Changing trends in the microvascular reconstruction and oral rehabilitation following maxillary cancer.

PURPOSE: The maxillectomy defect is complex and the best means to achieve optimal reconstruction, and dental rehabilitation is a source of debate. The refinements in zygomatic implant techniques have altered the means and speed by which rehabilitation can be achieved and has also influenced the choice regarding ideal flap reconstruction. The aim of this study is to report on how the method of reconstruction and oral rehabilitation of the maxilla has changed since 1994 in our Institution, and to reflect on case mix and survival. METHODS: Consecutive head and neck oncology cases involving maxillary resections over a 27-year period between January 1994 and November 2020 were identified from hospital records and previous studies. Case note review focussed on clinical characteristics, reconstruction, prosthetic rehabilitation, and survival. RESULTS: There were 186 patients and the tumour sites were: alveolus for 56% (104), hard palate for 19% (35), maxillary sinus for 18% (34) and nasal for 7% (13). 52% (97) were Brown class 2 defects. Forty-five patients were managed by obturation and 78% (142/183) had free tissue transfer. The main flaps used were radial (52), anterolateral thigh (27), DCIA (22), scapula (13) and fibula (11). There were significant changes over time regarding reconstruction type, use of primary implants, type of dental restoration, and length of hospital stay. Overall survival after 24 months was 64% (SE 4%) and after 60 months was 42% (SE 4%). CONCLUSION: These data reflect a shift in the reconstruction of the maxillary defect afforded by the utilisation of zygomatic implants.

HOPON (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis): A Randomized Controlled Trial of Hyperbaric Oxygen to Prevent Osteoradionecrosis of the Irradiated Mandible After Dentoalveolar Surgery.

PURPOSE: Hyperbaric oxygen (HBO) has been advocated in the prevention and treatment of osteoradionecrosis (ORN) of the jaw after head and neck radiation therapy, but supporting evidence is weak. The aim of this randomized trial was to establish the benefit of HBO in the prevention of ORN after high-risk surgical procedures to the irradiated mandible. METHODS AND MATERIALS: HOPON was a randomized, controlled, phase 3 trial. Participants who required dental extractions or implant placement in the mandible with prior radiation therapy >50 Gy were recruited. Eligible patients were randomly assigned 1:1 to receive or not receive HBO. All patients received chlorhexidine mouthwash and antibiotics. For patients in the HBO arm, oxygen was administered in 30 daily dives at 100% oxygen to a pressure of 2.4 atmospheres absolute for 80 to 90 minutes. The primary outcome measure was the diagnosis of ORN 6 months after surgery, as determined by a blinded central review of clinical photographs and radiographs. The secondary endpoints included grade of ORN, ORN at other time points, acute symptoms, pain, and quality of life. RESULTS: A total of 144 patients were randomized, and data from 100 patients were analyzed for the primary endpoint. The incidence of ORN at 6 months was 6.4% and 5.7% for the HBO and control groups, respectively (odds ratio, 1.13; 95% confidence interval, 0.14-8.92; P = 1). Patients in the hyperbaric arm had fewer acute symptoms but no significant differences in late pain or quality of life. Dropout was higher in the HBO arm, but the baseline characteristics of the groups that completed the trial were comparable between the 2 arms. CONCLUSIONS: The low incidence of ORN makes recommending HBO for dental extractions or implant placement in the irradiated mandible unnecessary. These findings are in contrast with a recently published Cochrane review and previous trials reporting rates of ORN (non-HBO) of 14% to 30% and challenge a long-established standard of care.

HOPON (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis): a randomised controlled trial of hyperbaric oxygen to prevent osteoradionecrosis of the irradiated mandible: study protocol for a randomised controlled trial.

BACKGROUND: Osteoradionecrosis of the mandible is the most common serious complication of radiotherapy for head and neck malignancy. For decades, hyperbaric oxygen has been employed in efforts to prevent those cases of osteoradionecrosis that are precipitated by dental extractions or implant placement. The evidence for using hyperbaric oxygen remains poor and current clinical practice varies greatly. We describe a protocol for a clinical trial to assess the benefit of hyperbaric oxygen in the prevention of osteoradionecrosis during surgery on the irradiated mandible. METHODS/DESIGN: The HOPON trial is a phase III, randomised controlled, multi-centre trial. It employs an unblinded trial design, but the assessment of the primary endpoint, i.e. the diagnosis of osteoradionecrosis, is assessed on anonymised clinical photographs and radiographs by a blinded expert panel. Eligibility is through the need for a high-risk dental procedure in the mandible where at least 50-Gy radiotherapy has been received. Patients are randomised 1:1 to hyperbaric oxygen arm (Marx protocol) : control arm, but both groups receive antibiotics and chlorhexidine mouthwash. The primary endpoint is the presence of osteoradionecrosis at 6 months following surgery, but secondary endpoints include other time points, acute symptoms and pain, quality of life, and where implants are placed, their successful retention. DISCUSSION: The protocol presented has evolved through feasibility stages and through analysis of interim data. The classification of osteoradionecrosis has undergone technical refinement to ensure that robust definitions are employed. The HOPON trial is the only multi-centre RCT conducted in this clinical setting despite decades of use of hyperbaric oxygen for the prevention of osteoradionecrosis. TRIAL REGISTRATION: European Clinical Trials Database, ID: EudraCT200700622527 . First registered on 5 November 2007.

