EFFECTS ON THE TEETH l6l 



left exposed that portion below the neck." Nearly normal structure of the 

 teeth had been recovered in a scorbutic guinea pig cured by one month on nor- 

 mal mixed diet. Scorbutic changes were also noted (but not in detail) in the 

 teeth of monkeys. 



Wells ('19 ,'21) added further data to the results of Zilva and Wells ('19). 

 Pregnant guinea pigs were fed scorbutic diet and six in advanced stages of preg- 

 nancy aborted after 11-15 days on the diet. "Microscopical sections were 

 made of the teeth of the mother and offspring and in every case an advanced 

 state of scurvy could be seen." Wells ('21) states that the irregularly osteoid 

 condition of the dentine is "probably due to the hemorrhagic condition of the 

 dentinal fibrils," an explanation which appears unintelligible. 



Howe ('20) confirmed the results of Zilva and Wells, finding a loosening of the 

 teeth and a condition resembling pyorrhea in scorbutic guinea pigs. Unless 

 the conditions are extreme, recovery follows the use of antiscorbutics. A similar 

 disorder was produced by Howe ('21) in guinea pigs on a diet deficient in all 

 three vitamins (A, B and C). Howe ('22) also reports loosening of teeth, exces- 

 sive tartar formation, etc., in monkeys on scorbutic diet. 



Robb, Medes, McClendon, Graham and Murphy ('21) in guinea pigs on scor- 

 butic diet (equal parts of white flour and alfalfa meal) report that "The teeth of 

 our scorbutic animals become very loose. The dropping-out-of-the-teeth 

 indicates a loss of cementum and possibly of material from the alveolar process. 

 The changes in the teeth proper were surprising. There was marked hyperemia 

 of the pulp with some hemorrhage. The odontoblasts lost their tall columnar 

 form and secreted osteodentine very rapidly. The osteodentine nearly filled the 

 pulp cavity in some cases." Unfortunately the normal process of development 

 in the teeth of the guinea pig is unknown; but osteodentine occurs normally in 

 the pulp of the incisor of the rat, which suggests a possible source of error in 

 interpretation. However, Hojer ('24) obtained similar results. 



In young rats fed McCollum's rachitic diet No. 291 1 (calcium-deficient), 

 Bracco ('23) obtained no gross appearance of rickets, but microscopically the 

 teeth showed intense congestion of the pulp and marked irregularities in the 

 formation of dentine. 



In the case of the pulpar degeneration observed by Zilva and Wells, it should 

 be noted that the histological changes closely resemble those described by Bur- 

 chard and Inglis ('08) following traumatic thrombosis or " jugulation," which 

 results in death of the pulp or extravasations leading to fibroid degeneration. 

 "Inflammation of a low grade may persist in the pulp for long periods, giving 

 rise to an increase of its fibrous tissue with atrophy of the cellular elements, 

 producing a condition found in chronic interstitial inflammation in some 

 other tissues — a sclerosis." Fibroid degeneration of the pulp may also occur 

 normally in old age, and is ascribed by Hopewell-Smith to capillary thrombosis. 

 It therefore seems probable that the scorbutic pulpar fibrosis described by Zilva 

 and Wells is not a unique condition, but is probably secondary to the hemor- 

 rhagic condition resulting in interference with the normal blood supply to the 

 bone and is thus related to the fibroid degeneration which occurs also in the 

 pulp marrow. 



