Growth Prediction and Age Estimation
INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
Introduction Growth spurts Skeletal Maturity Indicators 1. Hand wrist Radiographs 2. Cervical Vertebrae 3. Mid-palatal suture 4. Densitometry Method 5. Ante-gonial Notch 6. Symphysis Morphology
Dental Indicators 1. Tooth mineralization 2. 3rd molar development Frontal sinus development Somatomedin levels
As stated by Ricketts, to take the advantage of growth we must have an idea of – - its magnitude, - its direction, and - its timing . By using the element of timing of maximum growth in conjunction with ones knowledge of magnitude and direction, readily transforms orthodontics to a profession of “face forming , as well as tooth positioning”. A number of growth assessment methods like chronological age, dental age, morphological age, skeletal age & circumpubertal age are available. www.indiandentalacademy.com
ď Ž ď Ž
Chronological age is often not sufficient for assessing the developmental stage and somatic maturity of the patient. The biological age is determined from the skeletal, dental and morphologic age and the onset of puberty. Due to individual variations in timing, duration and velocity of growth, skeletal age assessment is essential in formulating viable orthodontic treatment plans.
Clinical Importance of Maturity Indicators
To determine the potential vector of facial development. To determine the amount of significant facial cranial growth potential left. To decide the onset of treatment timing and type of effective treatment. To evaluate the treatment prognosis. To understand the role of genetics and environment on the skeletal maturation pattern. www.indiandentalacademy.com
Anatomical Region Suitable For Skeletal Maturational Assessment
Head and Neck : Skull Cervical Vertebrae Upper Limb :Shoulder Joint-Scapula Elbow Hand Wrist and Fingers Lower Limb : Femur and Humerus Hip joint Knee Ankle Foot tarsals and Meta tarsals Tooth mineralization as an indicator. Frontal sinus www.indiandentalacademy.com
Periods of sudden acceleration of growth. Due to physiological alteration in hormonal secretion. Timing-sex linked.
Normal spurts are Infantile spurt : at 3 years age Juvenile spurt : 7-8 years (females); 8-10 years (males) Pubertal spurt : 10-14 years (females); 12-17years (males) www.indiandentalacademy.com
Periodic Variations in Growth Rate ď Ž
The typical growth pattern of a child is characterized by a growth rate that decreases from birth with a minor midgrowth spurt at approx. 6-8 years of age, a prepubertal minimum and a pubertal or adolescent growth spurt.
Pubertal growth spurt:
Important period for orthodontic treatment. Initiated in the brain-secretion of releasing factors, pituitary gonadotropins.
Sex hormones released-physiological changes occurclassic growth cure pattern.
Affected by genetic and environmental factors.
It can be defined as the period of life when sexual maturity is attained. It is a transitional period between the juvenile stage and adulthood during which adolescent growth spurt takes place. This period is particularly important in orthodontic treatment, because the physical changes at adolescence significantly affect the face and dentition. Major events that occur during adolescence include- Exchange from mixed to permanent dentition - Acceleration in overall rate of facial growth & - Differential growth of jaws. www.indiandentalacademy.com
GIRLS Total development of adolescent growth- 3Â˝yrs Stage 1 Beginning of adolescent growth Stage 2 (12 months later) Peak velocity in height. Stage 3 (12-18 months later) Growth spurt ending.
Appearance of breast buds, initial pubic hair Noticeable breast development, axillary hair, dark/more abundant pubic hair. Menses, broadening of hips with adult fat distribution, breasts completed
Contemporary Orthodontics â€“ W.R.Proffit, 3rd ed www.indiandentalacademy.com
BOYS Total development of adolescent growth- 5 yrs Stage 1 Beginning of adolescent growth
Fat spurt, weight gain, feminine fat distribution (“fat spurt”)
Stage 2 (12 months later) Height spurt beginning
Redistribution or reduction in fat, pubic hair, growth of penis
Stage 3 (8-12 months later) Peak velocity of height.
Facial hair appears on upper lip only, axillary hair, muscular growth with, harder/more angular body form
Stage 4 (15-24 months later) Growth spurt ending
Facial hair on chin and lip, adult distribution/colour of pubic and axillary hair, adult body form.
