308 



Compensatory 

 hypertrophy 

 (production of 

 specific tissue) 



Regeneration -- 



Atrophy 



I. REICHBORN-KJENNERUD 



Ph. limit 



Pathological changes 



Circ. disturbances, atrophy, 

 degeneration, mechanical 

 inflam., necrosis 



Hypofunction -N- Hyperfunction 



Fig. 7. Abscissa, mechanical functional stress, increasing from left to right. 

 Ordinate, tissue reactions to changes in the functional stress. N, normal func- 

 tional stress activating tissue regeneration. Hvperf unction from N to the physi- 

 ological limit is followed by compensatory tissue formation. Above this limit it 

 results in pathological alterations and destruction of tissue. Production of normal 

 tissues of different kinds decreases rapidlv. 



tion and development of inflammation in the snpra-alveolar gingiva. 



It is obvious that an increase of the functional stress above the 

 physiological limit will aggravate pathological changes already pres- 

 ent in the periodontium, and it has been found that it influences the 

 spread of a gingival inflammation (Orban, 1954; Macapanpan and 

 Weinmann, 1954; Glickman and Smulow, 1962). 



Alterations in the periodontal tissues caused by increased func- 

 tional stress during mastication can be studied clinicallv in cases of 

 hyperfunction in the front region due to a bite sinking in the lateral 

 segments (Ramfjord, 1959). 



A reduction in the height of the bite in the premolar and molar 

 region may have no effect on the front teeth, v^hich indicates that 

 compensatory periodontal tissue formation has taken place. But very 

 often, and particularly in older persons, the result is increased mobil- 

 ity and migration of the front teeth. These are clinical symptoms 

 of alveolar bone resorption. In the upper jaw, more or less or all of 

 the bone facial to migrated front teeth may be lost (Fig. 8). This 

 destruction is frequently followed by a deepening of the gingival 