Refining the definition of mandibular osteoradionecrosis in clinical trials: The cancer research UK HOPON trial (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis).

INTRODUCTION: Mandibular osteoradionecrosis (ORN) is a common and serious complication of head and neck radiotherapy for which there is little reliable evidence for prevention or treatment. The diagnosis and classification of ORN have been inconsistently and imprecisely defined, even in clinical trials. METHODS: A systematic review of diagnosis and classifications of ORN with specific focus on clinical trials is presented. The most suitable classification was evaluated for consistency using blinded independent review of outcome data (clinical photographs and radiographs) in the HOPON trial. RESULTS: Of 16 ORN classifications found, only one (Notani) appeared suitable as an endpoint in clinical trials. Clinical records of 217 timepoints were analysed amongst 94 randomised patients in the HOPON trial. The only inconsistency in classification arose where minor bone spicules (MBS) were apparent, which occurred in 19% of patients. Some trial investigators judged MBS as clinically unimportant and not reflecting ORN, others classified as ORN based on rigid definitions in common clinical use. When MBS was added as a distinct category to the Notani classification this ambiguity was resolved and agreement between observers was achieved. DISCUSSION: Most definitions and clinical classifications are based on retrospective case series and may be unsuitable for prospective interventional trials of ORN prevention or treatment. When ORN is used as a primary or secondary outcome in prospective clinical trials, the use of Notani classification with the additional category of MBS is recommended as it avoids subjectivity and enhances reliability and consistency of reporting.

Practical considerations for treatment of patients taking bisphosphonate medications: an update.

UNLABELLED: Osteonecrosis of the jaw--bisphosphonate-related (ONJ-BR) is an established clinical entity associated with both oral and intravenous (IV) bisphosphonate therapy. An update for the general practitioner on the indications for bisphosphonate therapy and both risk assessment and prevalence of ONJ-BR is provided. Management philosophy within a local unit is illustrated through four brief case studies. It is not uncommon to encounter patients on bisphosphonate therapy in the dental practice environment; the vast majority of these will be on oral bisphosphonates as part of their management for osteoporosis. The risk of developing ONJ-BR is rare in these patients compared with those receiving treatment for skeletal complications associated with cancer, many of whom will be managed with IV bisphosphonates. Although rare, it is important to recognize the potential risk of ONJ-BR. Whilst most patients on oral bisphosphonates can be managed no differently from other patients, it should be appreciated that the relative risk of long-term cumulative exposure, comorbidity and other factors are still to be determined. Surgical intervention and extractions can place the patient at risk of ONJ-BR and vigilance is necessary to ensure that healing progresses satisfactorily. Early referral to the local hospital should be sought if there is cause for concern. CLINICAL RELEVANCE: Although the risk of ONJ-BR is low in non-oncological indications, it is important to be aware that it exists and to know how the risk may be minimized.

Hyperbaric oxygen in the management of late radiation injury to the head and neck. Part II: prevention.

Osteoradionecrosis (ORN) of the jaws is a feared complication of treatment for head and neck cancer, and understandably much attention has been given to its prevention; good oral hygiene, careful preventative dental care, and extractions done before radiotherapy have been highlighted by many authors. Such necessary dental extractions when the healing capacity of the bone is normal will, it is hoped, reduce the incidence of subsequent ORN. This review considers the optimal dental management of patients before radiotherapy as well as the evidence base for treatment with hyperbaric oxygen (HBO) before extractions in patients who have had radiotherapy.

The responsiveness of the Liverpool Oral Rehabilitation Questionnaire (LORQ): a pilot study.

