Normal Tooth Mobility Total buccolingual crown excursion which

Normal Tooth Mobility Total bucco-lingual crown excursion which occurred following the application of a constant and horizontal force of 500 g, ranged between 4~12/100 mm. Mühlemann (1960) 1

Normal Tooth Mobility This crown excursion was found to vary between different groups of teeth ; the incisors having the highest (10~12/100 mm) and the molars the lowest (4~8/100 mm) mobility. Mühlemann (1960) 2

2 Parts of Tooth Mobility Curve • “Initial” tooth mobility part (ITM) • “Secondary” tooth mobility part (STM) Mühlemann (1960) 3

Initial Tooth Mobility Part (ITM) • Forces smaller than 100 g • Steep curve • Small increments of the force resulted in a relatively marked dislocation of the tooth Mühlemann (1954, 1960) 4

Initial Tooth Mobility Part (ITM) • Immediate displacement • Movement of the root within the PDL space • Progressed until the complete elongation of the fibers was achieved. Mühlemann (1954, 1960) 5

Secondary Tooth Mobility Part (STM) • Forces ranging between 100 -1500 g • Less steep line • Comparatively larger force increment was needed to obtain a certain additional movement Mühlemann (1954, 1960) 6

Secondary Tooth Mobility Part (STM) • Further, but slower root displacement • Obtained by the use of heavier (>100 g) forces • Accompanied by the distortion of marginal bone and compression of the soft tissues Mühlemann (1954, 1960) 7

Similar Studies to Those of Mühlemann • Parfitt 1961 permeance transducer • Körber 1971 non contact displacement transducer • Lukas et al. 1992 periotest and high speed filming 8

Current Opinion about Tooth Mobility Curves of continuous and smooth line 9

Parfitt and Körber’s Conclusion (I) A non-linear increase of the resistance to displacement was already present in the initial phase of the tooth displacement Parfitt (1961), Körber (1971) 10

Parfitt and Körber’s Conclusion (II) Transition from the 1 st into the 2 nd stage occurred in a more gradual manner than proposed by Mühlemann (1954) Parfitt (1961), Körber (1971) 11

The magnitude of the tooth displacement seems to increase, • If the loading time is increased (Körber 1971) • If the measurements are repeated • If the time interval between the thrusts is prolonged (Picton 1964) 12

Relative Factors of Tooth Mobility • Viscolestic properties of periodontal tissue Wills et al 1971 • Anatomical characteristics such as the amount of supporting alveolar bone and the width of the periodontal ligament space Lindhe & Nyman 1989, Schulte et al. 1992 13

Relative Factors of Tooth Mobility • Number, shape and length of the roots Lindhe & Nyman 1989 • Intrinsic elasticity of the tooth itself Körber 1962 14

“Return” Movement to Original Position • Initial phase of rapid elastic recovery followed by a slow, asymptomatic phase. • The duration of the asymptomatic phase : proportional to the magnitude and time of application of the dislocation force Parfitt (1961), Körber (1971) 15

Alteration of Mobility Characteristics • Increased Mobility may be associated with different physiologic or pathologic phenomena • Decreased Mobility usually is the result of therapy 16

Physiologic Increased Tooth Mobility • Tooth eruption due to the incomplete maturation of the periodontal membrane during the process. • Pregnancy as a result of the hormonal influences 17

Increased Tooth Mobility • Progressive phase ( developing phase) • Stabilized phase ( permanent phase) 18

Developing Phase of Tooth Hypermobility : Characteristic histologic findings • Enlargement of PDL space • Osteoclastic alveolar bone resorption • Vascular alterations and degenerative phenomena in the periodontal membrane Svanberg (1974) 19

Developing Phase of Tooth Hypermobility : Characteristic histologic findings • Reduced number of collagen fibers inserting in the root cementum, in the alveolar bone proper and in the crest Biancu et al. (1995 b) 20

Permanent Phase of Tooth Hypermobility : Characteristic histologic findings • Could be found : widened PDL space • Couldn’t be found active bone resorption and acute inflammatory lesions in the periodontal membrane, connective tissue attachment loss Svanberg (1974) 21

Occlusal Trauma vs C. T. Attachment Loss : Characteristic histologic findings Resulted in qualitative changes in the component of the supracrestal connective tissue which exhibited an increased amount of vascular structures and a reduced content of collagen. Neiderud (1992) 22

Periodontitis vs Tooth Hypermobility • Apical displacement of alveolar bone margin • Apical shift of the fulcrum of the movement of the crown of the teeth Ericsson & Lindhe (1984) 23

