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F Bosman

Publications and source records attributed to F Bosman.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Intraoral radiographs of dental implants in the edentulous mandible].

Radiographs of dental implants in the edentulous mandible, which are suitable for evaluation studies, are difficult to obtain. This article describes the development of an aiming device for intraoral radiography of the crestal bone around the neck of dental implants. Error analysis of serial radiographs indicated only small deviations in reproducibility. Subsequently three methods of measurements of marginal bone level around the neck of dental implants are described, measurements with: 1. a computerized image analysis system, 2. a magnifying glass, and 3. a digital sliding gauge. The intra- and interobserver error analysis showed that determining the precise bone height on the image is responsible for a large standard deviation for each method. Measurements with a digital sliding gauge are preferable, since this method is easy to put into practice, whereas the accuracy matches the accuracy of the two other methods.

Dental Implants↗
PubMed1995

Reliability of clinical findings in temporomandibular disorders.

The aim of the present investigation was to study the interexaminer reliability of orthopedic tests and palpation techniques routinely used in the clinical diagnosis of disorders of the masticatory system. The tests were performed by a dentist and a physiotherapist, who both used the tests routinely when examining patients with temporomandibular disorders. Seventy-nine patients participated in this study. In the analysis, percentage agreement, intraclass correlation, and Cohen's kappa were used. The interexaminer reliability of the tests measuring maximal active mouth opening and registration of clicking during active mouth opening was high. The interexaminer reliability was fair for the tests measuring the intensity of pain during active movements and moderate for tests recording joint sounds (kappa = 0.47 to 0.59). There was high interobserver agreement on several items of the traction and translation tests, although the kappa values were low. The interexaminer reliability of the multitest scores for compression was substantial for joint sounds (kappa = 0.66) and fair for pain (kappa = 0.40). The interexaminer reliability of the multitest scores for muscle palpation and joint palpation was moderate (kappa = 0.51) and fair (kappa = 0.33), respectively. It can be concluded that most variables determined during active movements can be measured with satisfactory reliability, whereas variables for other tests are not measured with the same reliability on the basis of the kappa scores. The main symptoms of temporomandibular disorders can be evaluated reliably with multitest scores. It is recommended that clinicians calibrate their techniques regularly to improve the reliability of results in daily practice.

Adolescent↗
PubMed1995

Diagnostic subgroups of craniomandibular disorders. Part I: Self-report data and clinical findings.

An overview is given of the most commonly investigated signs and symptoms associated with craniomandibular disorders as detected in a population of patients with craniomandibular disorders and in four defined diagnostic subgroups. The information was collected with a questionnaire and during an extensive clinical examination. Comparison of self-report and clinical data indicated that these two methods reveal different aspects of the patient's complaints and should be interpreted in their own way. The results showed that no statistically significant differences could be found between the four diagnostic subgroups with respect to occlusal factors, trauma, and clinically assessed parafunctional habits. The groups differed considerably with respect to general characteristics, pain variables, signs of craniomandibular disorders, self-reported para-functional habits, psychosocial factors, and general health factors. However, despite the reduction in clinical characteristics of the four subgroups, there was little reduction in the diversity of factors associated with craniomandibular disorders. This implicates that almost all factors associated with craniomandibular disorders may influence the initiation and perpetuation of the different disorders in the individual patient, and therefore, remain of interest in future research.

Adolescent↗
PubMed1995

Diagnostic subgroups of craniomandibular disorders. Part II: Symptom profiles.

An overview is given of the following four well-defined diagnostic subgroups of patients who have craniomandibular disorders: those with a mainly myogenous component; those with internal derangement with reduction; those with internal derangement without reduction; and those with osteoarthrosis. Although it was inevitable that the subgroups were not completely homogeneous, symptom profiles differed considerably. There even seemed to be reasons to distinguish two osteoarthrosis groups in future research. Although the identification of clinically significant factors in a given patient with craniomandibular disorders remains a difficult clinical task, the symptom profiles provide a framework that may give more insight into the background of the complaint and into possible contributing factors. The symptom profiles also provide the possibility of a more directed choice of treatment and a treatment evaluation that is more aimed at the specific characteristics of the subgroups. It therefore may be concluded that, to increase insight into craniomandibular disorders, the evaluation of diagnostic subgroups has to be preferred in the assessment of a heterogeneous group of patients with craniomandibular disorders.

