Biomedical subjects

B Stegenga

Publications and source records attributed to B Stegenga.

At least 37 records · Page 2Linked to original sources

PubMed2003

Craniofacial morphology and obstructive sleep apnoea: a cephalometric analysis.

The craniofacial morphology of 31 male patients diagnosed with obstructive sleep apnoea syndrome (OSAS) and 37 healthy male subjects were compared using cephalometric evaluation of lateral skull radiographs. The aim was to evaluate which cephalometric variables related to craniofacial morphology discriminate between OSAS patients and non-OSAS subjects. Sixteen cephalometric measurements were determined to study the craniofacial morphology. Differences in cephalometric variables between the two groups were analysed with unpaired Student t-tests (significance level 0.05). A multiple regression analysis was used to evaluate the joint predictive value of selected variables. With regard to five variables, significant differences were observed between OSAS patients and non-OSAS subjects (P < 0.05). Data indicated a relatively anterior position of the maxilla, an increase of the mid-facial height and a more inferiorly located hyoid bone in the OSAS patient group. The multiple regression analysis yielded a model discriminating between OSAS patients and non-OSAS subjects, which included two hyoid bone variables and one related with the intermaxillary relationship. A causal relationship between cephalometric variables of craniofacial morphology and OSAS is not sufficiently supported by our data. Presumably, hyoid bone position is of predictive value in the cephalometric discrimination between OSAS patients and non-OSAS subjects.

Adult↗

PubMed2003

Ultrasound stimulation of maxillofacial bone healing.

A substantial part of the maxillofacial surgery practice deals with maxillofacial bone healing. In the past decades, low-intensity ultrasound treatment has been shown to reduce the healing time of fresh fractures of the extremities up to 38%, and to heal delayed and non-unions up to 90% and 83%, respectively. Based on the assumption that the process of bone healing in the bones of the extremities and maxillofacial skeleton is essentially the same, the potential of ultrasound to stimulate maxillofacial bone healing was investigated. Although limited evidence is available to support the susceptibility of maxillofacial bone to the ultrasound signal, ultrasound may be of value in the treatment of delayed unions, in callus maturation after distraction, and in the treatment of osteoradionecrosis.

Animals↗

PubMed2003

A randomized prospective clinical trial on the effectiveness of three treatment modalities for patients with lower denture problems. A 10 year follow-up study on patient satisfaction.

Treatment of lower denture complaints of patients with an edentulous mandible with a height of at least 15 mm can consist of meticulous construction of a new set of dentures (CD), construction of a new set of dentures following preprosthetic surgery to enlarge the denture-bearing area (PPS), or construction of an implant-retained mandibular overdenture (IRO). The aim of this prospective randomized controlled clinical trial was to evaluate the satisfaction of the above mentioned treatment modalities in resolving lower denture related complaints. Ninety edentulous patients (Cawood class IV and V, mean mandibular height 20.7 +/- 2.7 mm) were randomly assigned to one of these treatment modalities. The main outcome parameters were denture satisfaction and chewing ability, which were assessed using validated self-administered questionnaires focusing on denture-related complaints and problems with chewing different types of food. These parameters were measured before treatment, and 1, 5 and 10 years after treatment. Differences among the three groups were tested by applying a one way analysis of variance and a Tukey's test for multiple comparison. At the 1 year evaluation, significantly better scores were observed in the two surgical groups (IRO, PPS) than in the CD group (P<0.05). At 5 year evaluation the 'complaints of the lower denture' showed a significantly better score in the IRO group when compared to the PPS and CD groups (P<0.05). No significant differences were observed between the PPS and CD group. At 10 year evaluation, the intention to treat analysis revealed no significant differences between the three groups, while a per protocol analysis showed that the IRO group was the most satisfied. From this study it is concluded that both on the short and long term denture satisfaction appears most favourable in the IRO group when compared to the PPS and CD groups. Implant-retained overdentures are, therefore, a favourable treatment modality for edentulous patients with lower denture problems.

Adult↗

PubMed2002

Groningen temporomandibular joint prosthesis. Development and first clinical application.

