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Biomedical subjects

J K Schulte

Publications and source records attributed to J K Schulte.

16 recordsLinked to original sources
PubMed1997

Forces and moments generated at the dental incisors during forceful biting in humans.

A miniature load sensor capable of measuring all forces and all moments simultaneously at a single location in space was used to assess the magnitude and direction of loads that affect the dental incisors during forceful, static biting. While prior approaches have not measured all necessary six degrees of freedom during biting, the complete set of loads is needed to serve as realistic boundary conditions for analytical or computational models of mandibular mechanics. Four subjects were asked to perform controlled and repetitive edge-to-edge incisal biting activities. Customized devices were used to rigidly hold the load sensor in place at pre-specified tooth separations of less than 1 mm. The results yielded force resultants with a magnitude range of 24.5 to 28.4 N. This range was intentionally limited in magnitude to avoid damage to the internal strain gauge assembly of the sensor. In all cases, the highest force component was oriented upwards. An additional simultaneous moment resultant (range: 8.9-17.0 N cm) with a main moment component oriented backwards and downwards towards the oral cavity was also detected. These data suggest that in order for the biting loads to be composed of six DOF, the remaining forces acting on the mandibular force system (i.e. muscular and/or articular) may indeed be non-coplanar and non-concurrent. Although useful for static biting activities, the bulk of the sensor would probably preclude meaningful measurements during dynamic events such as chewing or swallowing.

Adult↗
PubMed1997

Comparison of screw retention of nine abutment systems: a pilot study.

Fracturing or loosening of abutment and retaining screws is a frequent occurrence. This study was designed to evaluate the retaining ability of nine abutment systems. Abutment and retaining screws were secured to the appropriate implant using a digital torque gauge, with the abutment screws placed at 30 N-cm and the retaining screws at 10 N-cm. Removal torque was recorded three times for each sample 10 minutes after initial placement, 20 minutes after retightening, and 24 hours after retightening. There was no statistical difference in removal torque relative to time or repeated tightening. Of the nine abutment systems, three were statistically less retentive as compared with the most retentive system. The retaining screws were less retentive as compared with the abutment screws. For maximum retention the elimination of retaining screws from the restorative design and using 30 N-cm of torque for the abutment screws is suggested.

Analysis of Variance↗
PubMed1994

External hex manufacturing tolerances of six implant systems: a pilot study.

Quality control procedures of implant manufacturers are of concern to the profession, as a number of companies claim that their components are interchangeable with those of competitive systems. The external hex dimensions of six implant systems were measured and the ranges and coefficients of variance determined. Smaller ranges and coefficients of variance suggest better quality control. The results indicated a considerable difference in the quality control at implant manufacturing companies.

Dental Implants↗
PubMed1993

Reliability of the evaluation of occlusal contacts in the intercuspal position.

Reliability of clinical measurement is essential to any clinical discipline. This investigation assessed intraexaminer and interexaminer reliability achieved in identifying contacting teeth in the intercuspal position. Shim stock and an articulating film were compared in the evaluation of occlusal contacts of 337 antagonist occlusal pairs in 24 young adults by two examiners. Results were compared by use of a simple proportion of agreement and, when possible, the Kappa statistical test that corrects for chance agreement. Shim stock displayed better reliability than articulating film and appeared suitable for clinical measurement of occlusal contacts in intercuspal position.

Adult↗
PubMed1993

Psychometric profiles and related pain characteristics of temporomandibular disorder patients.

The psychological characteristics of patients with temporomandibular disorders have received much attention in the literature. A multivariate clustering technique has been used in the study of psychological characteristics of other chronic pain conditions, and this has recently been applied to "temporomandibular joint pain" patients to develop homogeneous psychometric subgroups. The primary objective of this study was to determine if these subgroups could be replicated in a separate sample. A group of 109 consecutive patients, presenting with complaints of jaw pain, were administered a Symptom Checklist-90 Revised and a questionnaire regarding characteristics of the pain complaint. A multivariate clustering technique was used to identify three discrete psychometric subgroups, as in previous studies. Although similar, these subgroups were not identical to those of previous studies. The small number of subjects in the psychometrically abnormal subgroup was of special interest.

Adolescent↗
PubMed1985

Comparative study of two treatment methods for internal derangement of the temporomandibular joint.

Orthopedic mandibular repositioning and flat plane occlusal splint therapy were compared in the treatment of 20 patients with internal TMJ derangement with reduction. The following conclusions can be drawn. Mandibular repositioning treatment produces significant subjective and objective improvement in the dysfunction of patients with internal joint derangements with reduction. Flat plane occlusal splint treatment produces no significant change in the dysfunction level of patients with internal joint derangements with reduction. Mandibular repositioning treatment may eliminate the reciprocal click of internal joint derangement with reduction. To realize improvement in dysfunction of internal joint derangement, it appears that the reciprocal click must be eliminated. Mandibular repositioning treatment produces a significant improvement in muscle pain associated with internal joint derangement.

Adolescent↗
PubMed1985

Working condylar movement and its effects on posterior occlusal morphology.

The movement of the mesiolingual cusp of the maxillary left first molar was studied in the frontal and horizontal planes. The movement was studied while varying the top wall, rear wall, and incisal guidance on the articulator. It can be concluded that the top wall inclination may significantly influence movement of the mesisolingual cusp of the maxillary first molar during working mandibular movement, the rear wall inclination has less influence than top wall inclination on cusp movement during a working mandibular movement, and the working side condylar movement should be considered when evaluating or restoring the dentition.

Dental Articulators↗
PubMed1980

Clinical evaluation of swinglock removable partial dentures.

Fifty-three patients were recalled for clinical examination to determine oral changes which occurred during the time that they wore swinglock removable partial dentures. Pertinent findings were as follows: 1. The swinglock removable partial denture should be considered as a treatment alternative for patients with unfavorable periodontal support and for patients missing key abutments. 2. Patients who have worn swinglock removable partial dentures for periods of 13 to 75 months did not demonstrate a continued periodontal breakdown, even when there was unfavorable periodontal support. 3. The swinglock removable partial denture may aid in reducing tooth mobility when the patient can maintain good levels of oral hygiene to control inflammation and the dentist can provide a proper occlusion. 4. As evidenced by responses to a satisfaction questionnaire, patient acceptance of the swinglock design was good. 5. The high prevalence of patients reporting for recall examination with one or more decayed teeth (22.4%) and removable partial dentures requiring relines (28.3%) emphasizes the need for proper recall of patients. 6. The swinglock removable partial denture will function satisfactorily if the dentist follows basic principles of removable partial denture construction and if the patient maintains a good level of oral hygiene and returns for regular recall visits.

Bone Resorption↗