Restorabite™: Phase II trial of jaw stretching exercises using a novel device for patients with trismus following head and neck cancer.

Patients treated for oral cancer, may experience restricted mouth opening (trismus). Barriers such as cost have limited the utilization of traditional jaw stretching devices, and consequently, patients experience problems with swallowing, oral care, communication, and cancer surveillance. The safety and efficacy of Restorabite™, a new device designed to overcome these barriers, is evaluated prospectively over 12 months. This phase II investigator-led trial included patients with chronic trismus underwent 10-weeks of trismus therapy using Restorabite™. Safety, adherence, changes in mouth opening, and patient-reported outcomes are presented. 114/120 participants with trismus completed the intervention, and 104 had their progress monitored for 12 months. Thirteen participants withdrew due to tumour recurrence. At the completion of the intervention, mouth opening improved by 10.4 mm (p < .001). This increased to 13.7 mm at 12 months (p < .001). Patient reported outcome all significantly improved and 47 participants were no longer classified as having trismus. There were no serious treatment related adverse events. In patients with trismus following head and neck cancer treatment, a 10-week programme of jaw stretching exercises using Restorbite™ safely improves mouth opening and associated quality of life outcomes with high adherence and the benefits are maintained for 12-months.

Expanding the digital workflow for a prefabricated prelaminated fibula flap: A dental technique.

The workflow for a prefabricated prelaminated fibula free flap has been almost entirely digitized. One of the last 2 remaining steps is the impression making in stage 1 surgery. This article describes a novel computed-tomography based digital scanning technique with an assessment of the resultant accuracy.

A comparison of different methods and materials for establishing maximal intercuspal position: A clinical study.

STATEMENT OF PROBLEM: Which method or material used to record the intercuspal position yields the best accuracy of location of the maxillary and mandibular casts is unclear. PURPOSE: The purpose of this clinical study was to determine the most reliable method of recording a patient's maximal intercuspal position by comparing 2 common methods with 2 popular registration materials. MATERIAL AND METHODS: Complete-arch impressions were made of both jaws with a polyvinyl siloxane impression material in a metal stock tray followed by 4 interocclusal registrations for each of the 17 participants. Two registration techniques were used. More than 1 record was obtained in the first technique, as the participant had to close through a wax sheet or a polyvinyl siloxane material. In the second technique, a polyvinyl siloxane material was injected from the buccal aspect between occluded tooth surfaces. Casts were made from Type 4 stone and vertical measurements of the casts were carried out by using digital vernier calipers, accurate to 100 µm. Hand articulation of the casts was used as the control. Consistency of measurement was assessed by the intraclass correlation coefficient, and comparisons were made by using repeated-measures regression analysis. RESULTS: Statistical analysis showed significant discrepancies when the participant closed through both wax and polyvinyl siloxane material (P<.001). No statistically significant differences to the control group were present when polyvinyl siloxane was injected laterally after closure. CONCLUSIONS: Hand articulation was the most accurate method of reproducing the maximal intercuspal position in a completely dentate individual with horizontal and vertical occlusal stability and was therefore considered the control. Recording the position after the participant had closed by using a polyvinyl siloxane material was the most accurate.

Surgical and health related quality of life outcomes following treatment with zygomatic implant perforated (ZIP) flaps.

BACKGROUND: The zygomatic implant perforated (ZIP) flap is a novel approach to the challenge of reconstructing the maxilla. We report on our experience using the ZIP flap technique for patients undergoing infrastructure maxillectomy at Chris O'Brien Lifehouse, Sydney, Australia. METHODS: Thirteen patients who underwent a ZIP flap reconstruction between August 2019 and August 2021 were identified. Demographic, surgical, and histopathological information was collected. Health Related Quality of Life (HRQOL) was assessed using the FACE-Q Head and Neck Cancer module, the M.D. Anderson Dysphagia Inventory, and the Speech Handicap Index. RESULTS: A total of 44 zygomatic implants were placed, of which 42 (95%) survived. The median time from surgery to dental rehabilitation was 35 days. HRQOL data was available for nine patients over 24 months, demonstrating improved speech and swallowing outcomes over the follow up period. CONCLUSIONS: The ZIP flap is a reproducible surgical technique that facilitates rapid dental rehabilitation post infrastructure maxillectomy.

