managing the developing dentition

lecture given 8/31/2026

t/f chronological age is the same as dental age

false

what is the eruption sequence for both primary arches with palmer notation?

A B C D E

what is the eruption sequence for maxillary permanent arch with palmer notation?

6 1 2 4 5 3 7 8

what is the eruption sequence for mandibular permanent arch with palmer notation?

6 1 2 3 4 5 7 8

primary dentition

no permanent teeth have erupted, ends ~6 yo

early mixed dentition

both permanent and primary teeth present, from time of eruption of first permanent tooth until eruption of lateral incisors

mid-late mixed dentition

both permanent and primary teeth present, from exfoliation of mandibular canine until all primary teeth exfoliate (ends ~13 yo)

adolescent dentition

all permanent dentition before the eruption of third molars

adult dentition

all permanent teeth have erupted

what does an extraoral orthodontic exam include?

symmetry

profile (concave, orthognathic, convex)

facial thirds

what does an intraoral orthodontic exam include?

overbite

overjet

primary molar terminal plane relationships

molar angle’s classification

canine angle’s classification

midline

arch length

primate spacing

leeway space

baume classification

open bite

crossbite (anterior and posterior)

overbite

% of mandibular incisor covered by maxillary incisiors

overjet

distance in mm from facial of upper incisor to facial of lower incisor

primary molar terminal plane relationships

mesial step

flush/edge to edge

distal step

what can mesial step primary molar terminal plane relationship lead to in permanent dentition?

class II or end to end

what can flush/edge to edge primary molar terminal plane relationship lead to in permanent dentition?

end to end or class I

what can distal step primary molar terminal plane relationship lead to in permanent dentition?

class I or class III

class I molar angle’s classification

MB cusp tip of upper molar aligned with buccal groove of lower molar

class II molar angle’s classification

MB cusp tip mesial to buccal groove

class II, div 1 molar angle’s classification

MB cusp tip mesial to buccal groove, upper incisors are protruding

class II, class 2 molar angle’s classification

MB cusp tip mesial to buccal groove, upper incisors are retroinclined

class III molar angle’s classification

MB cusp tip distal to buccal groove

class I canine angle’s classification

maxillary cusp tip aligned with contact point between canine and 1st premolar/1st primary molar

class II canine angle’s classification

maxillary cusp tip mesial to contact point

class III canine angle’s classification

maxillary cusp tip distal to contact point

midline

record which midline (maxilla or mandible) is off and by how much (mm)

arch length

adequate, crowding, spacing

primate spacing

space between lateral incisor and canine in maxilla

space between canine and 1st primary molar in mandible

preferable because space for perm teeth and easier to clean

leeway spacing

size difference between the primary molars and canine and the permanent premolars and canine

leeway spacing in the mandible

4.8mm

leeway spacing in the maxilla

2.2mm

baume type I

open type

baume type II

closed type

if a child has spacing of 3 to 6mm in primary dentition, what is the likely outcome in mixed/perm dentition?

no transitional crowding

if a child has spacing of less than 3mm primary dentition, what is the likely outcome in mixed/perm dentition?

20% with incisors crowding

if a child has no spacing in primary dentition, what is the likely outcome in mixed/perm dentition?

50% with incisor crowding

if a child has crowding in primary dentition, what is the likely outcome in mixed/perm dentition?

100% with incisor crowding

openbite

distance, in mm, from incisal edge of maxillary incisor to incisal edge of mandibular incisor

anterior crossbite

maxillary anterior teeth are positioned palatal/lingual to mandibular anterior teeth

can be dental or skeletal

posterior crossbite

maxillary posterior teeth are positioned palatal/lingual to mandibular posterior teeth

can be dental or skeletal

radiograph ortho exam

panorex

when should/can the first panorex be taken?

6-7 yo

what are common orthodontic issues?

oral habits

bruxism

arch length discrepancies- crowding (space loss, serial extraction), spacing (diastema)

ectopic eruption

impaction

anterior crossbite

posterior crossbite

congenitally absent teeth

ankylosis

class II and III growth patterns

nonnutritive sucking habits

thumb, pacifier fingers

should be stopped by age 3

can cause openbite, decreased maxillary arch width, posterior crossbite, increased overjet, increased lower face height

what are treatment options for nonnutritive sucking habits?

positive reinforcement- reward chart

pt/parent counseling

aids (bandage, nail polish, t guard)

appliances (crib, bluegrass appliance)

what does the AAPD suggest with pacifier usage?

use after 12 mo can increase the risk of acute otitis media

use after 18 mo can influence the developing orofacial complex leading to anterior open bite, posterior crossbite, and class II malocclusion

tongue thrust

abnoral tongue position

can cause anterior open bite and protrusion of incisors

what is the treatment for tongue thrust?

myofunctional therapy- instruct pt on correct swallowing and tongue placement

appliance therapy- crib appliance

bruxism

reptitive jaw movements characterized by tooth clenching and grinding

variable intensity and frequencyy during periods of sleep and wakefulness

evidence indicates the juvenile bruxism is self limiting and does not persist in adults

management ranges from pt/parent education, occlusal splints, behavioral strategies, and psychological techniques to medications

mild crowding in primary dentition

<4mm

delay ortho treatment until primary teeth exfoliate

maintain leeway space

can usually resolve on its own

moderate crowding in primary dentition

4-8mm

maintain leeway space

interceptive ortho

severe crowding in primary dentition

>8mm

serial extractions

serial extractions

primary canines

primary 1st molars

1st premolars

diastema closure

frenectomy during ortho treatment after space is closed

generally only performed after the eruption of the upper permanent canines

permanent molar’s abnormal mesioangular eruption path

diagnosed by asymmetric eruption, if mesial margina ridge is under the distal prominence of the second primary molar, or with radiographs

*what are the 2 types of ectopic eruptions?

those that self correct and those that remain impacted

*how often do ectopic eruptions self correct?

