lecture 3 761 pediatric dentistry 2011

8/13/2019 Lecture 3 761 Pediatric Dentistry 2011

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Life cycle of the tooth:

Eruption Stage

McDonald Chapter 9

174-202

Italicized notes havebeen questioned on

the Dental Decks


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Overview

Life cycle: Initiation/Bud; Cap;Bell; Apposition;Calcification, Eruption,

Attrition

Human Dentition Formulae

Average Eruption Chronology

Lingual Eruption of MandibularIncisors

Teething

Eruption anomaliesNeonatal and Natal teeth

Anomalies in Newborns

Premature loss teeth and space

maintenance


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3

Human Dentition Formulae

ReviewPrimary Dentition

2 1 2

I --- C --- M --- =10x2=20

2 1 2

Permanent Dentition

2 1 2 3

I --- C --- B --- M ---=16 x2=322 1 2 3

Recall that the formula is for the left or right half of the mouth athen needs to be multiplied by 2.


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Pre-eruptive phase

Bud/Cap/Bell/Apposition/C

alcification

Ends when root

development begins


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Pre-functional Eruptive phase

Eruption begins when crown formation is 100% androot development is 75% complete

No gender difference in first 3 stages of crown

formation/calcification

Girls ahead by 1/3 yr for crown completion in 4 teeth

Girls ahead by yr for root development

Interplay of osteoblasts, osteoclasts, regulatory

genes, and dental follicles to cause eruption


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Prefunctional Eruptive phase

- continued

Eruption is related to root formation

rather than chronological or skeletal age

Eruption of permanent teeth causesosteoclasts to resorb primary teeth


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Functional Eruptive phase

Tooth is in occlusion

Attrition StageA tooth will continue to erupt as it wears

Super-eruptioneither lack of opposing tooth or

excessive wear results in continued eruption ofa tooth


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Review Primary DentitionCalcification

begins

Centrals14 w iu 13 to 16 w iuLaterals16 w iu 14 2/3 to 16 w iu

1stmolars15 w iu 14 -17 w iu

Mx canines17 w iu 15-18 w iu

Md canines17 w iu 16-17 w iuMd 2ndmolars18 w iu 16-23 w iu

Mx 2ndmolars19 w iu 16-23 w iu

All teeth have begun to calcify by 4-6 mo

iu.

McDonald p. 52 4-1; p 178Researchers disagree over chronology. We will use

McDonalds as our reference. Primary teeth begin

to calcify at about 4 mo iu


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Review Primary Dentition Calcification Complete

Mx central 1.5 mo

Mx lateral Md central 2.5 mo

M lateral 3 mo

Md 1stmolars 5.5 mo

Mx 1stmolars 6 mo

Canines 9 mo

Md 2ndmolar 10 mo

Mx 2ndmolar 11 mo

Researchers disagree over chronology. We will

use McDonalds as our reference.


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Primary Dentition Eruption

Md central 8 mo*1

st

Primary to eruptMx central 10 mo

Mx lateral 11mo

Md lateral 13 mo

Md 1stmolar 16 mo

Mx 1stmolar 16 mo

Mx canine 19 mo

Md canine 20 moMd 2ndmolar 27 mo

Mx 2ndmolar 29 mo


use McDonalds as our reference. P.178


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Six/Four Guide to help parents/guardians

6 months of age4 new teeth

6 mo - 4 primary Md incisors

12 mo4 primary Mx incisors

18 mo4 primary 1stmolars

24 mo4 primary canines30 mo4 primary 2ndmolars

A mom would expect an 18 month old to have12 teeth; she would be waiting for canines andsecond molars.


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Cultural awareness: Ugandan and Sudanese

practice of ebino

Patients coming from Uganda or the Sudan mayhave experienced ebino

Ebinogouging of unerupted canine toothbuds(they look like a maggotmilky, flexible and are

thought to cause diarrhea)Occurrence-33% of children in Uganda

Instruments usedknitting needles, bicyclespokes, razor blades, scissors, broken glass and

finger nails shaped just for this purpose.Complications-septicemia, anemia, osteomyelitis,

AIDS, damage to permanent canine/malposition.

Educational efforts are underway.


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Chronology of Primary Teeth

By 19 w iu, all primary crowns start to calcify(By thebeginning of 3ndtrimester; by 3/4 of the 2ndtrimester, by 6 months iu)

1 y, all crowns have completed formation

2.5 y, all primary teeth erupted

1.5-2 months from clinical eruption to occlusal

3 y, all primary root formation and calcification

complete

Researchers disagree with dates, we will useMcDonalds as our reference (p178)


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Primary teeth exfoliation

Centrals 6-7 y

Laterals 7-8 y1stmolars 9-11 y

Md Canines 9-12 y

Mx Canines 10-12 y2nd molars 10-12


use McDonalds as our reference. 1st molars

begin to calcify at birth; 3rdmolars at 8-10 y.


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Permanent Dentition Calcification begins1stmolars 0 (birth)

Centrals, Md laterals 3-4 mo

Canines 4-5 mo

Mx laterals 10-12 mo

Mx 1stpremolars 1.5-1.75 y

Md 1stpremolars 1.75-2 y

Mx 2ndpremolars 2-2.25 y

Md 2ndpremolars 2.25-2.5 y

2ndmolars 2.5-3 y

Mx 3rdmolars 7-9 y

Md 3rdmolars 8-10 y

Tooth buds after birth: premolars, 2nd, 3rdmolars.

Researchers disagree over chronology. We will useMcDonalds as our reference. 1st molars begin to

calcify at birth; 3rdmolars at 8-10 y.


