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Biomedical subjects

G Widmark

Publications and source records attributed to G Widmark.

At least 19 recordsLinked to original sources

Histologic evaluation of the bone integration of TiO(2) blasted and turned titanium microimplants in humans.

Twenty-seven patients received 2 microimplants each during implant surgery. One microimplant was blasted with 25 microm sized particles of TiO(2); the other was left as machined i.e. a turned surface. Before insertion the surface topography was characterized with an optical confocal laser profilometer. The surface roughness was greater than standard implants, and was similar for both surface modifications averaging over all parts of the implant i.e. tops, valley and flanks. The mean surface roughness from flank measurements only replicated previously reported findings: i.e. significantly rougher surfaces on blasted implants. After a mean healing period of 6.3 months in the maxillae and 3.9 months in the mandible, the microimplants and surrounding tissue were removed with a trephine burr. The histomorphometrical evaluation demonstrated significantly higher bone-to-implant contact for the blasted implants, inserted in the maxilla or in the mandible. Significantly more bone was found inside the threaded area for the blasted implants in the mandible, but there was no difference for implants positioned in maxillae.

Aged↗

Nonresorbable versus resorbable sutures in oral implant surgery: a prospective clinical study.

BACKGROUND: Regarding the Brånemark implant system, nonresorbable sutures have been advocated for reapproximation of the flaps. Fast-absorbable sutures are frequently used in oral surgery, which is convenient for both the patient and the surgeon. It would be advantageous if fast-absorbable sutures are suitable in implant surgery as well. PURPOSE: The purpose of this study was to compare irradiated polyglactin 910 (Vicryl Rapide, Ethicon GmbH, Norderstedt, Germany) suture with a nonresorbable polyfilament suture (Supramid, Schwarz, Resorba GmbH, Nürnberg, Germany) used in oral implant surgery. MATERIALS AND METHODS: The study comprised 101 edentulous patients (52 females, 49 males) who were provided with 350 Brånemark implants. They were randomized to receive either Vicryl Rapide suture (n = 61) or 3-0 Supramid suture (n = 40). The patients were evaluated after 10 days and at the time of abutment surgery. Any wound complications and implant losses were recorded. RESULTS: The implant failure rate at abutment surgery was low (1.2%), and no difference was seen between the two suture groups. A higher incidence of complications (mainly wound dehiscence) was found in the absorbable suture group, especially when a continuous suture was used. CONCLUSIONS: The results of this study indicate that it is possible to use irradiated polyglactin 910 sutures in oral implant surgery without affecting the rate of early implant failure. However, it is recommended to add interrupted "security sutures" if a continuous suture technique is used in combination with fast-absorption suture material.

Absorbable Implants↗

Changes in function and in pain-related and cognitive-behavioral variables after arthroscopy of temporomandibular joints.

The purpose was to prospectively evaluate changes in clinical, pain, and cognitive-behavioral variables in a structurally homogenous group of patients with painful temporomandibular joints (TMJ), who had undergone an identical intervention, arthroscopy. Twenty-six consecutive patients who had previously undergone unsuccessful conservative treatment participated. They were evaluated with the Craniomandibular Index (CMI), pain-related measures on visual analogue scales (VASs) for 1 wk, questionnaires, and the Multidimensional Pain Inventory (MPI). The mean CMI decreased significantly, from 0.28 to 0.18, 3 months after surgery. Pain measures also decreased significantly as rated on questionnaires, and "at worst" and "most of the time" on VASs. Intrapsychic variables related to pain also decreased significantly, while interpersonal and activity measures remained unchanged. An overall MPI dysfunctional variable correlated significantly with pain. Few further changes were observed at 12 months. Lysis and lavage of the upper TMJ compartment appears to effectively alleviate persisting functional and pain-related symptoms with low morbidity, in line with previous findings. Recoveries seem to be accompanied by changes in certain pain-related cognitive-behavioral variables within a limited sphere. Biological and intrapsychic features may interact with interpersonal factors in a complicated way in patients with orofacial pain.

Adaptation, Psychological↗

Augmentation of exposed implant threads with autogenous bone chips: prospective clinical study.

BACKGROUND: Autogenous bone chips can be harvested during drilling of implant sites and may be used as a graft material for bone augmentation and coverage of exposed implant threads. PURPOSE: The aim of this prospective study was to evaluate the possibility of augmenting exposed implant threads with autogenous bone chips. MATERIALS AND METHODS: Twenty-one consecutive patients treated with screw-shaped oral implants with exposed threads due to buccal fenestration or marginal defects were augmented with autogenous bone harvested with a bone trap during drilling of the implant site. Both marginal (9 sites) and fenestration defects (12 sites), with 4 to 14 exposed implant threads, were registered clinically and with photography. The number of exposed implant threads was measured before and at second-stage surgery 6 months after augmentation. RESULTS: Complete bone coverage of the exposed implant threads was seen in 12 of the 21 implant sites. Six sites showed one to two remaining exposed threads, two showed about 40% coverage, and one showed flattening of the defect but with eight of nine exposed threads at 6 months follow-up. The mean bone gain was 81% in patients with a marginal defect and 82% in patients with a fenestration defect. CONCLUSION: The results from this clinical study show that it is possible to gain bone over exposed implant threads by augmentation with autogenous bone chips.