Adolescent↗
PubMed1994

Reductions in size and left-right asymmetry of teeth in human oligodontia.

Tooth size and left-right asymmetry of tooth dimensions in oligodontia were compared with those of a control group. Both early and late developing teeth were severely affected, and almost all teeth had significant reductions, compared to the control group, in mesiodistal and labiolingual dimensions. Left-right asymmetry of tooth dimensions was also found, but for the mesiodistal dimensions these were not significantly different from the control group. The occurrence of reductions in tooth size and left-right asymmetries suggests that oligodontia is not just an isolated phenomenon. The left-right asymmetry indicates a developmental instability in these individuals. More research is needed, to reveal the aetiology and pathogenesis of oligodontia.

Adolescent↗
PubMed1994

Location of implants in the interforaminal region of the mandible and the consequences for the design of the superstructure.

The location and the number of implants to support an overdenture is of major importance for the superstructure design. Sometimes, jaw bone anatomy or posteriorly placed implants enforce the use of an angular bar to achieve a position above the alveolar ridge. Loads on such a bar may introduce a moment on the implants which can result in high bone stresses and eventually the loss of the implants. This study on stress distribution in the bone around the implants in an edentulous mandible was performed using a three-dimensional finite element model. One model with two implants placed just anteriorly of the mental foramen and connected with an anteriorly placed bar, following the curvature of the alveolar ridge, was compared with two other designs. First with a similar model but now without a bar and secondly with a model with four implants connected with straight bars. It is concluded that loading a bar, which is placed anteriorly of the interconnecting line between two implants, causes extremely large compressive and tensile stress concentrations in the bone around the implants. Therefore, in those cases, it is advised not to connect the implants or, in case a bar-clip attachment is preferred, to place additional implants in the frontal region.

Bite Force↗
PubMed1994

Psychosocial aspects of craniomandibular dysfunction. An assessment of clinical and community findings.

This study was performed to assess whether subgroups of patients with signs and symptoms of craniomandibular dysfunction (CMD) and a control group of dental patients with and without signs of CMD can be characterized by psychosocial variables, and whether there is evidence of stress-induced muscle hyperactivity as a contributing factor in the development of signs and symptoms of CMD. A group of 127 care-seeking patients and a control group of 158 dental patients completed a Questionnaire Battery (QB) designed to measure external stressors, stress-related emotional reactions (anxiety and depression) and personal factors such as coping styles, health locus of control and personality. Patients with CMD with both a myogenous and an arthrogenous component reported more stress and stronger stress-related emotional reactions than patients with either an arthrogenous or a myogenous CMD. However, patients with arthrogenous CMD did not differ on psychosocial variables from patients with myogenous CMD. In contrast to expectations, controls with signs of CMD reported more stress than patients with CMD. Compared with controls, CMD-patients experienced less personal control over their health and they considered health to be determined by chance or fate. CMD-patients also reported to cope differently with stress than controls. Analyses of covariance showed that the results were not influenced by differences in age, sex or pain reported in the head, neck and/or shoulders. Results were interpreted with regard to the psychophysiological theory of the development of signs and symptoms of CMD as a consequence of the progression of stress-induced muscle hyperactivity. Differences between patients and controls in personal factors were interpreted with regard to treatment need for CMD.

Adaptation, Psychological↗
PubMed1994

Symptomatology of patients with oligodontia.

The aims of the present study were: (i) to identify the association of patterns of congenitally missing teeth with combinations of ectodermal symptoms occurring in patients with oligodontia; and (ii) to propose a diagnostic scheme for the general practitioner. For this study 167 patients with oligodontia, both isolated and as part of a syndrome, and 135 healthy controls were interviewed and documented. Chi-square tests, logistic regression and correspondence analysis were used to evaluate and test differences between the groups and associations between the congenitally missing teeth and ectodermal symptoms. No significant differences were found between the control group and the patients with isolated oligodontia with exception of the skin. It could be concluded from the present study that there were no clear associations between congenitally missing teeth, either individually or patterns, and the ectodermal symptoms or combinations of ectodermal symptoms. However, it could be concluded that if the most stable teeth are missing, or if the number of missing teeth is large the patient should be examined carefully for symptoms of ectodermal dysplasia. Using logistic regression a patient could be classified as having isolated oligodontia or oligodontia as part of a syndrome with a specificity and sensitivity of 88.2%.