Contemporary Orthodontics – W.R.Proffit, 3rd ed www.indiandentalacademy.com
Timing of Puberty
Velocity curves for growth at adolescence shows difference in timing between boys and girls. Pubertal growth spurt occurs on an average nearly 2 years earlier in girls than boys. Sex hormones are produced in adrenals by 6 years-‘adrenarche’. More prominent in girls due to greater adrenal component. Contemporary Orthodontics – W.R.Proffit, 3rd ed www.indiandentalacademy.com
Growth of the jaws correlates with physiologic events of puberty in about the same way as growth in height. Important clinically - careful assessment of physiologic age - plan orthodontic treatment.
Contemporary Orthodontics – W.R.Proffit, 3rd ed www.indiandentalacademy.com
Treatment must begin during
ď‚§ mixed dentition-for girls. ď‚§ Near completion of permanent dentition-for boysProffit.
Hand Wrist Radiographs
Assessment of the skeletal age is often made with the help of a hand wrist radiograph which can be considered the “Biological clock.” Hand wrist region is made up of numerous small bones. These bone show a predictable and scheduled pattern of appearance, ossification and union from birth to maturity. Hence, this region is one of the most suited to study growth. For the analysis of skeletal maturity up to the age of 9 years, the stage of mineralization of the carpel bones must be determined; thereafter the development of metacarpal bones & phalanx should be evaluated. www.indiandentalacademy.com
Indication Of Hand Wrist Radiographs
In patients who exhibit major discrepancy between dental and chronologic age. Determination of skeletal maturity status prior to treatment of skeletal malocclusion (class II & III). To assess the skeletal age in a patient whose growth is affected by infections, neoplastic or traumatic conditions. Help to predict future skeletal maturation rate and status. To predict the pubertal growth spurt. It is a valuable aid in research aimed at studying the role of heredity, environment, nutrition etc., on the skeletal maturation pattern. www.indiandentalacademy.com
Anatomy of Hand-Wrist The hand wrist region is made of four groups of bones 1) Distal ends of long bones of forearm. 2) Carpals (8) 3) Metacarpals (5) 4) Phalanges (14) www.indiandentalacademy.com
Anatomy of skeleton of Hand
Methods Of Assessing Skeletal Age
Atlas method by Greulich and Pyle
Bjork ,Grave and Brown method
Julian singer’s method
Fishman’s skeletal maturity indicators
Hagg and Taranger method www.indiandentalacademy.com
Greulich and Pyle Method
Greulich and Pyle (1959) published an atlas containing ideal skeletal age pictures of the hand-wrist for different chronological ages and for each sex. Each photograph in the atlas is representative of a particular skeletal age. The patient’s radiograph is matched on an overall basis with one of the photographs in the atlas.
Bjork , Grave And Brown Method
They have divided skeletal development into 9 stages. Each of these stages represents a level of skeletal maturity. Appropriate chronological age for each of the stages was given by Schopf in 1978 This method can differentiate maturation process of hand bones between 9 to 17 years of age. The ossification events are localized in the area of the phalanges, carpal bones, and radius (R) Orthodontic Diagnosis - Thomas Rakosi, I Jonas and T M. Graber www.indiandentalacademy.com
There are 3 stages of ossification of the phalanges: First stage: Epiphysis shows the same width as the diaphysis (=) Second stage: Capping stage (=cap); the epiphysis surrounds the diaphysis like a cap Third stage: U-stage (=U); bony fusion of epiphysis and diaphysis
First stage: PP2= -stage ď Ž
The epiphysis of the proximal phalanx of the index finger (PP2) has the same width as the diaphysis. This stage occurs approximately 3 years before the peak of the puberal growth spurt.
Second stage: MP3= -stage ď Ž
Epiphysis of the middle phalanx of the middle finger (MP3) is of the same width as the diaphysis
Stage three: Pisi-, H1-, and R= - stage ď Ž
This stage of development can be identified by three distinct ossification areas; these show individual variations but appear at the same time during the process of maturation. Pisi-stage = visible ossification of the pisiforme
H1-stage = ossification of the hamular process of the hamatum
R = -stage, same width of epiphysis and diaphysis of the radius
Fourth stage: S- and H2-stage ď Ž
S-stage=first mineralisation of the ulnar sesamoid bone of the metacarpophalangeal joiant of the thumb. H2-stage= progressive ossification of the hamular process of the hamatum The fourth stage is reached shortly before or at the beginning of the puberal growth spurt. www.indiandentalacademy.com
Fifth stage: MP3cap-, PP1cap- and Rcap-stage ď Ž
During this stage, the diaphysis is covered by the cap-shaped epiphysis
MP3cap-stage, the process begins at the middle phalanx of the third finger
PP1cap-stage, at the proximal phalanx of the thumb Rcap-stage, at the radius This stage of ossification marks the peak of the puberal growth spurt.