Adolescent↗

Mandibular bone graft in the anterior maxilla for single-tooth implants. Presentation of surgical method.

Nine patients with 10 implants were included in the study. A bone graft from the symphyseal region of the mandible was used to augment the ridge 4 months before implant insertion. All implant sites showed a sufficient amount of bone at the time of implant insertion. One implant was not integrated at the time of abutment connection. Bone resorption after augmentation was assessed by measurements of the width of the alveolar ridge at four different levels. The measurements were performed before and after the bone-grafting procedure, at implant insertion and at abutment connection. The bone resorption in the buccal/palatal direction was 60% when measured from the time of bone grafting to abutment connection. The bone resorption was already obvious after 4 months (25%). The results indicate that the described bone grafting technique is applicable in patients with a narrow alveolar ridge, even though the resorption of the graft was extensive.

Adolescent↗

Diskectomy in temporomandibular joints with internal derangement: a follow-up study.

OBJECTIVE: To follow up a series of patients treated consecutively who had undergone a diskectomy 2 years previously because of persistent pain and disk displacement in the temporomandibular joint. STUDY DESIGN: Sixteen subjects rated their current symptoms during 1 week and were systematically examined for signs of temporomandibular disorders clinically and radiographically by independent observers. RESULTS: Subjectively, all subjects were satisfied with the operation. Five rated their current pain as significant during masticatory function. Some signs of temporomandibular disorders, usually related to function, were registered in all subjects. Postoperative mandibular movements were improved but still below normal range. Signs and symptoms correlated significantly. Surgical complications were nonexistent, but radiographic changes were extensive. Erosion and flattening of the condyle were common. CONCLUSIONS: It was verified that subjects with persistent pain and disk displacement benefit subjectively and clinically from diskectomy. The radiographic outcomes appear less encouraging. Only prospective, randomized, and controlled studies can eventually clarify the effectiveness of diskectomy in relieving pain caused by displacements in the temporomandibular joint.

Adult↗

Cognitive-behavioral profiles among different categories of orofacial pain patients: diagnostic and treatment implications.

Psychological homogeneity in temporomandibular disorders (TMD) is not conclusive. The multidimensional pain inventory (MPI) has previously identified 3 cognitive-behavioral profiles in TMD and chronic pain patients. Our aims were to replicate these findings in another cultural setting and relate the profiles to the diagnosis and to the treatment demand and outcome. The MPI was administered to 112 referrals comprising 6 categories of patients diagnosed with TMD or intractable orofacial pain. Dysfunctional profiles (high in pain and distress) were most common in patients with orofacial pain of obscure origin and more common in myofascial pain patients than in patients with other TMD diagnoses. Interpersonally-distressed profiles were found in all categories. Among patients with disk displacement, the 3rd profile (adaptive copers with low pain and distress and high control and activity) was most common in earlier successfully diskectomized patients and least common in those about to undergo invasive interventions. A dysfunctional profile was associated with treatment failure, conservative or surgical, and with the demand for radical therapy. Some support for a cyclical causality between pain and psychological factors was found. It is concluded that the robustness of the MPI as a relevant assessment instrument was further strengthened.

Adaptation, Psychological↗

Management of chronic orofacial pain: attitudes among patients and dentists in a Swedish county.

The purpose was to survey attitudes towards management of chronic orofacial pain (COP). Questionnaires were mailed to 30 randomized dentists and to 30 consecutive COP patients, examined 16 months earlier by a pain group of dental specialists. Fifty-seven per cent of the patients reported that their pain was the same as or worse than before and was disturbing. Few were dissatisfied with the examinations. Fifty-nine per cent thought that the consultations had been good. The surveyed dentists judged the most common causes of COP to be neurogenic and psychogenic in origin; they were overwhelmingly positive to the idea of a pain group (93%) and could consider referring patients (97%). Pain-inducing local diseases occurred but were not dominant among these COP patients. We concluded that management of COP in a pain group appears to be meaningful, as reflected by the respondents' attitudes but would gain by a closer collaboration with medical expertise.

Adult↗

On surgical intervention in the temporomandibular joint.