66% by age 7

71% by age 9

what are treatments for ectopic eruption?

mild- elastic or metal ortho separators

severe- intervention required with brass wire or distalizing appliance

double row / shark teeth

permanent incisors can erupt lingual to the primary incisors

the tongue usually positions the permanent incisors forward into normal alignment

if the problem does not self correct, consider extraction of primary incisors

mesiodens

85% occur in the maxilla

25% erupt spontaneously

almost all are in the palatal position

inverted mesiodens warrants surgical removal (wait for 2/3 root development)

later removal of the mesiodens reduces the likelihood that the adjacent permanent incisor will…

erupt on its own, esp if the apex is closed

ectopic eruption of canines

common tooth to erupt ectopically

diagnose early to prevent

treated with comprehensive ortho

canine impaction

impaction should be suspected when the canine bulge is not palpable, asymmetric canine eruption is present, or peg shaped laterals are present

radiographs reveal abnormal inclination

flaring of laterals (ugly duckling stage)

slight canine impaction

crown of canine is in line with distal root surface of lateral incisor

monitor eruption

extract if canine is drifting mesially or asymmetric eruption

moderate canine impaction

crown of canine between midline and distal aspect of lateral incisor root

extraction of primary canine to prevent impaciton of permanent canine

most likely will self correct and erupt normally

severe canine impaction

crown of canine past midline of lateral incisor root

extraction of primary canine (up to 75% will self correct)

exposure of permanent canine with ortho treatment if it does not self correct

what are types of crossbite?

anterior, posterior

unilateral, bilateral

dental, skeletal, functional

functional crossbite

unilateral posterior crossbite with midline shift

tongue blade therapy for anterior crossbite

works well with mild crossbite and partially erupted permanent incisor

instruct pt to bite on tongue blade for at least 2 hrs daily

longer periods of pressure better than many short periods

may take a few months to correct

easy and inexpensive for pts

requires excellent pt compliance

hawley retainer with springs for anterior crossbite

single or multiple tooth crossbite

activate spring and follow up every 1-2 weeks

reactivate spring at each follow up

can correct in a few weeks

2×4 fixed therapy for anterior crossbite

2 bands on molars and 4 brackets

single or multiple tooth crossbite

main treatment for severe crossbite

follow up every 1-2 weeks

can correct in a few weeks

added benefit of aligning incisors as well as correcting crossbite

what are possible types of posterior crossbite?

unilateral or bilateral

single tooth or multiple teeth

lingual or buccal (brodie bite)

functional or non-functional

W arch or quad helix for posterior crossbite

slow movement

dental tipping, not skeletal expansion

suture expansion if done at a young age

haas or hyrax appliance

rapid palate expanders

each turn is 0.25mm of expansion

usually 1-2 turns a day

suture opening

what are the most common congenitally missing teeth?

3rd molars

mandibular 2nd premolars

maxillary lateral incisors

prevalence of 4.4-13.4%

what are the treatment objectives of congenitally missing teeth?

esthetically pleasing result with function

create space for prosthetic replacement

or

close space with existing teeth

what are possible treatments for congenitally missing teeth?

maryland bridge

essix retainer

RPD/flipper

hawley retainer

retain primary tooth

allow permanent to drift or ortho to close the space

prosthetic replacement

transplant

ankylosis

condition in which cementum fuses directly with the surrounding bone and the PDL is replaced with osseous tissue preventing further eruptive changes

incidence of 7-14% in primary dentition; most often primary molars

premanent dentition ankylosis usually results from trauma (luxation, ankylosis

how does ankylosis present clinically and radiographically?

submerged crown, lack of physiologic mobility, dull tone upon percussion

loss of PDL around root, external resorption, alveolar replacement

an ankylosed primary tooth may indicate…

missing permanent tooth

what is the treatment for ankylosis if it is a primary tooth?

usually no treatment necessary

extraction if primary tooth has not exfoliated in appropriate sequence and time

if not successor, either extract to create space for ortho or restore to occlusion to prevent tipping

what is the treatment for ankylosis if it is a permanent tooth?

extraction and prosthetic replacement or ortho closure

class II growth pattern

prognathic maxilla and/or retrognathic mandible

1 phase treatment for class II/III growth pattern

correct when all primary teeth have exfoliated with full ortho treatment

shortens treatment time

2 phase treatment for class II/III growth pattern

incerceptive followed by full ortho treatment (headgear, functional appliances)

improves esthetics at an early age

can prevent dental injuries with increased overjet

prolonged treatment time

class III growth pattern

prognathic mandible and/or retrognathic maxilla

treat early- may eliminate need for surgery or ortho treatment in future

growth is unpredictable so further treatment may be needed in perm dentition

what are the treatment objectives for early mixed dentition?

stop oral habits (by age 3)

address deficient arch length

treat ectopic eruption

maintain leeway space

correct crossbites

correct adverse skeletal growth

what are the treatment objectives for mid-late mixed dentition?

treat ectopic eruption

treat skeletal malocclusion

treat crowding

what are the treatment objectives for adolescent dentition?

final ortho treatment can be provided

what are the treatment objectives for adult dentition?

evaluate space and position of 3rd molars