Sixth stage: DP3u-stage ď Ž
Visible union of epiphysis and diaphysis at the distal phalanx of the middle finger (DP3). This stage of development constitutes the end of puberal growth
Seventh stage: PP3u-stage ď Ž
Visible union of epiphysis and diaphysis at the proximal phalanx of the little finger (PP3)
Eighth stage: MP3u-stage ď Ž
Union of epiphysis and diaphysis at the middle phalanx of the middle finger is clearly visible (MP3)
Ninth stage: Ru-stage ď Ž
Complete union of epiphysis and diaphysis of the radius.
The ossification of all the hand bones is complete and skeletal growth is finished. www.indiandentalacademy.com
Growth period Schopf, 1978
Pisi, H1,R= 12.6
S & H2
MP3,R,PP1 14.0 cap
As a rule, girls reach the various developmental stages 2 years earlier than boys. Orthodontic Diagnosiswww.indiandentalacademy.com - Thomas Rakosi, I Jonas and T M. Graber
Singerâ€™s method of assessment ď Ž
Julian singer in 1980 proposed a system of hand-wrist radiograph assessment that would enable the clinician to rapidly and with some reliability help determine the maturational status of the patient. To establish baseline for simple clinical reference, six stages of hand-wrist development are described. The stages and characteristics are:
Julian Singer: Physiologic timing of orthodontic treatment. Angle Orthod 1980, pg-322-333 www.indiandentalacademy.com
Stage 1 (Early) 1. 2.
Absence of the pisiform, Absence of the hook of Hamate and Epiphysis of proximal phalanx of second digit (pp2) narrower than its shaft.
Stage 2 (Prepuberal) 1.
Proximal phalanx of second digit and its epiphysis are equal in width (pp2=), Initial ossification of hook of Hamate and Initial ossification of the pisiform
Stage 3 (Puberal onset) 1.
Beginning calcification of ulnar sesamoid, Increased width of epiphysis of pp2 and Increased calcification of Hamate hook and pisiform
Stage 4 (Puberal) 1.
Calcified ulnar sesamoid and Capping of shaft of the middle phalanx of third digit by its epiphysis (MP3cap)
Stage 5 (Puberal deceleration) 1. 2.
Ulnar sesamoid fully calcified and Calcification of epiphysis of distal phalanx of third digit with its shaft (DP3u) All phananges and carpals fully calcified and Epiphysis of radius and ulna not fully calcified with respective shafts. www.indiandentalacademy.com
Stage 6 (Growth completion) 1.
No remaining growth sites.
Clinical implication ď Ž
Stage 2 represents that period prior to the adolescent growth spurt during which significant amounts of mandibular growth are possible. Maxillary orthodontic therapy in conjuction with mandibular growth might aid correction of a class II relationship with considerable speed and ease. Stage 5 represents that period of growth when orthodontic treatment might be completed and the patient is in retention therapy. www.indiandentalacademy.com
Fishman’s Skeletal Maturity Indicators (SMI)
Proposed by Leonard S Fishman in 1982.
Make use of anatomical sites located on thumb, third finger, fifth finger and Radius .
Leonard S. Fishman :Radiographic Evaluation of Skeletal Maturation. Angle orthodwww.indiandentalacademy.com vol.52, No.2 april 1982.
The Fishmanâ€™s system of interpretation Uses four stages of bone maturation 1. Epiphysis equal in width to diaphysis 2. Appearence of adductor sesamoid of thumb 3. Capping of epiphysis. 4. Fusion of epiphysis
Fishman method –Eleven SMIs Width of Epiphysis equal to Diaphysis SMI-1 Third finger-Proximal Phalanx SMI-2 Third finger-Middle Phalanx SMI-3 Fifth finger-Middle Phalanx SMI-4 Appearance of adductor sesamoid of the thumb Capping of Epiphysis SMI-5 Third finger –Distal Phalanx SMI-6 Third finger-Middle Phalanx SMI-7 Fifth finger-Middle Phalanx Fusion of Epiphysis and Diaphysis SMI-8 Third finger-Distal Phalanx SMI-9 Third finger-Proximal Phalanx SMI-10 Third finger-Middle Phalanx SMI-11 Seen in Radius
SMI 1,2,3 :- Occur approximately 3 years before the pubertal growth spurt. SMI 4 :- This stage occurs shortly before or at the beginning of pubertal growth spurt. SMI 5,6,7 :- This stage occurs at the peak of the pubertal growth spurt. SMI 8,9,10,11 :- The ossification of all hand bones is completed and skeletal growth is finished.
