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Biomedical subjects

B Stegenga

Publications and source records attributed to B Stegenga.

At least 19 recordsLinked to original sources
PubMed2006

A long-term in vitro biocompatibility study of a biodegradable polyurethane and its degradation products.

The biological safety of degradation products from degradable biomaterials is very important. In this study a new method is proposed to test the cytotoxicity of these degradation products with the aim to save time, laboratory animals, and research funds. A biodegradable polyurethane (PU) foam was subjected to this test method. The PU had soft segments of DL-lactide/epsilon-caprolactone and hard segments synthesized from butanediol and 1,4-butanediiosocyanate. Copolymer foams without urethane segments, consisting of DL-lactide/epsilon-caprolactone, were tested as well. Accumulated degradation products were collected by degrading the foams in distilled water at 60 degrees C up to 52 weeks. Cell-culture medium was prepared from powder medium with this water. In different tests the cytotoxicity of this medium was established. The first signs of cytotoxicity were observed after 3-5 weeks of degradation. This accounts for both materials and reestablishes the good short-term biocompatibility of these materials. The PU showed more toxicity toward the end stages of degradation in comparison with the copolymer. This is probably related to the accumulation of degradation products of the urethane segments. In the in vivo situation the degradation of the PU and the metabolism and excretion of degradation products may differ. Therefore, long-term in vivo studies will have to establish whether these in vitro results are representative for the in vivo behavior of the degrading PU.

Absorbable Implants↗
PubMed2006

Efficacy and safety of biodegradable osteofixation devices in oral and maxillofacial surgery: a systematic review.

The use of osteofixation devices should be evidence-based if uncomplicated bone healing is to be achieved. Numerous studies describe and claim the advantages of biodegradable over titanium devices as a bone fixation method. Here, we systematically review the available literature to determine the clinical efficacy and safety of biodegradable devices compared with titanium devices in oral and maxillofacial surgery. In addition, related general aspects of bone surgery are discussed. We conducted a highly sensitive search in the databases of MEDLINE (1966-2005), EMBASE (1989-2005), and CENTRAL (1800-2005) to identify eligible studies. Eligible studies were independently evaluated by two assessors using a quality assessment scale. The study selection procedure revealed four methodologically 'acceptable' articles. Owing to the different outcome measures used in the studies, it was impossible to perform a meta-analysis. Therefore, the major effects regarding the stability and morbidity of fracture fixation using titanium and biodegradable fixation systems were qualitatively described. Any firm conclusions regarding the fixation of traumatically fractured bone segments cannot be drawn, due to the lack of controlled clinical trials. Regarding the fixation of bone segments in orthognathic surgery, only a few controlled clinical studies are available. There does not appear to be a significant short-term difference between titanium and biodegradable fixation systems regarding stability and morbidity. However, definite conclusions, especially with respect to the long-term performance of biodegradable fixation devices used in maxillofacial surgery, cannot be drawn.

Absorbable Implants↗
PubMed2006

[Gagging during oral health care treatments. Available diagnostic and treatment tools].

The aim of this paper was to explore the diagnostic and treatment tools for patients who gag during oral health care treatment. Reference to such tools is not available in scientific literature. For diagnostic purposes, a questionnaire was developed. In due course the results of its reliability and validity will be published. As yet there is no preferred method of dealing with the problem of patients' gagging. A recommended option to treat the problem is based on a cognitive behavioural perspective with gradual exposure in vivo. In cases of extreme gagging, teamwork of oral health care provider and psychologist seems to be a prerequisite for success.

Dental Care↗
PubMed2006

[Examination for focal infections: sensible or superfluous?].

Detection of focal infections aims at the identification and subsequent treatment of sources of odontogenic inflammation in order to prevent health threats in patients who are often medically compromised. Examination for dental foci often precedes medical treatment of patients with increased risks of endocarditis, patients with a joint prosthesis, patients scheduled for chemotherapy or head and neck radiotherapy or candidates for organ transplantations. Although examination for possible sources of dental inflammation is performed on a routine basis in many hospitals, the scientific basis for this policy apparently is very limited, and there is an evident need for well-designed randomized clinical trials in this field.

