Mixed Dentition Lecture 10 PDF

Mixed Dentition  Tooth Eruption Times  Birth to 6 or 8 months: no teeth erupted “edentulous”  Primary teeth erupt from 6 months–2 years  All 20 primary teeth present from 2–6 years  Mixed dentition from 6–12 years  Only adult teeth after 12 years  Last permanent teeth erupt (third mol...

Mixed Dentition  Tooth Eruption Times  Birth to 6 or 8 months: no teeth erupted “edentulous”  Primary teeth erupt from 6 months–2 years  All 20 primary teeth present from 2–6 years  Mixed dentition from 6–12 years  Only adult teeth after 12 years  Last permanent teeth erupt (third molars) = late teens/early 20s  Definition  Dentition period between 6 and 12 years of age and has both primary and permanent teeth Teeth are Forming 3 year old  8 year old premolars have not yet erupted  9 year old note 6 year old molars have erupted  What happens?  The forming permanent tooth moves occlusally and begins to resorb the primary tooth root  Root resorption continues as the succedaneous teeth move closer to the surface and the deciduous teeth eventually become loose and fall out (like leaves fall off a deciduous tree)  This process of “shedding” is called exfoliation  Root Resorption  Definition: the gradual dissolving away of the root due to the underlying eruption of the succedaneous teeth What happens when the roots do not get resorbed by permanent teeth?  Need help from the dentist to remove primary teeth  Eruption Cysts  AKA “eruption hematoma”  Bluish, fluid filled swelling that occurs over an erupting tooth  Common in children  Usually resolves itself  Exfoliation Timeline Maxillary Teeth Eruption Shedding Central Incisor 8-12 mo 6-7 yrs Lateral Incisor 9-13 mo 7-8 yrs Canine 16-22mo 10-12 yrs First molar 13-19 mo 9-11 yrs Second Molar 25-33 mo 10-12 yrs  Exfoliation Times Mandibular Teeth Eruption Shedding Central Incisor 6-10 mo 6-7 yrs Lateral Incisor 10-16 mo 7-8 yrs Canine 17-23 mo 9-12 yrs First molar 14-18 mo 9-11 yrs Second Molar 23-31 mo 10-12 yrs Note shedding times are different from permanent eruption times… How can we identify which teeth are primary and permanent?  Remind yourself to:  Identify the child’s age  Identify the permanent 6 year and/or 12 year molars  Count from the midline  Compare the sizes of the teeth  Look across the arch  Xrays if taken Identify the teeth Erupted Teeth