Correction to: Alterations of posterior pharyngeal wall movement during swallowing in postoperative tongue cancer patients: assessment with a videofluoroscopic swallowing study

This study aimed to determine the association between the progressive contraction of the posterior pharyngeal wall and dysphagia in postoperative patients with tongue cancer. A videofluoroscopic swallowing study (VFSS) was performed in 34 patients after tongue cancer surgery. Images were analyzed using a two-dimensional video measurement software. Cases in which the processes on the posterior pharyngeal wall moved downward from the 2nd to 4th vertebral regions were defined as “normal type”, other cases were defined as “abnormal type”. Twenty-four patients showed normal movement of the posterior pharyngeal wall, whereas 10 patients showed the abnormal type. The results showed that there was a significant difference in dysphagia scores between the postoperative swallowing type and swallowing dysfunction score. This implies that dysphagia is related to the movement of the posterior pharyngeal wall after tongue cancer surgery. Furthermore, the extent of resection and stage were significantly different between the normal and abnormal groups in the posterior pharyngeal wall movement. There was also a significant difference between the two groups in terms of the following: whether the tongue base was included in the excision range (p < 0.01), whether neck dissection was performed (p < 0.01), or whether reconstruction was not performed (p < 0.01). VFSS results showed that posterior pharyngeal wall movement was altered after surgery in patients with tongue cancer who had severe dysphagia.

     

Is food particle size a criterion for the initiation of swallowing?

A small study on fifteen subjects found that brazil nut particles always broke down much more rapidly per chew than raw carrot particles. Both foods were swallowed, on average, after similar numbers of chews. However, a relationship was found which suggested that subjects that swallowed after few chews took less for carrots than brazils and vice versa for those that took more chews. An extended study with carrot showed a significant correlation between the rate of size breakdown and the number of chews required for swallowing in dentate subjects (r = 0.69) but not in full denture wearers. The whole sample (n = 79 including six wearers of partial dentures) gave a significant correlation of r = 0.65. It is concluded that some consideration of the physical properties (texture) of foods is necessary before results from this type of study can be interpreted as relevant or not for dentistry.     

Micro-CT observation of rat dental pulp healing after pulpotomy in in vivo study

We report the newly developed Micro-CT, which allows us to observe the individual animal over a long experimental period and to compare changes in pulp tissue in relation to growth and aging without considering individual differences. Further, we used pathological examination to prove similar the result observing from Micro-CT. We have examined wound healing of teeth after pulpotomy in rats, and could clearly observe histopathological changes in the affected teeth and the absorption of temporary filling material and pulp capping agents. In cases with breakage of the dental crown, the CT images agreed with the pathological observations, and it was possible to estimate the time of breakage. In vivo Micro-CT is possible to apply in continuous recording of small experimental animals, such as rats, under anesthesia and the result is sufficiently high. High-quality image was obtained in of the entire head region of the rat. It was suggested that this method can be used for long-term continuous observation of changes in the teeth conditions after pulpotomy in experimental animals. We report the newly developed Micro-CT, which allows us to observe the individual animal over a long experimental period and to compare changes in pulp tissue in relation to growth and aging without considering individual differences.     

Three-dimensional observation of internal structure in the region of mandibular deciduous canine using Micro-CT

The objective of this study is to clarify the changes in the internal structure of the surrounding area in deciduous canine and in relation to the development of successive permanent teeth. We observed the mandibles of the dry skulls of Indian children, using Micro-CT, and measured height of the compact bone at the mandibular base. When the first molars reached the occlusal line in addition to the deciduous dentition stage, the superoinferior position of canine bony crypt located lower than that of other permanent teeth. After this eruption stage, the bony crypts of canine showed inferior growth, resulting in compact substance's resorption of the mandibular base. When the central and lateral incisors reached the occlusal line, resorption of compact substance was advanced, but adjunction was observed after deciduous canine shed. Trabecular bone appeared for some directions in the region of sponge bone. The height of compact bone at the mandibular base was measured to elucidate the changes of the compact substance inside of the mandibular base with advancement of the dental eruption stage. The result of measurements quantitatively showed that the bone resorption advanced to the state of central and lateral incisors reached the occlusal line and adjunction occurred after deciduous canine shed.     