Patients with a severely degenerated temporomandibular joint (TMJ) may benefit from an alloplastic TMJ replacement. The aim of the study was to develop a safe and properly functioning TMJ prosthesis. The design was based on imitation of anterior condylar translation by an inferiorly located centre of rotation, unrestricted mandibular movements by a double articulation, correct fit to the skull by a self-adjusting skull part consisting of two connected parts, and stable fixation by bone screws that are rigidly connected to the prosthesis parts. The prosthesis consists of a titanium skull part with ceramic inlay, a titanium mandibular part with a ceramic spherical head, and an intervening polyethylene disc. Titanium-alloy bone screws are used for fixation. All parts are available in a number of different shapes. In vitro laboratory and in vivo animal tests showed a low wear rate, the possibility of a close fit to the skull, a stable fixation, sufficient mechanical strength, appropriate choice of materials and proper functioning. Thereafter the step to first patient application was made. First patient application was carried out without adverse events. In conclusion, the presented TMJ prosthesis passed the pre-clinical tests and has progressed to clinical application. The fit to the skull, the expected lifetime of the device and the reliability of the implantation procedure require further evaluation in well-designed clinical trials.

Adult↗

PubMed2002

Sialometry and sialochemistry: a non-invasive approach for diagnosing Sjögren's syndrome.

BACKGROUND: Analysis of salivary variables has frequently been proposed as a diagnostic tool for Sjögren's syndrome (SS). Because univocal salivary reference values are lacking, it is currently rather difficult to use sialometry and sialochemistry for diagnosing SS unless major changes have occurred in salivary secretion and composition. OBJECTIVE: To define reference values of several salivary variables, which offer a possible new and non-invasive means of diagnosing SS. METHODS: Cut off points were selected from receiver operating characteristic curves of gland-specific sialometrical and sialochemical variables, which have proved to be potentially relevant for diagnosing SS in a previous study-that is, sodium, chloride, and phosphate concentration in stimulated parotid and submandibular/sublingual (SM/SL) saliva, unstimulated and stimulated SM/SL flow rates, and lag phase of parotid secretion, respectively. By combining the most discriminating variables, two different diagnostic approaches for SS were applied in a group of 100 patients and subsequently evaluated in a second group of 20 patients. The first approach was to combine variables by applying their cut off points into sets of criteria for a positive diagnosis of SS. The second approach was to construct a logistic regression model that predicts the true state of a patient (SS or non-SS). From both approaches, the tests with highest likelihood ratio combined with the smallest number of rejected cases were selected for clinical use. RESULTS: The most accurate test combined the stimulated SM/SL flow rate and parotid sodium and chloride concentration as salivary variables for diagnosing SS; it had a sensitivity of 0.85 and a specificity of 0.96. The selected tests proved equally accurate in the second group of patients. CONCLUSIONS: Because the proposed non-invasive diagnostic tools can be easily applied, do not need a laboratory other than for routine blood testing, and are very accurate, gland-specific sialometry and sialochemistry may eventually replace other, more invasive, diagnostic techniques for diagnosing SS.

Adult↗

PubMed2002

The association between generalized joint hypermobility and temporomandibular joint disorders: a systematic review.

To analyze conflicting evidence in the literature for the association between temporomandibular joint disorders (TMD) and generalized joint hypermobility (GJH), we performed a bibliographic search. The methodological quality of the 14 papers found was assessed according to 14 criteria. Papers were included in the analysis if the study population was clinically relevant, if range of motion of 2 or more joints was assessed on the left and right sides, and if cases had a TMD. Four studies fulfilled these selection criteria. Data from 3 studies, 113, cases and 95 controls, were available for analysis. Twenty-six cases and five controls were hypermobile (odds ratio, 5.4). In a sensitivity analysis, the odds ratio changed from significant to non-significant in 2 of 5 scenarios. As a result, it is not clear whether GJH is associated with TMD, and more rigorous studies are needed.

Adult↗

PubMed2001

Maxillary bone grafting for insertion of endosseous implants: results after 12-124 months.