Maturation Assessment by Hagg and Taranger ď Ž
Hagg and Taranger in 1980 described 5 stages of MP3 growth , based primarily on epiphyseal changes. Skeletal development in the hand-wrist is analyzed from annual radiographs, taken between the ages of 6 and 18 years, by assessment of the ossification of the ulnar sesamoid of the metacarpophalangeal joint of first finger (S) and Certain specified stages of 3 epiphyseal bones: - Middle and distal phalanges of third finger (MP3 and DP3) - distal epiphysis of Radius (R). www.indiandentalacademy.com
Sesamoid ď Ž
Sesamoid is usually attained during the acceleration period of the pubertal growth spurt (onset of peak height velocity)
Third Finger Middle Phalanx MP3-F Stage
Start of the curve of pubertal growth spurt . Epiphysis is as wide as metaphysis
Acceleration of the curve of pubertal growth spurt. Epiphysis is as wide as metaphysis. Distinct medial and lateral border of epiphysis forms line of demarcation at right angle to distal border.
MP3-G Stage ď Ž
Maximum point of pubertal growth spurt. Sides of epiphysis have thickened and cap its metaphysis, forming sharp distal edge on one or both the sides.
MP3-H Stage ď Ž ď Ž
Deceleration of the curve of pubertal growth spurt. Fusion of epiphysis and metaphysis begins.
End of pubertal growth spurt Fusion of epiphysis and metaphysis complete.
Third finger distal phalanx ď Ž
DP3-1:Fusion of Epiphysis and Metaphysis is completed.
-This is attained during the deceleration period of pubertal growth spurt ( end of PHV) .
Radius R-I: Fusion of the epiphysis and Metaphysis has began. -This stage is attained 1 year before or at the end of growth spurt. R-IJ: Fusion is almost completed but there is still a small cap at one or both margin. R-J: Characterized by fusion of the epiphysis and metaphysis.
These stages were not attained before end of PHV.
Cervical Vertebrae Maturity Indicators (CVMI) ď Ž
The development of the cervical vertebrae showed similarities with skeletal maturity indicators found in the hand wrist area and could as such offer an alternative method of assessing maturity without the need for a hand-wrist radiograph. LAMPARSKI in 1972 was the first person to study cervical vertebrae and he developed a series of standards for assessing skeletal age in both males and female based on cervical vertebrae.
Hassel and Farman developed a system of skeletal maturation determination using cervical vertebrae. The shapes of the cervical vertebrae were found to be different at different levels of skeletal development. The shapes of the cervical bodies of C3 & C4 changed from somewhat wedge shaped, to rectangular, followed by square shape. The inferior vertebral borders were flat when immature, & they were concave when mature. Hassel and Farman put forward 6 stages in vertebral development using C2,C3, & C4 cervical vertebrae. Hassel, Farman : Skeletal maturation evaluation using cervical vertebrae. AJODO 1995; 107:58-66. www.indiandentalacademy.com
Kansal and Rajagopal modified MP3 Method ď Ž
Kansal and Rajagopal modified the MP3 indicators further and compared it to the cervical vertebrae maturation indicators (CVMI) as described by Hassel and Farman. Periapical radiographs were used for recording MP3 stages.
Rajagopal.R, Kansal.S : A Comparision of modified MP3 stages and the cervical vertrbrae as growth indicators. JCO/JULY 2002 www.indiandentalacademy.com
Start of the curve of pubertal growth spurt Epiphysis is as wide as metaphysis End of epiphysis are tapered and rounded. Radiolucent gap [representing cartilageous epiphyseal growth plate] between epiphysis and metaphysis is wide.
Initiation stage of cervical vertebrae C2,C3 and C4 inferior vertebral body borders are flat. Superior vertebral borders are tapered from posterior to anterior [wedge shape] 80-100% of pubertal growth remains.
Acceleration of the curve of pubertal growth spurt. Epiphysis is as wide as metaphysis. Distinct medial and/or lateral border of epiphysis forms line of demarcation at right angle to distal border. Metaphysis begins to show slight undulation. Radiolucent gap between metaphysis and epiphysis is wide.
Acceleration stage of cervical vertebrae. Concavities are developing in lower borders of C2 and C3. Lower border of C4 vertebral body is flat. C3 and C4 are more rectangular in shape. 65-85% of pubertal growth remains.
