312 I. REICHBORN-KJENNERrD 



Duffy and Driscoll, 1958; Biirket, 1961; Frandsen and Becks, 1962). 



Furthermore, some systemic disorders manifest themselves in 

 periodontal circulatory disturbances, as is the case in scurvy and 

 in hvperparathvroidism. They can also in different ways impede 

 regeneration and repair of alveolar bone and even lead to excess 

 formation of it. Clinical examinations sometimes do not reveal local 

 or systemic conditions responsible for an abnormal alveolar bone 

 picture. It may, however, be due to metabolic disturbances as in- 

 dicated by observations made by Person ( 1959 ) . Metabolic studies 

 should therefore be performed in these cases (Barr and Bulger, 

 1930; Albright and Reifenstein, 1948; Person, 1959; Silverman et al., 

 1962). 



Inherited factors should be mentioned because observations and 

 experiments in animals suggest that they may be of importance for 

 alveolar bone destruction (Baer and Lieberman, 1960; Baer et al., 

 1961; Shklar et al, 1962). 



In summarizing it can be said that periodontal and systemic con- 

 ditions may influence the loss of alveolar bone by promoting the 

 development and aggravation of periodontal circulatory disturb- 

 ances, and by preventing formation of alveolar bone. 



In individual cases these effects may or may not appear, owing 

 to the duration and the severity of the systemic disorder, and to the 

 influence of many other factors. This explains the controversial 

 reports as to the effect of systemic disorders on the periodontium. 



Dental Resorption in Periodontal Disorders 



It has been noted that the root tips and the surrounding bone can 

 be resorbed because of circulatorv disturbances incited by hyper- 

 function, which mav be the cause of tooth resorptions in other parts 

 of the pericementum. 



Tooth resorptions are also seen in the marginal region starting 

 from the gingiva. They appear in various types of periodontal dis- 

 orders, most frequently in cases of hyperplastic gingivitis. Extensive 

 gingival tooth resorptions are sometimes found in hyperplastic gin- 

 gival inflammations following a trauma, and in cases of epulis 

 tumors. Gingival resorptions from the connective tissue in gingival 



