CURRENT LITERATURE 231

cephalometric diagnosis offers individualized, accurate, and reliable assessment.

Quadrilateral analysis posits that in a balanced facial pattern a 1: 1 ratio exists between maxillary bony base length and mandibular bony base length and also that the average of the anterior lower facial height and posterior lower facial height equals these bony base lengths. When orienting the lower face vertically within the total face, it was found that the ratio of anterior upper facial height to anterior lower facial height is 1:l.Z. Likewise, when ori- enting the lower face horizontally within the total face, it was found that the anterior posterior maxillary and man- dibular position should be harmonious (equal posterior legs) and that its ratio to the total anterior posterior length (sagittal ratio) is 1: I .5 in adolescents and 1: 1.45 in adults. Quadrilateral Analysis, therefore, indicates the area and magnitude of skeletal discrepancy and differentiates be- tween problems in size and/or position of the jaws, indi- vidually correlates jaw size to its appropriate anterior and posterior lower facial height, it relates the lower facial complex to the upper face. The writers believe that visual interpretation of cephalometric films is unreliable and that one must instead identify and treat the dysplasia rather than alter normal bones to achieve a desired overall arrangement of facial components. It is the au- thors’ contention that accurate diagnosis, correct place- ment of the dentition within each jaw, and appropriate orthognathic surgery within the area of dysplasia will re- sult in an individualized balanced facial pattern.

Reprint requests to Dr. Di Paolo: I IO Fuller Place, Hackinsack, NJ 07601.

Protein Synthesis Measured In Vivo in Muscle and Liver of Cachectic Tumor-bearing Mice. Emery P, Love11 L, Rennie M. Cancer Res 44:2779. 1984

A prominent feature of cancer cachexia is the loss of body protein, but it is not clear whether this is due to changes in the rate of protein synthesis, the rate of pro- tein breakdown, or both. Protein synthesis has been mea- sured in vivo in liver and muscle of mice bearing the XKl tumor, an appropriate model for cancer cachexia. Two different methods were used involving measurement of tracer incorporation into tissue protein either at the end of a 4-hour constant infusion of [14C]tyrosine or 10 min- utes after IV injection of a flooding dose of [3H]phenylalwine. Whole-body tyrosine flux was de- creased by 60% in cache&c tumor-bearing mice, and protein synthesis was depressed by 70% in muscle and by 40% in liver. The depression of protein synthesis in muscle was due to a reduction in both RNA content (i.e., protein-synthesizing capacity) and RNA activity (i.e., protein synthesized per g of RNA per hour). In liver, the depression of protein synthesis was due entirely to a de- crease in RNA activity. The results also suggest that the synthesis of export proteins was affected more than the synthesis of fixed liver protein. Restriction of food intake by up to 50% in normal mice caused a loss of body weight and reductions in protein synthesis in liver and muscle that were less severe than those caused by the presence of the tumor. It is concluded that the wasting that is as- sociated with advanced malignant disease is brought about by a reduction in the rate of protein synthesis in the tissues. and that this cannot be explained by depres- sion of food intake alone.

Reprint requests to Dr. Emery: Department of Nutrition, Queen Elizabeth College, Campden Hill Road. London WX 7AH, England.

Complications of Surgery for Oral Malignancy. Price JD. Br J Oral Surg 22:4, 1984

The complications that occur postoperatively in pa- tients treated surgically for oral malignancy are exam- ined. The factors predisposing to such sequelae are also investigated. In this retrospective study 65 of the 100 pa- tients developed one or more complications in the im- mediate (30 days) postsurgical period. The problem most often encountered was wound breakdown. Age was de- termined to have little effect on the rate of complications of patients under age 80 years. There was. however, a direct relationship between the rate of complication and the amount of surgery performed, as well as the staging of the lesion. Previous radiation therapy was also an im- portant factor leading to increased postoperative compli- cations. Several theories were advanced by the author to explain the prevalence of wound breakdown in these pa- tients such as malnutrition, altered defense mechanisms, and poor oral hygiene. The complication rate was also correlated with the site of the neoplasm, with the floor of the mouth having the worst prognosis. Methods of preventing wound breakdown were also discussed, and included the use of systemic antibiotics and strict oral hygiene measures. A low mortality rate in the immediate postoperative period led the author to conclude that most complications of oral malignancy surgery are correct- able.--LYLE NELSON

Reprint requests to Dr. Price: Department of Dental Surgery. Charles Clifford Dental Hospital, Wellesley Road, Sheffield, SlO-2SZ England.

Drug Interaction in Anesthesia: Chronic Antihyperten- sive Therapy. Craig DB, Bose D. Can Anaesth Sot J 31:5, 1984

Antihypertensives present a significant potential for drug interactions during anesthesia. Most antihyperten- sives should be continued up to the time of surgery. Monoamine inhibitors. due to exaggerated effects of in- directly acting vasopressors, should be discontinued at least two weeks prior to surgery. This review includes diuretics, vasodilators, drugs influencing adrenergic transmission, and inhibitors of angiotensin-converting en- zyme and angiotensin. The discussion of each drug cat- egory includes a brief examination of the mechanism of action of the drug group, followed by a summary of their known or predicted drug interactions.-DAVID C. BUL- LARD

Reprint requests to Dr. Craig: Department of Anaesthesia, Health Sciences Centre, Room LB-315, 700 William Avenue. Winnipeg, Manitoba, Canada R3E073.

Two-dimensional Echocardiographic Assessment of the Aorta in Infants and Children with Congenital Heart Disease. Huhta JC, Gutgesell HP, La&on LA. et al. Cir- culation 70:3, 1984

To determine the accuracy of two-dimensional echo- cardiography in the identification of congenital anomalies of the aorta, two-dimensional echocardiographs were compared with angiographic results in 261 consecutive