptotic bodies, microvesicles and small EV) from three periodontal cells (periodontal ligament cells-PDLCs, alveolar bone-derived osteoblasts-OBs and gingival fibroblasts-GFs), and assess uptake and cell function changes in buccal fat pad-derived mesenchymal stromal cells (BFP-MSCs). BACKGROUND: Periodontal cells such as PDLCs, OBs and GFs have the potential to enhance bone and periodontal regeneration, but face significant challenges, such as the regulatory and cost implications of in vitro cell culture and storage. To address these challenges, it is important to explore alternative 'cell-free' strategies, such as extracellular vesicles which have emerged as promising tools in regenerative medicine, to facilitate osteogenic differentiation and bone regeneration. METHODS AND MATERIALS: Serial centrifuges at 2600 and 16 000 g were used to isolate apoptotic bodies and microvesicles respectively. Small EV-sEV was enriched by our in-house size exclusion chromatography (SEC). The cellular uptake, proliferation, migration and osteogenic/adipogenic differentiation genes were analysed after EVs uptake in BFP-MSCs. RESULTS: Three EV subtypes were enriched and characterised by morphology, particle size and EV-associated protein expression-CD9. Cellular uptake of the three EVs subtypes was observed in BFP-MSCs for up to 7 days. sEV from the three periodontal cells promoted proliferation, migration and osteogenic gene expression. hOBs-sEV showed superior levels of osteogenesis markers compared to that hPDLCs-sEV and hGFs-sEV, while hOBs-16k EV promoted adipogenic gene expression compared to that from hPDLCs and hGFs. CONCLUSIONS: Our proof-of-concept data demonstrate that hOBs-sEV might be an alternative cell-free therapeutic for bone tissue engineering.

The Impact of Orbital Volume on Post-traumatic Enophthalmos: A Systematic Review and Meta-analysis.

PURPOSE: Orbital volume increase has been previously linked with post-traumatic enophthalmos. However, this varies and some studies show no correlation. This systematic review and meta-analysis aimed to synthesize the correlation between orbital volume and enophthalmos and to determine if surgical intervention, enophthalmos measurement method, fracture location, or timing affect this correlation. METHODS: Automation tools were used to assist in this review of 6 databases. Searches were performed across all dates. Included studies quantitatively reported orbital volume and enophthalmos following traumatic orbital wall fractures in at least 5 adult subjects. Correlational data were extracted or calculated. Random-effects meta-analysis was used with subgroup analyses for each of the secondary aims. RESULTS: Twenty-five articles describing 648 patients were included. The pooled correlation between orbital volume and enophthalmos was r =0.71 ( R2 =0.50, P <0.001). Operative status, enophthalmos measurement method, and fracture location did not affect pooled correlation. The delay between trauma or surgery and enophthalmos measurement was not shown to modulate correlation for unoperated patients ( R2 =0.05, P =0.22) but showed a negative relationship for postoperative patients ( z =-0.0281, SE=0.0128, R2 =0.63, P =0.03), but this was heavily influenced by a single article. All results had high residual heterogeneity. Studies were rated as moderate, low, or very low quality with few stating explicit hypotheses or limitations. CONCLUSIONS: Bony orbital volume expansion accounts for around 50% of post-traumatic enophthalmos. The other half is probably explained by soft tissue or geometric bony, rather than volumetric, changes.

Surgical management of frontal bone and naso-orbito-ethmoidal fractures: a 7-year multi-center retrospective review.

OBJECTIVE: Frontal and naso-orbito-ethmoidal (NOE) fractures are rare but important injuries due to their anatomical complexity and proximity to vital structures. This study aims to describe the patient factors, procedural factors, and postoperative outcomes in the surgical management of these fractures. STUDY DESIGN: Retrospective review of patients aged 18 years or older who were surgically treated for these fractures at two Australian tertiary hospitals (2014-2020). Patient factors (demographics, mechanism of injury, fracture pattern, concomitant injuries); procedural factors (operation timing, surgical approach); and postoperative outcomes (complications, revision surgeries) were recorded. RESULTS: 60 cases were included (41 frontal; 29 NOE; 10 combined). Mean age was 37 (frontal) and 39 years (NOE). Most cases were male (87.8%; 75.9%). The most common mechanism was traffic accidents (29.3%; 34.5%). The most common associated facial fractures were Le Fort fractures (46.3%; 89.7%). The most common associated systemic injuries were brain injuries (36.6%; 34.5%). Mean operation timing was 13 days (frontal) and 11 days (NOE). Coronal flap was most commonly used (68.3%; 82.8%). Postoperative complication rates were 39.0% (frontal) and 37.9% (NOE). Three cases required revision surgeries. CONCLUSION: Further larger longitudinal studies are required to build knowledge and improve patient outcomes.