序列调法治疗运动型食物嵌塞的临床观察

目的探讨治疗运动型食物嵌塞的调方法及效果。方法选择邻面接触关系正常的食物嵌塞患者36例为研究对象,分析其咬合面形态及咬合关系,采用序列调方法进行治疗,并培养合理的饮食习惯。序列调法包括：调磨并消除对杵臼式牙尖、加深面发育沟、调磨嵌塞间隙远中牙齿的近中斜面。治疗后1周、2周和6个月复查食物嵌塞情况。结果术后1周,36例患者中有32例的食物嵌塞症状消失,4例症状改善;术后2周,所有患者食物嵌塞症状完全消失;术后半年后复查,并无1例发生食物嵌塞。结论序列调法是治疗某些运动型食物嵌塞的有效方法。     

The influence of thickeners of food on the particle size of boluses: a consideration for swallowing

Odontology - The purpose of this study was to examine the influence of thickeners with different levels of thickness on the sizes of particles in food boluses. In medical and nursing care,...     

International standardisation of the test of masticating and swallowing solids in children

The Test of Masticating and Swallowing Solids (TOMASS) is a validated assessment tool measuring the efficiency of solid bolus intake by four quantitative parameters: discrete bites, masticatory cycles, swallows and time to ingest a single cracker. A normative database for adults (20‐80+ years) has previously been established. The objective of this study was to investigate the applicability and reliability of the TOMASS in children and adolescents (TOMASS‐C) and to establish the normative database for this younger population. We collected data from 638 participants (male: 311, female: 327) in five age groups (4‐18 years) with five different but very similar test crackers in four countries. Significant effects of bolus type (cracker), age group and gender on the TOMASS parameters were identified, requiring stratification of the TOMASS‐C database by these variables. Intra‐rater reliability was excellent (ICC > 0.94) for all parameters; inter‐rater reliability was moderate for “number of swallows” (ICC = 0.54), good for “bites” (ICC = 0.78) and “time” (ICC = 0.82), and excellent for “masticatory cycles” (ICC = 0.96). The “Test of Masticating and Swallowing Solids in Children (TOMASS‐C)” was identified to be a reliable diagnostic tool for the comprehensive measurement of discrete oral stage components of solid bolus ingestion, standardised by a large normative database that covers age groups from preschoolers to young adults. While differences between gender groups were less pronounced than in the adult population, previous results relating to changes in masticatory and swallowing as a function of age are confirmed by our data.     

A new dynamic corrosion test for dental materials

A new laboratory technique has been developed in an effort to simulate the deterioration processes occurring in dental amalgam restorations while they are exposed to attack by the oral environment and simultaneously subjected to biting forces during mastication. This combined mechanical wear and corrosion action may be one of the major contributors to the degradation of dental amalgam restorations. The technique provides the capability of varying and measuring electrochemical and mechanical parameters during a sliding-wear process in a corrosive environment. A high-copper dental amalgam was selected and tested to demonstrate the applicability of the method in evaluating and studying the effects of the combined action of wear and corrosion processes on dental materials. For the particular amalgam material tested in the present study, it was found that sliding-wear significantly lowered its corrosion potential and increased corrosion rates by at least one order of magnitude.     

MI sensor-aided screening system for assessing swallowing dysfunction: application to the repetitive saliva-swallowing test

PurposeAssessment of swallowing dysfunction, particularly the risk of aspiration, is extremely important to clinicians because it provides crucial information for preventing morbidity and mortality from dysphagia. The purpose of this study was to describe a magneto-impedance sensor-aided screening system (MISS) for assessing swallowing function and clarify its effectiveness with the repetitive saliva-swallowing test (RSST).MethodsAn MI sensor attached to the skin over the sternum detected the distance from a magnet attached to the skin over the thyroid cartilage during swallowing as the change of magnetic fields. The MISS was validated by videofluoroscopic and videoendoscopic observations. Further, the swallowing behavior of 93 individuals was assessed by using the MISS and then analyzed with the RSST.Swallowing behavior can be recorded and investigated objectively by signal inspection in the MISS compared with the conventional methods. The MISS is a simple and straightforward method for recording and safe because of dry swallow.The MISS system was validated by using simultaneous recordings with videofluoroscopic or videoendoscopic examinations, and compared with the conventional RSST method.ConclusionsThe MISS combined with the RSST is an effective screening test for swallowing function.     

