DEVELOPMENT AND ERUPTION OF THE TEETH



Dr. Samir M. Ziara

   

B.D.S. (Alexandria Univ.) D. D. P. H. Royal Collage of Surgeon (London) M. Sc. P. H. Al-Quds Univ.

Diploma of H. Administration

Two years old

Five years

8 years

8 YEARS

DEVELOPMENT AND ERUPTION OF THE TEETH

• Historically the term

eruption has been used to denote emergence of

the tooth through the gingiva although it denotes more completely continuous tooth movement from the dental bud to occlusal contact .

• However, the terms

eruption and emergence will be used here at this time in such a way as to avoid any

confusion between historical use of

emption and its more recent expanded meaning.

• Dental age has been assessed on the basis of the number of teeth at each chronological age or on stages of the formation of crowns and roots of the teeth. • Dental age during the mixed dentition period may be assessed on the basis of which teeth have erupted, the amount of resorption of the roots of primary teeth, and the amount of development of the permanent teeth.

• Calcification or mineralization (most often visualized radiographically) of the organic matrix of a tooth, root formation, and tooth eruption are important indicators of dental age.

• Dental age can reflect an assessment of physiologic age comparable to age based on skeletal development, weight. or height.

• However, when forming, the crowns and roots of the teeth appear to be the the tissues single juveniles least endocrinopathies.

best affected etc.), by environmental influences (nutrition, and dentition may be considered to be physiological indicator of chronological age in

Dental development may be based also on the emergence (eruption) of the teeth; however, because caries, tooth loss. and severe malnutrition may influence the emergence of teeth through the gingiva, chronologies of the eruption of teeth are less satisfactory formation.

for dental age assessment than those based on tooth

In addition, tooth formation may be divided appropriately into a number of stages that cover continuously the development of of tooth eruption.

teeth, in contrast to the single episode

The importance of the emergence of the teeth to the development of oral motor behavior is frequently overlooked, no doubt partly as a result of the paucity of information available.

However, the appearance of the teeth in the mouth at a strategic time in the maturation of the infant's nervous system and its interface with the external environment must have a profound effect on the neurobehavioral mechanisms underlying the infant‘s development and learning of feeding behavior, particularly the acquisition of masticatory skills.

TOOTH FORMATION STANDARDS

• Events in the formation of human dentition are based primarily on data from studies of dissected prenatal anatomic material and from radiographic imaging of the teeth of the same subjects over time (longitudinal data) or of different subjects of different ages seen once (cross-sectional data).

•From these kinds of studies both descriptive information and chronological data may be obtained.

•To assemble a complete description or chronology of human tooth formation it would seem necessary to use data based on more than one source and methodology.

•However, it is not easy to define ideal tooth formation standards from studies based on different variables and many different statistical methods.

• Subjects surveyed in most studies of dental development are essentially of European derivation, and population differences can only be established by studies that share methodology and information on tooth formation in nonwhite/non-European-derived populations

SCHOUR AND MASSIER (1940)