Maximum point of pubertal growth spurt. Sides of epiphysis have thickened and cap its metaphysis, forming sharp distal edge on one or both sides. Marked undulations in metaphysis give it “Cupid’s bow’’ appearance. Radiolucent gap is moderate.
Transition stage of cervical vertebrae
Distinct concavities are seen in lower borders of C2 and C3.
Concavity is developing in lower border of C4.
C3 and C4 are rectangular in shape. 25-65% of pubertal growth remains.
Deceleration of the curve of pubertal growth spurt. Fusion of epiphysis and metaphysis begins. Side of epiphysis form obtuse angle to distal border. Epiphysis is beginning to narrow. Slight convexity under central part of metaphysis. Typical Cupid’s bow appearance is absent Radiolucent gap is narrow.
Deceleration stage of cervical vertebrae. Distinct concavities are seen in lower borders of C2, C3 and C4. C3 and C4 are nearly square in shape. 10-25% of pubertal growth remains.
Maturation of the curve of pubertal growth spurt Superior surface of epiphysis shows smooth concavity. Metaphysis shows smooth, convex surface, almost fitting into reciprocal concavity of epiphysis. No undulation present in metaphysis. Radiolucent gap is insignificant.
Maturation stage of cervical vertebrae.
Accentuated concavities of
and C4 inferior vertebral body borders are observed.
C3 and C4 are square in shape. 5-10% of pubertal growth remains.
End of pubertal growth spurt
Completion stage of cervical vertebrae.
Fusion of epiphysis and metaphysis complete. No radiolucent gap.
Deep concavities are present in C2,
Dense, radiopaque epiphyseal line forms integral part of proximal portion of middle phalanx.
C3 and C4 are greater in height than
C3 and C4 inferior vertebral body borders. in width.
Pubertal growth is completed.
Advantages of modified MP3 method
Significantly low radiation exposure. High degree of clarity on the radiographs. Close correlation to the six stages of CVMI. No need to obtain equipment beyond the standard periapical x-ray film and dental x-ray machine.
Mid Palatal Suture as an Indicator of Maturity ď Ž
In 1982, Fishman developed the system of skeletal maturation assessment (SMA) which involves the identification of 11 skeletal maturity indicators on H/W radiographs that occur serially from the onset to termination of adolescence. All measurements associated with the growth of the mandible correlate in intensity and timing with growth in stature. The maxilla demonstrates less conformity.
Revelo.B, Fishman.L.S : Maturational evaluation of ossification of the midpalatal suture. AJODO 1994; 105;288-92 www.indiandentalacademy.com
Therefore knowing more about the development of the maxilla can help a clinician to better time procedures like maxillary expansion. Fishman in 1994 conducted a study to evaluate the ossification pattern of the mid-palatal suture and whether this could be used as a maturity indicator.
Stages of ossification of midpalatal suture were compared with Fishman’s SMI stages. Certain landmarks were identified on the occlusal films which formed the basis of comparision.
Point A - Most anterior point on premaxilla Point B – Most posterior point on the posterior wall of
the incisive foramen. Point P – point tangent to a line connecting the posterior walls of greater palatine foramen. www.indiandentalacademy.com
All measurements were made for – a. Length b. Percentage of development. These were recorded for the following dimensions : A-P - total dimension of the suture A-B - anterior dimension of the suture B-P - posterior dimension of the suture The results reveled that there is significant correlation b/n maturational development and the beginning of ossification of the mid-palatal suture. www.indiandentalacademy.com
SMI SMI 3
Only about 8% fused
Before SMI 4 Very little or no midpalatal approximation exists
Before beginning of puberty
b/w SMI 4 - 7 An osseous interdigitation is very evident with approximation in some areas
Occurs during pubertal growth spurt
Increase in rate of approximation (25%)
Deceleration of pubertal growth spurt
Only 50% approximated End of adolescence (higher %age occurs posteriorly) www.indiandentalacademy.com
No differences were seen in the pattern of approximation b/w males and females. This study has also verified the fact that midpalatal approximation occurs more posteriorly during the entire adolescent period.