This study aimed to evaluate the responsiveness of denture patients to the Liverpool Oral Rehabilitation Questionnaire (LORQ). Changes in scores for 20 core items completed from 2000 to 2005 by 16 patients both before and after oral rehabilitation were assessed. The median age of respondents was 68 years and the median time between questionnaires was 2.6 years. Results indicated that masticatory efficiency impacted both food choice (P = .03) and social life (P = .06). After rehabilitation there was less worry about maxillary prostheses falling out (P = .07), less embarrassment while conversing (P = .02), and less worry about losing self-confidence from embarrassment caused by dentures (P = .06). Also, drooling problems deteriorated (P = .03). This exploratory study reports encouraging findings, but a larger prospective multicenter study is required to determine the responsiveness of the current version of the LORQ (version 3).

The further development and validation of the Liverpool Oral Rehabilitation Questionnaire (LORQ) version 3: a cross-sectional survey of patients referred to a dental hospital for removable prostheses replacement.

STATEMENT OF PROBLEM: The Liverpool Oral Rehabilitation Questionnaire (LORQ) is a health-related quality of life instrument assessing the impact of oral rehabilitation on patients' health-related quality of life (HRQOL) following treatment for oral cancer. The small number of patients wearing prostheses in previous studies limited the validation of the denture/denture satisfaction part of the questionnaire. PURPOSE: The purpose of this study was to further validate the LORQ by obtaining HRQOL data from patients requiring replacement dentures. MATERIAL AND METHODS: The LORQv3, together with items assessing mood and anxiety, was administered with the Oral Health Impact Profile 14-item (OHIP-14) questionnaire to 104 consecutive patients, between the ages of 40 and 79, referred by their general dentists to the department of prosthodontics at the Liverpool University Dental Hospital for replacement of removable prostheses between November 2004 and June 2005. The Mann-Whitney and Kruskal-Wallis tests compared scores between patient groups. Internal consistency was measured by Cronbach's alpha. Spearman's correlation investigated associations between items on the LORQv3 and items from the OHIP-14. Test-retest was measured by the kappa coefficient, weighted by applying standard weights according to the number of categories in error. RESULTS: Patients wearing complete dentures in 1 or both arches generally scored worse for oral function and mandibular denture problems/satisfaction than patients wearing removable partial dentures. Thirty-three percent of patients were somewhat or extremely depressed, 25% were anxious or very anxious, and 15% were both depressed and anxious. CONCLUSIONS: The denture section of the LORQv3 identified expected differences among various patient subgroups in this cohort confirmed by similar findings for the OHIP-14 and the literature. Thus, this part of the LORQv3 referring to dentures and patient satisfaction demonstrated good construct and criterion validity.

Ventilatory control during intermittent high-intensity exercise in humans.

Intermittent supra-maximal cycling of varying work: recovery durations was used to explore the kinetics of respiratory compensation for the metabolic acidosis of high-intensity exercise (> lactate threshold, thetaL). For a 10:20s duty-cycle, blood [lactate] ([L-]) was not increased, and there was no evidence of respiratory compensation (RC); i.e, no increase in the ventilation (VE)-CO2 output (Vco2) slope, nor fall in end-tidal PCO2 (PETCO2). For longer duty-cycles, [L-] was elevated, stabilizing (30s:60 s exercise) or rising progressively (60s:120s, 90s: 180s exercise). In addition, Vco2 and VE now oscillated with WR, with evidence of delayed RC (progressive increase in VE - VCO2 slope; decrease in PETCO2) being more marked with longer duty-cycles. These results, which extend earlier findings with supra- thetaL step and ramp exercise, are not consistent with an appreciable contribution to RC from zero-order central command or peripheral neurogenesis. The reasons for the slow RC kinetics are unclear, but may reflect in part the H(+)-signal transduction properties of carotid chemoreceptors.

A survey of consultants and specialists in restorative dentistry on their use of health-related quality of life questionnaires.

A national survey of 178 consultants and specialists in restorative dentistry was undertaken to assess their use of health-related quality of life questionnaires in patients having oral rehabilitation following treatment for oral cancer. The response rate was 74% (132). 42% treated patients following oral cancer, 25% forming part of the head and neck multidisciplinary team. Only 19% had ever used questionnaires. Main barriers to their use were lack of experience with evaluation (27%), lack of staff to administer questionnaires (21%) and insufficient time (18%). Few clinicians thought that questionnaires were not clinically relevant or that no suitable instrument existed. In order to facilitate the use of an oral rehabilitation-specific questionnaire in clinical practice there needs to be greater awareness of the potential benefits, training in the process and the means of reducing the administrative burden.

Management of peri-implant bone loss using guided bone regeneration: a clinical report.

This clinical report presents a patient who developed peri-implant bone loss around 2 maxillary endosseous root-form implants after restoration with cement-retained single crowns. Significant localized bone loss occurred around 1 of the implants due to retained excess cement. Reparative treatment consisted of a guided bone regeneration technique. Following a 9-month period of submerged healing, the implants were re-exposed and restored to complete function.