Abnormalities, Multiple↗
PubMed1994

Interexaminer reliability of six orthopaedic tests in diagnostic subgroups of craniomandibular disorders.

Interexaminer reliability is defined as the degree of consistency among examiners when making observations of the same clinical variable. In the present study, the interexaminer reliability of six orthopaedic tests was determined in a group of 79 patients with signs and/or symptoms of craniomadibular disorders (CMD), subdivided into three subgroups of patients with a mainly myogenous, a mainly arthrogenous, and a combined myogenous and arthrogenous disorder. Multi-test scores were composed for each test and combinations of tests for the three main symptoms of CMD, viz. pain, joint noises and restriction of movement. Although the orthopaedic tests showed different reliability scores, overall reliability of the determination of these three main symptoms of CMD was satisfactory. In the subgroups, arthrogenous signs and symptoms could be determined reliably with the set of six tests, whereas the reliability of the tests in determining pain and joint noises in the myogenous group was rather low. It may be concluded that the tests are well suited to evaluate arthrogenous signs and symptoms, but that the clinician should be aware of erroneous results of the tests in evaluating pain of a myogenous origin.

Adult↗
PubMed1994

A computer-controlled experimental set-up enabling the quantification of motor performance in man, applied to mastication.

This paper describes a computer-controlled experimental set-up, which enables the simulation and manipulation of the resistance of food, the bolus size and reflex evoking events during chewing in man. Food resistance was simulated by an external downward directed force on the mandible during the closing phase. The force was supplied by a magnet-coil system. A coil, rigidly attached to the subject's mandible, was located in a permanent magnetic field. By varying the current through the coil, the force on the coil and thus on the mandible could be adjusted. The current was on line computed as a function of the jaw gape. Food resistance and bolus size could be simulated and manipulated by varying the amplitude of the force and the jaw gape at which the force started, respectively. The possibility of varying these parameters could be used simultaneously and independently. Reflex evoking events were simulated by an additional loading or unloading force pulse, superimposed on the food-simulating force. The set-up has been tested during experiments in which food resistance, bolus size and reflex evoking events were simulated. Examples of these experiments are presented in this paper.

Bite Force↗
PubMed1994

Multidimensional evaluation of craniomandibular dysfunction. I: Symptoms and correlates.

To standardize clinical history taking, a comprehensive anamnestic questionnaire was developed (Screen). Screen includes questions about (i) pain, (ii) other symptoms of CMD, (iii) correlates of CMD, (iv) psychosocial factors, and (v) general health. Variables discriminating between subgroups of clinical cases and controls were described successively. This study was performed to assess whether subgroups of patients with signs and symptoms of craniomandibular dysfunction (CMD), and a control group of dental patients with and without signs and symptoms of CMD, can be characterized by differential report of signs and symptoms of CMD, as reported in Screen. Results indicate that Screen can be used to discriminate between (i) subgroups of subjects with signs or symptoms of CMD (both clinical cases and controls) and controls without signs or symptoms of CMD; (ii) subgroups of clinical cases and controls with signs and/or symptoms of CMD; and (iii) patients with CMD with mainly a myogenous component and patients with CMD with mainly an arthrogenous component. Differences between patients and controls are interpreted with regard to the correct classification of patients with CMD with mainly a myogenous component and patients with CMD with mainly an arthrogenous component, and with regard to the subjective treatment need for CMD. The results of logistic regression analyses indicate that subsets of items of Screen correctly classified up to 80% of patients with myogenous or arthrogenous CMD. Implications for further research were discussed.

Adolescent↗
PubMed1994

Multidimensional evaluation of craniomandibular dysfunction. II: Pain assessment.