Focal Infection, Dental↗
PubMed2006

[Manifestations of orofacial pain. Preface].

Pain is possibly the most common reason for patients to seek dental help, and is, therefore, a phenomenon with which dentists are frequently confronted. This special issue of the Dutch Dental Journal considers several aspects of orofacial pain as they are presented by patients. Both common and less frequent disorders causing pain in the orofacial area are described and discussed.

Diagnosis, Differential↗
PubMed2006

[Diagnosis and classification of orofacial pain by dental and general practitioners].

Dental practitioners as well as general practitioners are frequently confronted with patients complaining of pain in the orofacial region. Diagnosing these pains often poses a challenge to the clinician. Currently, the diagnosis of orofacial pains is biaxial. In determining a diagnosis, it is important to consider, in addition to the condition which is causing the pain (axis I-diagnosis), the impact of the pain on the patient's ability to function (axis II-diagnosis). The compilation of a thorough medical history represents the most important diagnostic tool and basis for clinical examination. Based on the axis I-diagnosis several treatment options are suggested; the strategy for managing the pain is, however, largely determined by the axis II-diagnosis.

Adult↗
PubMed2006

[Tooth and molar pains].

A patient's pain history is the primary source of information in case of toothache (dentoalveolar pain); revealing its location, its main characteristics and its course, both from the onset and during the day. Clinical diagnostic tests that provoke (such as pulp testing or percussion) or eliminate (such as local anaesthesia) pain are most useful. Several mechanisms may underlie dentoalveolar pain. Pain caused by pulpitis shows characteristics of visceral types of pain, whereas pain originating from the periodontal ligament is characterized by musculoskeletal features. It also happens fairly often that the pain is found to originate from a different tooth than the one in which it is perceived, or from an even more distant source (referred pain). These mechanisms emphasize the importance of differential diagnostics.

Anesthetics, Local↗
PubMed2006

[Pain on mandibular movements].

Pain or fatigue in the masticatory muscles or pain in the temporomandibular joints are well-known complaints. Diagnosing these complaints, that have a relation with mandibular movements, can be challenging since they can arise from the teeth and surrounding tissues, the temporomandibular joints or other musculoskeletal structures. Also referred pains are a common finding in this area. Pain history and clinical examination are crucial for a comprehensive diagnosis. Besides the disorders underlying the pain (so called axis I), the impact of the pain on the patient's physical and psychosocial functioning can play an important role in the diagnosis (axis II).

Craniomandibular Disorders↗
PubMed2005

Short-term in vitro and in vivo biocompatibility of a biodegradable polyurethane foam based on 1,4-butanediisocyanate.

In this study short-term in vitro and in vivo biocompatibility apects of a biodegradable polyurethane (PU) foam were evaluated. The PU consists of hard urethane segments and amorphous soft segments based on a copolyester of dl-lactide and epsilon-caprolactone. The urethane segments are of uniform length and synthesized with 1,4-butanediisocyanate. The foam has good mechanical properties and will be used for tissue regeneration applications. Degradation tests were carried out in a buffer solution for twelve weeks. Cytotoxicity was determined using extract and direct contact test methods with incubation periods varying form 24 to 72 h. The foam was implanted subcutaneously for one, four and twelve weeks and the tissue response to the material was histologically evaluated. In vitro, the mass loss was 3.4% after twelve weeks. In the cytotoxicity tests the PU caused no abnormal growth behaviour, nor morphological changes or inhibition in metabolic activity. The in vivo studies showed no toxic tissue response to the PU. Connective tissue ingrowth, accompanied by vascular ingrowth was complete at twelve weeks. In vivo degradation had started within four to twelve weeks. In conclusion, the PU shows a good in vitro and in vivo biocompatibility in these short-term experiments.

Absorbable Implants↗
PubMed2005

Function impairment and pain after closed treatment of fractures of the mandibular condyle.

