Download - Age Estimation in Fetus
Age EstimationAge EstimationGwen RobbinsGwen Robbins
Appalachian State UniversityAppalachian State University
Prenatal agePrenatal ageDifficult to know exactly when fertilization Difficult to know exactly when fertilization took placetook placeDefining gestation length in humansDefining gestation length in humans
Clinical setting: Clinical setting: 280 days from first day of LMP280 days from first day of LMPWeight 2550Weight 2550--3360g; Length 283360g; Length 28--32 cm (CRL)32 cm (CRL)Neurological and developmental maturityNeurological and developmental maturity
Embryological definition:Embryological definition:From fertilization (LMP + 14 days)From fertilization (LMP + 14 days)9.5 months or 266 days9.5 months or 266 days
Perinatal AgePerinatal AgeAge around the time of birth established by long bone lengths anAge around the time of birth established by long bone lengths and d
dental materialdental material
Means and ranges for maximum lengths of Means and ranges for maximum lengths of diaphysesdiaphyses (shafts) of major long bones at 10 lunar months (shafts) of major long bones at 10 lunar months (40 lunar weeks)(40 lunar weeks) Fazekas and Kosa (1978)Fazekas and Kosa (1978)
Mean (mm) Range
Humerus 64.9 61.6 - 70.0
Radius 51.8 47.5 – 58.0
Ulna 59.3 55.0 – 65.5
Femur 74.3 69.0 – 78.7
Tibia 65.1 60.0 – 71.5
fibula 62.3 58.0 – 68.5
Dental Development: Deciduous DentitionDental Development: Deciduous Dentition
Beginning of Mineralization (lunar weeks)
Tooth mean range
Central incisor 15 13-17
Lateral incisor 17 14-19
Canine 19 17-20
First molar 16 14-17
Second molar 19 18-20
(Sunderland et al 1987)
Perinatal AgePerinatal AgeAge around the Age around the
time of birth time of birth established by established by long bone long bone lengths and lengths and dental materialdental material
Postnatal agePostnatal age
SubSub--adults = time from birth to adulthoodadults = time from birth to adulthoodInfancy (birth Infancy (birth –– 3 years)3 years)Childhood (3Childhood (3--7 years)7 years)
•• Juvenile (beginning at 7)Juvenile (beginning at 7)•• Adolescent Adolescent
•• 1010--18 in girls18 in girls•• 1212--18 in boys18 in boys
By the wayBy the way……
Before we talk about age estimation methods for Before we talk about age estimation methods for subsub--adults and adults, we need to decide adults and adults, we need to decide ““When When does adulthood begin?does adulthood begin?””
•• we already defined adolescence aswe already defined adolescence as•• 1010--18 in girls18 in girls•• 1212--18 in boys18 in boys
•• adulthood can be defined by physical attribute or adulthood can be defined by physical attribute or physiological states independent of chronological agephysiological states independent of chronological age
•• when growth of the body ceaseswhen growth of the body ceases•• when full biological fertility is achievedwhen full biological fertility is achieved
SubSub--Adult Age Estimation Methods: Long Bone LengthAdult Age Estimation Methods: Long Bone Length
Antenatal Bone Growth
Example: Femur (Fazekas and Kosa 1978)
Age (wks) Length Distal width
12 8.5 1.9
40 74.4 19.9
Juvenile Long Bone Growth
Example: Femur (Maresh 1970)
Age Male Female (yrs) n Mean sd n Mean sd
diaphyseal length
0.125 59 86.0 5.4 68 87.2 4.3
SubSub--adult Age Estimation Methods: Long Bone Lengthadult Age Estimation Methods: Long Bone Length
Predicted Age from Regression
Perinatal: Scheuer et al 1980
Age (wks) = 0.3303 (length) + 13.5583 (ME = +/- 2.08)
Dental Age (mo)
12010896847260483624120-12
Hum
erus
leng
th (m
m)
220
200
180
160
140
120
100
80
60
40
20
0
Maresh
(1970)
Humerus INM
Late Jorwe
While you CAN establish age from growth and development, long bone length is heavily influenced by environment, can become circular
Dental Age Estimation MethodsDental Age Estimation Methods
Perhaps the most accurate methodsPerhaps the most accurate methods
Formative:Formative:crown formationcrown formationeruptioneruptionroot developmentroot development
Degenerative:Degenerative:attrition (wear)attrition (wear)colorcolorperiodontal attachmentperiodontal attachment
Histological:Histological:neonatal lineneonatal linecementumcementum
Age Estimation: Dental Formation and EruptionAge Estimation: Dental Formation and Eruption
SubSub--adult Ages of Crown and Root Completionadult Ages of Crown and Root Completion
Tooth mean MFH 63 Smith 91 LDM 93
