Orthodontics, principles and practices

DEPARTMENT Edited

OF REVIEWS

AND

ABSTRACTS

by

Dr. J. A. Salzmann New Pork City

Orthodontics,

Principles

and

T. M. Graber Phi~ladelphia, Third edition. figures. Price, $24.00

Practices

1976, W. I?. Snumders Company. 953 pages, with

791

The latest version of Graber’s widely used textbook, like the first two editions, is directed primarily toward the undergraduate dental student, the general dental practitioner, the pedodontist, and the beginning orthodontic graduate student. Basic chapter organization and sequence has been changed minimally, and most updating is confined to bibliographic expansion. Disappointingly few text modifications serve to reflect the increased body of orthodontic knowledge resulting from clinical and basic research activities of recent years. A major deficiency of this edition relates to the distinction between orthodontic problems which are designated as being within the province of the general dental practitioner and those which are treatable only by the orthodontic specialist. Graber states that the treatment of incipient skeletal Class IT and Class III malocclusions with “orthopedic force” ext,raoral appliances in the deciduous and early mixctl dentitions “should play a part of evergday dental practice.” This, in spite of the fact that patients with such malocclusions require the most stringent of differential diagnostic understanding and serial growth analysis and that little, if any, long-term data exist regarding the eventual influence (positive or negative) of such thcrap~. In contrast, the role that the general dentist, shoultl play in serial extraction treatment planning is de-emphasized, notwithstanding the ready availability of essential diagnostic aids in the general practitioner’s armamentarium and the relatively large boc1.vof knowledge available for study and guidance. The hardware necessary for facial orthopedic treatment perhaps makes it more attractive to the general practitioner, but the potential for reduction of the impact of malocclusion on dental health of the population lies more with well-executed serial extraction treatment by t,he astute, informed dentist. The need for emphasis on orthopedic interceptive treatment of skeletal malocclusions in a text, directed at the nonspecialist is questionable. The format for many illustrat,ions has been enlarged, facilitating in particular the interpretation of radiographs. Composite cephalometric tracings are used extensively to depict growth ancl treatment changes, but since they include (with one exception) no separate maxillary and mandibular superpositionings, interpretation of tooth movement and eruption is not possible. Illustrations from 320

Enlow’s and Mayne’s publications make the sections on facial growth and on serial extraction, respectively, of particular value in undergraduate teaching. Because of its comprehensive nature, profuse illustration, and commcndabl> readable style, this textbook edition is highly recommended as a basic text for dental student instruction and as a reference source for general practitionrrs and pedodontists. R. IT’illicrnt XcSeilT Comparisons and

Dizygous

of

Craniofacial

Features

in

Monozygous

Triplets

D. M. Menezes and T. D. Foster 1970 Dent. Pratt. 21: 103-106, November,

Craniofacial features of three sets of triplets were assessed by means of measurements on standardized lateral skull radiographs. Blood grouping and fingerprint ridge counts indicated that two of the triplet sets were monozygous and the third set contained two monozygous individuals and one separate individual. Only in a small number of the individual features measured did the dizygous triplets show greater differences than the monozygous triplets, but on superimposition of the tracings of the triplet sets a much greater difference in the over-all conformation of the face was seen in the dizpgous triplets. This suggests that small differences in the individual components of the face are compounded to make the larger over-all differences in facial form. The

Relation

Between

Orthodontic

J. J. Crabb and H. J. Wilson Dent. Pmct. 22: Z33-.CZ40,February,

Spring

Force

and

Space

Closure

1976

A reliable method has been described to measure orthodontic forces applied by springs. Twenty patients were diyidcd into three groups. The rates of space closure within each group were not related to sex or to side of the mouth, and t,here was no significant difference in rate between the three groups. There appears to be a fairly wide force range within which space closure will occur at equal rates, all other factors being favorable. Despite the similar rates of space closure for different activation forces, there were problems of appliance management and tooth movement in the higher force group. IThen the activation force was 0.5 S, pain was experienced initially in three patients, appliances tended to be inserted with the spring being displaced to the distal side, and there seemed to be much tilting distally of the upper canines. Tracings made from lateral skull radiographs indicated that there was no significant anchorage loss in any of the three groups. Load/deflexion tables for standard springs are a guide as to how much deflexion is needed to produce a certain load.