Clinical implication : An ideal time to initiate orthopedic expansion is during the early maturational stage, SMI 1 to 4. Theoretically less orthopedic force values would be required if treatment is initiated early. www.indiandentalacademy.com
Symphysis morphology as a predictor of the direction of mandibular growth
Nanda et al determined in their study that Symphysis morphology could be used as a predictor of the direction of mandibular growth. The direction of mandibular growth was evaluated with seven cephalometric measurements that included – 1. y – axis (FH to S-Gn) 2. SN to mandibular plane 3. Palatal plane to mandibular plane 4. Gonial angle 5. Sum of saddle, articular and gonial angle (Bjork sum) 6. Percentage lower facial height 7. Posterior/Anterior face height (Jaraback ratio) www.indiandentalacademy.com
The mandibular symphyseal dimensions studied were height, depth, ratio (height/depth), and angle. The Symphysis height was defined as the distance from the superior to the inferior limit on the grid. The Symphysis depth was defined as the distance from the anterior to the posterior limit on the grid
Symphysis ratio was calculated by dividing Symphysis height by depth. The Symphysis angle was determined by the posteriorsuperior angle formed by the line through menton and point B and the mandibular plane.
Large Symphysis ratio – receding chin, high mandibular plane, high angle SN-MP, large saddle, articulare & gonial angles,
large anterior facial height, large percentage lower facial height Small Symphysis ratio – large chin low mandibular plane low angle SN-MP low saddle, articular & gonial angles Small anterior facial height www.indiandentalacademy.com Small percentage lower facial height
The axiom about the chin is that those children who have, will get more with growth, whereas those who do not will not get much growth at the chin. Symphysis ratio was strongly related to the direction of mandibular growth in men. Symphysis with an anterior growth direction of the mandible had a short height, large depth, small ratio, and large angle. In contrast, a Symphysis with a large height, small depth, large ratio, and small angle demonstrated a posterior growth direction. www.indiandentalacademy.com
Growth changes in Symphysis continued up to adulthood in both female and male subjects, with the female subjects having a smaller and earlier occurring change compared with the male subjects. Symphysis height, depth, and ratio increased while Symphysis angle decreased with age.
Todd Aki, RS Nanda, Frans Currier : Assessment of Symphysis morphology as a predictor of the direction of mandibular growth. AJODO 1994; 106; 60-9. www.indiandentalacademy.com
Ante gonial Notch – As an indicator of mandibular growth potential
The presence of a prominent mandibular ante gonial notch is a commonly reported finding in subjects with disturbed or arrested growth of the mandibular condyles. In unilateral condylar hypoplasia, marked mandibular notching develops only on the affected side. Bjork’s implant studies have showed that in forward rotating mandibles apposition occurs below the Symphysis and resorption takes place under the angle. Conversely, in backward mandibular rotation apposition beneath the angle is common and resorption underneath the Symphysis is possible. www.indiandentalacademy.com
The direction of mandibular growth rotation is reflected in the location and degree of remodeling on the inferior surface of the mandible and most pronounced area of remodeling is below the angular region. Singer and Hunter did a study to compare the craniofacial characteristics and growth potential of orthodontically treated patients with deep mandibular ante gonial notch; with those of a similar group of shallow notch subjects by use of lateral cephalometric radiographs. CP Singer, AH Mamandras, WS Hunter : The Depth of the mandibular antegonial notch as an indicator of mandibular growth potential. AJODO 1987; 91; 117-24. www.indiandentalacademy.com
> 3 mm - Very deep mandibular ante gonial notch < 3 mm - Very shallow mandibular ante gonial notch These extremes were examined by them with the hope that any biologic relationship might be more readily apparent in extremes of population.
Concluding remarks were: Deep notch subjects – more retrusive mandible with short corpus, less ramus height, and a greater gonial angle than did shallow notch subjects. Mandibular growth direction was more vertically directed Longer total facial height and longer lower facial height Smaller saddle angle Required a longer duration of orthodontic treatment (extractions 3 times the frequency, high-pull and straight-pull head gear, shallow notch subjects – wore low pull head gear exclusively) www.indiandentalacademy.com
During the average 4-year period examined, the deep notch subjects experienced less mandibular growth as evidenced by1. a smaller increase in total mandibular length. 2. corpus length, and 3. less displacement of the chin in a horizontal direction than did the shallow notch subjects.
Clinical implication ď Ž
The results of this study suggest that the clinical presence of a deep mandibular ante gonial notch is indicative of a diminished mandibular growth potential and a vertically directed mandibular growth pattern.
An explanation for this could be when the growth of the mandibular condyle fails to contribute to the lowering of the mandible, the masseter and medial pterygoid by their continued growth, cause the bone in the region of the angle to grow downward, producing notching.
