Biomedical subjects

Andries van der Bilt

Publications and source records attributed to Andries van der Bilt.

14 recordsLinked to original sources

PubMed2006

Effects of added fluids on the perception of solid food.

The production of sufficient saliva is indispensable for good chewing. Recent research has demonstrated that salivary flow rate has little influence on the swallowing threshold. We examined the hypothesis that adding fluid to a food will influence the chewing process. Twenty healthy subjects chewed on melba toast, breakfast cake, carrot, peanut and Gouda cheese. In addition they chewed on these foods after we added different volumes of tap water or a solution of alpha-amylase. We measured jaw muscle activity and the number of cycles until swallowing. Furthermore, we obtained visual analogue scale (VAS) scores for texture and sound attributes for all foods and fluid conditions. The additional fluids significantly lowered muscle activity and swallowing threshold for melba, cake and peanut. The effect of alpha-amylase in the solutions was rather limited. Doubling the volume of tap water had a larger effect. Several texture and sound attributes of melba, cake and peanut were also significantly affected by the additional fluids. For melba, cake, and peanut we observed significant correlations between the physiology parameters and several attributes for the various fluid conditions. This indicates that the added fluid affects both the physiology (muscle activity and number of cycles) and the sensory perception of a number of texture and sound attributes. Adding fluid facilitates the chewing of dry foods (melba, cake), but does not influence the chewing of fatty (cheese) and wet products (carrot).

Adult↗

PubMed2006

The influence of mandibular advancement surgery on oral function in retrognathic patients: a 5-year follow-up study.

PURPOSE: Previous studies have shown that patients with mandibular retrognathism who were scheduled for orthognathic surgery have a lower maximum bite force and an impaired chewing performance. Surgical correction of this deformity is supposed to lead to an improvement of these oral functions. One year after surgery, no significant changes could be shown in these patients. However, a longer follow-up might demonstrate an improvement after all. PATIENTS AND METHODS: Maximum bite force and chewing performance were determined in 12 patients with a mandibular retrognathism before mandibular advancement surgery and at least 5 years after surgery. Chewing performance (median particle size) was determined with a sieving method after chewing 15 strokes on an artificial test food. Maximum bite force was recorded bilaterally at the level of the first molars. RESULTS: Five years after surgery, chewing performance was improved, especially in patients with a poor performance before treatment. An increase of the maximum bite force could not be shown. CONCLUSION: Surgical correction of mandibular retrognathism had a positive effect on oral function 5 years after surgery, although it could not be detected 1 year after surgery. However, the function of the masticatory system was still impaired when compared with controls.

Adult↗

PubMed2006

Masticatory function with mandibular implant-supported overdentures fitted with different attachment types.

Oral Rehabilitation by means of implant-retained mandibular overdentures is known to improve the oral function. The improvement may depend on the degree of retention and stability of the denture and thus on the type of attachment. In this within-patient cross-over clinical trial, we examined the hypothesis that more retention and stability of the overdenture improves the masticatory function. Eighteen patients received two permucosal implants, a new overdenture, and, successively, three different suprastructure modalities: a magnet, a ball, and a bar-clip attachment. We quantified aspects of the oral function by measuring the electromyographic activity of the jaw muscles and the jaw movement during chewing. The muscle activity was significantly lower for the unsupported new mandibular denture compared with values for the supported new denture. No significant differences in muscle activity were observed among the three attachment types. Furthermore, we did not observe significant differences in jaw muscle activity between the old unsupported denture and the new supported denture, despite significant differences in masticatory performance. Measuring muscle activity during chewing will thus not provide adequate information about masticatory function. Thus, subjects chewed more efficiently after implant treatment. No changes in cycle duration or in jaw movement parameters were observed among the various measurement moments.

Adult↗

PubMed2005

Relating particles and texture perception.

Practically all foods contain particles. It has been suggested that the presence of particles in food may affect the perception of sensory attributes. In the present study we investigated the effect of size and type (hardness and shape) of particles added to a CMC based vanilla custard dessert. The two types of particles included in the study were silica dioxide and polystyrene spheres, varying in size from 2 to 230 microm. Eighteen trained adults participated in the study. They rated the sensation of 17 sensory flavour and texture attributes on a 100-point visual analogue scale (VAS). The results indicate that the addition of particles increased the sensation of roughness attributes and decreased the ratings of a number of presumably favorable texture attributes (smoothness, creamy, fatty and slippery) significantly. These effects increased with increasing particle size up to 80 microm. Roughness ratings deceased for larger particles sizes. Surprisingly, even particles of 2 microm had significant effects: they increased perceived rough lip-tooth feel, and decreased slippery lip-tooth feel and smoothness of the product. The affected attributes had previously been related to lubricative properties of foods. Particles added to semi-solid foods with relatively low levels of fat seem to counteract the lubricating effects of the fat resulting in increased oral friction. In a separate study on size perception the silica dioxide particles were used. By sampling the stimuli between the tongue and palate, subjects rated the size of the particles on a 100-point scale in comparison to anchor stimuli containing no particles and particles of 250 microm. The perceived particle size significantly increased for larger particles. Furthermore, perceived particle size was negatively correlated with roughness ratings. Thus, subjects who were sensitive and perceived the particles as being relatively large reported the same stimuli to have less rough after-feel. In conclusion, particles added to a product induce large effects on texture sensations, and texture sensation is related to individual size perception.