BACKGROUND: To determine the prognosis of fractures of the mandibular condyle after closed treatment. METHODS: Patients (n = 144) with a fracture of the mandibular condyle, all treated closed, were included in the study. Fracture types and position of the fracture parts were determined on radiographs. Follow-up was after 12 months in which the average pain, experienced during the last week (visual analog scale, 100 mm), and mandibular functioning were assessed (mandibular function impairment questionnaire (MFIQ)). RESULTS: Data of 116 (81%) patients, 41 women (35%) and 75 men (65%), were available for analysis. Condylar neck fractures were most common (52%). Bilateral fractures were present in 28% of the patients. Pain (visual analog scale score >0) was found in 9% of the patients. Impaired mandibular function was found in 40% (MFIQ >0) and 24% (MFIQ > or =4) of the patients. The most important risk factor for pain was being a woman. The most important risk factors for function impairment were > or =25 years of age and gross displacement of the fracture parts. CONCLUSION: The overall prognosis of mandibular function and pain after closed treatment of condylar fractures is good. The most important risk factor for pain persisting for 1 year after closed treatment of a condylar fracture is being a woman. The most important risk factors for function impairment are an age of > or =25 years and gross displacement of the fracture parts.

Age Factors↗
PubMed2005

Masticatory function in patients with an extremely resorbed mandible restored with mandibular implant-retained overdentures: comparison of three types of treatment protocols.

The objective of the present study was to analyse the effects of implant supported overdentures on masticatory function in patients with an extremely resorbed mandible, and to compare the masticatory function in these patients using three differing types of implant treatment protocols. The mandibular overdentures were retained by a transmandibular implant, by four endosseous implants following augmentation of the mandible, and by four short endosseous implants, respectively. Sixty patients (50 women, 10 men, mean age 59.4 years) were randomly allocated to one of the three treatment groups. Masticatory function was assessed before and after treatment using a questionnaire, a masticatory performance test, and a structured interview. The patient-based masticatory function improved significantly. Concerning these parameters there were no significant differences between the three groups before and after treatment. A significant difference existed between the three groups for the laboratory-assessed masticatory function before treatment, but after treatment this difference was no longer significant. From this study it can be concluded that patients with an extremely resorbed mandible and functional complaints of their lower denture report significant improvement in masticatory function after implant-overdenture treatment. Differences in masticatory function between the three studied modalities were not significant after treatment.

Aged↗
PubMed2005

An animal model for oroantral communications: a pilot study with Göttingen minipigs.

A pilot study was performed to investigate whether the Göttingen minipig is a suitable animal model for creating and closing oroantral communications (OACs) and to test whether these defects can be closed with a biodegradable polyurethane (PU) foam. In three adult minipigs, an OAC was created on both sides of the maxilla. The left side was closed by a standard surgical buccal flap procedure, the right side by applying a PU foam. The pigs were killed after two weeks, one month and three months, respectively. Postmortem and histological examination showed that an OAC was created in only one of six cases. In the remaining cases, the infraorbital canal was perforated instead of the floor of the maxillary sinus. It was concluded that the Göttingen minipig is not a suitable animal model for OAC investigations. As a result, the closure of OACs with a biodegradable PU could not be evaluated.

Animals↗
PubMed2005

[Trigeminal neuralgia by an acoustic neuroma. The need of imaging].

In a 43-year old female with neuralgia of the second and third branch of the trigeminal nerve, the diagnosis was made on the basis of clinical findings. After the patient was treated with 2 x 200 mg of carbamazepine, all initial symptoms resolved, which confirmed the diagnosis. To distinguish between idiopathic and secondary trigeminal neuralgia, magnetic resonance imaging was scheduled. This investigation showed an acoustic neuroma in the cerebellopontine angle. Without magnetic resonance imaging this benign tumour would be diagnosed in a much later stage and the patient would have suffered unnecessary co-morbidity. Due to the relatively high incidence of secondary trigeminal neuralgia, routine magnetic resonance imaging in patients with a trigeminal neuralgia is justifiable.

Adult↗
PubMed2004

Efficacy and co-morbidity of oral appliances in the treatment of obstructive sleep apnea-hypopnea: a systematic review.

The Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS) is a common sleep-related breathing disorder characterized by repetitive obstructions of the upper airway during sleep. Modification of pharyngeal patency by Oral Appliance (OA) therapy has been suggested as an alternative to various treatment modalities for OSAHS. To determine the evidence base with respect to the efficacy and co-morbidity of OA therapy in OSAHS, we conducted a systematic review of the available literature. Primary outcome measures were the reduction in number of upper-airway obstructions and co-morbidity related to the craniomandibular or craniofacial complex, respectively. Eligible studies regarding efficacy were independently assessed by two assessors using a quality assessment scale. Effect sizes of methodologically sound studies were calculated. In identical interventions, effect sizes were pooled with the use of a random-effects model. Given the scarcity of controlled studies related to co-morbidity, appraisal was confined to a description of eligible studies. Sixteen controlled trials related to efficacy were identified. With respect to the primary outcome measure, OA therapy was clearly more effective than control therapy (pooled effect size, -0.96; 95% confidence interval [CI], -1.49 to -0.42) and possibly more effective than uvulopalatopharyngoplasty. Although patients generally preferred OA therapy, improvement of respiratory variables, such as the number of upper-airway obstructions, was usually better in Continuous Positive Airway Pressure (CPAP) therapy (pooled effect size, 0.83; 95% CI, 0.59 to 1.06). Moreover, specific aspects related to OA design may influence patient-perceived efficacy and preference. Twelve patient-series and one controlled trial related to co-morbidity were identified. Analysis of the data suggests that OA therapy may have adverse effects on the craniomandibular and craniofacial complex. Although CPAP is apparently more effective and adverse effects of OA treatment have been described, it can be concluded that OA therapy is a viable treatment for, especially, mild to moderate OSAHS. Controlled studies addressing the specific indication and co-morbidity of OA therapy are warranted.

Comorbidity↗
PubMed2004

[Vicryl Rapide versus Safil Quick. A prospective comparison of two fast resorbing suturing materials].

Currently, there are two fast-resorbing suturing materials on the Dutch market, viz. Vicryl Rapide and Safil Quick. The aim of this study was to compare the clinical suitability of both suturing materials, which was defined as minimal discomfort or pain for the patient, good knot security and tensile strength, predictable resorption, minimal tissue response, and good wound healing. In a group of 120 patients (60 patients randomized in each group), who were referred for apectomy, the clinical suitability of Vicryl Rapide and Safil Quick as fast-resorbing suturing materials was prospectively studied. The results showed that the tested materials were equivalent with regard to most aspects of their clinical suitability.

Absorption↗
PubMed2004

[Nerve injury during mandibular third molar surgery. The importance of preoperative diagnosis and surgical skill].

A 26-year-old woman was referred by a dentist to an oral and maxillofacial surgeon after an unsuccessful attempt to remove a mandibular third molar. A panoramic radiograph showed the remaining root of the third molar and the patient suffered from insensitivity of the lower lip. The root of the third molar was removed surgically. The sensitivity of the lip recovered completely within three months. Injury of the inferior alveolar nerve and the lingual nerve is a serious complication after mandibular third molar removal. The inferior alveolar nerve is at risk for injury if the third molar root is intimately connected with the mandibular canal. Refraining from preoperative clinical and radiographic diagnostics is malpraxis. Surgical skill is a prerequisite to reduce the risk of nerve injury.

Adult↗
PubMed2004

[Root canal retreatment or surgical apicoectomy?].

Failure of root canal therapy is usually due to re-infection of the root canal system. In most of these cases, an endodontic retreatment is indicated. Patients with persisting apical periodontitis frequently are referred to an oral surgeon for apical surgery, although endodontic retreatment would have been possible in a majority of these cases. When endodontic retreatment is not possible or does not resolve the patient's problems, surgical apicoectomy or extraction might be the only possibilities left. Apical surgery is usually performed by an oral sugeon or by a specially trained dentist. In most surgical clinics beveled resection, followed by an preparation and restoration is performed. New developments, such as microscopic sugery, ultrasonic preparation and newly developed restorative materials are described in this article. Since there is a lack of well-designed comparative clinical studies, no definite conclusions can be drawn with regard to the clinical value of these modern techniques.

Apicoectomy↗