Surgical management of naso-orbito-ethmoidal fractures: a systematic review.

OBJECTIVE: Naso-orbito-ethmoidal fractures (NOE) fractures are uncommon but critical injuries. This review aims to investigate the patient factors, procedural factors, and postoperative outcomes associated with the surgical management of NOE fractures. STUDY DESIGN: PubMed and Scopus databases were systematically searched between 1993 and 2023 using the search strategy "(naso-orbito-ethmoidal OR nasoethmoid OR nasoorbitoethmoidal) AND fracture." Articles reporting clinical studies investigating the surgical management of NOE fractures were included. Articles that were duplicates, non-English, or non-full text; reported an unclear age range; reported insufficient data; and/or reported on a sample size less than 10 were excluded. Data on patient factors, procedural factors, and postoperative outcomes were extracted. RESULTS: Of the 412 articles identified, 6 eligible articles (retrospective case series) representing 95 adult cases and 84 pediatric cases were included. The mean ages were 29.0 and 10.2 years, respectively. Most cases were male (65.3%; 73.9%). Motor vehicle accidents were the most common mechanism of injury (79.2% and 50.0%, respectively). Coronal incision was the most common approach. Epiphora (n = 33) and scar problems (n = 21) were the most common complications in adult and pediatric cases, respectively. CONCLUSIONS: Further robust longitudinal studies with a clear description of fracture classification and surgical timing would be helpful. Gaps in knowledge include concomitant injuries, digitally-assisted applications, and risk factors for adverse outcomes.

3D bioprinted small extracellular vesicles from periodontal cells enhance mesenchymal stromal cell function.

Recent research indicates that combining 3D bioprinting and small extracellular vesicles (sEVs) offers a promising 'cell-free' regenerative medicine approach for various tissue engineering applications. Nonetheless, the majority of existing research has focused on bioprinting of sEVs sourced from cell lines. There remains a notable gap in research regarding the bioprinting of sEVs derived from primary human periodontal cells and their potential impact on ligamentous and osteogenic differentiation. Here, we investigated the effect of 3D bioprinted periodontal cell sEVs constructs on the differentiation potential of human buccal fat pad-derived mesenchymal stromal cells (hBFP-MSCs). Periodontal cell-derived sEVs were enriched by size exclusion chromatography (SEC) with particle-shaped morphology, and characterized by being smaller than 200 nm in size and CD9/CD63/CD81 positive, from primary human periodontal ligament cells (hPDLCs) and human gingival fibroblasts (hGFs). The sEVs were then 3D bioprinted in 10 % gelatin methacryloyl (GelMA) via microextrusion bioprinting. Release of sEVs from bioprinted constructs was determined by DiO-labelling and confocal imaging, and CD9 ELISA. Attachment and ligament/osteogenic/cementogenic differentiation of hBFP-MSCs was assessed on bioprinted GelMA, without and with sEVs (GelMA/hPDLCs-sEVs and GelMA/hGFs-sEVs), scaffolds. hBFP-MSCs seeded on the bioprinted sEVs constructs spread well with significantly enhanced focal adhesion, mechanotransduction associated gene expression, and ligament and osteogenesis/cementogenesis differentiation markers in GelMA/hPDLCs-sEVs, compared to GelMA/hGFs-sEVs and GelMA groups. A 2-week osteogenic and ligamentous differentiation showed enhanced ALP staining, calcium formation and toluidine blue stained cells in hBFP-MSCs on bioprinted GelMA/hPDLCs-sEVs constructs compared to the other two groups. The proof-of-concept data from this study supports the notion that 3D bioprinted GelMA/hPDLCs-sEVs scaffolds promote cell attachment, as well as ligamentous, osteogenic and cementogenic differentiation, of hBFP-MSCs in vitro.

Enhanced Fano resonance of organic material films deposited on arrays of asymmetric split-ring resonators (A-SRRs).

