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F Lobbezoo

Publications and source records attributed to F Lobbezoo.

At least 19 recordsLinked to original sources
PubMed2006

Is condylar position a predictor for functional signs of TMJ hypermobility?

Temporomandibular joint (TMJ) hypermobility is noted only when it interferes with smooth mandibular movements. These interferences (viz. clicking sounds and jerky mandibular movements) result from condylar dislocation in front of the eminence at wide mouth opening, or alternatively in front of the articular disc (posterior disc displacement). The aim of this study was to test the hypothesis that condyles of hypermobile persons are positioned more anterosuperiorly to the crest of the eminence during maximum mouth opening than those of persons without TMJ hypermobility. Possible posterior disc displacement was also evaluated. Nine persons with symptomatic hypermobility and nine control persons free of internal derangements were included, their diagnoses being based upon opto-electronic movement recordings. Condylar positions during maximum mouth opening were analysed on magnetic resonance images with two slightly different methods, showing the degree to which the condyles are displaced around the eminence. No posterior disc displacements were found in any of the magnetic resonance images. After excluding an outlier and using both measurement methods, a small difference in condylar position was found between the two groups of subjects. The condyles of all hypermobile persons travelled beyond the eminence; however, so were the condyles of nearly half of the non-hypermobiles. The large overlap between both groups suggests that condylar position alone is not a good predictor for symptomatic TMJ hypermobility. It is probably the combination of condylar location in front of the eminence with a particular line of action of the masticatory muscles, which gives rise to functional signs of hypermobility.

Adult↗
PubMed2006

Dental implants in patients with bruxing habits.

Bruxism (teeth grinding and clenching) is generally considered a contraindication for dental implants, although the evidence for this is usually based on clinical experience only. So far, studies to the possible cause-and-effect relationship between bruxism and implant failure do not yield consistent and specific outcomes. This is partly because of the large variation in the literature in terms of both the technical aspects and the biological aspects of the study material. Although there is still no proof for the suggestion that bruxism causes an overload of dental implants and of their suprastructures, a careful approach is recommended. There are a few practical guidelines as to minimize the chance of implant failure. Besides the recommendation to reduce or eliminate bruxism itself, these guidelines concern the number and dimensions of the implants, the design of the occlusion and articulation patterns, and the protection of the final result with a hard occlusal stabilization splint (night guard).

Biomechanical Phenomena↗
PubMed2006

Bruxism: its multiple causes and its effects on dental implants - an updated review.

There is a growing interest in bruxism, as evidenced by the rapidly increasing number of papers about this subject during the past 5 years. The aim of the present review was to provide an update of two previous reviews from our department (one about the aetiology of bruxism and the other about the possible role of this movement disorder in the failure of dental implants) and to describe the details of the literature search strategies used, thus enabling the readers to judge the completeness of the review. Most studies that were published about the etiology during the past 5 years corroborate the previously drawn conclusions. Similarly, the update of the review about the possible causal relationship between bruxism and implant failure reveals no new points of view. Thus, there is no reason to assume otherwise than that bruxism is mainly regulated centrally, not peripherally, and that there is still insufficient evidence to support or refute a causal relationship between bruxism and implant failure. This illustrates that there is a vast need for well-designed studies to study both the aetiology of bruxism and its purported relationship with implant failure.

Bruxism↗
PubMed2006

[Evidence-based management of temporomandibular dysfunction. Think before you begin!].

Nowadays, dentists are expected to base their treatment decisions on the strongest available evidence. This so-called evidence-based approach has four steps: the formulation of a clinical problem, the search for evidence, the evaluation of the evidence, and the treatment of the patient. As part of this approach, the strongest evidence comes from systematic reviews, which are free of any author-related bias. Since working according to the principles of evidence-based dentistry is time consuming, dental schools should assist general practitioners through producing sufficient numbers of high-quality systematic reviews. The ever-increasing emancipation of patients stresses the need of adopting the principles of evidence-based dentistry. 'Think twice' should be the motto.

Dentistry↗
PubMed2006

[Occupational differentiation in dentistry 2. From Brueghel's syndrome to a radiant smile. An advanced postgraduate programme in oral kinesiology].

Oral movement disorders, jaw pain, and tooth wear are examples of clinical problems that are part of the dental discipline 'oral kinesiology'. About half of the advanced postgraduate programme in oral kinesiology involves the diagnosis, indication, and management of patients with one or more oral kinesiologic problems. The remaining time is available for thematic courses and a research project. The breadth of the programme will hopefully lead to improved care for patients whose treatment until now has been dispersed between various dental specialists. Successful candidates will obtain an advanced postgraduate diploma in Oral Kinesiology, and can also apply to be recognized as a gnathologist.