Age of crown completion (months)
Central incisor - - 1-2.5 1
Lateral incisor - - 2.5 5
Canine 8.5 5-12 8.5 8.5-17
First molar 4 1-8.5 6 5-9.5
Second molar 8.5 5-12 9.5-11 8.5-17
Age of root completion (years)
Central incisor - - 1.5 1.1-1.6
Lateral incisor - - 1.5-2 1.5
Canine 3 2.3-3.8 3.25 2.6-2.9
First molar 2 1.3-2.5 2.25 2.6
Second molar 3 2.2-3.9 3 3
SubSub--Adults: Tooth Formation and Eruption TimingAdults: Tooth Formation and Eruption Timing
Formation Times for the Permanent DentitionFormation Times for the Permanent DentitionStage I1 I2 C P3 P4 M1 M2 M3
Female
Ci - - 0.6 2.0 3.3 0.2 3.6 9.9
Cco - - 1.0 2.5 3.9 0.5 4.0 10.4
Coc - - 1.6 3.2 4.5 0.9 4.5 11.0
Cr1/2 - - 3.5 4.0 5.1 1.3 5.1 11.5
Cr3/4 - - 4.3 4.7 5.8 1.8 5.8 12.0
Crc - - 4.4 5.4 6.5 2.4 6.6 12.6
Ri - - 5.0 6.1 7.2 3.1 7.3 13.2
R1/4 4.8 5.0 6.2 7.4 8.2 4.8 9.5 15.2
R1/2 5.4 5.6 7.7 8.7 9.4 5.4 10.3 16.2
R2/3 5.9 6.2 - - - - - -
R3/4 6.4 7.0 8.6 9.6 10.3 5.8 11.0 16.9
Rc 7.0 7.9 9.4 10.5 11.3 6.5 11.8 17.7(Smith 1991)
Age Estimation from Length of CrownAge Estimation from Length of Crown
Deciduous dentition
di1 -0.653 + (0.144 * length) +/- 0.19
di2 -0.581 + (0.153 * length) +/- 0.17
dc -0.648 + (0.2.9 * length) +/- 0.22
dm1 -0.814 + (0.222 * length) +/- 0.25
dm2 -0.904 + (0.292 * length) +/- 0.26
Permanent Dentition
I1 0.237 – (0.018 * length) + (0.42 * length2) +/- 0.21
I2 -0.173 – (0.538 * length) + (0.003 * length2) +/- 0.14
I2 0.921 – (0.281 * length) + (0.075 * length2) +/- 0.12
C -0.163 – (0.294 * length) + (0.028 * length2) +/- 0.25
M1 -0.942 – (0.441 * length) + (0.010 * length2) +/- 0.25(Liversedge et al. 1998)
Older subOlder sub--adults: Age from Skeletal Developmentadults: Age from Skeletal Development
SubSub--adult Age Estimation Methods: Epiphyseal Fusionadult Age Estimation Methods: Epiphyseal Fusion
Epiphyseal Fusion Timing
Example: Ulna
Epiphyseal center appears 5.5-7 yrs
Fusion 15-17 yrs in females
17-20 yrs in males
While age of subWhile age of sub--adults is determined by adults is determined by growth and developmental processes, growth and developmental processes, which have a predictable sequence and which have a predictable sequence and relatively short window of timing,relatively short window of timing,
Adult ages must usually be determined by Adult ages must usually be determined by degenerative processes, which are much degenerative processes, which are much more variable larger margin of errormore variable larger margin of error
Many methods for adults are sex specificMany methods for adults are sex specific
AdultAdult Age Estimation Methods: Pubic SymphysisAge Estimation Methods: Pubic Symphysis
Suchey-Brooks MethodFemale
Male
Adult Age Estimation Methods: Auricular SurfaceAdult Age Estimation Methods: Auricular Surface
Lovejoy et al 1985
Adult Age Estimation Methods: Cranial SuturesAdult Age Estimation Methods: Cranial Sutures
1. Midlambdoid 6. Midcoronal2. Lambda 7. Pterion3. Obelion 8. Sphenofrontal4. Anterior Sagittal 9. Inferior Sphenotemporal5. Bregma 10. Superior Sphenotemporal
Composite scores are obtained by summing scores for five “vault” sites and five “lateral-anterior” sites.
0 = open: There is no evidence of any ectocranial closure1 = minimal closure: Some closure has occurred. Score is assigned to any minimal to moderate closure, i.e. from a single bony bridge across the suture to about 50% synostosisat the site.2 = significant closure: There is a marked degree of closure but some portions of the site is still not completely fused.3 = complete obliteration. The site is completely fused.
Age Estimation Methods: Cranial SuturesAge Estimation Methods: Cranial Sutures
Age Estimation Methods: Age Estimation Methods: SternalSternal End of the Right 4End of the Right 4thth RibRib
Dental Age Estimation MethodsDental Age Estimation Methods
Perhaps the most accurate methodsPerhaps the most accurate methods
Formative:Formative:crown formationcrown formationeruptioneruptionroot developmentroot development
Degenerative:Degenerative:attrition (wear)attrition (wear)colorcolorperiodontal attachmentperiodontal attachment
Histological:Histological:neonatal lineneonatal linecementumcementum
Adults: AttritionAdults: Attrition
Using Attrition to Estimate Age (Brothwell 1981)Using Attrition to Estimate Age (Brothwell 1981)
Using Attrition to Estimate Age (Miles 1962)Using Attrition to Estimate Age (Miles 1962)
Cementum AnnulationsCementum Annulations