Adult↗

PubMed2005

The influence of product and oral characteristics on swallowing.

The urge to swallow food could be triggered by a threshold level in both food particle size and lubrication of the food bolus. Thus, both oral physiology and product characteristics may influence the swallowing threshold. We quantified the swallowing threshold in a group of 266 healthy adult subjects (age 42 +/- 12 years) by counting the number of chewing cycles needed to prepare food for swallowing. The influence of oral physiology on the swallowing threshold was determined by measuring salivary flow rate, maximum bite force and masticatory performance. We used about 10 cm(3) of bread, toast, melba toast, breakfast cake, peanuts and cheese to determine the influence on the swallowing threshold of various food characteristics, e.g. hardness, moisture and fat. Furthermore, we tested the effect of buttering the bread, toast, melba toast and breakfast cake on the swallowing threshold. Salivary flow rates were significantly and negatively correlated with the number of chewing cycles of melba toast and breakfast cake. Hence, subjects with more saliva needed less chewing cycles for these dry products. Maximum bite force and masticatory performance had an influence on the swallowing threshold for the hard products only (carrot and peanut). Although significant, the correlation coefficients were less than 0.28. Thus, the oral physiology parameters explained less than 10% of the variance in the swallowing threshold. We found significantly different numbers of chewing cycles for the various foods, ranging from 17 for cake to 63 for carrot. Hard and dry products needed more chewing cycles until swallowing. Buttering the food significantly reduced the number of chewing cycles needed before swallowing. This was especially true for the dry products cake, melba toast and toast. Hard and dry products require more chewing cycles and longer time in mouth until swallowing for sufficient breakdown to take place and for enough saliva to be added to form a coherent bolus safe for swallowing. In spite of this, more saliva, higher maximum bite force and better masticatory performance were only weakly correlated with a smaller number of chewing cycles. Butter enhanced lubrication and bolus formation of dry products, thus reducing the number of chewing cycles until swallowing. In conclusion, product characteristics and to a lesser extent oral physiology significantly affect swallowing threshold.

Adult↗

PubMed2005

The effect of maximum bite force on marginal bone loss in mandibular overdenture treatment: an in vivo study.

The impact of bite force on the marginal bone response around implants is a subject of debate. This study focused on the effect of maximum bite force on marginal bone levels in mandibular implant overdenture treatment. In addition, the effect of the sequence of 3 different loading conditions on marginal bone loss was evaluated in vivo. The patient population consisted of a group of 18 patients. They received 2 implants in the mandible and a new denture without attachments during the period of submerged implant healing. After second stage surgery, the denture was provided with a ball, magnet or bar-clip attachment. There was a transition of attachment type after 3 and 6 months of function. The sequence in which the attachments were used was randomised. Radiographic marginal bone loss was measured after the period of submerged implant healing and after 3, 6 and 9 months of functional implant loading. Maximum bite force measurements were obtained just prior to second stage surgery with the new denture without attachment. Bite force measurements were also obtained after 3, 6 and 9 months of loading with the implant-retained overdenture. The latter 3 values were averaged. The mean bone loss during the period of submerged healing and during functional loading was 1.7 mm (0.7 mm) and 1.3 mm (0.6 mm), respectively. A relationship between maximum bite force during the period of submerged healing or during the period of functional loading on the one hand and the amount of marginal bone loss on the other could not be demonstrated. The sequence in which the different attachment types were used did not influence the observed amount of marginal bone loss.

Adolescent↗

PubMed2004

Masticatory function in retrognathic patients, before and after mandibular advancement surgery.