To standardize clinical history taking, a comprehensive anamnestic questionnaire was developed (Screen). Screen includes questions about: (i) pain, (ii) other symptoms of craniomandibular dysfunction (CMD), (iii) correlates of CMD, (iv) psychosocial factors, and (v) general health. The current study focuses on variables in Screen concerning pain reported somewhere in the head, neck and/or shoulders. This study was performed to assess whether subgroups of patients with signs and symptoms of CMD and a control group of dental patients with and without signs and symptoms of CMD can be characterized by differences in areas reported to be painful, in quantitative and qualitative characteristics of pain, and in factors exacerbating pain. Results indicate that several characteristics of pain as measured in Screen can be used to discriminate between: (i) subgroups of subjects with signs and/or symptoms of CMD and controls without signs or symptoms of CMD, (ii) subgroups of clinical cases and controls with signs or symptoms of CMD, and (iii) patients with CMD with mainly a myogenous component and patients with CMD with mainly an arthrogenous component. The results of logistic regression analysis indicate that four adverbs describing pain correctly classified 75% of patients with CMD-myo and patients with CMD-arthro. Differences between patients and controls are interpreted with regard to the correct classification of patients with CMD with a mainly myogenous component and patients with CMD with a mainly arthrogenous component and the subjective treatment need for CMD. Implications for further research are discussed.

Adolescent↗
PubMed1994

Assessment of treatment outcome in patients with craniomandibular dysfunction.

Psychosocial, socio-demographic and symptom characteristics have been shown to be associated with treatment outcome in patients with craniomandibular dysfunction (CMD). This study was performed to assess to what extent symptoms and correlates of CMD change as a consequence of conservative treatment for CMD. Treatment outcome in a group of CMD patients treated with a stabilization splint (experimental group) was compared with that of a group of patients with CMD who were not treated for CMD (control group). Patients in the experimental group had fewer symptoms of CMD at the end of treatment. However, several symptoms and correlates of CMD also improved in the control group (severity of pain, joint noises, ear symptoms). It was therefore questioned whether all improvements in symptoms and correlates of CMD in the experimental group could be attributed to the treatment received. Results suggest that the main improvement that might be ascribed to therapy was a decrease in 'jaw symptoms'. There was a noticeable decrease in depression and an increased use of 'planned actions and rational thinking' as a coping style in the experimental group whereas these variables did not change in the control group. Implications and suggestions for further research are discussed.

Adaptation, Psychological↗
PubMed1994

Craniomandibular dysfunction: patient characteristics related to treatment outcome.

In a previous study it was concluded that only a few changes in symptoms related to craniomandibular dysfunction (CMD) could be attributed to therapy. It was suggested that psychosocial and socio-demographic variables, as well as symptom characteristics, could be responsible for the unconvincing treatment outcome in patients treated with a splint. The present study was performed to investigate whether socio-demographic characteristics, symptom characteristics and various psychosocial variables are associated with treatment outcome in patients with CMD treated with a splint. Treatment outcome was determined by using self-reported follow-up data. Results showed that patients with a negative treatment outcome were older, reported more and more severe symptoms and correlates of CMD, reported fewer stressors and more frequently considered health to be determined by external factors than patients who were treated successfully. The two groups could not be differentiated with regard to anxiety and depression. Results are interpreted with regard to the prediction of treatment outcome.

Adult↗
PubMed1994

Rate modulation of jaw-elevator motor units as revealed from the low-frequency power spectrum of the surface electromyogram in myogenous CMD patients.

The firing pattern of the motor units (MUs) in jaw-elevator muscles was studied within a wide range of isometric contraction levels by means of changes in the frequency and broadness of the primary peak in the low-frequency (5-40 Hz) power spectral density function of the surface EMG. EMG was recorded from both masseter and anterior temporal muscles in 11 myogenous CMD patients as well as in 11 gender- and age-matched controls who clenched in intercuspal occlusion under the control of visual feedback at various levels (0.5-67% MVC for the various muscles studied). The EMG was digitized for 12 periods of 1.6 s per condition; the power spectrum was averaged and smoothed for the various clenching levels. Linear regression analysis showed that the positive slope in the peak frequency (PF)/% MVC relationship, a measure of rate modulation of the MUs, did not differ significantly between patients and controls. At a low clenching level, PF was smaller (p < 0.01) for the anterior temporal muscles of the patients, suggesting lower firing rates for a wide range of clenching levels of the patients because of a similar rate modulation for patients and controls. Furthermore, the variance in the slope values was larger (p < 0.05) for the masseteric muscles of the patients, which may be explained by more heterogeneity of the masseteric rate modulation in the patient group. The broadness of the primary peak was smallest at a low clenching level (p < 0.001) for the anterior temporal muscles of the patients, suggesting a more uniform firing rate or more synchronization between MUs.

