Eruption and Occlusion of the Permanent Dentition Mark

Don’t Fake Knowledge! • Know Nolla's stages of calcification • Know time of eruption

Nolla's 10 Stages of Calcification • Stage 2 - initial calcification • Stage 6

Why Know Calcification Times? Enamel hypoplasia

Factors Affecting Eruption • Genetics - sequence & timing mostly genetically controlled • Nutrition

Eruption Facts • Girls 5 months faster than boys • 6 -1 -2 -4

Mesial Drift and Anterior Component of Force • • Mesial drift Ectopic eruption Axial

Crossbites • Unilateral vs. bilateral • Dental vs. skeletal • Appliance types

Absence of Permanent Teeth • 4 -6% congenital absence • Females more frequently missing

Extra Permanent Teeth • Supernumerary teeth found most frequently in the maxillary incisor region

Changes in Arch Width • Intercanine and intermolar growth – significant increases between 6

Changes in Arch Length and Overbite • Arch length decreases* – late mesial shift,

Angle Classification • Class I Molar (65%) • Class II Molar (30%) • Class

Cuspid Classification • Neutro (Class I) • Disto (Class II) • Mesio (Class III)

Divisions of Class II • Division I - excess OJ • Division II -

Six Keys to Occlusion • • • Class I molar relationship Mesial crown angulation

Types of Faces • Brachycephalic broad & short • Dolichocephalic long & narrow •

Mesocephalic For the gentlemen. . . For the ladies….

Mesocephalic For the intellectual dental student….

Slides: 73

Download presentation

Eruption and Occlusion of the Permanent Dentition Mark H. Taylor, D. D. S. , F. A. C. D.

Don’t Fake Knowledge! • Know Nolla's stages of calcification • Know time of eruption of permanent teeth

Nolla's 10 Stages of Calcification • Stage 2 - initial calcification • Stage 6 - eruptive movement begins (crown formation complete) • Stage 8 - alveolar crest pierced (2/3 root development) • Stage 9 - gingival margin pierced (3/4 root development) • Interval between Stage 6 and full interdigitation is about 5 years

Time of Eruption (Years)

Why Know Calcification Times? Enamel hypoplasia

Fluorosis

Fluorosis and Hypoplasia

Factors Affecting Eruption • Genetics - sequence & timing mostly genetically controlled • Nutrition • Premature loss of a primary tooth Eruption… heh… get it?

Eruption Facts • Girls 5 months faster than boys • 6 -1 -2 -4 -3 -5 -7 and 6 -1 -2 -4 -5 -3 -7 most common in maxilla • (6 -1)-2 -3 -4 -5 -7 and (6 -1)-2 -4 -3 -5 -7 most common in mandible

Mesial Drift and Anterior Component of Force • • Mesial drift Ectopic eruption Axial inclination produces mesial force Space maintenance

Ectopic Eruption

Space Maintenance - PHA

Space Maintenance - LLHA

Space Maintenance - BLS

Space Maintenance - Distal Shoe

Crossbites • Unilateral vs. bilateral • Dental vs. skeletal • Appliance types

Functional Cross Bite

Quad Helix Appliance

Distalizing Appliance

Absence of Permanent Teeth • 4 -6% congenital absence • Females more frequently missing teeth • Most common congenitally absent teeth: – mandibular 2 nd premolar – maxillary lateral incisor – maxillary 2 nd premolar

Missing Permanent Teeth

Extra Permanent Teeth • Supernumerary teeth found most frequently in the maxillary incisor region (mesiodens), and occasionally in the premolar area • 2 -3% supernumerary teeth, males more common

Supernumerary Teeth

Supernumerary Permanent Tooth

Changes in Arch Width • Intercanine and intermolar growth – significant increases between 6 weeks and 2 years of age – significant increases between 3 and 13 years – mandibular intercanine width established by 8 years of age – after permanent teeth erupted, slight decrease in arch width in the intercanine area Bishara, et al; “Arch width changes from 6 weeks to 45 years of age” AJO, April 1997

Changes in Arch Length and Overbite • Arch length decreases* – late mesial shift, mesial drift, interproximal wear – do not affect interach relationships • Overbite – decreases in primary dentition – increases in mixed dentition – OB/OJ relatively stable in adult* *Harris, “A longitudinal study or arch size and form in untreated adults” AJO, April 1997. (20 -55 yoa)

Intercanine Growth

Angle Classification • Class I Molar (65%) • Class II Molar (30%) • Class III Molar ( 5%)

Class I Molar Distal Mesial

Class II Molar Distal Mesial

Class III Molar Distal Mesial

Cuspid Classification • Neutro (Class I) • Disto (Class II) • Mesio (Class III)

Neutro Cuspid (Class I) Distal Mesial

Disto Cuspid (Class II) Distal Mesial

Mesio Cuspid (Class III) Distal Mesial

Divisions of Class II • Division I - excess OJ • Division II - "rabbited" incisors • Subdivision - one side

Divisions of Class II Division 1

Divisions of Class II Division 2

Six Keys to Occlusion • • • Class I molar relationship Mesial crown angulation Proper crown inclination No rotations Tight contacts Flat occlusal plane

Types of Faces • Brachycephalic broad & short • Dolichocephalic long & narrow • Mesocephalic normal

Brachycephalic

Dolichocephalic

Mesocephalic For the gentlemen. . . For the ladies….

Mesocephalic For the moviegoer….

Mesocephalic For the intellectual dental student….

You Tell Me.

Profile?

Overbite - Overjet?

Occlusion?

Huskers!!!!