The effect of common dental fixtures on treatment planning and delivery for head and neck intensity modulated proton therapy.

PURPOSE: Proton treatment plan perturbation by common dental fixtures such as amalgams (Am) and porcelain-fused-to-metal (PFM) crowns has, to date, been uncharacterized. Previous studies have been conducted to determine the physical effect of these materials within the beam path for single spots, but their effects on complex treatment plans and clinical anatomy have not yet been quantified. The present manuscript aims to study the effect of Am and PFM fixtures on proton treatment planning in a clinical setting. METHODS: An anthropomorphic phantom with removable tongue, maxilla, and mandible modules was simulated on a clinical computed tomography (CT) scanner. Spare maxilla modules were modified to include either a 1.5 mm depth central groove occlusal amalgam (Am) or a porcelain-fused-to-metal (PFM) crown, implanted on the first right molar. Modified tongue modules were 3D printed to accommodate several axial or sagittal oriented pieces of EBT-3 film. Clinically representative spot-scanning proton plans were generated in Eclipse v.15.6 using the proton convolution superposition (PCS) algorithm v.15.6.06 using a multi-field optimization (MFO) technique with the goal of delivering a uniform 54 Gy dose to a clinical target volume (CTV) typical of a base-of-tongue (BoT) treatment. A typical geometric beam arrangement of two anterior oblique (AO) beams and a posterior beam was employed. Plans optimized without any material overrides were delivered to the phantom A) without implants; B) with Am fixture; or C) with PFM crown. Plans were also reoptimized and delivered with inclusion of material overrides to equate relative stopping power of the fixture with that of a previously measured result. RESULTS: Plans exhibit slightly greater dose weight towards AO beams. The optimizer accounted for inclusion of fixture overrides by increasing beam weights to the beam closest to the implant. Film measurements exhibited cold spots directly within the beam path through the fixture in plans with and without overridden materials. Cold spots were somewhat mitigated in plans including overridden materials in the structure set but were not entirely eliminated. Cold spots associated with Am and PFM fixtures were quantified at 17% and 14% for plans without overrides, respectively, and 11% and 9% with using Monte Carlo simulation. Compared with film measurements and Monte Carlo simulation, the treatment planning system underestimates the dose shadowing effect in plans including material overrides. CONCLUSIONS: Dental fixtures create a dose shadowing effect directly in line with the beam path through the material. This cold spot is partially mitigated by overriding the material to measured relative stopping powers. Due to uncertainties in modeling perturbation through the fixture, the magnitude of the cold spot is underestimated using the institutional TPS when compared to measurement and MC simulation.

Utilizing orthodontic appliances to retain and disguise a pediatric maxillary obturator throughout growth.

Unique challenges are encountered when providing an obturator for an adolescent patient. Challenges include the need to modify the obturator throughout growth, engaging the mixed dentition or partially erupted teeth with minimal undercuts, the psychosocial challenges of an actively maturing patient, and the possible need for coincidental orthodontic therapy. This clinical report describes the ongoing rehabilitation of a patient who presented at the age of 10 with a biopsy-confirmed palatal mucoepidermoid carcinoma. Incorporating orthodontic brackets for retention of innovative adjustable obturator clasps allowed for the favorable function of the obturator prosthesis and the ability to alter the prosthesis over time.

Fabrication of custom oral positioning devices in head and neck proton radiotherapy.

With complex head and neck diseases that closely approximate crucial organs or have advanced spread and cannot be surgically resected, intensity modulated proton beam radiotherapy is favored due to its superior dose targeting through magnetic manipulation of the proton energy. A radiation mask and an oral positioning device immobilize craniofacial, cervical, and oral structures for accurate and reliable radiation delivery. Widely available prefabricated thermoplastic oral positioning devices are manufactured in standardized forms and materials that unpredictably affect the proton beams' pathways and range. This technique article showcases a workflow that combines analog and digital dental techniques to produce a customized 3D-printed oral positioning device within 2 appointments.