PURPOSE: Mandibular retrognathia is a dentofacial deformity that can be surgically corrected. The purpose of this study was to evaluate the influence of orthognathic surgery on masticatory function in a sample of retrognathic patients and to compare these findings with those of controls. PATIENTS AND METHODS: Eleven retrognathic patients were tested before and 1 to 1.5 years after mandibular advancement surgery and compared with 12 controls. The median particle size after chewing a silicon rubber test food, the maximum bite force, and the electromyographic activity (EMG) of the anterior temporalis and the masseter muscles during isometric clenching and during chewing were determined. Patients, before and after treatment, and controls were statistically compared by analysis of variance. RESULTS: Surgical correction of mandibular retrognathia did not change chewing efficiency, maximum bite force, EMG during maximal clenching, EMG during chewing, or the EMG/bite-force relationship. Compared with controls, the chewing efficiency, maximum bite force, EMG during maximal clenching, and EMG during chewing values were lower. No difference for the EMG/bite-force ratio at maximal clenching was found, indicating similar muscle efficiency for patients and controls. However, in the range of 10% to 40% of the maximum bite force, the slope of the EMG/bite-force regression line was steeper for the patients than for the controls, indicating decreased muscle efficiency for patients. CONCLUSIONS: The results of this study suggest that in retrognathic patients, function of the masticatory system is impaired. Oral function was not influenced by mandibular advancement surgery.

Adult↗

PubMed2004

Chewing behavior and salivary secretion.

We determined the salivary flow rate in 16 healthy subjects in rest and while chewing artificial and natural foods (Parafilm, Melba toast with and without margarine, and three different volumes of breakfast cake and cheese). We also determined the duration of a chewing cycle, the number of chewing cycles until swallowing, and the time until swallowing. The physical characteristics of the foods were quantified from force-deformation experiments. The flow rates of the saliva as obtained without stimulation, with Parafilm stimulation, and with chewing on the various foods were significantly correlated. An increase in chewing cycle duration, number of chewing cycles until swallowing, and time until swallowing was observed as a function of the volume of the food. More chewing cycles were required for Melba toast than for an equal volume of cake or cheese. This may be caused by the low water and fat percentage of the Melba toast. The number of chewing cycles and the time until swallowing significantly decreased when the Melba toast was buttered. The decrease may be caused by facilitation in bolus formation and lubrication of the food due to buttering the toast. The number of chewing cycles until swallowing was not correlated to the salivary flow rate.

Adolescent↗

PubMed2003

The relation between saliva flow after different stimulations and the perception of flavor and texture attributes in custard desserts.

Salivary flow rates were measured at rest and after three types of stimulation; odor, Parafilm chewing, and citric acid. The highest flow rate was elicited by citric acid followed by Parafilm and odor, while the lowest flow rate was unstimulated. In order to investigate whether and how the amount of saliva a subject produces influences the sensory ratings, the four types of salivary flow rates were correlated with sensory ratings of three different types of vanilla custard dessert. No significant correlation could be found between any of the salivary flow rates and the sensory ratings. A subject with a larger saliva flow rate during eating did not rate the foods differently from a subject with less saliva flow. The same pattern was seen for all types of stimulation. This finding could indicate that subjects are used to their respective amounts of saliva to such a degree that the differences in sensory ratings between subjects cannot be explained by the interindividual difference in saliva flow rate.

Adult↗

PubMed2003

A comparison of the effects of added saliva, alpha-amylase and water on texture perception in semisolids.

The effect of adding saliva or a saliva-related fluid (alpha-amylase solution and water) to custard prior to ingestion on the sensory ratings of odour, flavour and lip-tooth-, mouth- and after-feel sensations was investigated. Saliva had previously been collected from the subjects and each subject received his/her own saliva. Sixteen subjects from a trained panel assessed 17 flavour and texture attributes of soy- and milk-based custard desserts. Immediately prior to administration, two different volumes (0.25 and 0.5 ml) of three different saliva-related fluids (saliva, alpha-amylase solution and water) were added to the product. The added volumes represented an approximately 33% and 66% increase of the volume of saliva present in the mouth during ingestion. The results show that addition of a fluid affected the mouth-feel attributes of melting, thickness and creamy. Melting was the only attribute on which the type of fluid had an effect, where saliva elicited a stronger melting effect than the alpha-amylase solution and water. The volume of the added fluid affected a number of attributes (thick and creamy mouth-feel and fatty after-feel). It can be concluded that in general the sensory attributes of semisolids were relatively stable. Mouth- and after-feel sensations were partly affected, while odour, flavour and lip-tooth-feel sensations were not affected by an increase in volume of saliva or other saliva-related fluid during ingestion.

Adult↗

PubMed2003

Retention and postinsertion maintenance of bar-clip, ball and magnet attachments in mandibular implant overdenture treatment: an in vivo comparison after 3 months of function.