Effect of head rotation on the pathway of a food bolus through the pharynx as evaluated by a videofluoroscopic swallow study

Purposes  

Head rotation is widely used as a postural technique for dysphagic patients. In this study, we evaluated the effects of head rotation on pharyngeal swallowing in healthy subjects.     

A new screening test for toxicity testing of dental materials

OBJECTIVES: The development of a micro plate assay for cytotoxicity testing of dental materials based on a bioassay using brine shrimp larvae (artemia salina) as sensitive organisms. METHODS: Brine shrimp larvae are commonly used for cytotoxicity assays in pharmacology. These larvae are sensitive to toxic substances. The ratio between dead larvae (no motility) and living larvae (high motility) in comparison to a control without any toxic substances is used to estimate the toxicity of the test solutions.The test materials (Arabesk((R)), Solitaire((R)), Pertac((R)) II, Tetric((R)), Herculite((R)) and the compomer materials Dyract((R)), Hytac((R)), Compoglass((R))) were polymerized and consecutively milled. After incubation of 1g in 4ml distilled water at 37 degrees C for 48h, the solid materials were separated by centrifugation. The solutions were equibrilated with NaCl to a salt content of 25g/l. Aliquots of 200microl were distributed in eight micro wells and 50microl of a artemia salina containing (n=8-14) solution were added to each well. As controls eight wells with 250microl salt solution containing a comparable number of brine shrimp were used. At baseline, after 2, 5, 24 and 48h, the dead shrimp were counted using a stereo microscope. Finally all shrimps were sacrificed using Na-acid (5%) and counted to get the number of shrimps per well.Results: All compomers and Solitaire caused 100% brine shrimp lethality after 24h and showed significantly (p<0.01, signed rank test) higher toxicities than the remaining composites. With the exception of Pertac II, all composites showed significantly higher toxic values than the control. Pertac II did not show any differences from the controls used. CONCLUSIONS: This new technique has some advantages for toxicity testing of restorative materials, because it can quickly be carried out at low costs. The disadvantage is the high quantity of material used and the low sensitivity.     

Recommendations for conducting controlled clinical studies of dental restorative materials

About 35 years ago, Ryge provided a practical approach to evaluation of clinical performance of restorative materials. This systematic approach was soon universally accepted. While that methodology has served us well, a large number of scientific methodologies and more detailed questions have arisen that require more rigor. Current restorative materials have vastly improved clinical performance and any changes over time are not easily detected by the limited sensitivity of the Ryge criteria in short term clinical investigations. However, the clinical evaluation of restorations not only involves the restorative material per se but also different operative techniques. For instance, a composite resin may show good longevity data when applied in conventional cavities but not in modified operative approaches. Insensitivity, combined with the continually evolving and non-standard investigator modifications of the categories, scales, and reporting methods, has created a body of literature that is extremely difficult to meaningfully interpret. In many cases, the insensitivity of the original Ryge methods is misinterpreted as good clinical performance. While there are many good features of the original system, it is now time to move to a more contemporary one. The current review approaches this challenge in two ways: (1) a proposal for a modern clinical testing protocol for controlled clinical trials, and (2) an in-depth discussion of relevant clinical evaluation parameters, providing 84 references that are primarily related to issues or problems for clinical research trials. Together, these two parts offer a standard for the clinical testing of restorative materials/procedures and provide significant guidance for research teams in the design and conduct of contemporary clinical trials. Part 1 of the review considers the recruitment of subjects, restorations per subject, clinical events, validity versus bias, legal and regulatory aspects, rationales for clinical trial designs, guidelines for design, randomization, number of subjects, characteristics of participants, clinical assessment, standards and calibration, categories for assessment, criteria for evaluation, and supplemental documentation. Part 2 of the review considers categories of assessment for esthetic evaluation, functional assessment, biological responses to restorative materials, and statistical analysis of results. The overall review represents a considerable effort to include a range of clinical research interests over the past years. As part of the recognition of the importance of these suggestions, the review is being published simultaneously in identical form in both the “Journal of Adhesive Dentistry” and the “Clinical Oral Investigations.” Additionally an extended abstract will be published in the “International Dental Journal” giving a link to the web full version. This should help to introduce these considerations more quickly to the scientific community. An erratum to this article can be found at