PubMed Health⌕ Search

Biomedical subjects

R Fränkel

Publications and source records attributed to R Fränkel.

At least 19 recordsLinked to original sources
PubMed2001

Clinical implication of Roux's concept in orofacial orthopedics.

Long-term follow-up studies have revealed that the shields of the function regulator are capable of influencing the circumoral soft tissue capsule in size and shape. As a result, the disturbed or restricted displacement of teeth and jaw bones could be corrected. The dramatic changes in dentoskeletal development thus achieved demonstrate the morphogenetic impact of the circumoral capsule. In clinical application, the function regulator offers the opportunity to realize Roux's concept of functional orthopedics in the treatment of orofacial dysmorphology, as has long been practiced in the medical field of orthopedics.

Biomechanical Phenomena↗
PubMed1989

Clinical relevance of step-by-step mandibular advancement in the treatment of mandibular retrusion using the Fränkel appliance.

The effect of the Fränkel appliance was evaluated in patients with mandibular retrusion who were monitored during an active treatment phase of approximately 14 months in the early mixed dentition. The sample treated with the Fränkel appliance consisted of 120 subjects. In 60, the initial construction bite was taken with the incisors in an end-to-end relationship (Fränkel group A). In 60 patients (Fränkel group B), mandibular position was advanced sequentially in small steps. Fifty untreated subjects of approximately the same age and with almost identical characteristics of skeletal Class II malocclusion served as a comparison group. Permanent teeth were not extracted during the period studied in any of the subjects. For statistical analysis of the difference between the variables used in this study, analysis of variance and the t test were used. The results of this study indicate that the distances between pogonion and condylion or articulare increased in both Fränkel groups A and B significantly more than in the untreated sample. However, the anteroposterior position of pogonion relative to the maxillary landmarks remained unchanged in Fränkel group A. The increase in the distance between pogonion and articulare or condylion primarily resulted from a positional change of pogonion inferiorly, which was accompanied by a significant increase of the mandibular plane angle and the gonial angle. In contrast, pogonion moved anteriorly in Fränkel group B significantly more than in the untreated group, that is, the sagittal discrepancy between maxilla and mandible significantly improved in Fränkel group B, whereas it remained unchanged in Fränkel group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Activator Appliances↗
PubMed1987

The uprighting effect of the Fränkel appliance on the mandibular canines and premolars during eruption.

The effect of the Fränkel (FR) appliance on the eruptive path of the mandibular canines and premolars was evaluated in patients who were monitored from 8 to 13 years of age. The sample treated with the FR appliance consisted of 84 subjects with Class I or Class II malocclusion associated with crowding in the mandibular dental arch. Twenty-seven subjects of approximately the same age and with almost an identical space deficiency in the mandibular arch not subjected to FR treatment served as a comparison group. Permanent teeth were not extracted during treatment in any of the subjects in either group. The primary criterion of patient selection was based on the availability of standardized serial lateral and posteroanterior cephalograms, permitting an exact identification of the canine and premolar contours during eruption. Increases in width between the tips of the mandibular canines and the buccal tips of the mandibular premolars during eruption were significantly greater in the FR group than in the comparison group (P less than 0.001). The expanding effect of the FR appliance was evidenced particularly in the region of the mandibular first premolars. The distance between the buccal tips of these teeth increased by an average of 3.5 mm more in the FR group than in the comparison group. Likewise, the width between the root landmarks of the first mandibular premolars increased during eruption in the FR group 2 1/2 times more than in the untreated sample, a difference that was statistically significant (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Activator Appliances↗
PubMed1983

A functional approach to treatment of skeletal open bite.

In general orthopedics the relationship between postural behavior and skeletal deformities has long been recognized. The primary therapeutic problem in functional orthopedics is to overcome functional disorders. In this article the applicability of this functional concept to orofacial orthopedics is discussed on the basis of a longitudinal study of skeletal open bite. A comparison of a series of lateral cephalograms of thirty patients with skeletal open bite who were treated with functional regulators developed by Fränkel and those of eleven untreated open bite cases suggests that some dentofacial deformities in the skeletal open bite cases can be corrected to the average norms. In addition, as a result of overcoming the poor postural pattern of the orofacial musculature and re-establishment of a competent lip seal, a considerable change in the soft-tissue profile occurred.

Activator Appliances↗
PubMed1980

The applicability of the occipital reference base in cephalometrics.

An occipital reference system, located outside the anterior half of the skull, has been designed which reveals sagittal as well as vertical relationships among facial components. The anatomic structures chosen had consistent behavior during growth, were located close to the midsagittal plane, and could be identified in a lateral cephalograph. Among the basal structures of the neurocranium, the occipital bone around the foramen magnum is the first to ossify. This appears to be indispensably necessary as the head is supported by the trunk precisely in the area of this individual bone. The ventrocaudal contour of the basal part of the occipital bone, anterior to the foramen magnum, and the internal occipital (sagittal) ridge, posterior to the foramen magnum, form the reference base. The intersection of the ventrocaudal contour and the anterior outlines of the occipital condyles serve as the key reference point (occipital point O') for constructing the occipital coordinate system whose horizontal axis is oriented to the earth's surface. This orientation is accomplished by a special photographic registration of the natural head position. The coordinate system has its center at the O' point and its abscissa thus adjusted to the horizontal. The use of a template permits the transfer of the occipital reference cross from the first to subsequent radiographs in the same relation to the occipital reference line as first registered. By the aid of a digitizer or a transparent graph paper with millimeter and centimeter squares on which the coordinate cross is marked, all measurements can be made on the radiograph directly as the reference points O' and O'' are marked on the radiograph itself, thus defining the position of the horizontal coordinate. In the past 50 years, a considerable amount has been learned about the function-form relationship in skeletal morphogenesis. It has been recognized that a faulty or poor postural behavior must be regarded as a major contributory factor to the maldevelopment in skeletal morphology and is taken into consideration in this reference system.

Cephalometry↗