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Biomedical subjects

O Eckerdal

Publications and source records attributed to O Eckerdal.

At least 19 recordsLinked to original sources
PubMed1991

The petrotympanic fissure: a link connecting the tympanic cavity and the temporomandibular joint.

Morphological traits of the petrotympanic fissure, a soft tissue containing connection between the middle ear and the temporomandibular joint, are described. The description is based on sagittal histological sections of 67 petrous bones with the proximal part of the mandible. The morphological pattern of the soft tissues within the petrotympanic fissure does not, other than in association with exceptional anatomic conditions, support the opinion that forces may be transferred from the joint to the middle ear. The petrotympanic fissure is mainly to be looked upon as a reminder of earlier evolutionary stages. It may also call attention to a developmentally caused special neurological pattern where the innervation of chewing muscles and some middle ear and pharyngeal muscles are closely related to each other. Taking the developmental facts into account in the clinical situation, it may not be so confusing that a primary pathological stimulus in the chewing apparatus and its muscles may, secondarily, manifest itself as ear symptoms. This symptomatology is known as the "otomandibular syndrome."

Adult↗
PubMed1991

Influence of scattered radiation and tube potential on radiographic contrast: comparison of two different dental X-ray films.

The fundamental concept in image quality of contrast has been analysed in terms of its elements; film, radiation and object contrast, and the theoretical formula to describe their interrelationship have been evaluated. Experiments were designed to investigate the dependence of radiographic contrast on the kV, the type of generator and dental film used (D and E speed). An ivory wedge was used as the object, both alone and within a polymethyl methacrylate phantom as scattering medium. Precise definition and control of the X-ray generators were achieved by means of measurements of the primary X-ray spectra using a Compton spectrometer. D speed was found to have higher film contrast than E speed when compared at the same optical density, due to its lower base and fog and lower level of saturation in these experiments. On the other hand, E speed was found to have wider latitude. The experimental object was reproduced with the highest radiographic contrast using D-speed film and, with a given type of generator, this increased when the kV was decreased. While no difference in scatter/primary ratios was observed using the two different films, a weak dependence on kV in the range from 36 to 77 kV was found and confirmed by Monte Carlo calculations. The results indicate that the D and E speed films used had equal energy absorption properties; the difference in radiographic performance is due to their different film characteristics. The importance of controlling the physical parameters (photon energy spectrum, base and fog and optical density level) when comparing image qualities is clearly demonstrated.

Radiography, Dental↗
PubMed1991

Osseointegrated implants in the oral habilitation of a boy with ectodermal dysplasia: a case report.

The most characteristic oral feature in ectodermal dysplasia is hypodontia. Children and adolescents suffering from ectodermal dysplasia often need extensive and complicated prosthetic treatment. The development of techniques for osseointegrated implants offers new possibilities for the oral habilitation of these children. This paper describes the oral habilitation of a boy with severe ectodermal dysplasia and where Brånemark osseointegrated implants have been used as part of the treatment. The patient was seen at the dental department at the age of 1.5 years. Two conically-shaped upper incisors were at that time the only teeth that had erupted. The treatment was planned in a multidisciplinary odontological group involving paediatric dentistry, orthodontics, prosthodontics, oral surgery and maxillofacial radiology. At the age of 3 years it was verified that the boy had four primary teeth (53, 51, 61, 63) and four permanent teeth (16, 11, 21, 26). There were no teeth in the lower jaw. The alveolar ridges in the edentulous areas were low or missing. During the period 3-6 years of age the boy used an upper partial denture adapted to allow the mesial drift of the 16 and 26 teeth. At the age of 6 years, two Brånemark implants were inserted in the lower front-cuspid region. A specially designed overdenture for the lower jaw was constructed. The overdenture was retained in contact with the male attachments by two cuffs of heat-polymerized resilient silicone. Over the next 4 years the dentures were modified due to the eruption of permanent teeth and growth. However, only minor corrections were necessary concerning the retention system of the lower denture. The implants are well osseointegrated and stable and allow the boy to use a lower denture without any complications.