Jaw in a day surgery: early experience with 19 patients at an Australian tertiary referral center.

BACKGROUND: The Jaw-in-a-Day (JIAD) procedure aims to achieve immediate functional occlusion via a single-stage approach to maxillofacial reconstruction. While JIAD has gained popularity since its inception by Levine and colleagues, efficacy and outcome data remain limited. In this report, we discuss our experience with the JIAD technique at an Australian tertiary referral centre. METHODS: A retrospective review of all JIAD procedures performed from April 2022 to December 2023 was conducted. Clinicopathologic data reviewed included demographic information, primary diagnosis, anatomical site of disease, and history of pre-operative radiotherapy. Outcome measures of interest included operative time, number of implants placed, post-operative complications and implant survival. RESULTS: Nineteen patients were identified for the study. Two maxillary and 17 mandibular JIAD procedures were performed. The most common indications were squamous cell carcinoma (n = 8) and ameloblastoma (n = 5). Surgical complications included recipient site wound infection (n = 3), flap dehiscence (n = 2), haematoma formation (n = 1), and neck abscess associated with partial flap failure (n = 1). No total flap failures were identified. Of the 55 total implants placed, one implant failure occurred 2-months post-operatively. No loss of irradiated implants (n = 21) was observed. The median time to adjuvant radiotherapy was 57 days (range, 32-61). Eighteen of 19 patients (95%) achieved immediate dental rehabilitation, and 15/19 patients (79%) retained a functional prosthesis by the end of the follow-up period. CONCLUSIONS: Our series supports the feasibility of single-stage reconstruction for both benign and malignant indications. Further research is required to understand the long-term functional, aesthetic, and health-related quality-of-life outcomes with the JIAD technique.

Outcomes of immediate dental implants in vascularised bone flaps for mandibular reconstruction.

BACKGROUND: The aim of this study is to assess the outcomes of immediate implant placement for dental rehabilitation following mandibular reconstruction with vascularised bone flaps in a single Australian tertiary cancer centre. METHODS: A retrospective analysis of patients who underwent immediate dental implant or delayed placement in vascularised bone flaps was performed. Primary outcome measures assessed included the number of implants placed, operative time, complication rates, time to radiotherapy initiation, dental rehabilitation rates and time to dental rehabilitation. RESULTS: In total, 187 dental implants were placed in 52 patients, of which 34 patients underwent immediate implant placement and 18 had delayed implant placement. There were no significant differences in the postoperative complication rate (32% immediate vs. 33% delayed, P = 0.89) or time to postoperative radiotherapy (median 42 days immediate vs. 47 days delayed, P = 0.24). Dental rehabilitation was achieved in 62% of the immediate cohort versus 78% of the delayed cohort. The time to be fitted with a dental prosthesis was significantly shorter in the immediate cohort (median 150 days immediate vs. 843 days delayed, P = 0.002). CONCLUSIONS: The placement of immediate dental implants at the time of primary reconstruction of the mandible is a safe procedure and facilitates timely dental rehabilitation.

A Comparison of In Vivo Bone Tissue Generation Using Calcium Phosphate Bone Substitutes in a Novel 3D Printed Four-Chamber Periosteal Bioreactor.