Serializing prosthetic rehabilitations to minimize time for patients with a maxillectomy without dentoalveolar support.

An oral prosthesis can help maintain a sense of normalcy by preserving psychosocial and physiologic function in the aftermath of a maxillary resection. Rehabilitating the resulting defect in a timely manner requires strategic choices in treatment sequencing and prosthetic design. This clinical report describes the process of fabricating a series of removable and implant-retained prostheses to minimize a patient's time without the restoration of critical craniofacial structures.

Prosthetic Rehabilitation with Amyloidosis of the Tongue.

Amyloidosis of the tongue can result in significant and irreversible alterations of tooth position and function due to prolonged application of imbalanced force on the teeth by the enlarged tongue. Due to the rarity of this oral form of systemic disease, little has been elucidated on management of the resulting impaired oral function. While surgery can address the size of the tongue, it carries significant morbidities, enlargement can recur, and does not address adverse tooth positioning. Prosthetic rehabilitation can more aptly restore oral function but it also needs to be tailored based on the patient's expectations and goals as well as biologic and mechanical parameters of treatment. This report discusses an effective and noninvasive application of a tooth-supported, removable prosthesis with an onlay occlusal design to restore occlusion, speech, and esthetics in a patient with tongue-based amyloidosis.

Association Between Early Implant Failure and Prosthodontic Characteristics.

PURPOSE: To identify associations between early implant failure and prosthodontic characteristics that could be used to guide subsequent continuous quality improvement efforts of patient care. MATERIALS AND METHODS: An implant-level analysis was performed in which data were abstracted from a prospective clinical database of all adult patients treated with implants and followed up from January 2000 through December 2014 at the Department of Dental Specialties at Mayo Clinic in Rochester, Minnesota. These data were used to determine time to implant failure. Associations between prosthodontic characteristics and early implant failure were evaluated with Cox proportional hazards regression models and summarized with hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Among 8762 implants in 2787 patients, 395 (4.5%) failed within the first year of placement at a mean (SD) of 127 (97) days (range, 2-364 days). Univariable analysis showed no associations between early implant failure and use of a cover screw, prosthesis, or definitive or provisional prosthesis at implant placement. Three of 25 single crowns failed, and use of a single crown was significantly associated with early implant failure (HR, 3.94; 95% CI, 1.08-14.35; P = 0.04). This study identified no significant associations between prosthodontic characteristics identified after implant placement and early implant failure. CONCLUSIONS: Use of a prosthesis at implant placement, use of a definitive or provisional prosthesis, and early mechanical complications were not associated with increased risk of early implant failure. Quality improvement efforts should focus on aspects of decision making that aim to decrease surgical complications.

Early Implant Failure Associated With Patient Factors, Surgical Manipulations, and Systemic Conditions.

PURPOSE: Systematic monitoring of important clinical outcomes is increasingly important for health-care decision making, especially in the context of continuous quality improvement. Dental implant failure within the first year (early failure) has been previously shown to be more common than subsequent failure. The purpose of this study was to identify associations between early implant failure and patient factors, surgical manipulations, and systemic conditions. MATERIALS AND METHODS: The authors retrospectively identified the records of consecutive adult patients with dental implants seen between 2000 and 2014 in the Department of Dental Specialties, at the Mayo Clinic. Demographic, surgical, and medical data were extracted from the database and individual medical records to determine time to first implant failure. Cox proportional hazards regression models were used to assess associations of demographic, surgical, and systemic conditions with implant failure during the first year post-implantation, summarized as hazard ratio (HR) (95% confidence interval [CI]). RESULTS: Among 8540 implants identified during the study period, 362 (4.2%) failed within the first year of placement at a mean (SD) of 129 (96) days after placement. On univariate analysis, most candidate predictors were not shown to influence first-year failure. Preplacement surgical manipulations associated with increased early implant failure were bone augmentation only (HR, 1.45; 95% CI, 1.02-2.05; p = 0.04), socket preservation (HR, 2.67; 95% CI, 1.33-5.38; p = 0.006), and xenogenic material (HR, 2.12; 95% CI, 1.11-4.04; p = 0.02). Alveoloplasty only at placement was associated with decreased early implant failure (HR, 0.33; 95% CI, 0.17-0.65; p = 0.001). Overall, 318 implants (3.7%) had surgical complications within the first year of placement at a mean (SD) of 110 (114) days after placement; any surgical complication was significantly associated with early implant failure (hazard ratio, 15.84; 95% CI, 11.10-22.61; p < 0.001). After adjustment for age, sex, and implant era, no single or multiple medical condition(s) and no single or multiple medication(s) increased patient risk of implant failure in the first year after placement. CONCLUSIONS: These findings support a targeted effort to reduce the incidence of surgical complications to reduce early failure of dental implants.