Insertion of endosseous implants in the atrophic maxilla is often complicated because of lack of supporting bone. Augmentation of the floor of the maxillary sinus with autogenous bone graft has been proven to be a reliable treatment modality, at least in the short term. The long-term clinical and radiographic outcome with regard to the grafts, the implants and satisfaction of the patients with their implant-supported overdenture was studied in 99 patients. The sinus floor was augmented with bone grafts derived from the iliac crest (83 subjects, 162 sinuses, 353 implants), the mandibular symphysis (14, 18, 37), or the maxillary tuberosity (2, 2, 2). Before implant installation, the width and height of the alveolar crest were increased in a first stage procedure in 74 patients, while in the other 25 patients augmentation and implant installation could be performed simultaneously (width and height of the alveolar crest >5 mm). Perforation of the sinus membrane occurred in 47 cases, which did not predispose to the development of sinusitis. Loss of bone particles and sequestration were observed in one (diabetic) patient only, in whom a dehiscence of the oral mucosa occurred. A second augmentation procedure was successful in this patient. Symptoms of transient sinusitis were observed in 3 patients. These symptoms were successfully treated with decongestants and antibiotics. 2 other patients developed a purulent sinusitis which resolved after a nasal antrostomy. In all cases, the bone volume was sufficient for implant insertion. 32 of 392 inserted Brånemark implants (8.2%) were lost during the follow-up. After the healing period of the bone grafts, no sinus pathology was observed. The patients received implant-supported overdentures (72 patients) or fixed bridges (27 patients). Overall, the patients were very satisfied with the prosthetic construction. We conclude that bone grafting of the floor of the maxillary sinus floor with autogenous bone for the insertion of implants is a reliable treatment modality with good long-term results.

Adolescent↗

PubMed2001

Osteoarthritis of the temporomandibular joint organ and its relationship to disc displacement.

To overcome disagreements with regard to the relationship between disc displacement and osteoarthritis of the temporomandibular joint (TMJ), the evidence for suggested disease mechanisms and clinical course of these disorders is reviewed. The TMJ behaves as a complex organ in which biochemical and biomechanical processes regulate the physiology of cartilage, bone, synovium, ligaments, and synovial fluid. In this concept, TMJ osteoarthritis is an organ failure involving all its structures. The development of as well as recovery from disease appears to be intimately related to exceeding and supporting the adaptive capacity of the tissues that make up the joint organ. Loss of fibrocartilage and inflammation appear to be major pathobiologic processes, while serious doubts exist about the significance of disc position in joint pathology.

Adaptation, Physiological↗

PubMed2000

Effectiveness of three treatment modalities for the edentulous mandible. A five-year randomized clinical trial.

Currently, 3 treatment options are available for patients with denture complaints and an edentulous mandible with a height of at least 15 mm: meticulous construction of a new set of dentures (CD), construction of a new set of dentures following preprosthetic surgery to enlarge the denture-bearing area (PPS), and construction of an implant-retained mandibular overdenture (IRO). The aim of this study was to evaluate patient satisfaction and subjective chewing ability of edentulous patients treated with one of these treatment modalities. Ninety edentulous patients (Cawood class IV and V, mean mandibular height 20.7 mm) were randomly assigned to receive 1 of these 3 groups. Denture satisfaction and chewing ability were assessed using questionnaires focusing on denture-related complaints and problems chewing different types of food were assessed before treatment, and 1- and 5-years after treatment. At the 1-year evaluation, significantly better scores were observed in the 2 surgical groups (IRO, PPS) than in the CD group. At 5-year evaluation the "complaints of the lower denture" showed a significantly better score in the IRO group when compared to the PPS and CD groups. No significant differences were observed between the PPS and CD group. From this study it is concluded that both in the short and long term denture satisfaction appears most favourable in the IRO group when compared to the PPS and CD groups. Implant-retained overdentures are therefore a satisfactory treatment modality for edentulous patients with problems with their lower denture, even in cases of not severely resorbed mandibles.

Analysis of Variance↗

PubMed2000

Smallest detectable difference of maximal mouth opening in patients with painfully restricted temporomandibular joint function.

Changes in maximal mouth opening reflect the impact of temporomandibular disorders and the effect of a therapeutic intervention. No information about the amount of change in maximal mouth opening with regard to reasoned decision-making is available. The smallest detectable difference, as a measure of reliability assessment, provides this information and is expressed in the unit of the measurement instrument. Twenty-five consecutive patients (5 males, 20 females) with a painfully restricted temporomandibular joint participated in this study. Measurements of maximal mouth opening were performed by two well-trained observers on two separate measurement days, one week apart. The maximal mouth opening measurements were repeated three times. Inter-observer, intra-observer, and test-retest reliability varied between 0.90 and 0.96. Inconsistency in measurement results analyzed in terms of absolute error variance, i.e. the measurement facets plus all the interactions, represented 11% of total variance. The smallest detectable difference of maximal mouth opening varied from 9 to 6 mm. For being successful in painfully restricted temporomandibular joint patients, statistically as well as clinically, the clinician has to measure at least 9 mm of improvement in maximal mouth opening. To reduce the smallest detectable difference from 9 to 6 mm, repeated measurement is necessary.