Autologous bone replacement remains the preferred treatment for segmental defects of the mandible; however, it cannot replicate complex facial geometry and causes donor site morbidity. Bone tissue engineering has the potential to overcome these limitations. Various commercially available calcium phosphate-based bone substitutes (Novabone®, BioOss®, and Zengro®) are commonly used in dentistry for small bone defects around teeth and implants. However, their role in ectopic bone formation, which can later be applied as vascularized graft in a bone defect, is yet to be explored. Here, we compare the above-mentioned bone substitutes with autologous bone with the aim of selecting one for future studies of segmental mandibular repair. Six female sheep, aged 7-8 years, were implanted with 40 mm long four-chambered polyether ether ketone (PEEK) bioreactors prepared using additive manufacturing followed by plasma immersion ion implantation (PIII) to improve hydrophilicity and bioactivity. Each bioreactor was wrapped with vascularized scapular periosteum and the chambers were filled with autologous bone graft, Novabone®, BioOss®, and Zengro®, respectively. The bioreactors were implanted within a subscapular muscle pocket for either 8 weeks (two sheep), 10 weeks (two sheep), or 12 weeks (two sheep), after which they were removed and assessed by microCT and routine histology. Moderate bone formation was observed in autologous bone grafts, while low bone formation was observed in the BioOss® and Zengro® chambers. No bone formation was observed in the Novabone® chambers. Although the BioOss® and Zengro® chambers contained relatively small amounts of bone, endochondral ossification and retained hydroxyapatite suggest their potential in new bone formation in an ectopic site if a consistent supply of progenitor cells and/or growth factors can be ensured over a longer duration.

Knowledge and perceptions of Australian postgraduate veterinary students prior to formal education of antimicrobial use and antimicrobial resistance.

Antimicrobial resistance (AMR) is widely perceived as a threat to human and animal health and a significant One Health issue with extensive and complex factors contributing to its occurrence and spread. Previous studies have surveyed human and animal health professionals to determine their perceptions regarding AMR and antimicrobial use (AMU). There are limited studies exploring the understanding of veterinary students despite their critical role as future antimicrobial prescribers. A cross-sectional survey was administered to an entire cohort of Doctor of Veterinary Medicine Year 2 (DVM2) students (n = 136) to investigate their knowledge and perceptions regarding AMR and AMU prior to formal education on this issue. Ninety students (66.2% of the cohort) completed the survey. There was overwhelming agreement regarding the immediacy of the problem, with 84.4% of students indicating that 'We must take action on AMR'. Despite more than 94.4% of students correctly defining AMR, specific knowledge regarding AMR impact, contributory causes to AMR and strategies to solve the challenge of AMR was variable. Most students perceived livestock producers to have a significant role in the perpetuation of AMR due to AMU for prophylaxis (71.1% substantial/moderate contribution) and treatment (56.7% substantial/moderate contribution). Over a third of respondents (37.8%) were unsure if AMR could spread from animals to humans. Respondents perceived that various groups (dentists, doctors, veterinarians, professional organisations) are all important in ameliorating the issue of AMR. The implementation of restrictive measures to reduce veterinary prescription of antimicrobials was viewed as less important than strategies involving education, hygiene, surveillance, and guideline development/availability. To encourage the development of good antimicrobial stewardship (AMS) practices, professional veterinary education needs to foster an understanding of the scientific, behavioural and social issues that contribute to AMR and inappropriate AMU, as well as prescribers' personal contribution to AMR perpetuation and amelioration.

Health-related quality of life in maxillectomy patients undergoing dentoalveolar rehabilitation.

OBJECTIVES: Surgical resection of the maxilla impairs aesthetics, speech, swallowing, and mastication. Maxillary reconstruction is increasingly performed with virtual surgical planning (VSP) to enhance functional dental rehabilitation with a conventional denture or osseointegrated implants. The aim of this study was to determine whether dental status and VSP is associated with health-related quality of life (HRQOL) and function in patients who have undergone maxillectomy. MATERIALS AND METHODS: A cross-sectional study was conducted among patients who underwent free flap reconstruction or obturation of the maxilla between July 2009 and December 2020. The FACE-Q Head and Neck Cancer (FACE-Q) module, M.D. Anderson Dysphagia Inventory (MDADI), and Speech Handicap Index (SHI) were used to evaluate HRQOL. RESULTS: Forty-three patients (response rate 59%) completed questionnaires and 48% underwent dental rehabilitation. In Okay Class II and III defects, adjusting for the effect of radiotherapy and time from surgery, there was a positive association between denture status and FACE-Q smiling (p = 0.020), eating (p = 0.012), smiling (p = 0.015), and MDADI global (p = 0.015), emotional (p = 0.027), functional (p = 0.028), and composite (p = 0.029) scores. VSP was associated with FACE-Q swallowing (p = 0.005), drooling (p = 0.030), eating (p = 0.008), smiling (p = 0.021), MDADI global (p = 0.017), emotional (p = 0.041), functional (p = 0.040), composite (p = 0.038), and SHI total scores (p = 0.042). CONCLUSIONS: Dentoalveolar rehabilitation and VSP were associated with higher HRQOL scores relating to eating and drinking, smiling, and speaking.