Action Potentials↗
PubMed1994

Chewing performance before and after rehabilitation of post-canine teeth in man.

Missing teeth are often replaced by fixed or removable prosthodontic appliances to improve masticatory function. However, there have been few studies directly determining the influence of prosthodontic treatment on masticatory function. Our aim was to obtain information on the objective and subjective masticatory function of partially edentulous subjects before and after prosthetic restoration. In this way, the improvement of the masticatory function as a result of the treatment could be quantified. The objective and subjective masticatory function of a group of 15 subjects was determined before and after replacement of an average of 3.1 post-canine teeth. The results were compared with data from a control group of 26 subjects having a complete dentition. The total number of occluding post-canine teeth increased as a result of the prosthodontic treatment, yielding a significantly improved objective masticatory function. The average masticatory performance was found to approach the level of the control group if all occlusal units of the longest posterior side were replaced. Subjects with an incomplete dentition tended to chew predominantly on the side of the longest posterior arch. The average subjective masticatory function improved as a result of the treatment. The appreciation of the masticatory function after treatment was equal to that of the control group, despite an average of 2.7 missing teeth. However, no correlation was found between the additional number of occlusal units and the change in subjective masticatory performance. Rehabilitation of post-canine teeth restores some objective masticatory function and leads to an increased appreciation of the masticatory function, although no correlation was found between the changes in objective and subjective masticatory function.

Adult↗
PubMed1993

Gain and threshold of the jaw-jerk reflex in man during isometric contraction.

The control of mandibular posture has been related to the activity of the anterior temporal muscles, whereas the masseter muscles have been viewed mainly as force producers. However, these groups of muscles, especially in the deep layers, are highly endowed with muscle spindles, so that a difference in function should imply a difference in the reflex sensitivity. By studying the jaw-jerk reflex by means of bipolar surface electromyogram, the reflex sensitivity was determined from relationships between reflex amplitude and jaw displacement from both groups of muscles in eight subjects. At a constant level of background muscle activity, and hence with a constant excitability of the alpha motoneurons, the reflex sensitivity can be determined from these relationships in terms of gain and threshold. In order to account for differences in thickness of the soft tissues overlying the various muscles studied, the reflex amplitude was normalized with respect to the level of maximal voluntary contraction (MVC). In experiments where the inter-electrode distance was 18 mm over both groups of muscles, the reflex gain of the anterior temporal muscles was larger than that of the masseter muscles (P < 0.05). The threshold value did not differ significantly from zero for either group of muscles. Normalization of the reflex amplitude with respect to MVC can be carried out correctly only if the reflexly activated muscle fibres are distributed uniformly within the muscle. In order to gain an insight into this distribution, control experiments were performed with three subjects in which the inter-electrode distance was varied, thus influencing the depth in the muscle from which active muscle fibres were recorded. The reflex gain of the masseter muscle with an inter-electrode distance of 22 mm, which records from deeper layers of the muscle as well as superficial ones, was larger than with a distance of 11 mm (P < 0.01-0.10 in the various subjects). No such differences were found for the anterior temporal muscle. It was concluded that the afferents of the spindles in the jaw-elevator muscles do not project uniformly upon the motoneurons, but involve mainly fibres in the deeper layers of the muscle. The difference in gain found between the masseter and the anterior temporal muscles with the same inter-electrode distance of 18 mm is likely to be due to a larger distance of the reflexly activated muscle fibres in the masseter muscle with respect to the electrodes rather than to a difference in reflex sensitivity between the muscles.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