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Permanent Dentition Eruption

Md centrals, 1stmolars 6-7 y

Md laterals, Mx centrals 7-8 y

Mx laterals 8-9 y

Md canines 9-10 y

Mx 1stpremolars 10-11 y

Md 1stpremolars 10-12 y

Mx 2ndpremolars 10-12 y

Mx canines 11-12 y

Md 2ndpremolars 11-12 y

Md 2ndmolars 11-13 y

Mx 2nd

molars 12-13 y3rdmolars 17-21 y

1stsuccedaneous to eruptMd central

Researchers disagree over chronology.We will use McDonalds as ourreference.

McDonald 179 9-2


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Desirable and most commonsequence for permanent

teeth:

Mx: 1stmolars

centralslaterals

1stpremolars

2ndpremolars

(canines)

2ndmolars

McDonald 179 9-2


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Desirable and mostcommon sequence forpermanent teeth:

Md: 1stmolars

centralslaterals

canines

1stpremolars

2ndpremolars

2ndmolarsMcDonald 179 9-2


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Activity: Create an eruptionsequence with the

specific tooth number or

letter distributed.

We will form a simulatedmouth as eruption times

are called.

McDonald 179 9-2


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Rule of Fours for Permanent Teethexcludes 3rdmolars

Birth-1st molars initiated calcification

4 y--all crowns initiated calcification

8 y--all crowns complete

12 y--all crowns emerge

16 y--all roots complete

Excludes 3rdmolars


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Root formation completed

First Molars 9-10 y

Mandibular Incisors 9-10 y

Maxillary Incisors 10-11 yCompletion of apex: 2 to 3 y after eruption

Can a root canal procedure be done on a firstmolar or incisor on a child with a dental ageof 11 years old? YESroot closure hasoccurred


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TeethingEruption of Primary TeethExcessive salivation/ DroolingDesire to chew

Hand or fingers in the mouth

Chill teething rings

Irritable

Disturbed eatingDisturbed sleeping

Possible elevated temperatureUnsubstantiated with research

Obtain medical consult if itcontinues

No evidence of relationship withvomiting, diarrhea, or rhinitis


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Eruption hematoma (Eruption cyst)

Location: alveolar mucosa

generally primary 2ndmolar/1stperm molar

Self-limited, no treatmentnecessary unlesssymptomatic:Child refuses food

Facial swelling

Fever

If symptomatic, uncover tooth

Be sensitive to parents anxietyMcDonald 182 9-5


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Eruption sequestrum

Small spicule of calcified

tissue extruded

through the alveolarmucosa over an

erupting molar

Can be easily removed

May not be bone buttooth tissues

McDonald 182 9-6

N t l d N t l T th


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Natal and Neonatal TeethNatal teeth- present at birth

Neonatal teeth- erupt between

0-30 days oldPrevalence- from 1:3667 to

1:716 (often in pairs)

85%--mandibular incisor area

Some are the actual teethRemainder--may resemble

normal teeth or be poorlydeveloped, small, conical,yellow brown, opaque,

hypermobile

Nursing problems possible

TX: none unless symptomaticin which case, extract

(hypermobile/concern of

McDonald 184 9-9


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Epstein pearls

palate raphe

Along mid-palatine raphe

Epithelial tissue trapped

along the raphe

Occur in 56% neonates

No TX necessary

Disappear spontaneously in

few months


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Bohn nodules

Buccal/lingual

Formed along the

buccal and lingual

aspects of the dental

ridges and on thepalate away from the

raphe

Remnants of mucous

gland tissue

No TX necessary


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Dental lamina cysts

Found on the Mx andMd edentulous ridges

Originated fromremnants of thedental lamina

Similar to gingival cystin an adult

No TX necessary

McDonald 185 9-11


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Overview: Considerations in

Managing the developing occlusion

Premature loss of primary molars

Lingual eruption of incisors

Ectopic eruptionSupernumerary teeth

Congenitally missing teeth

Ankylosed teethFrenum problems


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Premature loss of primary molars and

space maintenance

Eruption of the premolar teeth will be

delayed in children who lose primary

molars at 4 or 5 years or earlier

Space maintenance is important

At 8, 9, 10, premolar eruption resulting from

premature loss of primary teeth is greatly

accelerated Space maintenance may not be needed

Determining when to place


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Determining when to place

space maintainers

Time elapsed since loss of a tooth

Dental age of the patient

Amount of bone covering the unerupted tooth

Sequence of the eruption of teeth

Delayed eruption of the permanent tooth

Congenital absence of the permanent tooth

Actively erupting teeth next to the space oftencauses more space loss


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Overview of Space maintainers

Band and loop

Distal shoe

Fixed appliances

Acrylic partial dentureLingual arch

Removable partial dentures/appliances

Researchers disagree about space maintenanceat an early age


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Distal shoe

Directs eruption of the

1stpermanent molar

when 2ndprimary

molar is prematurelylost

McDonald 639 27-14


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Upper lingual or Nance appliance

Space maintenance appliance that crosses the midline

McDonald 644 27-47


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Lingual arch


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Lingual Eruption of Mandibular

Permanent Incisors

Common/normal for Mdpermanent incisors to eruptlingually

Remove over-retained primaryincisors only if firm and theroot had failed to resorb(8.2y for centrals/ 8.4 forlaterals)

Spontaneous correction oflingually erupted permanentincisors is likely

McDonald 180 9-3

Interceptive Orthodontic


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Interceptive Orthodontic

corrections: Crossbites

Occur in the anterior

and posterior:

Treat or

Obtain orthodonticconsult

McDonald 654 27-36

H l li ith h li l


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Hawley appliance with a helical

spring to treat a crossbite


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Next week we will continue withappliances related to eruption

disturbances

lecture 3 761 pediatric dentistry 2011

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