Biomedical subjects

Atalia Wasserstein

Publications and source records attributed to Atalia Wasserstein.

9 recordsLinked to original sources

PubMed2004

Angular changes and their rates in concurrence to developmental stages of the mandibular second premolar.

In the early developmental stage of the mandibular second premolar (MnP2), it is not unusual to find the tooth extremely angulated to the lower border of the mandible, as seen in the panoramic roentgenogram. On eruption, the tooth, in most cases, is close to being upright. However, impaction or other types of malocclusions due to its ectopic eruption are not rare. This study follows the angular changes of the MnP2 during development. Two hundred two panoramic roentgenograms of 101 patients were retrospectively analyzed. All patients had two sequential films with a minimal time interval of nine months. Each MnP2 was traced, and its developmental stage as well as its angulation to the lower border of the mandible was registered. We found that normally more MnP2 are distally (56.5%) than mesially (25%) inclined. There is a statistically significant difference in the inclination of the teeth during their development from stage D to stage F (D = 75.17 degrees +/- 15.25 degrees, E = 79.35 degrees +/- 12.18 degrees, F = 83.38 degrees +/- 10.79 degrees). The average amount of total angular change rate of the MnP2s from stage D to stage G is 0.09 +/- 0.25 degrees/mo, and the absolute angular change rate is 0.19 +/- 0.25 degrees/mo.

Bicuspid↗

PubMed2004

The accuracy of the cementoenamel junction identification on periapical films.

In the study of orthodontically induced inflammatory root resorption, many researchers use the cementoenamel junction (CEJ) as a bisecting reference point to measure the amount of root shortening. The accuracy of the identification of the CEJ point might affect the conclusions of those studies. This study aims to find the effects of angular changes between the tooth and the film on the validity and reproducibility of identifying three different CEJ points, ie, the most apical CEJ point between the crown and the root, the most mesial CEJ point, and the most distal CEJ point. An extracted maxillary central incisor was placed in a special jig and radiographed at four different tooth to film angulations. Eight examiners were asked to identify the buccal and palatal CEJ, whereas six examiners were asked to identify the mesial and distal CEJ points, all on a computer monitor. The distances between the identified points and the apex were computed and compared with the actual ones. The angular changes between the tooth and the film did have a statistically significant effect on the identification of some of these CEJ points. The difference was significant on the identification of the buccal and palatal points but not on the mesial and the distal ones.

Analysis of Variance↗

PubMed2004

The use of an individual jig in measuring tooth length changes.

The parallel periapical radiographic technique hides several problems that might affect the image seen on the film. To overcome these problems a special jig with an external wire attached to the tooth surface and parallel to its long axis was suggested. This study examines the accuracy of using an external object for measuring root length differences due to angular changes between the tooth and the film. The rule of three was used for all calculations as a compensating formula. A human central incisor was placed in a special jig. Two different wire lengths (11.8 +/- 0.1 mm and 16 +/- 0.1 mm) were attached to the tooth in six different ways. The tooth was radiographed at four different film to tooth angulations. The tooth and wire lengths were measured on the model itself and directly on the scanned film on a computer monitor. The results reveal that a wire, placed nine mm from the crown and parallel to the long axis of the tooth was the best jig for accurately measuring tooth length changes. Neither palatal nor buccal metal wires, intimately attached to the crown of the tooth, can serve as a tool to measure tooth length changes. The study could not find a way to skip the need for a cephalometric radiograph to verify the parallelism between the wire and the long axis of the tooth for this matter.

Cephalometry↗

PubMed2004

A comparison of three methods to accurately measure root length.

Measuring the severity of root shortening after orthodontic treatment is a common problem in the dental fields as well as in litigation, legislation, and the ethics arena. The most common method to evaluate root length shortening is by using periapical radiographs. Surprisingly, root elongation after orthodontic treatment in adult patients was reported in the past. The aims of this study were to measure the effects of angular changes between the tooth and the film on the length of the image of a tooth model, to compare three methods to accurately measure root length in different films, and to find the most accurate reference points on the tooth for calculating root lengths. Five amalgam dots were placed on an acrylic model of a maxillary central incisor: ie, most apical, most incisal, mesial CEJ, distal CEJ, and most apical CEJ on the buccal side. The tooth model was placed in a special jig and radiographed at four different film-to-tooth angulations. Root and crown lengths were measured on both the model itself and on a computer monitor displaying the image that resulted from scanning the film into the computer. The results revealed that angular changes between the tooth and the film affect the measured tooth length. The midpoint between the mesial CEJ point and the distal CEJ point (median CEJ) was the best reference point for measuring root length. This was true when the calculations were done with the rule-of-three formula.

Adult↗

PubMed2002

Orthodontically induced inflammatory root resorption. Part I: The basic science aspects.