Chronological and dental age are synchronous in the normal patient. A child is labeled as an early or late developer if there is a difference of +/- 2 years from the average value. If the chronologic age of the patient is younger than the dental age, one can rely on increased growth to a greater degree than when dental age is retarded in relation to the chronologic age ( and possibly biologic age). Dental age can be determined two methods: - Stage of eruption - stage of tooth mineralization on radiograph www.indiandentalacademy.com
Stage of Eruption
Determination of dental age from observation of eruption has been the only method available for a long time In certain cases however, the accuracy of the method is limited. During the quiescent period in eruption, this appoach is inadequate.
Orthodontic Diagnosis www.indiandentalacademy.com - Thomas Rakosi, I Jonas and T M. Graber
Stage of tooth mineralization on radiograph (Demirjian et al 1973) ď Ž
When determining dental age radiographically according to the stages of germination, the degree of the development of individual teeth is compared to a fixed scale. For age determination one does not rely on the last stage of tooth formation but on the entire process of dental mineralization. The procedure can be used for the entire deciduous and mixed dentition period, and is not influnced by early loss of deciduous teeth. www.indiandentalacademy.com
The calculation is made using a point evaluation system. Each tooth is given a point value according to its state of development. The sum of individual points gives the development value, which can be transferred into the dental age with the aid of standard tables.
The smaller the sum of points, the younger the dental age; the higher the sum, the older the dental age. Experience shows that the method is sufficiently accurate if the stage of mineralization of teeth 1-7 in the left lower quadrant is examined. The procedure is not valid for patients with several congenitally absent teeth.
Orthodontic Diagnosiswww.indiandentalacademy.com - Thomas Rakosi, I Jonas and T M. Graber
Orthodontic Diagnosis - Thomas Rakosi, I Jonas and T M. Graber www.indiandentalacademy.com
Lower third molar development in relation to Skeletal Maturity and Chronological Age ď Ž
Most of the studies correlating dental maturation to skeletal maturation have not included the lower 3rd molars. Engstrom in 1983 conducted a study to analyze development of the lower 3rd molar and whether it could be correlated to skeletal maturity. A probable reason for the great variability seen in previous studies regarding 3rd molar development might be because its development was related to chronological age rather than skeletal age.
Engstrom.C Engstrom.H, Sagne.s : Lower third molar development in relation to skeletal maturity and chronological age. Angle orthodontist; vol.53, no.2, april 1983. www.indiandentalacademy.com
Developmental stages of the lower 3rd molar ď Ž ď Ž
The stages of development of the lower 3rd molar were determined from OPGs. The developmental stages were categorized into-
Hand wrist x-rays were taken and their skeletal development classified as
: proximal phalanx of second finger, the epiphysis as wide
as diaphysis. MP3cap : Middle phalanx of third finger, the epiphysis cap its
diaphysis. : Distal phalanx of third finger, complete epiphyseal union. : Distal epiphysis of radius, www.indiandentalacademy.com
Development of lower third molar appeared slightly earlier in boys than in girls. Strong correlation was found between chronological age and third molar development. A strong correlation was also found between third molar development and skeletal maturity. At stage PP2- The 3rd molar showed signs of completed crown molar mineralization in most subjects. (B) At stage MP3cap- Lower third molar crown formation was complete in most subjects and root development has begun in some. (C) www.indiandentalacademy.com
At stage DP3u- Lower third molar crown was still incomplete in some subjects but full root length was attained in others. (E) At stage Ru- Only the crown was completed in 1/3rd of subjects. Half the root had developed in 1/3rd and full length was seen in another 1/3rd. (E) The results seem to show that lower third molar development on the whole seems to be correlated with skeletal maturation.
Frontal Sinus Development as an Indicator for Somatic Maturity at Puberty ď Ž
The possibility of predicting the stage of somatic maturity by analyzing frontal sinus growth was evaluated. The development of the frontal sinus as seen in lateral cephalograms was assessed at various ages. The material composed of 53 boys. Lateral head films existed for each individual over a 2 year period along with body height data for 7 years including the pubertal period. The head films were taken at yearly intervals and body height readings were taken every 3-6 months. Sabin Ruf, Hans Pancherz : Frontal sinus development as an indicator for somatic maturity at puberty? AJO-DO 1996;110;476-82 . www.indiandentalacademy.com
Two lateral head films of each subject were analysed at 1year and 2 year intervals. Two prediction intervals T1 and T2 (1yr & 2yr) were formed.