Bruxism↗
PubMed2006

[Occupational differentiation in dentistry 3. Hypermobility of the temporomandibular joint and condylar position at maximal mouth opening].

Hypermobility of the temporomandibular joint is only noted when it interferes with smooth mandibular movements. These interferences may result from a condylar dislocation beyond the temporal eminence at maximum mouth opening. Aim of this study was to test whether the condyle of a symptomatically hypermobile temporomandibular joint is positioned more anterosuperiorly to the temporal eminence at maximum mouth opening than a condyle without hypermobility. Nine persons with a hypermobile temporomandibular joint and 9 control persons participated. Diagnostics were based upon opto-electronic mandibular movement recordings. Condylar positions at maximum mouth opening were assessed by magnetic resonance imaging. A small significant difference in condylar position was found between groups. Condyles of persons with a hypermobile temporomandibular joint moved beyond the temporal eminence. However, this was also true for nearly half of the control persons. This suggests that condylar position alone is not a sufficient condition for symptomatic hypermobility of the temporomandibular joint. Maybe, symptoms of hypermobility only become apparent in combination with a particular line of action of the masticatory muscles.

Adult↗
PubMed2005

Effects of masticatory muscle fatigue without and with experimental pain on jaw-stretch reflexes in healthy men and women.

OBJECTIVE: To examine the effects of experimentally evoked masticatory muscle fatigue, without and with experimental muscle pain, on the short-latency jaw-stretch reflex, using a randomised crossover design. METHODS: Reflexes were evoked in both the masseter and temporalis muscles in 15 men and 13 women. The study was performed in two blocks, both containing 3 experimental conditions (before, directly after, and 15 min after provocation). Provocation consisted of a fatiguing chewing test, followed by an intramuscular injection of either isotonic saline (IS; non-painful) or hypertonic saline (HS; painful). RESULTS: No significant effects of the experimental condition 'fatigue+IS' were found for any of the reflex outcome variables. For each muscle, the 'fatigue+HS' condition yielded significantly higher normalized reflex amplitudes than the other conditions. Several muscles displayed gender differences regarding both onset latency and normalized reflex amplitude. CONCLUSIONS: Experimentally evoked mild-to-moderate muscle fatigue does not modulate the human jaw-stretch reflex. On the other hand, experimental muscle pain, evoked after the performance of a fatiguing chewing test, does yield a facilitation of this reflex. The gender differences found in both onset latency and peak-to-peak amplitude stress the need to take gender into consideration in future jaw reflex studies. SIGNIFICANCE: The sensitivity of the human jaw-stretch reflex can be modulated by HS-induced muscle pain; not by muscle fatigue that is provoked by intense chewing.

Adult↗
PubMed2005

Short-term effects of a mandibular advancement device on obstructive sleep apnoea: an open-label pilot trial.

Obstructive sleep apnoea (OSA) is a common sleep disorder, which is, among others, associated with snoring. OSA has a considerable impact on a patient's general health and daily life. Nasal continuous positive airway pressure (nCPAP) is frequently used as a "gold standard" treatment for OSA. As an alternative, especially for mild/moderate cases, mandibular advancement devices (MADs) are prescribed increasingly. Their efficacy and effectiveness seem to be acceptable. Although some randomized clinical trials (RCTs) have been published recently, most studies so far are case studies. Therefore, our department is planning a controlled RCT, in which MADs are compared with both nCPAP and a control condition in a parallel design. As a first step, an adjustable MAD was developed with a small, more or less constant vertical dimension at different mandibular positions. To test the device and the experimental procedures, a pilot trial was performed with 10 OSA patients (six mild, four moderate; one women, nine men; mean age = 47.9 +/- 9.7 years). They all underwent a polysomnographic recording before as well as 2-14 weeks after insertion of the MAD (adjusted at 50% of the maximal protrusion). The apnoea-hypopnoea index (AHI) was significantly reduced with the MAD in situ (P = 0.017). When analysed as separate groups, the moderate cases showed a significantly larger decrease in AHI than the mild cases (P = 0.012). It was therefore concluded from this pilot study that this MAD might be an effective tool in the treatment of, especially, moderate OSA.

Adult↗
PubMed2005

[Oral problems in divers].