Mean Oral Cavity Organ-at-Risk Dose Predicts Opioid Use and Hospitalization during Radiotherapy for Patients with Head and Neck Tumors.

BACKGROUND: Approximately 75% of all head and neck cancer patients are treated with radiotherapy (RT). RT to the oral cavity results in acute and late adverse events which can be severe and detrimental to a patient's quality of life and function. The purpose of this study was to explore associations between RT dose to a defined oral cavity organ-at-risk (OAR) avoidance structure, provider- and patient-reported outcomes (PROs), opioid use, and hospitalization. METHODS: This was a retrospective analysis of prospectively obtained outcomes using multivariable modeling. The study included 196 patients treated with RT involving the oral cavity for a head and neck tumor. A defined oral cavity OAR avoidance structure was used in all patients for RT treatment planning. Validated PROs were collected prospectively. Opioid use and hospitalization were abstracted electronically from medical records. RESULTS: Multivariable modeling revealed the mean dose to the oral cavity OAR was significantly associated with opioid use (p = 0.0082) and hospitalization (p = 0.0356) during and within 30 days of completing RT. CONCLUSIONS: The findings of this study may be valuable in RT treatment planning for patients with tumors of the head and neck region to reduce the need for opioid use and hospitalization during treatment.

Stress and pain response of neonates after spontaneous birth and vacuum-assisted and cesarean delivery.

OBJECTIVE: The objective of the study was to compare the stress response and pain expression of newborns (NBs) in the early postpartum period. STUDY DESIGN: This was a prospective study with 280 NBs enclosed at 3 Swiss university hospitals. Stress response and pain reaction were analyzed according to the mode of delivery: elective cesarean section (ELCS), spontaneous vaginal delivery, and assisted vaginal delivery by vacuum extraction (VE). Saliva cortisol and clinical pain expression were evaluated after delivery and before and after heel prick for metabolic screening. RESULTS: Significant differences were evident during the first 72 hours postpartum with highest nominations in the VE group. Meconium-stained amniotic fluid was the only intrapartum stress factor with an impact on clinical pain expression. CONCLUSION: NBs delivered vaginally show a higher incidence of stress response and pain expression than infants of the ELCS group. The long-term impact of these findings remains to be determined.

Empirical Relative Biological Effectiveness (RBE) for Mandible Osteoradionecrosis (ORN) in Head and Neck Cancer Patients Treated With Pencil-Beam-Scanning Proton Therapy (PBSPT): A Retrospective, Case-Matched Cohort Study.

