6 eruption.pdf

Tooth eruption Dr Sandeep Gupta Oral Pathologist  ERUPTION The word eruption properly means “cutting of the tooth through the gum” Tooth eruption is defined as the process of movement of a tooth from its developmental position within the jaws to its functional positi...

Tooth eruption Dr Sandeep Gupta Oral Pathologist  ERUPTION The word eruption properly means “cutting of the tooth through the gum” Tooth eruption is defined as the process of movement of a tooth from its developmental position within the jaws to its functional position in the oral cavity. 1. Active 2. Passive  ACTIVE TOOTH ERUPTION The term active tooth eruption implies the emergence of crown into the oral cavity. This eruptive process is usually divided into 3 stages 1. Preeruptive stage 2.Eruptive stage 3.Post eruptive stage  TOOTH ERUPTION Pre-oral phase Intra-oral phase  PREERUPTIVE STAGE This movement is made by both deciduous and permanent tooth germs within tissues of the jaw before they begin to erupt. It is also known as ‘Follicular phase of eruption’  PREERUPTIVE STAGE The preeruptive stage begins as the crown starts to develop.  PREERUPTIVE STAGE Total bodily movement of the tooth germ Growth in which one part of the tooth germ remains fixed while the rest continues to grow, leading to a change in the center of the tooth germ.  ERUPTIVE STAGE  During the phase of eruptive tooth movement the tooth moves from its position within the bone of the jaw to its functional position in occlusion.  The eruptive or prefunctional stage begins with the development of root.  The principal direction of movement is occlusal or axial.  RELATIVE POSITION OF PRIMARY AND PERMANENT INCISOR TEETH Prefunctional Preeruptive eruptive period period. RELATIVE POSITION OF PRIMARY AND PERMANENT MOLAR TEETH. Prefunctional Preeruptive eruptive period period.  This stage continues until the erupting teeth meet the opposing teeth. The tooth movement tends to be occlusal and facial,more facial in case of anteriors.  TOOTH ERUPTION Once the teeth meet in occlusion, their further eruption separates the jaws Once the teeth meet in occlusion, they influence each other mechanically  POSTERUPTIVE STAGE The stage begins when the teeth come into occlusion and continues until they are lost or death occurs. The type of movement is axial and mesial migration.  POSTERUPTIVE STAGE Also acts as a compensatory mechanism. It is most active between the ages of 14 and 18 years of age.  TOOTH MOVEMENTS OCCURING IN ERUPTION By root growth & AXIAL - in long axis of the tooth bone remodelling DRIFTING e.g., mesially, laterally By bone remodelling & TILTING PDL reorganization ROTATORY Basil STAGES OF TOOTH ERUPTION.  HISTOLOGY OF TOOTH ERUPTION (permanent tooth) The fibrous cord,the gubernacular cord leads the way and with the help of macrophages and osteoclasts,breaks down the bone between the tooth and the surface oral epithelium.  Go Gubernacular cord of Gubba!! fibrous tissue Gubernacular cord runs through a canal left in the bony crypt, where the dental lamina Permanent extended down to tooth establish the germ for the 2nd tooth HISTOLOGY OF TOOTH ERUPTION As the successional tooth erupts ,its gubernaculum canal is widened rapidly by local osteoclastic activity , delineating the eruptive pathway for the tooth.  HISTOLOGY OF TOOTH ERUPTION In a dried skull holes can be identified which are the once containing the gubernacular canals.  THEORIES OF ERUPTION 1. Root growth 2. Bone remodeling 3. Periodontal ligament traction 4. Vascular pressure in dental tissues  MECHANISMS OF ERUPTION Construction & Reorganization of PDL Formation of the root Deposition of alveolar bone? Remodelling of bone overall FURTHER INFLUENCES from: tooth/teeth in occlusion; muscle actions  ROOT GROWTH It has been said that the increase in root length,or root elongation,forces the tooth into oral cavity.  BONE REMODELING The alveolar process forms in areas where teeth are developing and is deficient in areas where teeth fail to develop. Alveolar bone changes involve both formation and resorption,and these metabolic events are dependent on the presence of the various parts of the dental sac or dental follicle.  The cycle of bone development is rythmic both in crest and crypt of the alveolar bone, i.e instances of osteoblastic followed by osteoclastic activity. In multirooted teeth the interradicular bone seems to have a fairly significant role in the eruption process. PERIODONTAL LIGAMENT TRACTION Periodontal ligament has a role to play, probably more so toward the end of the eruption than at the beginning. It was believed that the contractile fibers play a role in eruption.  The theory of the periodontal ligament having a major role in determining tooth eruption. Periodontal ligament, which is derived from the dental follicle, provides the force required for eruption.  VASCULAR PRESSURE IN DENTAL TISSUE THE VASCULAR PRESSURES are present in pulpal tissues as well as in the periodontal ligament. These pulsating pressure not only enhance cellular activity but seem to have a direct eruptive role. POST ERUPTIVE STAGE PASSIVE ERUPTION Gingival recession onto & down the cementum with loss of alveolar- crest bone  Clinical Consideration 1. Teething – Breaking out of teeth through oral epithelium leading to pain and feaver. 2. Variation in schedule of eruption. 3. Premature eruption 4. Natal teeth--teeth present in oral cavity at time of birth--- deciduous mandibular central incisor  Clinical Consideration 5. Impaction of teeth--- Due to lack of space in jaw and failue of eruption common teeth  3rd molars  Maxillary canines Thank You