Divers can have several oral problems. Firstly, problems caused by pressure changes. These are barodontalgia and odontocrexis. Barodontalgia is toothache by barotrauma. Odontocrexis is restorations coming lose or breaking or tooth fractures by expansion of air beneath restorations. Other problems can occur by cements used to fix casted restorations, by inflammations in the orofacial region, and by not yet fully healed oral wounds. Secondly, there are problems related to the diver's mouthpiece. To keep the mouthpiece in place, the mandible has to be forced in a forward position. Holding this position often and for long periods of time, may develop or aggravate temporomandibular dysfunction. Insufficient fit of the mouthpiece may induce oral mucosal lesions. Therefore, it is recommended to produce individual diver mouthpieces. It is also recommended to produce individual diver mouthpieces for complete dentures wearing divers and for divers with fixed orthodontic appliances.

Barotrauma↗
PubMed2004

Oral kinesiology. A new postgraduate programme in the Netherlands.

As one of the dental differentiations in The Netherlands, temporomandibular disorders (TMD) focuses on the diagnosis and treatment of pain and dysfunction of the masticatory system. Bruxism (i.e. tooth clenching and/or grinding) is thought to play an important aetiological role in TMD. Among others, bruxism may result in TMD pain and dental attrition. The close relationship between TMD, bruxism, and attrition necessitates an integrated approach to these clinical problems. This could be achieved through the multidisciplinary differentiation 'oral kinesiology', that covers not only the diagnosis and treatment of TMD and bruxism but also the restoration of worn dentitions. This article focuses on the background of oral kinesiology, as well as on the rationale to develop a curriculum for the postgraduate training of dentist-kinesiologists in the Netherlands. Further, the oral kinesiology curriculum of the Academic Centre for Dentistry Amsterdam will be introduced. This curriculum will ensure that specialized professionals, who are able to approach the different aspects of oral kinesiology in an integrated manner, are available not only for general dental practice but also for centres for special dental care and university departments. This will lead to improved care for patients, whose management is until now dispersed between various dental specialists.

Bruxism↗
PubMed2004

Craniomandibular pain, oral parafunctions, and psychological stress in a longitudinal case study.

In a single case study, the most frequently suggested contributing factors to craniomandibular pain, viz., oral parafunctions and psychological stress, were studied in more detail. During a 13-week study period, questionnaires were completed, in which, among others, jaw muscle pain, bruxism behaviour, and experienced/anticipated stress were noted. During about 40% of the nights, nocturnal masticatory muscle activity (NMMA) was recorded, using single-channel electromyography (EMG). The number of NMMA events per recorded hour was scored, using a detection threshold of 10% of the maximum voluntary contraction level. This threshold was established in a separate study, in which EMG was compared with polysomnography. Stepwise regression analyses indicated, that morning jaw muscle pain could be explained by evening jaw muscle pain for 64% and by alcohol intake for another 2%. In turn, evening jaw muscle pain was explained by daytime clenching for 56% and by vacuum sucking of the tongue for an additional 6%. Finally, daytime clenching was significantly explained by experienced stress for 30%. Data of the recorded nights showed, that variations in NMMA did not contribute to variations in morning jaw muscle pain. This case study corroborates the paradigm that experienced stress may be related to daytime clenching and, in turn, to evening and morning jaw muscle pain.

Electromyography↗
PubMed2004

Recognition of internal derangements.

One of the most common symptoms of temporomandibular disorders is an internal derangement (ID). The aim of this study was to test the inter-observer reliability of the recognition of IDs by means of auscultation, palpation or both. To that end, 120 women and 100 men were screened by two trained examiners for the presence of IDs. Anterior disc displacement was diagnosed in 14% of the cases and hypermobility in 12%. In 4% of the cases, the ID was classified as 'other'. The inter-rater reliability (Cohen's kappa) was moderate for the presence of an ID for all techniques, while for the classification into type, an almost perfect reliability was found for the combined technique. It was concluded that the type of ID can best be established with the combination of auscultation and palpation; for the establishment of an ID as such, any of the three techniques would suffice.

Adolescent↗
PubMed2004

[Dental implants in tooth grinders].

Bruxism (tooth grinding and clenching) is generally considered a contraindication for dental implants, although the evidence is usually based on clinical experience only. So far, studies to the possible cause-and-effect relationship between bruxism and implant failure do not yield consistent and specific outcomes. This is partly due to the large variation in the technical and the biological aspects of the investigations. Although there is still no proof that bruxism causes overload of dental implants and their suprastructures, a careful approach is recommended. Practical advices as to minimize the chance of implant failure are given. Besides the recommendation to reduce or eliminate bruxism itself, these advices concern the number and dimensions of the implants, the design of the occlusion and articulation patterns, and the use of a hard nightguard.

Bite Force↗
PubMed2003

Effects of TMJ anesthesia and jaw gape on jaw-stretch reflexes in humans.