Orthodontically induced inflammatory root resorption (OIIRR) or, as it is better known, root resorption, is an unavoidable pathologic consequence of orthodontic tooth movement. It is a certain adverse effect of an otherwise predictable force application. Although it is rarely serious, it is a devastating event when it is radiographically recognized. Orthodontics is probably the only dental specialty that actually uses the inflammatory process as a means of solving functional and esthetic problems. Force application initiates a sequential cellular process. We know exactly how and when it is evoked, but we are unable to predict its actual overall outcome. The extent of this inflammatory process depends on many factors such as the virulence or aggressiveness of the different resorbing cells, as well as the vulnerability and sensitivity of the tissues involved. Individual variation and susceptibility, which are related to this process, remain beyond our understanding. We are therefore unable to predict the incidence and extent of OIIRR after force application. This contemporary review is divided into two parts. In Part I, we discuss the basic sciences aspects of OIIRR as a continuation of our previously published work. In Part II, we present the clinical aspects of this subject.

Animals↗

PubMed2002

Orthodontically induced inflammatory root resorption. Part II: The clinical aspects.

Over the past 10 years, orthodontically induced inflammatory root resorption (OIIRR) has been increasingly recognized as an iatrogenic consequence of orthodontic treatment. With this in mind, orthodontists should take all known measures to reduce the occurrence of OIIRR. The evidence that we present in this review suggests several procedures known today that can avert this phenomenon; however, none of them can be relied on to completely prevent OIIRR. We believe that future studies might clarify the exact cause and course of OIIRR and, hopefully, help eliminate it. In Part I, we discussed the basic sciences aspects of OIIRR; in Part II, we present the clinical aspects of this phenomenon.

Animals↗

PubMed2002

Pathognomonic cephalometric characteristics of Angle Class II Division 2 malocclusion.

The Class II division 2 (Class II/2) malocclusion as originally defined by E.H. Angle is relatively rare. The orthodontic literature does not agree on the skeletal characteristics of this malocclusion. Several researchers claim that it is characterized by an orthognathic facial pattern and that the malocclusion is dentoalveolar per se. Others claim that the Class II/2 malocclusion has unique skeletal and dentoalveolar characteristics. The present study describes the skeletal and dentoalveolar cephalometric characteristics of 50 patients clinically diagnosed as having Class II/2 malocclusion according to Angle's original criteria. The study compares the findings with those of both a control group of 54 subjects with Class II division I (Class II/1) malocclusion and a second control group of 34 subjects with Class I (Class I) malocclusion. The findings demonstrate definite skeletal and dentoalveolar patterns with the following characteristics: (1) the maxilla is orthognathic, (2) the mandible has relatively short and retrognathic parameters, (3) the chin is relatively prominent, (4) the facial pattern is hypodivergent, (5) the upper central incisors are retroclined, and (6) the overbite is deep. The results demonstrate that, in a sagittal direction, the entity of Angle Class II/2 malocclusion might actually be located between the Angle Class I and the Angle Class II/1 malocclusions. with unique vertical skeletal characteristics.

Adolescent↗

PubMed2002

Malposition of unerupted mandibular second premolar associated with agenesis of its antimere.

Aberrant tooth positions--such as infraocclusion, mesially ectopic maxillary first molar, palatally displaced canine, tooth transposition, and tooth rotation--are gaining attention as variables in a putative, genetically related pattern of dental anomalies. This study, using panoramic roentgenograms, was undertaken to measure the angular position of the unerupted mandibular second premolar (MnP2) in children. The experimental subjects were 17 children with an unerupted MnP2 and agenesis of the other MnP2, a likely indicator of site-specific genetic disturbance. An age/sex-matched control-reference group was similarly measured for comparison. The hypothesis tested was that the unerupted, developing MnP2 teeth in the experimental subjects would show measurably greater malpositions than those of the control sample. The results indicated a 10 degrees increase in distoangular inclination for the unerupted MnP2 in the agenesis sample; this was a highly significant difference statistically (P = .003), compared with the MnP2 inclinations in the control sample. These findings, associating exaggerated distoangular malposition of the unerupted MnP2 in children with agenesis of the contralateral MnP2, identify a new phenotype of dental developmental disturbance to add to the accumulated evidence supporting shared genetic mechanisms for dental anomaly patterns.

Adolescent↗

PubMedDate not supplied

Adequacy of mandibular premolar position despite early loss of its deciduous molar.

The mandibular second premolar (MnP2) tooth is one of the most commonly impacted teeth. Early loss of its deciduous predecessor has long been suggested to be a factor in the etiology of the MnP2 impaction. In this study, panoramic roentgenograms were used to measure the angular position of the unerupted MnP2 in 85 children. The study was carried out to test whether early loss of the lower second primary molar (dM2) correlates with MnP2 malpositions that are measurably greater than those from a control sample. The results show a small and statistically insignificant difference between the mean angles in cases with (79.6 degrees) and without (83.2 degrees) dM2. To eliminate individual factors, e.g., genetics, 2 sides of the same patient, with and without dM2, were compared. The group with the missing dM2 on one side showed higher angle differences, compared with the control group. However, the differences were still small (approximately 4 degrees) and statistically insignificant. Our findings do not show a significant influence of early loss of dM2 on the inclination of the unerupted MnP2, suggesting that environmental factors may be of less significance, compared with genetic ones.

Adolescent↗