Unlike the tricuspid valve, the mitral valve has frequently received the attention of anatomists. Indeed, the drawings made by Leonardo da Vinci still retain their currency,1 whilst it was no less a personage than Andreas Vesalius who, as far as we know, first likened the bifoliate appearance of the valve to the Episcopal mitre. It was also Vesalius who recommended that the two leaflets be described as aortic and mural, reflecting their respective relationships to the aortic valve and the parietal atrioventricular junction. It was Roberts and Perloff,2 however, who emphasized the necessity, for clinical purposes, of analyzing not only the valvar leaflets, but also the overall valvar complex. As we will demonstrate in our review, this approach to analysis also proves its worth for the echocardiographic recognition of the congenitally malformed valve.

This report describes the clinical and radiographic findings together with surgical management of temporomandibular joint contents herniation through the tympanic plate of the external auditory canal. Two patients are reported. A review of the literature is presented, including a brief discussion of the embryological development of the external auditory canal. Excluding infection, trauma or neoplasm, the defect in the tympanic plate of the external auditory canal represents a developmental aberration with failure of the foramen of Huschke to close during development.

A pre-auricular approach with insertion and fixation of an onlay polyethylene implant to prevent prolapse of the peri-articular tissues into the ear canal is presented and described.

Loss of bony integrity of the temporomandibular joint may result in prolapse of the joint capsule into the external auditory canal. This in turn gives rise to arthralgia, trismus and earache and a risk of septic arthritis.

We describe a technique of repair which is simple, uses autologous tissue and has an acceptable cosmetic and functional result.

Females of four strains of commercial turkeys, including one large strain with a characteristically high rate of oviducal prolapse, were given food either ad libitum or controlled to reach proportionately 0·8 or 0·6 of the body weight of birds fed ad libitum at 24 weeks of age. Two pens of five turkeys from each treatment were photostimulated at 24 and 30 weeks of age. Each turkey was autopsied after it had laid its first egg. The relationships between egg weight and body weight, and between the weight of abdominal fat, diameter of the vent and distance between the pubic bones and egg weight were studied by regression analysis. Egg weight was a function of body weight raised to the power 0·29 which was significantly different from the allometric relationship for Galliform species of 0·64. There was no evidence that differences existed in the quantity of abdominal fat which could impede oviposition and contribute to oviducal prolapse. There were strain differences in the diameter of the vent and distance between the pubic bones in relation to egg weight but the smallest and largest strains were similar. It was concluded that artificial selection had changed the species relationship between egg weight and body mass and that the susceptibility to oviducal prolapse in sire line turkeys was probably physiological in origin.