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Biomedical subjects

R J Schulhof

Publications and source records attributed to R J Schulhof.

At least 19 recordsLinked to original sources
PubMed1978

The mandibular dental arch: part II. Effects of lower incisor position on the soft tissue profile.

It has been demonstrated that there are reliable methods of predicting the ultimate position of the lower incisor and the soft tissue. However, the concept of treating this tooth to any one number for every individual was not supported by the evidence. An optimum system would allow the clinician to select and combine factors from all methods and arrive at a balance of esthetics, function, and stability, obtaining a suitable compromise for his individual patient. This is undoubtedly attempted intuitively by many experienced clinicians.

Dental Arch↗
PubMed1978

The mandibular dental arch: part III. Buccal expansion.

The tendency toward relapse in intercuspid width has been examined with those cases having final intercuspid width less than 27 mm showing significantly less relapse than those cases with final intercuspid width of 28 mm or more. The point of contact between the cuspid and first premolar has been introduced as a key point on the arch, determining arch width. An individualized norm has been derived for this measurement as a function of the patient's tooth size, facial pattern, and other variables based upon stable normal occlusions in treated cases. Those cases expanded to a dimension exceeding the norm by more than 1 mm showed a greater propensity toward relapse. The group following the norm was significantly more stable than the over- and underexpansion groups at the .025 significance level. An individual norm for intermolar width based upon the patient's facial pattern (using frontal and lateral X-rays) has been established. Cases showing relapse showed considerably less space between the lower molar and the JAG plane, and greater lower face height than stable cases. The results show that the space available for the permanent dentition can be estimated in advance of treatment based on the patient's own skeletal measurements, thus minimizing unnecessary extractions, relapse, and extended treatment time due to errors in diagnosis.

Adolescent↗
PubMed1977

Prediction of abnormal growth in class III malocclusions.

Four significant factors have been identified in the lateral cephalometric head film which would indicate the likelihood of the patient growing in an abnormal Class III manner. The normal person grows approximately the same amount from nasion to nasion as he does on the corpus axis of the mandible. The abnormal Class III syndrome grows greater increments on the mandible than at the cranial base. For the purpose of determining the accuracy of computer prediction of abnormal growth, fourteen skeletal Class III cases were selected from the files of the Hokkaido University Orthodontic Department. A significant relationship was shown between abnormal growth and the sum of the standard deviation from the normal of the four cephalometric "predictor measurements." These data would give the clinician insight as to which patients might require early orthopedic treatment (chin cup), conventional orthodontic treatment, or surgical orthodontic correction after growth is complete. This is the first published demonstration of computerized cephalometric methods showing the ability to distinguish between normal and abnormal growth in a particular patient type. It is hoped that, through the comparison of thousands of predictions with actual data, more recognizable abnormal growth patterns will appear in the future.

Adolescent↗
PubMed1977

The mandibular dental arch: Part I, lower incisor position.

The position of the lower incisor with respect to hard tissue references has been evaluated. Two samples were used for this purpose: one containing 78 patients with posttreatment records having a postretention period of at least 4 years, and the other composed of 82 normal occlusions. The results indicated: 1) There was no significant difference in relapse of lower incisor crowding between cases where the lower incisor had been moved lingually, labially, or held in the same relative position during treatment. 2) The position of the maxilla should be considered when placing the lower incisor. The APo plane adequately serves as a guide to this purpose, whereas other reference lines such as mandibular plane or facial plane do not. 3) The positions of the incisors with respect to popular cephalometric reference lines such as APo, NB, or mandibular plane were not correlated with the relapse of mandibular crowding. Therefore, other clinical guides might be more successful for determining stability.

Dental Arch↗