Prominence of the zigoma or cheek-bone has been noted by many observers, especially in sexual offenders, among whom Marro found it in 30 per cent. as against 22 per cent. in normal persons. This recalls a remark made many years ago by Charles Kingsley: "I have generally seen with strong animal passion a tendency to high cheek-bone;" but he confines this generalisation to women, and to those who are dark-complexioned. Virchow believes that the large development of the jaws and the cheek-bones (to which powerful muscles are attached) is favoured by coarse and hard food through many generations.
A few isolated observations have been made on the teeth of criminals by Lombroso, Zuccarelli, and others, who have observed certain anomalies, such as exaggerated or deficient development of the canines; and Dr. Prascovia Tarnowskaia, in her one hundred women thieves, found defects of the bony palate and undeveloped teeth among the most frequent anomalies. So far as I know, however, no extensive and careful series of observations has yet been made on the teeth of criminals. It is desirable that this should be done. The course of dental evolution among the higher mammals is now fairly well known. Atavism in dental anomalies is well recognised among the races of man; a fourth molar, for instance, found generally among the platyrhine apes, is occasionally found in man: in what proportion is it found among criminals? What, again, is the relative condition of the canine teeth? The wisdom-teeth are dying out; they are only absent among lower races in 19 per cent. cases, while in the higher races they are absent in 42 per cent. of the observed cases (Mantegazza). How do criminals stand in this respect? The development of the teeth is very closely related to the development of the nerves and brain. The extraordinary frequency of dental and palatal anomalies in idiots was pointed out in England in 1860 by Ballard and Langdon Down, and they have been carefully studied of recent years by Dr. Talbot, of Chicago, and by Dr. Alice Sollier at the Bicêtre in Paris. It is worth noting, in reference to the undeveloped teeth so frequently found by Dr. Tarnowskaia among women thieves, that Dr. Sollier found abnormally small teeth in 13 per cent. of her idiots. Among the insane dental anomalies are comparatively rare.