Periodontitis vs Tooth Hypermobility • Loss of alveolar bone • Quantitative and qualitative alterations in the periodontal ligament and supralveolar soft tissues Persson & Svensson (1980) 24

Changes in PDL vs Tooth Hypermobility Qualitative alterations > Quantitative changes might contribute more to tooth mobility alterations than in the bone level. Mühlemann (1960, 1967) 25

Reduced Mobility Below Normal Value • Root ankylosis following replantation Hammarström et al. 1989 • If autogenous bone grafts are placed in contact with a detached root surface. Bernard 1991 26

Reduced Mobility vs Treatment of Gingivitis & Periodontitis Effective control of inflammation often also results in a reduction of a pathologically increased tooth mobility. 27

Effects of Treatment Modalities on Tooth Mobility 1. Scaling & root planing Persson 1980 2. Gingivectomy Persson 1981 a 3. Gingivectomy & flap surgery Persson 1981 b 28

Effects of Treatment Modalities on Tooth Mobility All procedures resulted in 1. Improved gingival conditions 2. Markedly reduced tooth mobility 3. No changes in the alveolar bone level Persson (1980, 1981 a, b) 29

Reduction of a pathologically increased tooth mobility which results following periodontal treatment 1. Reorganization of the gingival connective tissue 2. Narrowing of the periodontal ligament following bone fill in angular bone defects 30

치주치료 후의 치아동요도 감소 1. Reorganization of the gingival connective tissue 2. Narrowing of the periodontal ligament following bone fill in angular bone defects 31

Reorganization of Gingival C. T. • Persson 1980, 1981 a, b • Lindhe & Nyman 1975 • Lindhe & Ericsson 1976 • Neiderud et al. 1992 • Giargia et al. 1994 32

Narrowing of the periodontal ligament following bone fill in angular bone defects • Rosling et al. 1976 • Polson et al. 1979 33

Mobility Changes After Treatment Most probably due to a reorganization of the supra-alveolar tissue following the resolution of the inflammatory lesion. Persson (1980, 1981 a) 34

Mobility Changes After Treatment At sites having a reduced periodontium the condition of the supracrestal connective tissues plays an important role for tooth stability. Giargia et al. (1994) 35

Reduced Mobility Following Occlusal Therapy • Tooth mobility due to occlusal interferences • Significant reduction in mobility despite the fact that no improvement had occurred in the gingival condition. Vollmer & Rateitschak (1975) 36

Progression of Periodontal Disease & Effects of Tooth Mobility , TFO Increased tooth mobility as a result of jiggling forces, neither induces inflammation in a previously healthy gingiva. Ericsson & Lindhe (1982, 1977) 37

Progression of Periodontal Disease & Effects of Tooth Mobility , TFO Nor causes attachment loss in a gingival lesion, Svanberg (1974) 38

Progression of Periodontal Disease & Effects of Tooth Mobility , TFO Nor establishes conditions favoring a rapid progression of plaque associated periodontal disease. Ericsson & Lindhe (1984), Ericsson et al. (1993) 39

Effects of Tooth Mobility on Progression of Periodontal Disease The progression of the periodontal lesion did not differ between stable and mobile teeth. Ericsson & Lindhe (1984) 40

Effects of Tooth Mobility on Progression of Periodontal Disease Tooth movement did not enhance the apical down growth of plaque within the pocket. Ericsson & Lindhe (1984) 41

Effects of Tooth Mobility on Progression of Periodontal Disease : controversial Traumatic forces able to produce a progressively increasing mobility can result in a severe progression of plaque associated lesions. Nyman et al. (1978) 42

Effects of Tooth Mobility on Healing after Treatment of Periodontal Disease Even if tooth mobility did not detrimentally affect the healing of the periodontal tissue, the removal of traumatic factors could lead to a more favorable outcome of treatment. Lindhe & Ericsson (1976): dog experiments 43

Effects of Tooth Mobility on Healing after Treatment of Periodontal Disease Plaque removal resulted in resolution of the inflammation in the soft tissues and bone regeneration at both mobile and non-mobile teeth. Polson et al. (1983): monkey experiments 44

Effects of Fixed Splint on Progression of Periodontal Disease Do not provide advantages either in preventing progression of experimental periodontitis. Ericsson et al. (1993) 45

Effects of Fixed Splint on Progression of Periodontal Disease Do not provide advantages during the initial healing phase after periodontal therapy Kegel et al. , Galler et al. (1979) 46