Anomalies Flashcards
Deciduous dentition
Calcification 12 weeks in utero
Eruption starts 6-9 months
Lower: ABCDE
Upper: ABDCE
fully established 2.5-3 years
Incisor spacing
Tooth wear of incisors when they are 5/6
Commonly edge to edge
Calcification time importance
Can help identify timing and aetiology of disturbance in tooth development
Systemic- illness/systemic upset (illness or treatment)
Localised - trauma to deciduous precursor (commonly incisor) or persistent pathology (dental infection)
Chronological enamel hypoplasia (generalized)
Systemic upset
Metabolic disturbance
Could be due to GI problems- malabsorption of food … Or a systemic upset during the third semester/ birth
Enamel hypoplasia (localised-single tooth)
Local factors
Trauma to deciduous incisor
Second premolar due to carious second deciduous molar and chronic infection
“Turners tooth”- due to infection in the precursor so the sinus affects the developing permanent tooth
Eruption time of permanent teeth
Eruption pattern/sequencing is important to monitor
Females usually have earlier eruption
Mandibular teeth erupt earlier than maxillary
Sequence:
Upper: 61243578
Lower: 61234578
Accommodating permanent dentition
Incisor region:
Deciduous teeth have spacing in primary dentition
Increased intercanine width due to transverse growth
Permanent incisors more proclaimed especially upper
Buccal segments:
Leeway space
Permanent teeth (3,4,5) are smaller than deciduous precursors (C,D,E)
On average:
Maxilla: 1.5 mm
Mandibular: 2.5 mm
* Early loss of deciduous teeth can cause crowding in permanent dentition due to the loss of Leeway space
Management of developing occlusion
In primary dentition/erupting (0-3 years)
-monitor the eruption
- preventative advice/reinforcement
3-6 years
- retain/preserve deciduous teeth
- future problems predictors: lack of incisal spacing, early loss of deciduous teeth (due to caries)
Deciduous dentition (anomalies)
Natal teeth: present at birth
Neonatal teeth: soon after birth ( within 30 days)
Those teeth would usually be of normal series/often mobile due to little root development but may form up with time (if too loose-xla due to inhalation risk or if causing trauma to the soft tissues)
Fused/geminated teeth (double-tooth)
- can happen in primary dentition (usually incisor region)
-fusion of two teeth of normal series
-or fusion of normal and supernumerary tooth
- fusion is when they have separate canal systems and germination- when they have single canal
-may predict anomalies in permanent dentition but not always
-may predict missing or extra tooth/small tooth
Most commonly - fused lower B and C
Dental mid line shift
Due to asymmetric xla in crowded cases
Particularly loss of Cs
Need for balanced xla
During the early mixed dentition (6-9 years)
Importance of eruption of 6s and incisors
Look at median diastema
Lateral incisor anomalies
Delayed eruption of central incisors
Habits
Crossbites
Ectopic upper first molars:
- Es are retained and so 6s will impact under distal of the E and cause resorption of distal root (of E)
Generally asymptomatic
Familiar:20%
Equal in males and females
Common 2%
Delayed eruption of upper incisors
History may be relevant (trauma…)
If more than 6 months difference for contralateral incisor or more than 6 months of normal eruption dates
Looks for local aetiological reasons: supernumerary or dilaceration
Supernumerary teeth
3% incidence
2x likely in boys than girls
90% in premaxilla- mesiodens
Can have systemic associations: cleidocranial dysotosis, cleft lip and palate, Gardener’s syndrome
Types:
1. Supplemental : resemble tooth normal series
2. Conical: develop early/often erupt
3. Tuberculate: develop later/seldom erupt
4. Odontomes (complex and compound)
Management:
Surgical removal of supernumerary if obstructing eruption
Monitor if not interfering with eruption and no pathology
Expose and bond (golden chain)
Dilacerated incisors
Aetiology:
1. Developmental (more in girls)
- crown displaced labially (usually one incisor only)
- no enamel/dentine disturbance
- Trauma (more in boys due to intrusion of As)
-crown displaced palatally
- often enamel/dentine disturbance
Median diastema
May be transitional and close after eruption of canines
Aetiology:
1. Midline supernumerary (mesiodens)
2. Small teeth (microdontia)
3. Missing teeth/hypodontia (commonly 2s)
4. Proclamation of UL?
5. Low frenum- low evidence
Peg lateral (diminutive lateral incisor)
Contralateral will be small or missing
Strong association with impaction of upper 3s
Build up if aesthetic concern
Tumb sucking
If more than 6 hours a day:
Increased overjet- upper incisors are proclined and lower incisors are retroclined
Decreased overbite- anterior open bite /asymmetrical
Narrowing of lower arch- crossbites due to lower tongue position
Maxillary canine impaction
Incidence: 1-2% population
More common in female
8% bilateral
60% palatally placed
Aetiology: long development/eruptive path
Environmental/focal factors
Lateral incisor anomalies (loss of eruption guidance)
If buccally placed-usually due to crowding
Impacted Cs can cause resorption of laterals
Alarm bells:
Delayed eruption relative to the age
Retention due to deciduous canine
Asymmetrical eruption
Non-palpated at 10-11 years of age
Infraoccluded 2nd deciduous molars
Common when 5s are missing so Es retain
Can become ankylosed
Stage 1: above contact point
Stage 2: at the contact point
Stage 3: below the contact point
Developing skeletal problems
Class 2 malocclusion with increased overjet:
-consideration of growth modification with functional appliances (class 2)
-refer to Ortho when around 10-11 years of age as most effective then
Class 3
-reverse overjet
-growth modification less effective
-best to monitor and review when older
At what age should a pt with hypodontia be referred for combined Ortho and resto treatment
15-16 years of age for treatment planning
- Same for Ortho and surgical
When can implant be placed in
When they are 18-20 years old/end of growth period
Same for orthognathic surgery