Effect of Radiotherapy on Functional and Health-Related Quality of Life Outcomes after Jaw Reconstruction.

Long-term health-related quality of life (HRQOL) and functional outcomes following mandibular and maxillary reconstruction are lacking. To determine these outcomes, a cross-sectional study of patients with a history of cancer who underwent jaw reconstruction was undertaken. Participants were identified from a database of jaw reconstruction procedures at the Chris O'Brien Lifehouse (Sydney, Australia). Eligible patients had at least one month follow-up, were aged ≥18 years at surgery, and had history of malignancy. HRQOL was measured using the FACE-Q Head and Neck Cancer Module (FACE-Q H&N). Functional outcomes were measured using the FACE-Q H&N, MD Anderson Dysphagia Inventory (MDADI) and Speech Handicap Index (SHI). Ninety-seven questionnaires were completed (62% response rate). Mean age of respondents was 63.7 years, 61% were male, and 64% underwent radiotherapy. Treatment with radiotherapy was associated with worse outcomes across 10/14 FACE-Q H&N scales, three MDADI subscales and one composite score, and the SHI. Mean differences in scores between irradiated and non-irradiated patients exceeded clinically meaningful differences for the MDADI and SHI. Issues with oral competence, saliva, speaking, and swallowing worsened with increasing time since surgery. Younger patients reported greater concerns with appearance, smiling, speaking, and cancer worry. Women reported greater concerns regarding appearance and associated distress. History of radiotherapy substantially impacts HRQOL and function after jaw reconstruction. Age at surgery and gender were also predictors of outcomes and associated distress. Pre-treatment counselling of patients requiring jaw reconstruction may lead to improved survivorship for patients with head and neck cancer.

Maxillofacial reconstruction with prefabricated prelaminated osseous free flaps.

BACKGROUND: The prefabricated fibula flap is an advanced method of occlusal-based reconstruction that combines placement of osseointegrated dental implants with prelamination, using a split skin graft on the fibula, weeks prior to the definitive reconstruction. This approach is resource intensive but has several advantages including eliminating the delay from reconstruction to dental rehabilitation. METHODS: A retrospective cohort study of all prefabricated fibula flaps used for mandible and maxillary reconstruction from 2012 to 2020 was performed. Outcome measures were implant survival, implant utilization and functional dental rehabilitation. RESULTS: A total of 17 prefabricated fibula flaps were performed including two analogue and 15 digital plans. There were nine maxillary and eight mandibular reconstructions, of which 11 were primary and seven were secondary. There were no free flap failures. A total of 65 implants were placed (average 3.8, median 3 implants). There was one implant failure at 6 years giving a 1.5% failure rate. There was 91% implant utilization and 94% functional dental rehabilitation. CONCLUSION: The prefabricated fibula flap provides outstanding dental rehabilitation in well-selected patients.

Occlusal-based planning for dental rehabilitation following segmental resection of the mandible and maxilla.

Reconstruction of the maxilla and mandible incorporating a dental prosthesis supported by dental implants is a complex process but has tremendous benefit to patient rehabilitation following ablative procedures. This study presents a protocol that can be used to aid other institutions to provide the highest standard of reconstruction.

Dentoalveolar outcomes in maxillary reconstruction: A retrospective review of 85 maxillectomy reconstructions.