Depositing very thin organic films on the surface of arrays of asymmetric split-ring resonators (A-SRRs) produces a shift in their resonance spectra that can be utilized for sensitive analyte detection. Here we show that when poly-methyl-methacrylate (PMMA) is used as an organic probe (analyte) on top of the A-SRR array, the phase and amplitude of a characteristic molecular Fano resonance associated with a carbonyl bond changes according to the spectral positions of the trapped mode resonance of the A-SRRs and their plasmonic reflection peaks. Furthermore, we localize blocks of PMMA at different locations on the A-SRR array to determine the effectiveness of detection of very small amounts of non-uniformly distributed analyte.

Knee pain during the first three months after unilateral total knee arthroplasty: a multi-centre prospective cohort study.

Many patients have an unfavourable pain outcome post total knee arthroplasty (TKA). This multi-centre prospective cohort study recorded weekly pain scores one week before TKA and 12 weeks post TKA. 96 patients were enrolled into the study. Patients kept a record of their weekly scores pre-operation and post-operation by using the visual acuity score. Pain was divided into "best" pain score (lowest pain score) and "worst" pain score (highest pain score). Patients with a pre-operative pain scores ≤ 4 were identified as an at risk group for poor pain outcome. Female gender, age and anaesthetics type were not identified as risk factors for poor pain outcome. Pain trajectory analysis also identified general patterns of pain response post TKA.

E-Scooters and Craniofacial Trauma: A Systematic Review.

Study Design: Systematic review. Objective: Standing electric scooters (e-scooters) provide a cheap and environmentally friendly transport alternative, but also elicit substantial concern regarding their volume of associated injuries especially in the craniofacial region. This review aims to explore the demographics, risk factors, types of injury and surgical management of craniofacial trauma associated with e-scooters. Methods: PubMed and Scopus databases were systematically searched. Inclusion criteria were clinical studies investigating craniofacial trauma associated with e-scooters. Exclusion criteria were duplicates; non-English publications; non-full-text publications; studies with insufficient data. Results: Of the 73 articles identified, 10 eligible articles representing 539 patients were included. The mean age was 31.5 years. Most cases were male (63.7%). Common risk factors were alcohol/drug intoxication, absence of distal extremity injuries and lack of helmet use. The most common mechanism of injury was mechanical falls (72.4%). The most common facial fracture pattern was middle third fractures (58.3%). Surgical management was required for 43.3% of fractures. Other types of injuries reported were traumatic brain injuries (17.6%), soft tissue injuries (58.3%), dental injuries (32.9%) and ophthalmological injuries (20.6%). Conclusions: The findings of this review suggest common presentations for craniofacial trauma associated with e-scooters. Robust longitudinal evaluations with standardised descriptions of types of injuries are required. Gaps in knowledge relate to surgical management, post-operative complications and associated risk factors.

Rigid versus non-rigid fixation for bilateral mandibular angle fractures: a retrospective multicentre review.

BACKGROUND: Fractures involving the bilateral mandibular angle are an uncommon occurrence with limited evidence to inform the ideal fixation requirements for adequate treatment. The aim of this study was to evaluate the outcomes of managing bilateral mandibular angle fractures and determine if rigid fixation on one side improves outcomes compared to bilateral non-rigid fixation. METHODS: Patients with isolated bilateral mandibular angle fractures surgically treated at the Royal Brisbane and Women's Hospital, Princess Alexandra Hospital, Gold Coast University Hospital and Townsville University Hospital between January 1, 2010 and December 31, 2022 were retrospectively identified. Data collected included patient demographics, mechanism of injury, fixation scheme, postoperative occlusion and the occurrence of postoperative complications and subsequent management. RESULTS: Eighty-four patients met the inclusion criteria. Fifty-two patients had non-rigid fixation applied to both fractures, and thirty-two had rigid fixation placed on at least one side. All cases proceeded to union. There was no statistically significant difference between the groups for occlusal outcomes, wound dehiscence, infection or plate or screw loosening. CONCLUSION: Our results suggest that bilateral non-rigid fixation can be used to treat bilateral mandibular angle fractures in the appropriate clinical context.

The dental management of patients irradiated for head and neck cancer.

Patients undergoing radiotherapy for head and neck cancers are prone to a range of dental complications, including mucositis, trismus, xerostomia, radiation caries and osteoradionecrosis. Specific considerations include the preventive, restorative and rehabilitative management of such patients, and the prevention and treatment of complications. This article aims to highlight the current understanding and management of dental needs for patients who have had or will undergo radiotherapy.