Adult↗

PubMed2000

Fitting a temporomandibular joint prosthesis to the skull.

Fitting a temporomandibular joint (TMJ) prosthesis to the skull by using stock prostheses seems to be an appropriate method. However, fitting the skull with one stock part requires many differently shaped parts. Therefore, we fitted the skull with two connected stock parts. The aim of the study was to test whether it is possible to achieve a close fit to the skull with this design, with a maximum of 10 different parts. The articular eminence was fitted with a gully-shaped fitting member, which was rotationally connected to a basic part that fitted to the lateral side of the TMJ. The relevant dimensions of 20 dry skulls were measured and the results were used to derive the optimal dimensions of the prosthesis parts. Prototypes were subsequently fabricated. The fit of the prototypes was tested by measuring the maximum gap between fitting member and skull. All skulls could be fit with a set of four different basic parts and three different fitting members. The average maximum gap between fitting member and skull was 0.20 mm (range 0.11-0.43 mm). It was concluded that a close fit to the skull can be achieved with two connected stock parts and with a total number of seven parts.

Feasibility Studies↗

PubMed2000

A comparison of labial and crestal incisions for the 1-stage placement of IMZ implants: a pilot study.

PURPOSE: The aim of this study was to compare the crestal incision with the labial flap design when inserting a 2-stage implant system in a nonsubmerged manner. PATIENTS AND METHODS: Ten consecutive edentulous patients with a severely resorbed mandible (Cawood Class V to VI) that resulted in reduced stability and insufficient retention of the lower denture were included. In all patients, 2 IMZ implants were inserted in a 1-stage procedure in the mandibular canine regions as part of an implant overdenture treatment. In 5 patients, the labial flap approach was used, and a crestal incision approach was used in the other 5 patients. Standardized evaluations were performed at 2, 6, and 12 weeks after implant placement and 12 months after placement of the new prosthesis. RESULTS: In the first postoperative weeks, more hyperplasia occurred around the implants inserted by the crestal incision than the labial flap. However, after 1 year of function, no striking differences between the 2 groups were present with regard to the clinical and radiographic parameters. CONCLUSIONS: From this pilot study, it was concluded that both the crestal incision and the labial flap approach are reliable procedures for insertion of IMZ implants in a 1-stage procedure. However, because of the smaller risk of soft tissue overgrowth, there is a preference for the labial flap approach.

Adult↗

PubMed2000

[Diagnosis and treatment of orofacial pain].

Management of orofacial pain should address factors that contribute to the continuation of the pain complaint. This requires elimination of etiologic factors, modification of nociceptive mechanisms, and support of adaptive mechanisms. In addition, methods that help the patient to cope with (remaining) complaints should be applied. A specific diagnosis of the pain problem is the basis for successful management. From the history and clinical examination it should become clear whether the pain problem is acute or chronic, whether its characteristics suggest a somatic or neuropathic basis, and whether the experienced pain is primary or secondary (i.e., hyperalgesia, referred pain). It is important to regard pain as a multidimensional phenomenon, in which psychosocial factors are involved. It is the responsibility of the dentist to judge as early as possible whether he/she is capable of managing the pain problem, or further consultation or referral is necessary for diagnosis and/or management.

Acute Disease↗

PubMed2000

[Bruxism and temporomandibular disorders].

Bruxism is generally regarded as an important predisposing as well as an initiating factor in temporomandibular disorders. Many studies have demonstrated an association between bruxism and symptoms and signs of temporomandibular disorders, in adults as well as in children. However, a causal relationship has not been established. Currently, the most probable hypothesis is that other factors, reducing the adaptive capacity of the temporomandibular joint and associated tissues, have to be present for bruxism to play an initiating role.

Adult↗

PubMed1999

Influence of mandibular length on mouth opening.