Purpose: To retrospectively investigate empirical relative biological effectiveness (RBE) for mandible osteoradionecrosis (ORN) in head and neck (H&N) cancer patients treated with pencil-beam-scanning proton therapy (PBSPT). Methods: We included 1,266 H&N cancer patients, of which, 931 patients were treated with volumetric-modulated arc therapy (VMAT) and 335 were treated with PBSPT. Among them, 26 VMAT and 9 PBSPT patients experienced mandible ORN (ORN group), while all others were included in the control group. To minimize the impact of the possible imbalance in clinical factors between VMAT and PBSPT patients in the dosimetric comparison between these two modalities and the resulting RBE quantification, we formed a 1:1 case-matched patient cohort (335 VMAT patients and 335 PBSPT patients including both the ORN and control groups) using the greedy nearest neighbor matching of propensity scores. Mandible dosimetric metrics were extracted from the case-matched patient cohort and statistically tested to evaluate the association with mandibular ORN to derive dose volume constraints (DVCs) for VMAT and PBSPT, respectively. We sought the equivalent constraint doses for VMAT so that the critical volumes of VMAT were equal to those of PBSPT at different physical doses. Empirical RBEs of PBSPT for ORN were obtained by calculating the ratio between the derived equivalent constraint doses and physical doses of PBSPT. Bootstrapping was further used to get the confidence intervals. Results: Clinical variables of age, gender, tumor stage, prescription dose, chemotherapy, hypertension or diabetes, dental extraction, smoking history, or current smoker were not statistically related to the incidence of ORN in the overall patient cohort. Smoking history was found to be significantly associated with the ORN incidence in PBSPT patients only. V40Gy[RBE], V50Gy[RBE], and V60Gy[RBE] were statistically different (p<0.05) between the ORN and control group for VMAT and PBSPT. Empirical RBEs of 1.58(95%CI: 1.34-1.64), 1.34(95%CI: 1.23-1.40), and 1.24(95%: 1.15-1.26) were obtained for proton dose at 40 Gy[RBE=1.1], 50 Gy[RBE=1.1] and 60 Gy[RBE=1.1], respectively. Conclusions: Our study suggested that RBEs were larger than 1.1 at moderate doses (between 40 and 60 Gy[RBE=1.1]) with high LET for mandible ORN. RBEs are underestimated in current clinical practice in PBSPT. The derived DVCs can be used for PBSPT plan evaluation and optimization to minimize the incidence rate of mandible ORN.

Novel Smartphone Game Improves Physical Activity Behavior in Type 2 Diabetes.

INTRODUCTION: Many type 2 diabetes patients show insufficient levels of physical activity and are often unmotivated to change physical activity behaviors. This study investigated whether a newly developed smartphone game delivering individualized exercise and physical activity promotion through an elaborate storyline can generate sustained improvements in daily physical activity (steps/day). STUDY DESIGN: Thirty-six participants were enrolled in this 24-week RCT between August 2016 and April 2018. After baseline assessment, participants were randomized in equal numbers to the intervention or control condition. Data analysis was performed in May-June 2018. SETTING/PARTICIPANTS: Inactive, overweight type 2 diabetes patients, aged 45-70 years, were recruited through advertising and from hospitals and diabetes care centers in the Basel, Switzerland, metropolitan area. INTERVENTION: Participants were instructed to play the innovative smartphone game (intervention group) or to implement the recommendations from the baseline lifestyle counseling (control group) autonomously during the 24-week intervention period. MAIN OUTCOME MEASURES: Primary outcomes were changes in daily physical activity (steps/day); changes in aerobic capacity, measured as oxygen uptake at the first ventilatory threshold; and changes in glycemic control, measured as HbA1c. RESULTS: Daily physical activity increased by an average of 3,998 (SD=1,293) steps/day in the intervention group and by an average of 939 (SD=1,156) steps/day in the control group. The adjusted difference between the two groups was 3,128 steps/day (95% CI=2,313, 3,943, p<0.001). The increase in daily physical activity was accompanied by an improved aerobic capacity (adjusted difference of oxygen uptake at the first ventilatory threshold of 1.9 mL/(kg·min), 95% CI=0.9, 2.9, p<0.001). Glycemic control (HbA1c) did not change over the course of the intervention. CONCLUSIONS: A novel, self-developed smartphone game, delivering multidimensional home-based exercise and physical activity promotion, significantly increases daily physical activity (steps/day) and aerobic capacity in inactive type 2 diabetes patients after 24 weeks. The ability of the game to elicit a sustained physical activity motivation may be relevant for other inactive target groups with chronic diseases. TRIAL REGISTRATION: This study is registered at www.clinicaltrials.gov NCT02657018.