Emission characteristics of photonic crystal light-emitting diodes.

Experimentally measured optical properties of photonic crystal LEDs are reported here. Photonic crystal and photonic quasi-crystal structures were fabricated on GaN epilayer LED wafer material using both direct-write electron beam lithography and nanoimprint lithography. Some of these structures were processed to make finished LEDs. Both electroluminescence and photoluminescence measurements were performed on these structures. Devices were characterized for their current-voltage characteristics, emission spectra, far-field emission pattern, and angular emission pattern. These results are useful for fabricating photonic crystal LEDs and assessing their operational properties.

Impact of titanium adhesion layers on the response of arrays of metallic split-ring resonators (SRRs).

At higher frequencies (visible and infrared) both the dimensions and the individual metal properties play an important role in determining the resonant response of arrays of SRRs. As a result, a substantial difference between the responses of gold- and Al-based SRR arrays has been observed. Additionally, deposition of gold SRRs onto a substrate typically involves the use of an additional adhesion layer. Titanium (Ti) is the most common adhesive thin-film material used to attach gold onto dielectric/semiconductor substrates. In this paper we investigate the impact of the Ti adhesion layer on the overall response of Au-based nano-scale SRRs. The results quantify the extent to which the overall difference in the resonance frequencies between Au- and Al-based SRRs is due to the presence of the Ti. We show that even a 2-nm-thick Ti layer can red-shift the position of SRR resonance by 20 nm. Finally, we demonstrate that by intentional addition of titanium in the Au-based SRRs, their overall resonant response can be tuned widely in frequency, but at the expense of resonance magnitude.

Magnetic response of split ring resonators (SRRs) at visible frequencies.

In this paper, we report on a substantial shift in the response of arrays of similarly sized Split Ring Resonators (SRRs), having a rectangular U-shaped form--and made respectively of aluminium and of gold. We also demonstrate that it is possible to obtain the polarization dependent LC peak in the visible spectrum--by using SRRs based on aluminium, rather than gold. The response of metallic SRRs scales linearly with size. At optical frequencies, metals stop behaving like nearly perfect conductors and begin displaying characteristically different behaviour, in accord with the Drude model. The response at higher frequencies, such as those in the visible and near infra-red, depends both on their size and on the individual properties of the metals used. A higher frequency limit has been observed in the polarization dependent response (in particular the LC resonance peak) of gold based SRRs in the near infrared region. By using aluminium based SRRs instead of gold, the higher frequency limit of the LC resonance can be further shifted into the visible spectrum.

All-optical switching in silicon-on-insulator photonic wire nano-cavities.

We report on experimental demonstration of all-optical switching in a silicon-on-insulator photonic wire nanocavity operating at telecom wavelengths. The switching is performed with a control pulse energy as low as approximately 0.1 pJ on a cavity device that presents very high signal transmission, an ultra-high quality-factor, almost diffraction-limited modal volume and a footprint of only 5 microm(2). High-speed modulation of the cavity mode is achieved by means of optical injection of free carriers using a nanosecond pulsed laser. Experimental results are interpreted by means of finite-difference time-domain simulations. The possibility of using this device as a logic gate is also demonstrated.

Dental anxiety in adult patients treated by dental students: A systematic review.

PURPOSE/OBJECTIVES: Dental anxiety is common and can propagate a vicious cycle of dental neglect and anxiety-provoking treatment. Patient, procedural, and operator factors are important contributions. This review aims to explore risk factors for dental anxiety in adult patients treated by dental students, in order to improve awareness of relevant factors and aid patient management. METHODS: Systematic searching of PubMed and Scopus databases was performed. Inclusion criteria were: studies assessing at least 1 risk factor for dental anxiety in patients aged 18 years and above treated by dental students, with use of a specific measurement scale for dental anxiety. Exclusion criteria were: duplicates, non-English publications, non-full-text publications, studies with a pediatric sample. RESULTS: Nine hundred thirty-one articles were identified. Eight eligible articles representing 1702 patients were included. Seven studies had a cross-sectional design and 1 study had a pretreatment/posttreatment design. Sixteen factors for dental anxiety were assessed. A significant correlation (P < 0.05) was found for: age (younger), gender (female), general/waiting room anxiety, irregular dental attendance, invasive treatment, poor emotional well-being, postponement of dental visit due to anxiety, previous negative dental experience and village residence. No significant correlation was found for: education, employment, income, perceived oral health, presence of a previous dental visit, symptom duration and time since last dental visit. CONCLUSIONS: These findings provide a good foundation for future research, but clinical generalization is limited by the heterogeneity among included studies. A well-structured comparison of risk factors for dental anxiety between patients treated by dental students and dentists is required.