The aim of this thesis was to evaluate the indications for and the results of temporomandibular joint (TMJ) surgery in patients with long-standing severe orofacial pain and dysfunction as well as in patients with fractures of the condylar neck. The patients with long-standing pain and dysfunction had had symptoms for a mean time of 4 years, had been treated conservatively for a mean time of 2.5 years, and had undergone numerous conservative treatment methods without improvement except for a minor increase in mouth opening capacity. The indications for surgery were strict; only 1% or less of all the patients referred to the departments with a diagnosis of temporomandibular disorder (TMD) were prescribed surgery, which was considered to be the only remaining option. The TMJ surgery reduced pain, sleeping problems, and analgesic consumption and improved mouth opening capacity. The procedure showed low morbidity except for a facial nerve disturbance in three patients. Postoperatively, the bite force was observed to be normalised, and the radiographic examination showed moderate to severe osteoarthrotic changes. These changes, though extensive, were considered to be the normal outcome of diskectomy and without clinical significance, even though they resembled degenerative joint disease. In study V, surgery was performed on patients with a clear diagnosis of anterior disk displacement (ADD) with or without reduction. The preoperative pain and mouth opening capacity were markedly improved as well as other subjective symptoms. Although surgical morbidity was low, some radiographic changes were clearly detectable. In agreement with earlier reports, patients with a distinct diagnosis of ADD with or without reduction were clearly helped by diskectomy. In cases of ADD with or without reduction, it can be concluded that unsuccessful conservative treatment should not exceed 3-6 months but be discontinued in favour of the documented advantages of surgery in these cases. Patients with ankylosis should be treated surgically without delay. Unclear diagnoses such as arthralgia and osteoarthrosis with symptoms should be excluded from surgery unless overlapping muscular hyperactivity has been excluded as a major cause of the patients problem. Diskectomy is a useful surgical procedure for patients with severe long-standing TMD. It was shown in study VI that patients with dislocated fractures of the condylar neck can be successfully treated with open surgical reduction when the dislocation is large and associated with symptoms and limited function. When cognitive-behavioural profiles were measured psychometrically in study VII, a dysfunctional profile was more common in patients with myofascial pain and pain with an obscure origin than in other patients diagnosed with TMD. The dysfunctional profile was also common in patients in whom treatment of a conservative or surgical nature had failed. Among TMD patients with disk displacement, adaptive copers were most common in successfully diskectomized patients and least common in patients about to undergo invasive treatment.

Adaptation, Psychological↗

Structural alterations in the TMJ disk in patients surgically treated for internal derangements (ADD).

Twenty-eight patients with temporomandibular dysfunction problem have been subjected to diskectomy unilaterally. The diagnosis was in 23 patients ADD (anterior disk displacement) without reduction and in another five ADD with reduction. The disk was removed in total according to a routine procedure. Surgical observation of a firm connection between the inferior surface of the disk and the condylar head was noted in eighteen patients. The disk tissue was orientated on a cork sheet according to its position in the fossa and subjected to histological examination. Histopathological analysis showed that the posterior attachment was a considerable part of the specimen in 12 out of 28 disks. Splitting of the disk was confined to the inferior surface. Chondrocytes were found close to the inferior surface. Surface irregularities, tags, were noticed on the inferior surface in thirteen cases. However, cellular signs of inflammation were found in the retrodiskal tissue in eight cases.

Adult↗

Open reduction of subcondylar fractures. A study of functional rehabilitation.

Open reduction of dislocated subcondylar fractures was carried out in 19 adult patients between 1990 and 1992. A comparison of the results between two groups of patients was made 1 year after trauma. The reference group consisted of patients with the same type of fracture but treated with only intermaxillary fixation (IMF) and moderate jaw exercises after release of IMF. Dysfunction of the masticatory system was noticed in only a few cases of either group. Open reduction with plate osteosynthesis made it possible to avoid IMF in 12 of 19 patients. The results in the two groups did not differ significantly from a functional point of view. There are, however, specific indications for open reduction based on the degree of dislocation and concomitant subjective symptoms.

Adolescent↗

Radiographic morphology in the temporomandibular joint after diskectomy.

The purpose of the study was to evaluate the radiographic appearance in the temporomandibular joint after diskectomy in patients refractory to conservative treatment. The diskectomies were performed in patients in which the common diagnosis were internal derangement or symptoms of osteoarthrosis. Postoperative radiographs were taken in 25 patients after 1-17 yrs and compared with the preoperative from both the operated and the nonoperated joints. Moderate to severe osteoarthrotic changes were found on the operated side in all but two patients in contrast to on the nonoperated side where such changes were absent in all patients except in one who had minor to moderate changes. The radiographic examinations showed flattening of the condylar head but also irregularities and bone apposition. In almost all patients the fossa showed a sclerotic surface, flattening but only occasionally bone apposition and irregularities. Sclerotic changes were found in about 50% of the patients but erosions only rarely. Similar postsurgical changes were also seen on the articular eminence. A reduced joint space was seen in 18 patients. The postsurgical radiographic changes are the normal out come of diskectomy and do not have clinical significance even though they resemble degenerative joint disease.