It could be hypothesised that attachments, which provide more retention against vertical and horizontal dislodgement, will be associated with more favourable parameters of oral function. This in vivo study is designed to provide data regarding initial retention force, loss of retention force after 3 months of function and postinsertion maintenance and complications associated with the use of magnet, bar-clip and ball attachments in mandibular overdenture treatment. Eighteen edentulous subjects received two permucosal implants in the inter-foramina region of the mandible, a new denture and three successive suprastructure modalities (magnet-, bar-clip and ball attachments). The retention force of the attachments at baseline and after 3 months was measured in a standardised way. The amount and type of postinsertion maintenance that was related to the attachment were evaluated. No differences in retention force at baseline and after 3 months of loading were observed for all three attachment types. The mean retention forces of magnet attachments, bar-clip attachments and ball attachments were 8.1, 31.3 and 29.7 N respectively. Functional maintenance complications related to the attachments were predominantly observed in 11/36 magnet attachments. Functional problems in the ball attachment group were relatively rare, easily manageable and seen in 4/36 attachments. The bar-clip attachments exhibited no maintenance problems at all.

Adult↗

PubMed2002

The effect of oral temperature on the temperature perception of liquids and semisolids in the mouth.

This work examined the influence of oral temperature on oral perception of temperature in liquids and semisolids. A panel of 20 adults assessed the temperature of water, custard dessert and mayonnaise. Oral temperatures were manipulated by 5-s mouth rinses of 10, 35 and 55 degrees C performed prior to assessments, which resulted in oral temperatures of 27, 35 and 43 degrees C, respectively. The products were evaluated at 10, 22 and 35 degrees C. Results show that subjects were able to differentiate between the product temperatures. A large effect of type of product was seen on perceived temperature, where water was, overall, perceived as significantly colder than custard dessert and mayonnaise. The range of perceived thermal ratings was widest for custard dessert, followed by water and mayonnaise. This might be due to differences in composition and structure of the products. Even though oral temperature was varied considerably in the present study, this did not exert large effects on perceived temperature.

Adolescent↗

PubMed2002

Nasolabial esthetics after Le Fort I osteotomy and V-Y closure: a statistical evaluation.

The Le Fort I osteotomy results in predictable long-term effects. The soft tissues, however, can be difficult to control because of considerable variation in their adaptation. Several adverse reactions can take place, including thinning and lateral retraction of the lip, accentuation of the nasolabial groove, reduced vermilion exposure, and increase of the nasolabial angle. In this study on 51 selected patients, the V-shaped wound in the vestibule of the maxilla after the Le Fort I osteotomy was closed with a "Y," with the bast of the "Y" in the midline of the upper lip (V-Y closure). Forward multiple regression analysis was calculated for each bony landmark. Regression equations were formulated if P < .05. The equation with the bony point with the highest r2 value was considered the most important independent variable. The selected independent variables were used to form 4 subgroups with identical vectors of movements: impaction, advancement, impaction and advancement, and dorsal impaction. In these 4 subgroups, forward multiple regression analysis was used to select equations with the highest r2 value (P < .05). The selected equations demonstrated that a V-Y plasty as single soft tissue procedure suffices only in advancement cases, and only if the nose does not need additional upward rotation. In the other 3 subgroups, additional procedures are necessary, such as alar cinch suture, reduction of the anterior nasal spine, or grinding of the paranasal area in order to prevent the above-mentioned adverse soft tissue changes.

Adolescent↗

PubMedDate not supplied

Patient satisfaction and preference with magnet, bar-clip, and ball-socket retained mandibular implant overdentures: a cross-over clinical trial.

PURPOSE: The purposes of this study were to: (1) determine patient satisfaction with implant-supported mandibular overdentures using magnet, bar-clip, and ball-socket attachments; and (2) assess the relation between maximum bite force and patient satisfaction. MATERIALS AND METHODS: In a cross-over clinical trial, 18 edentulous patients with mandibular denture complaints received two mandibular implants and new mandibular and maxillary dentures. The mandibular denture was initially without any kind of attachment system, but it was fitted with one of the attachment types after 3 months. The attachments were changed 3 months thereafter, in random order. A questionnaire on denture complaints was administered at baseline (with the old denture), after 3 months of function with the new denture without attachments, and after 3 months of function with each of the attachments (within-subject comparison). In addition, patients were asked to express their overall appreciation of their dentures on a VAS. Patients' preferences were determined at the end of the experiment. Maximum bite forces were obtained from a previous study with the same population. Five scales of denture complaints were constructed. Mean scale and VAS scores at the five evaluation points were compared among the groups. Pearson correlation was calculated between maximum bite force and scale and VAS scores. RESULTS AND CONCLUSION: Mandibular implant-supported overdenture treatment reduced various denture complaints. The VAS score better reflected patients' preferences than did scale score. Patients strongly preferred bar-clip (10/18 subjects) and ball-socket attachments (7/18 subjects) over magnet attachments (1/18 subjects). Patients' preferences could not be predicted on the basis of baseline observations. Maximum bite force was not correlated to scale or VAS score. Hence, patients with higher maximum bite forces were not necessarily more satisfied.

Adult↗