Anodontia↗
PubMed1991

Craniomandibular function in juvenile chronic arthritis. A clinical and radiographic study.

Craniomandibular function was studied in 70 subjects with juvenile chronic arthritis (JCA). The subjects represented the total group of children and adolescents with the diagnosis JCA in a Swedish county. At examination, the median age of the subjects was 11.9 years and the median duration of the disease was 2.6 years. The most important finding of the study was the high prevalence (41%) of radiographic signs of temporomandibular joint (TMJ) pathology. Few subjects showed the typical craniofacial abnormalities associated with JCA, like mandibular micrognathia, facial asymmetries and open bite. Subjective symptoms of dysfunction were almost absent in subjects younger than seven years but were reported by 56% of the older subjects. TMJ sounds and pain on jaw movements were the most frequent symptoms reported. At the clinical examination, TMJ crepitations and restricted horizontal jaw movements were noted in 26% and 32% respectively. The high prevalence of TMJ involvement found in this study underlines the importance that dentists become part of the medical team responsible for the treatment of children and adolescents with JCA.

Adolescent↗
PubMed1986

Skeletal remodelling in the temporomandibular joint after oblique sliding osteotomy of the mandibular rami.

Skeletal remodelling of the temporomandibular joints took place in 80% of cases after oblique sliding osteotomies of the rami. The new bone formation was found in both the condylar and temporal parts of the joint. It was mostly located on the posterior surface of the condyle and in the roof of the temporal part of the joint. No differences in skeletal remodelling were found between wiring and nonwiring cases.

Adolescent↗
PubMed1986

Presurgical planning for osseointegrated implants in the maxilla. A tomographic evaluation of available alveolar bone and morphological relations in the maxilla.

A clinical tomographic method of defining and demonstrating the hard and soft tissue morphology of those parts of the maxilla which are intended for osseointegrated implants is described. This preoperative examination is an useful aid in the choice and planning of the treatment as such, and in the decision concerning the calibre and position of the implants. Hence, it facilitates the surgical procedure.

Alveolar Process↗
PubMed1983

Intraosseous wiring in ramus osteotomy.

The value of intraosseous wiring of the fragments after oblique osteotomy of the mandibular rami was studied. A wired group (14 patients) and a nonwired group (15 patients) were compared cephalometrically. There were only small differences between the groups but there was a tendency toward a smaller postoperative posterior rotation of the mandible in the wired group. It was concluded that in routine cases of mandibular prognathism wiring is not necessary.

Adolescent↗
PubMed1983

Changes in the temporomandibular joint after oblique sliding osteotomy of the mandibular rami. A longitudinal radiological study.

Changes in the temporomandibular joint following oblique sliding osteotomy of the mandibular rami were studied using axial, frontal and lateral radiographs. The condyle/fossa relationship was also studied with regard to the effect of intraosseous wiring of the proximal fragment. Antero-inferior displacements of the condyles were regularly seen after the osteotomies. The use of intraosseous wiring had no adverse effects on the temporomandibular joint.

Adolescent↗
PubMed1980

External bony auditory canal and the tympanic bone. Morphologic properties and influences on the tomographic reproduction.

The external bony auditory canal is morphologically defined as concerns the shape and calibre in successive plane parallel histologic sections of the petrous bone. The sagittal dimensions and structural appearances of the tympanic bone are demonstrated. The morphologic properties defined constitute a basis for the evaluation of the tomographic image formation in this region.

Adult↗
PubMed1979

[Hypocycloidal tomography of the temporomandibular joint region].

Tomography has become an important diagnostic method today. Clinically it is necessary to recognize the interpretative problems with tomographs. The reason for and the development of a few frequent tomographic phenomena were described using the results of comparative anatomic and roentgenographic examinations.

Autopsy↗