BACKGROUND: Although microvascular free flaps are often used to reconstruct maxillary defects, dentoalveolar rehabilitation is arguably less common despite its importance to midface function and aesthetics. The aim of this study is to review the contemporary management of maxillary defects in a single quaternary referral institution to identify factors that assist or impede dentoalveolar rehabilitation. METHODS: A retrospective review of maxillary reconstructions performed between February 2017 and December 2020 was performed. Patient characteristics, defect classification, operative techniques, complications and dentoalveolar outcomes were recorded. RESULTS: A total of 85 maxillary reconstructions were performed in 73 patients. Of the 64 patients where dental rehabilitation was required, 31 received a functional denture (48%) with 24 (38%) being implant-retained. Significant predictors of successful rehabilitation included the use of virtual surgical planning (VSP; 86% vs. 25%, p < 0.001), preoperative prosthodontic assessment (82% vs. 21%, p < 0.001), prefabrication (100% vs. 40%, p = 0.002) and use of the zygomatic implant perforator flap technique (100% vs. 39%, p = 0.001). Preoperative prosthodontic consultation was associated with 21-fold increase in the odds of rehabilitation (odds ratio 20.9, 95% confidence interval 6.54-66.66, p < 0.005). CONCLUSION: Preoperative prosthodontic evaluation, VSP and reconstructive techniques developed to facilitate implant placement are associated with increased dental rehabilitation rates. Despite using an institutional algorithm, functional dentures are frequently prevented by factors including soft tissue constraints, disease recurrence and patient motivation.

Opportunities and challenges to improving antibiotic prescribing practices through a One Health approach: results of a comparative survey of doctors, dentists and veterinarians in Australia.

OBJECTIVES: To explore and compare the knowledge, attitudes and experiences of doctors, dentists and veterinarians (as prescribers) in relation to antibiotic use and antibiotic resistance (AbR), and to consider the implications of these for policy-making that support a One Health approach. DESIGN: A cross-sectional survey conducted online. SETTING: Doctors, dentists and veterinarians practising in primary, secondary or tertiary care in Australia. PARTICIPANTS: 547 doctors, 380 dentists and 403 veterinarians completed the survey. MAIN OUTCOME MEASURES: Prescribers' knowledge, attitudes and perceptions of AbR, the extent to which a range of factors are perceived as barriers to appropriate prescribing practices, and perceived helpfulness of potential strategies to improve antibiotic prescribing in practice. RESULTS: There was substantial agreement across prescriber groups that action on AbR is required by multiple sectors and stakeholders. However, prescribers externalised responsibility to some extent by seeing the roles of others as more important than their own in relation to AbR. There were common and context-specific barriers to optimal prescribing across the prescriber groups. Prescriber groups generally perceived restrictive policies as unhelpful to supporting appropriate prescribing in their practice. CONCLUSIONS: The results have implications for implementing a One Health approach that involves doctors, dentists and veterinarians as key players to tackling the crisis of AbR. The findings are that (1) prescribers understand and are likely receptive to a One Health policy approach to AbR, (2) policy development should be sensitive to barriers that are specific to individual prescriber groups and (3) the development and introduction of interventions that might be perceived as reducing prescriber autonomy will need to be carefully designed and implemented.

Angled Implant Design to Accommodate Screw-retained Implant-supported Prostheses.

Anatomical constraints at implant sites often precipitate a conflict between surgical and prosthodontic prerequisites for screw retention of implantsupported prostheses. This article discusses use of a dual-axis implant designed to help clinicians overcome these challenges by facilitating accuracy of surgical placement and prosthetic simplicity, as well as improving biomechanics and enhancing esthetics.

Surgical modifications to the Brånemark zygomaticus protocol in the treatment of the severely resorbed maxilla: a clinical report.

PURPOSE: The Zygomaticus dental implant, designed by Nobel Blocare, was developed for the treatment of the severely resorbed maxilla. Brånemark has reported an overall success rate of 97.6% with the placement of 183 implants over the last 12 years. The purpose of this article was to present a modification to the original Brånemark surgical approach to achieve better access and optimal Implant placement. MATERIALS AND METHODS: There are parameters within the patient's resorbed skeletal frame that guide the surgical placement of the currently used Implant However, there are shortcomings in the current surgical protocol. This report describes a simplified surgical approach in 45 patients (77 implants) using an Implant with a modified head angulation of 55 degrees and a placement appliance to assist the surgeon in placing the implant as close to the crest of the edentulous ridge as possible. RESULTS: The placement appliance identifies accurately the anatomic constraints of the resorbed skeletal frame that limit implant placement. This, together with the modified surgical protocol, has resulted in improved access and in ideal positioning of the restorative head. DISCUSSION: The present technique allows restorative clinicians to achieve a more ideal restorative result In the posterior maxillary alveolus using the zygomatic implant, while reducing the buccal cantilever, improving tongue space, and access for maintenance. CONCLUSION: By placing the implant closer to the crest of the alveolar ridge using the placement appliance and an implant with a 55-degree head, the emergence of the restorative head and resultant buccal cantilever can be reduced by as much as 20%.