Adult↗

Evaluation of TMJ surgery in cases not responding to conservative treatment.

The aim of the study was to evaluate the treatment outcome after temporomandibular joint (TMJ) surgery, which was performed in 33 patients (27 women and six men) between 1970 and 1986. Before surgery, the patients received different types of conservative treatment for an average time of 29 months. The most common diagnosis was anterior disk displacement (ADD) with or without reduction (n = 10), followed by unspecified arthralgia (n = 8), osteoarthrosis (n = 7) and ankylosis (n = 4). Standardized clinical records served as the basis for comparison of symptomatology at comparable time points. Furthermore, 31 of the 33 patients were subjected to a clinical follow-up, including anamnestic, clinical, radiological and cast analysis, 2-17 years after operation. Pain, sleeping problems and consumption of analgesics were significantly reduced after surgery. The anamnestic, as well as the clinical dysfunction indices, according to Helkimo, were also significantly reduced. TMJ clicking was reduced, but crepitations increased in number. The best improvements were seen in patients with ADD without reduction and in patients with ankylosis.

Ankylosis↗

Functional evaluation after TMJ surgery.

Oral function was evaluated in 30 patients (25 women and five men) after TMJ surgery by means of bite force measurements. Twenty-seven discectomies and three condylectomies had been performed. The follow-up period was, on average, 2.5 years. The mean bite force values on the function level 'biting as when chewing' was for the whole group 125.3 N on the right side and 128.8 N on the left side. The maximal bite force was on average 362.5 N and maximal endurance time on average 32 s. All test results showed big ranges. No significant differences between right and left side or operated and non-operated side could be found on the tested function level 'biting as when chewing'. The found bite force values were high in comparison with another similar study. The results were also compared with another group of patients (n = 6) who were examined before and 6 months after surgery. As far as bite force reflects oral function the results are indeed very encouraging.

Bite Force↗

Correction of open bite by maxillary osteotomy. A comparison between bone plate and wire fixation.

A clinical and cephalometric standardized study of surgical correction of open bite deformity was performed on 19 individuals. The mode of fixation of the maxilla after surgical correction was by direct wires in 9 of the patients combined with suspension wires to the infraorbital rim and in 10 patients plate fixation. The follow-up time was 18 months and the results in both groups were clinically and cephalometrically stable in the short (2 and 6 months) and medium terms (18 months). No statistically significant difference was found between the groups regarding tendency to relapse. It was, however, concluded that the advantages of plate fixation both on clinical grounds and for patient comfort are factors in favour of using miniplates for maxillary surgical procedures.

Adolescent↗

Effects of conservative treatment in patients who later will be candidates for TMJ surgery.

In an attempt to evaluate the effect of conservative treatment in 33 patients with longstanding symptoms from the joint and later subjected to temporomandibular joint surgery, a retrospective study was made based on careful case records and personal follow-up. The treatment period varied widely between the patients but was on average 2.5 years. The result of the conservative treatment in these patients was, however, very slight and limited to a minor increase in mouth-opening capacity. All TMJ-patients, including those with the diagnosis ADD and suspected ankylosis, ought to have a strict treatment and follow-up programme in order to reduce doctor's delay if and when surgical intervention should be necessary. Efforts should be focused on development of diagnostic methods to support the selection of patients for TMJ surgery earlier so as to avoid prolonged unsuccessful conservative treatment.

Adolescent↗

Anterior tooth replacement with implants in patients with a narrow alveolar ridge form. A clinical study using guided tissue regeneration.

Clinical and radiographic examination was used to select patients with a suspected need of guided tissue regeneration (GTR). Fifteen patients with 20 fixtures were included in the study. Nine (45%) of the fixtures were completely covered with bone at fixture surgery and no GTR was required in these cases. On the remaining 11 fixtures, one or more sites were exposed and thus an expanded polytetrafluoroethylene membrane was used. The regenerative results were assessed using 2 methods, a) calculation of exposed threads in the mouth and on projected colour slides, b) photometric evaluation of exposed area. In total, the membrane group showed a bone gain of 81% when threads were calculated. Almost complete agreement in percentage of bone gain was observed between buccal (80.7%) and lingual (82.6%) sites. Photometric evaluation for the buccal sites showed a bone gain of 74%. Complete bone regeneration (100%) was achieved when healing was free from complications and also under an exposed membrane when infection was absent. The results indicate that the membrane technique is highly successful for treatment of exposed implants when healing is free from complications. It also shows that clinical and radiographic examination is not precise enough to differentiate between those patients planned for routine fixture surgery and those with a supplementary need for GTR. Thus access to GTR technique is important when treatment is planned for borderline cases.

Adolescent↗