Asymmetric split ring resonators for optical sensing of organic materials.

Asymmetric Split Ring Resonators are known to exhibit resonant modes where the optical electric field is strongest near the ends of the arms, thereby increasing the sensitivity of spectral techniques such as surface enhanced Raman scattering (SERS). By producing asymmetry in the structures, the two arms of the ring produce distinct plasmonic resonances related to their lengths - but are also affected by the presence of the other arm. This combination leads to a steepening of the slope of the reflection spectrum between the resonances that increases the sensitivity of the resonant behavior to the addition of different molecular species. We describe experimental results, supported by simulation, on the resonances of a series of circular split ring resonators with different gap and section lengths--at wavelengths in the mid-infra red regions of the spectrum--and their utilization for highly sensitive detection of organic compounds. We have used thin films of PMMA with different thicknesses, resulting in characteristic shifts from the original resonance. We also demonstrate matching of asymmetric split ring resonators to a molecular resonance of PMMA.

Ultra high quality factor one dimensional photonic crystal/photonic wire micro-cavities in silicon-on-insulator (SOI).

We present experimental results on photonic crystal/photonic wire micro-cavity structures that demonstrate further enhancement of the quality-factor (Q-factor)--up to approximately 149,000--in the fibre telecommunications wavelength range. The Q-values and the useful transmission levels achieved are due, in particular, to the combination of both tapering within and outside the micro-cavity, with carefully designed hole diameters and non-periodic hole placement within the tapered section. Our 2D Finite Difference Time Domain (FDTD) simulation approach shows good agreement with the experimental results.

Ophthalmological injuries associated with fractures of the orbitozygomaticomaxillary complex.

Our aim was to evaluate ophthalmological injuries associated with fractures of the orbitozygomaticomaxillary complex that required operative treatment, and we collected data retrospectively over a period of five years (2012-2016 inclusive). Of the 190 patients, 162 were male with a median age of 31 (IQR 25 -39) years. Assault was the most common mechanism of injury (125/190, 66%). Minor ophthalmic injuries (those unlikely to cause permanent visual disturbance) and major ophthalmic injuries (those with the potential to cause permanent visual disturbance) were recorded. The common minor ophthalmic injuries were: diplopia, enophthalmos, proptosis, subconjunctival haemorrhage, and restriction of the extraocular muscles. Commotio retinae, traumatic mydriasis, retro-orbital haemorrhage, and hyphaema were the common major ophthalmic injuries. All 13 different major ophthalmic injuries were recorded in the group who had had orbital fractures reconstructed, which suggested that more intraocular damage can be caused by this type of fracture than by others. Visual acuity was reduced in 26/190 patients with only four having persistent postoperative changes at six weeks. The odds ratio for those patients who had a major ophthalmological injury and were unable to drive was 0.07 (95% CI 0.02 to 0.21, p=0.001), which was highly significant. Ophthalmological assessment is strongly recommended for patients with fractures of the orbitozygomaticomaxillary complex.

Inherent risks associated with manufacture of bioengineered ocular surface tissue.

OBJECTIVE: To review the potential health risks associated with bioengineered ocular surface tissue, which serves as a bellwether for other tissues. METHODS: All clinical trials using bioengineered ocular surface tissue published between July 1, 1996, and June 30, 2005, were reviewed with respect to materials used and statements of risk assessment, risk remediation, adverse events, manufacturing standards, and regulatory oversight. RESULTS: Ninety-five percent of investigational protocols used 1 or more animal-derived products and an overlapping 95% used 1 or more donor human tissues. Consideration of risks reveals a very low probability of potential harm but a significant risk of disability or death if such an event were to occur. Details of ethics approval, patient consent, and donor serologic test results were not consistently provided. No references were made to risk assessment or to codes of manufacturing and clinical practice. CONCLUSION: While a degree of risk is associated with bioengineered ocular surface tissue, investigational reports of this new technology have yet to address issues of risk management and regulatory oversight. CLINICAL RELEVANCE: Attention to risk and codes of manufacturing and clinical practice will be required for advancement of the technology. We suggest the adoption of international standards to address these issues.