James E. Harris

Age and Race as Factors in Craniofacial Growth and Development

Large samples of adult American black and white males are being studied to determine the extent to which age and race are important factors in craniofacial mophology and growth. It is shown that a number of dentofacial dimensions continue to change throughout adulthood and that the amount and direction of these changes may be race-specific. Applications in orthodontics and prosthetic dentistry are indicated.

A cephalometric template: Its construction and clinical significance

IN THE University of Michigan Orthodontic Clinic the growth pattern of each patient is considered to be an individual factor which must be studied wit,11 great carp. For this reason, patients are accepted in the clinic when they arcquite young, even though orthodontic treatment may not be initiated for somc~ time. Unfortunately, it is not always possible in practice to accumulate growth records on patients, and an immediate evaluation of present and potentia~l growth factors must be made. Est,imating the level of growth and development of a child at any givcll t imc is a matter of judgment. However, guide lines may be drawn t,o direct the clinician’s observations to critical relationships. To derive these guide lines, the I)cpartmcnt of Orthodontics has for many years c,ooperated with the Univcrsit!: of Michigan School of Education in a program known as the Universit.y 01 Michigan Wementary School Growth Study. One of the results of this project has been the compilation of a set of ccphalometric norms or standards. TIN transformation of tbesc data into a visual form or template suitable for t,ho rapid evaluation of lateral cephalograms by t,he clinician will be presented hcrc from a statist,&& biometric, and clinical viewpoint.

Dentofacial Differences between “Normal” Sibs of Class II and Class III Patients

Abstract No Abstract Available. From the Department of Orthodontics and Dental Research Institute, University of Michigan, Ann Arbor, Michigan. This study was supported, in part, by Grant No. NIDR SR01-DE 03013-06.

Discrimination between groups of chromosomes and individual chromosomes in the normal human karyotype.

The karyotypes of 200 normal individuals are examined in a study designed to investigate the extent to which the cytologists classification of chromosomes into the A–G autosomal groups and identification of individual chromosomes are reflected in the values of measurements made on these chromosomes. The statistical technique of discriminant function analysis is employed to obtain linear functions of the chromosomal measurements which may be used to classify and identify chromosomes. The results of the study indicate that while chromosomes can be grouped with a reasonably high probability of success using measurements alone, identification of individual chromosomes is somewhat more difficult.

Orthodontics' contribution to UNESCO's campaign to save the monuments of Nubia: A 1970 field report

Abstract The primary purpose, of this project, then, was the preservation of human biologic data of Nubia of the past and the present. Obviously, the importance of this type of data to the basic and clinical research efforts of the orthodontist was not lost on the dental schools of either Michigan or Alexandria. The fact that the orthodontist, perhaps alone, was equipped to record this material, now lost forever under the great Lake Nasser, was a matter of great personal pride not only to the research team directly involved but also to the Department of Antiquities, which subsequentially invited the Michigan-Alexandria teams to study and record the mummies of the great Pharoahs of the New Kingdom in the Cairo Museum. The study of the Nubians also resulted in the cephalometric examination of the Reisner collection of nobles from the Giza Necropolis (Old Kingdom) and, this year, the New Kingdom nobles and priests found in the Valley of the Kings at Luxor.

Human chromosomes: Evidence for autosomal sexual dimorphism

Abstract The karyotypes of 100 males and 100 females, each assembled by the trypsin banding method, are examined in a study designed to investigate sex differences among autosomes. It is shown that female autosomes are consistently longer than those of the males, with respect to both the short and long arm measurements. In addition, discriminant analysis is used to distinguish between the male and female karyotypes. We find that, using autosomal measurements alone, this can be done with a high probability of success.

Chromosome surface area: Further evidence for autosomal sexual dimorphism

SUMMARY The karyotypes of 76 males and 84 females, each assembled by the trypsin banding method, are examined in a study designed to investigate sex differences among autosomes. It is shown that female autosomes have consistently larger surface areas than the males, with respect to both the short and long arm measurements. In addition, discriminant function analysis is used to distinguish between the male and female karyotypes. We find that, using autosomal measurements alone, this can be done with a high probability of success. In a recent paper we showed that female autosomes were consistently longer than male autosomes [5]. The karyotypes of 100 males and 100 females, each assembled by the trypsin banding method, were used in this and the average lengths of each of the autosomes were computed separately for each sex. We found the average value for the female cells to be consistently longer than that of the male cells, and that this was mirrored in both the short and long arms. With the single exception of the short arm of chromosome number 19, the arms of the female autosomes were longer than the corresponding arms of the male autosomes. Analysis of the arm ratios and centromere indices of these chromosomes also revealed certain shape differences, but the pattern of these differences proved to be more diffcult to characterize. Discriminant function analysis was also used to differentiate between male and female cells. Depending on which set of measurements was used in the discriminant function analysis, some 75 % of the cells could be correctly classified as either male or female on the basis of autosomal measurements alone. The purpose of the present paper is to report analogous results obtained on the basis of surface area measurements. It is shown that female autosomes have consistently larger surface areas than the male autosomes. Certain “shape” differences also exist, when these are defined in the obvious way using arm ratios and centromere indices. In addition, the technique of discriminant function analysis is used to classify karyotypes as either male or female. Using only autosomal surface area measurements, we again find that this identifica

SNA and SNB Angles in a Population of Nubian Schoolchildren

The descriptive statistics for the sella-nasion-A Point (SNA) and sella-nasion-B point (SNB) angles computed from a sample of Nubian schoolchildren are presented, by age and sex, and compared with the analogous statistics for American Caucasian schoolchildren .

The craniofacial morphology of Nubian schoolchildren.

Abstract No Abstract Available. From the Department of Orthodontics and Dental Research Institute, University of Michigan, Ann Arbor, Michigan.

The length of the Y chromosome in Nubian males and its location in metaphase spreads.

SummaryA total of 242 metaphase plates from the peripheral blood of Nubian males living near Aswan, Egypt were studied with respect to the length of the Y chromosome and its location in metaphase spreads. The length of the Y was similar to that found in American Negroes, and the Y chromosome was peripherally located in 79 of the 242 cells.