Biomedical subjects

J E Treder

Publications and source records attributed to J E Treder.

4 recordsLinked to original sources

PubMed1998

Soft tissue profile changes from 5 to 45 years of age.

The purpose of this study was to describe the changes in five soft tissue parameters that are commonly used by orthodontic practitioners in their diagnosis and treatment planning as well as in their evaluation of profile changes that occur with growth and orthodontic treatment. The subjects in this study were 20 males and 15 females for whom lateral cephalograms were available between 5 and 45 years of age. The parameters evaluated were two angles of facial convexity, the Holdaway soft tissue angle, and the relationship of the upper and lower lips to Rickett's esthetic line. Descriptive statistics for the absolute and incremental changes were collected on a yearly basis between 5 and 17 years of age as well as at early (25 years) and middle (45 years) adulthood. Growth profile curves were constructed for each parameter to describe the age-related changes in the five parameters for both males and females. The analysis of variance was used to compare the absolute and incremental changes both longitudinally and cross-sectionally. Significance was predetermined at P </=.05. The present findings indicated that (1) in general, the changes in males and females were similar in both magnitude and direction. On the other hand, the timing of the greatest changes in the soft tissue profile occurred earlier in females (10 to 15 years) than in males (15 to 25 years); (2) the angle of soft tissue convexity that excludes the nose expressed little change between 5 and 45 years; (3) the upper and lower lips became significantly more retruded in relation to the esthetic line between 15 and 25 years of age in both males and females; the same trends continued between 25 and 45 years of age; (4) the Holdaway soft tissue angle progressively decreased between 5 and 45 years of age. It is important for clinicians to be aware of these changes when planning the orthodontic treatment of the still growing adolescent patients because the changes might influence the extraction/nonextraction decision.

Adolescent↗

PubMed1996

Changes in the dental arches and dentition between 25 and 45 years of age.

The purpose of this longitudinal investigation was to study changes in the dental arches and dentition that occur in midadulthood in an untreated, normal sample. The subjects had Class I molar and canine relationships with less than 4.0 mm of overjet and less than 50% overbite. None had undergone previous orthodontic treatment. Evaluations and measurements were made from dental casts and periapical radiographic surveys of 15 females and 15 males from approximately 25 years to 46 years. The findings indicate that over the span of the study, significant changes occur in the maxillary and mandibular dental arches and dentition in both males and females, including a clinically significant increase in tooth size-arch length (circumference) discrepancy. These changes should be considered part of the normal maturational process and should be taken into consideration when planning treatment and retention options for adolescent and adult patients.

Adult↗

PubMed1994

Facial and dental changes in adulthood.

The purpose of this longitudinal investigation was to study the dentofacial changes occurring between 25 and 46 years of age in an untreated normal sample. Measurements were made from cephalograms and dental casts available on 15 women and 15 men at age 25 and 46 years. The findings indicate that females exhibited significant increases in all skeletal facial linear dimensions, a decrease in cranial base angle and mandibular prominence, an increase in skeletal convexity and facial divergence. Most of these changes were of relatively small magnitude. Over the span of the study, significant crowding occurred in the mandibular arch. Males exhibited similar significant increases in all skeletal linear dimensions, a decrease in cranial base angle, and increases in maxillary skeletal prominence and skeletal convexity. Increased crowding with age was seen in both maxillary and mandibular arches. In conclusion, the findings indicate that a clinically significant increase in tooth size-arch length discrepancies occurred between 25 and 46 years of age. These changes should be considered as part of the normal "maturational" process. Furthermore, the relative changes in the position of the lips, nose, and chin, cause the lips to appear more retrusive at 46 years of age. These changes should be taken into consideration when orthodontists are considering various treatment and retention options for their adult patients.

Adult↗

PubMed1989

Changes in the maxillary and mandibular tooth size-arch length relationship from early adolescence to early adulthood. A longitudinal study.

The purpose of this study was to determine the association between the changes in maxillary and mandibular tooth size-arch length discrepancies (TSALD) and various dentofacial variables for 18 male and 14 female subjects with normal occlusion. All subjects were participants in the Iowa Longitudinal Growth Study and records were evaluated at two stages of dental development: stage I, when the permanent second molars initially erupted into occlusion (X age = 13.3 years); and stage II, at early adulthood (X age = 26.0 years). The following sets of variables were evaluated: mesiodistal crown diameters of single and groups of permanent teeth, dental arch widths and lengths, curve of Spee, maxillary and mandibular anterior and total crowding or spacing, anterior tooth rotations, and various cephalometric dentofacial parameters. Student's t test were used to compare subjects with the most and least changes. Regression analyses also were used to assess the relationships between these parameters and the changes in the maxillary and mandibular tooth size-arch length relationship. The most consistent finding from the t test comparisons is the significantly greater reduction in the available arch length in the group with the most TSALD at early adulthood. No other variables were found to be consistently different in the comparisons between the two groups. The results of the regression analysis indicated that a number of dentofacial variables are associated with the changes in the maxillary and mandibular TSALD--for example, the mesiodistal diameter of different teeth and the changes in anterior and posterior facial heights. The clinical implications of the present findings are discussed.

Adolescent↗