A comparison of the accuracy of polyether, polyvinyl siloxane, and plaster impressions for long-span implant-supported prostheses.

PURPOSE: The purpose of this study was to compare the capacity of different impression materials to accurately reproduce the positions of five implant analogs on a master model by comparing the resulting cast with the stainless steel master model. The study was motivated by the knowledge that distortions can occur during impression making and the pouring of casts and that this distortion may produce inaccuracies of subsequent restorations, especially long-span castings for implant superstructures. MATERIALS AND METHODS: The master model was a stainless steel model with five implant analogs. The impression materials used were impression plaster (Plastogum, Harry J Bosworth), a polyether (Impregum Penta, 3M ESPE), and two polyvinyl siloxane (PVS) materials (Aquasil Monophase and Aquasil putty with light-body wash, Dentsply). Five impressions were made with each impression material and cast in die stone under strictly controlled laboratory conditions. The positions of the implants on the master model, the impression copings, and the implant analogs in the subsequent casts were measured using a coordinate measuring machine that measures within 4 µm of accuracy. RESULTS: Statistical analyses indicated that distortion occurred in all of the impression materials, but inconsistently. The PVS monophase material reproduced the master model most accurately. Although there was no significant distortion between the impressions and the master model or between the impressions and their casts, there were distortions between the master model and the master casts, which highlighted the cumulative effects of the distortions. The polyether material proved to be the most reliable in terms of predictability. The impression plaster displayed cumulative distortion, and the PVS putty with light body showed the least reliability. CONCLUSIONS: Some of the distortions observed are of clinical significance and likely to contribute to a lack of passive fit of any superstructure. The inaccuracy of these analog materials and procedures suggested that greater predictability may lie in digital technology.

The three-dimensional casting distortion of five implant-supported frameworks.

The aim of this study was to assess three-dimensional distortion in cast full-arch, screw-retained titanium implant frameworks. A conventional commercial laboratory one-piece casting was used implementing the lost-wax technique. Five wax patterns were fabricated on a die-stone cast poured from a plaster impression of a five-implant brass analog. A reflex microscope was used to determine the three-dimensional casting error. Significant differences were found in distortion between wax patterns and castings, which, given the need to keep within 150 microm of misfit for passivity, were larger than the wax frameworks by between 416 and 477 microm. The greatest distortion occurred at the terminal implant abutments and in the vertical dimensions, but the distortion was inconsistent, indicating its three-dimensional nature. It is doubtful whether any conventionally cast titanium framework can be made to the degree of accuracy required to fit passively on its abutments because of the multiple variables inherent in this process.

A protocol for maxillary reconstruction following oncology resection using zygomatic implants.

The purpose of this clinical report is to present a surgical and prosthodontic reconstructive protocol for 20 patients who underwent maxillary resection following malignancy to the head and neck region. This protocol was developed over a period of 7 years while treating a series of 20 maxillary resections due to oncology. Patients were reconstructed prosthodontically using fixed-removable overdentures or fixed prostheses, with and without separate obturators. The treatment protocol includes a comprehensive diagnostic phase, resection surgery with immediate implant placement and temporary obturation, post resection evaluation, and prosthodontic rehabilitation. Treatment periods ranged from 6 to 96 months and success was evaluated using strict clinical, radiologic, esthetic, and functional criteria. Postsurgical radiology was undertaken at 6 monthly intervals. Almost all maxillary defects resulting from anatomic disruption of the maxillofacial complex can be well rehabilitated functionally and esthetically using this protocol in conjunction with standard implantology and fixed/fixed-removable prosthodontic principles. This protocol simplifies the rehabilitation and management of these defects by reducing surgical intervention, hosptilization, postoperative morbidity and treatment time, and prosthodontic procedural complications.