OBJECTIVE: To study the roles of afferent sensory inputs in the temporomandibular joint (TMJ) and of muscle length in the modulation of the jaw-stretch reflex in humans. METHODS: Reflexes were evoked in both the masseter and temporalis muscles under standardized conditions in 11 young women. The study was performed in two sessions; experimental conditions were jaw gape and injection of local anesthetics. For jaw gape, 4, 14, and 24 mm were used in random order. One milliliter TMJ injections (carbocaine, 10 mg/ml, versus isotonic saline, 0.9%) were given in a randomized, double blind manner. When a participant received carbocaine during the first session, isotonic saline was injected during the second one. A total of 480 reflexes were evoked in every participant. RESULTS: No significant differences were found between carbocaine and isotonic saline. ANOVA and post hoc paired t tests did show, however, a significant effect of jaw gape for the left masseter and anterior temporalis muscles, with the 14 mm gape having the highest amplitude. CONCLUSIONS: Blocking the afferent sensory input (including the mechanoreceptors) from the TMJ seems to have no influence on the sensitivity of the human jaw-stretch reflex. Instead, muscle spindles are the most likely receptors to be responsible for the reflex modulation that was observed in the present study.

Adult↗
PubMed2002

Variation in masticatory muscle activity during subsequent, submaximal clenching efforts.

In previous studies to the relative contribution of the jaw closing muscles to the maintenance of submaximal clenching levels, a considerable variation in the electromyography (EMG) activities of these muscles during subsequent efforts was found. In this study, it was examined to what extent this variation could be explained by coincidental variations in mandibular positioning. From seven healthy individuals, a total of 90 EMG sweeps was recorded: three conditions (intercuspal position and two types of stabilization appliances) x three clenching levels (10, 30 and 50% of maximum voluntary contraction level) x 10 repetitions. Mandibular position was monitored with a six degrees of freedom opto-electronic jaw movement recording system. Variations in mandibular positioning during subsequent, submaximal clenching efforts explained up to 25% of the variance in the indices that quantify the relative contribution of the jaw closing muscles to the total clenching effort (P=0.000; ANOVA). Only a weak dependency of positioning upon clenching condition was found whereas during higher clenching levels, the positioning effect tended to be smaller than during lower levels. In conclusion small, coincidental variations in mandibular positioning during subsequent clenching efforts partly explain the variance in EMG activity of jaw closing muscles, especially at lower clenching levels.

Adult↗
PubMed2002

Is there a relationship between head posture and craniomandibular pain?

An often-suggested factor in the aetiology of craniomandibular disorders (CMD) is an anteroposition of the head. However, the results of clinical studies to the relationship between CMD and head posture are contradictory. Therefore, the first aim of this study was to determine differences in head posture between well-defined CMD pain patients with or without a painful cervical spine disorder and healthy controls. The second aim was to determine differences in head posture between myogenous and arthrogenous CMD pain patients and controls. Two hundred and fifty persons entered the study. From each person, a standardized oral history was taken and blind physical examinations of the masticatory system and of the neck were performed. The participants were only included into one of the subgroups when the presence or absence of their symptoms was confirmed by the results of the physical examination. Head posture was quantified using lateral photographs and a lateral radiograph of the head and the cervical spine. After correction for age and gender effects, no difference in head posture was found between any of the patient and non-patient groups (P > 0.27). Therefore, this study does not support the suggestion that painful craniomandibular disorders, with or without a painful cervical spine disorder, are related to head posture.

Adult↗
PubMed2001

Psychological distress in chronic craniomandibular and cervical spinal pain patients.

Recent studies to chronic pain have shown that the number of painful body areas is related to the level of psychological distress. Therefore, the first aim of this study was to analyse differences in level of psychological distress between craniomandibular pain patients with or without cervical spinal pain. In this analysis, the number of painful body areas below the cervical spine was also taken into account. The second aim was to determine psychological differences between subgroups of craniomandibular pain patients. In this study, 103 out of 250 persons with or without craniomandibular pain were included in the final analyses. Patients who suffered from both craniomandibular and cervical spinal pain showed higher levels of psychological distress, as measured with the Symptom Checklist 90 (SCL-90) than patients with local craniomandibular pain and persons without pain. Further, a positive relationship was found between the number of painful body areas below the cervical spine, as measured on a body drawing, and the SCL-90 scores. No psychological differences were found between myogenous and arthrogenous craniomandibular pain patients. In conclusion, chronic craniomandibular pain patients with a coexistent cervical spinal pain showed more psychological distress compared to patients with only a local craniomandibular pain and asymptomatic persons.

Adult↗