Biomedical subjects

D Pajoni

Publications and source records attributed to D Pajoni.

At least 19 recordsLinked to original sources

PubMed1999

[Radio-anatomy of the temporomandibular joint].

Explore the source record for details and available documents.

Biomechanical Phenomena↗

PubMed1998

Kinetic magnetic resonance imaging analysis of swallowing: a new approach to pharyngeal function.

The emergence of turbo-FLASH MR sequences allows us to acquire five 10-mm sections each second and thus to catch images of the soft tissues during function. One can trace the pathway of a liquid between the tongue, the soft palate, the epiglottis and the pharyngeal apparatus and analysis the role of the anatomic structures during swallowing. Restricted to the sagittal plane for the purpose of this preliminary study, this technique can be extended to the other planes to provide a three-dimensional analysis of oropharyngeal function or dysfunction.

Adult↗

PubMed1998

MR of 732 TMJs: anterior, rotational, partial and sideways disc displacements.

OBJECTIVE: The purpose of this study was to determine the prevalence of anterior, sideways, rotational and partial anterior disc displacements, as well as degenerative changes in patients with clinical signs and symptoms of internal disorders. MATERIALS AND METHODS: 732 MR Images of temporomandibular joints (TMJ) were produced for 366 symptomatic patients. Image analysis included assessment of disc positions and mobility, as well as recapture in coronal and mediolaterally divided sagittal planes in closed and open positions. RESULTS: Of these images, 545 TMJ showed an internal derangement comprised of 52% anterior disc displacements without reduction, 26% anterior disc displacements with reduction, 11% partial anterior disc displacement, 5% pure sideways displacements and 4% stuck discs. Rotational disc displacements were observed in 34% of the anterior disc displacements without reduction group and in 53% of the anterior disc displacements with reduction group. A total of 97% of the partial anterior disc displacement occurred laterally. Degenerative changes increased with age, mainly in the anterior disc displacements without reduction group. CONCLUSION: Magnetic resonance imaging (MRI) investigations show that the disc is subject to a great variety of displacements and that there is a need for further research to refine the clinical therapy for TMJ internal derangements.

Adolescent↗

PubMed1998

[MRI study of temporomandibular joint disk behavior in chilren with hyperpropulsion appliances].

Orthodontic and orthopaedic effects of hyperpropulsors have been studied, evaluating the possible adaptation of the temporo mandibular joint. Before the event of MR imaging, the positional modification of the disc could not be seen. The study has been carried out on 15 subjects, skeletal Class II, with a mean age of 11.6 years (SD = 1 year). A bilateral MR investigation has been done before and after the wear of an activator (Herbst or Monobloc with Head Gear). All patients underwent bilateral imaging in sagittal and modified coronal planes in closed and opened mouth. The qualitative analysis of the temporo-mandibular joints reveals the appearing of internal derangements, often asymptomatic, in one case out of five; the disc being anteriorly displaced on an average of 8.3 degrees (p = 0.023). These results need to be confirmed on larger samples but may modified functional approach of orthopaedic treatments in order to take into account the TMJ change.

Activator Appliances↗

PubMed1995

[Value of the "Dentascanner"al in dento-maxillary diseases (infectious and cystic)].

MATERIAL AND METHODS: From July 1993 to April 1994, forty dentascans were performed at Bicetre Hospital, on an Elscint Elite Plus scanner for: chronic sinusitis (18 cases); cystic pathologies (8 cases); pre-operative assessment for dental implantation (14 cases). RESULTS: Dentascan images permitted a precise analysis of dentomaxillary anomalies. In all cases they demonstrated the anatomical relationships of the lesions, permitting a determination of potential complications. In chronic sinusitis dental pathology was demonstrated including peri-apical granulomas or cysts breaks or elevations of the floor of the maxillary sinus, malplaced dental filling material in the maxillary antrum and fistula tracks. Among the 14 pre-operative assessments, four cases of infectious lesions were demonstrated, thereby counter-indicating dental implantation. CONCLUSION: The dentascan appears to be very useful for dentomaxillary pathology by facilitating diagnosis and the formulation of treatment and operative strategies.

Chronic Disease↗

PubMed1995

[The temporomandibular joint meniscus in MRI].

The continuing improvement of the MRI's equipment and software led us to a continuous adaptation of the exam technique. We use today a bilateral coil technique, 3 inches in diameter. Four slices are performed for each articulation (4 mm thick) in the true sagittal plane. A fast spin echo, balanced in proton density, for one minute, allows the study of 15 steps inside a full open/close cycle. Oblique coronal cuts are also performed parallel to the long axis of the condyle in a T1-weighted spin echo sequence in close and half-open positions. The analysis of 350 subjects allows to detail more precisely the meniscal displacement. Beside the classic anterior luxation, the meniscus slips medially, laterally and may rotate. These different situations may be isolated or combined. The dynamic study is specifically useful in the displacement with reduction exams. It enables permits to point out the timing of the disk disturbance: this information may be of great help in therapeutic decisions.

Adolescent↗

PubMed1993

[Three-dimensional x-ray computed tomographic imaging of the dentition after bone subtraction].

Owing to computer programs, computed tomography allows obtaining sections of the facial structures in all spatial planes and to "pile up" all sections to reconstruct the structural unit studied. In addition, these images can be reconstructed by selecting a density threshold, for example that of dentin or of enamel, isolating those from their bony environment, and thus the patient's dental arch can be visualized as if one was manipulating a pair of dental models. The first results obtained with this technique are presented, and they seem to be highly promising.

Humans↗

PubMed1990