ď‚§ The peripheral borders of the
frontal sinus were traced. The highest point Sh &the lowest point Sl were marked. A line was drawn connecting Sh & Sl. A perpendicular to this line was drawn at the widest pt and the max. width of the sinus was assessd. www.indiandentalacademy.com
The average yearly growth velocity (mm/yr) of frontal sinus was calculated seperatedly for each of prediction intervals T1 or T2. The average yearly body height increase in mm was calculated. The max body growth velocity at puberty was assigned a term body height peak or Bp.
Frontal sinus growth velocity is closely related to body height growth velocity during puberty. Frontal sinus growth shows a well defined pubertal peak (Sp). This occurs approx. 1.4 yrs after Bp or body height peak. www.indiandentalacademy.com
In males the average age at frontal sinus peak is 15.1 yrs. In a 1 yr period, growth of 1.3 mm/yr is seen in frontal sinus in 84% of subjects. (T1) In a 2 yr period, growth of 1.2 mm/yr is seen in 70% of subjects in frontal sinus region. (T2) Prediction procedure: The frontal sinus growth velocity Sv was compared with T1 & T2 values. If Sv value was as high as or higher than T values, it can be assumed that the frontal sinus peak was reached during the prediction interval. Therefore Bp has been reached approx. 1.4 yes before the midpoint of the observation interval.
If Sv value was lower than T values, it cannot be said whether the subject is prepeak or post peak in frontal sinus growth. The age of the subject is also needed. As the frontal sinus peak is reached at 15.1 yrs, a low subject age means that the frontal sinus peak has not yet been reached. Therefore Bp (body ht peak) has not been reached. If subjects age is more than 15.1 yrs with a Sv value lower than T value, it can be assumed that the frontal sinus growth peak has passed and also that the Bp has passed more than 1.4 yrs before the beginning of the observation interval. (T1 or T2). www.indiandentalacademy.com
If the only prediction was whether the pubertal growth peak in height has been passed, the precision of the method was rather high.(90%) However, if the age of body height peak was to be predicted, the method accuracy was lower.(55%) The study suggests that the somatic maturity stage may be predicted rather accurately by analyzing frontal sinus developmental on pre-existing lateral head films.
Assessment of Physical Maturation by Somatomedin Levels During Puberty ď Ž
This study was undertaken by leonard Rothenburg in 1977. it was performed on 27 caucasian subjects, all females. Growth hormone has long been known to play an important role in linear growth. However, growth hormone determination is not of any value because growth hormone does not act directly on linear growth but acts through an intermediary called Somatomedin. Somatomedin is stimulated by growth hormone and has a direct effect on cartilage. www.indiandentalacademy.com
This study determines whether Somatomedin levels could serve as markers for assessing maturation levels. 3 developmental categories were established based on a physical examination by a pediatrician – Category A Prepubertal stage 1 Category B Circumpubertal stage 2,3 Category C Postpubertal stage 4,5 Blood samples were taken and the somatomedin levels assessed.
Results: ď Ž
There was a significant difference between the somatomedin levels in plasma of circumpubertal and post-pubertal females. No significant difference was seen in the levels of prepubertal and circumpubertal females.
Evaluation of skeletal maturation by using a computed X-ray Densitometry method
This study was conducted in japan in the year 1995. The aim of this study was to obtain data about bone density in normal children. It examined relationships between bone density, chronological age, bone age and cephalometric measurements. The subjects consisted of 462 girls and 298 boys from 6-20 years. Hand wrist pictures were taken of all the subjects and the densitometric pattern of the 2nd metacarpal bone was measured by computed x-ray densitometry method www.indiandentalacademy.com
Results: ď Ž
Bone density increased significantly until the age of 14 years in girls and 16 years in boys. There were differences between the sexes at each age. Bone density showed a strong co-relation with bone age rather than chronological age. Therefore Bone Density may be an efficient indicator for estimating bone maturation in a person.
Conclusion ď Ž
Maturational development embodies the biologic progression through life. In the growing years, indicators of the level of maturational development of the individual provide the best means for evaluating biologic age. Maturational development can be assed with the help of all the indicators previously described. However, it must be kept in mind that every child demonstrates a unique sequential pattern of events. No child is the same as the other.
Skeletal indicators of maturation have been proved to be the most reliable. A combination of skeletal and dental indicators tend to give a very accurate picture of each child’s developmental status. Finally it must be kept in mind that in orthodontic practice it may be more relevant to evaluate the development of the patient in relation to his own growth potential in order to assess whether peak velocity growth is imminent, present or completed. The choice of indicators to be used finally depends upon an orthodontist’s preference. www.indiandentalacademy.com
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