Theoretically, mouth opening not only reflects the mobility of the temporomandibular joints (TMJs) but also the mandibular length. Clinically, the exact relationship between mouth opening, mandibular length, and mobility of TMJs is unclear. To study this relationship 91 healthy subjects, 59 women and 32 men (mean age 27.2 years, s.d. 7.5 years, range 13-56 years) were recruited from the patients of the Department of Oral and Maxillofacial Surgery of University Hospital, Groningen. Mouth opening, mobility of TMJs and mandibular length were measured. The mobility of TMJs was measured as the angular displacement of the mandible relative to the cranium, the angle of mouth opening (AMO). Mouth opening (MO) correlated significantly with mandibular length (ML) (r = 0.36) and AMO (r = 0.66). The regression equation MO = C1 x ML x AMO + C2, in which C = 0.53 and C2 = 25.2 mm, correlated well (r = 0.79) with mouth opening. It is concluded that mouth opening reflects both mobility of the TMJs and mandibular length.

Adolescent↗

PubMed1999

Therapeutic outcome assessment in permanent temporomandibular joint disc displacement.

In permanent temporomandibular disc displacement (TMJ-DD) outcome studies many authors claim positive effects of arthroscopic surgery, arthrocentesis and physical therapy. This literature review was undertaken to analyse whether the claimed effects are based on acceptable methodology. The recorded papers were analysed by two independent observers according to (1) method of investigation, (2) therapeutic intervention studied, (3) therapeutic outcome variables used, and (4) claimed effectiveness of the intervention. Agreement between observers was calculated. Twenty-four papers were found in which therapeutic outcome of interventions on temporomandibular disorders were studied. Six studies applied a true experimental design. Each of these six studies compared a different set of interventions. Twenty-two papers used maximal mouth opening (MMO) as an outcome variable, nine studied pain intensity on a visual analogue scale, one paper assessed the mandibular function impairment questionnaire. Kappa for overall agreement concerning the reviewing criteria was 0.82 (P < or = 0.001). No distinguishing effects on MMO, pain or function impairment were reported between arthroscopic surgery, arthrocentesis and physical therapy. Results of methodological sound outcome studies evaluating the effects of arthroscopic surgery, arthrocentesis and physical therapy are needed.

Arthroscopy↗

PubMed1999

The theoretical optimal center of rotation for a temporomandibular joint prosthesis: a three-dimensional kinematic study.

A unilateral temporomandibular joint (TMJ) prosthesis may cause dysfunction of the contralateral, natural TMJ because of lack of translatorial movements of the prosthetic side. The natural translatorial capacity of the mandible can be restored in part by a TMJ prosthesis with a fixed center of rotation (CR), positioned inferiorly to the center of the natural mandibular condyle. The aim of this study was to determine the optimal position for the fixed CR of a unilateral TMJ prosthesis. A mathematical model was used to analyze different positions of the CR. These positions were evaluated based on the calculated rotation of the mandible in the frontal (theta f) and horizontal (theta h) plane, and the mediolateral movement (MLM) of the contralateral natural condyle. For current TMJ prostheses, with the CR positioned in the center of the natural condyle, theta h exceeded the natural limits. When the CR was shifted inferiorly, all parameters improved, particularly theta h. The addition of an anterior shift to an inferior shift slightly worsened theta f, while the addition of a posterior shift to an inferior shift slightly improved theta f and worsened MLM. We concluded that the functioning of the contralateral TMJ improves by shifting the CR inferiorly. An anterior shift may be added to remain within the contour of the mandibular ramus. The proposed position of the CR is 15 mm inferior to the center of the natural condyle, combined, if necessary, with an additional anterior shift of 5 mm.

Humans↗

PubMed1999

Smallest detectable difference in outcome variables related to painful restriction of the temporomandibular joint.

The smallest detectable difference is the smallest statistically significant change in measurement results. In the field of temporomandibular disorders, the smallest detectable difference is not a commonly used concept. Most outcome studies are based on comparisons of group means, although this does not provide information about individual changes or about the clinical relevance thereof. The smallest detectable difference for maximal mouth opening was calculated from previously published reliability coefficients and the standard deviations of different samples of healthy subjects and patients with complaints of the temporomandibular joint. The smallest detectable difference of pain intensity measured with different visual analogue scales was calculated from the reliability coefficients and standard deviations of a heterogeneous group of pain patients. The smallest detectable difference of function impairment was calculated for a group of patients with complaints of the temporomandibular joint. For maximal mouth opening in healthy subjects, the smallest detectable difference was 5 mm. Repeated measurements improved it to 3 mm. The smallest detectable difference on a visual analogue scale was 28 mm for actual pain intensity and 22 mm for minimal pain as well as for maximal pain intensity. For total function impairment of patients with complaints of the temporomandibular joint, the smallest detectable difference was 8 units on a 0 to 68 scale.

Adult↗