........ DENTAL MIRACLE .........: Role of Puberty in Orthodontics

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INTRODUCTION

Puberty means Adolescence . Period of life which lead to adulthood from childhood through dramatic physiological and psychological change . Period of development during which human typically acquire their reproductive capability

Adolescence is characterised by increased growth rate in practically all the bones and muscles of the body . Composition of body and face changes dramatically during adolescence

Clinical orthodontic considerations associated with pubertal growth spurt are concerned with amount of growth and its effect on the outcome of treatment

GROWTH SPURTS

Defined as periods of growth acceleration

Normal spurts are

· Infantile spurt : at 3 years age

· Juvenile spurt : 7-8 years (females)

8-10 years (males)

· Pubertal spurt : 10-11 years(females)

14-15 years (males)

TIMING OF PUBERTY

Timing of puberty in both males and females shows greater variation

• Adolescent growth spurt generally occur earlier in females than in males

• Female precedes males by 2 years in pubertal growth spurts

Boys are

1. Slow growers

2. Longer period of adolescence ( 5 years )

3. Cut offing time puberty not well defined compared to female

4. Cartilage to bone transformation less prominent

Girls are

1. Fast growers

2. Short period of adolescence ( 3 ½ years)

3. Cut offing time puberty well defined compared to male

4. Cartilage to bone transformation more prominent

FACTORS AFFECTING TIMING OF PUBERTY

1. Genetic Factor : Early maturing and late maturing families

2. Environmental Factor

3. Ethnic Factor

4. Body Type : Girls with slender body type maturing late ( E g : Athletic girls)

5. Amount of Fat : Girls with more fat mature early

6. Seasonal Factor (Spring and Summer season : Growth faster )

7. Hormone ( GH , Oestrogen , Adrenal hormones , Thyroid hormones )

CHANGES DURING PUBERTY

· Physical changes

· Psycological changes

· Hormonal changes

· Cranio facial changes

PHYSICAL CHANGES DURING PUBERTY

1. Increase in body Stature

2. Increased Weight

3. Longer arms and Legs

4. Bigger hands and feet

5. Face look less child like

6. Appearance of secondary sexual characteristics

7. Menarche seen in Girls

PSYCOLOGICAL CHANGES DURING PUBERTY

1. Puberty may bring on powerful emotions

2. Mood swings occur due to hormonal changes ; fluctuations in your emotions are signs that you are maturing emotionally

3. More self conscious about Beauty

4. Teenagers make decisions with their emotions rather than logic

They are highly influenced by PEER GROUP in this time

If the adolescent patient comes for treatment alone or with a friend and not escorted by mother/father

Better for Orthodontist – Patient relationship

ENDOCRINOLOGY OF ADOLESCENCE

Puberty is a period during which many dramatic hormonal changes occur

Growth is controlled by many hormones during puberty

1. Growth hormone

2. Anterior pituitary hormones

3. Thyroid hormone

4. Gonadal hormones : Oestrogen , Progestron and Testosterone

5. Adrenal androgens

6. Releasing and Inhibiting hormones of hypothalamas

GROWTH HORMONE

Protein : Stimulate protein synthesis and protein deposit cause increase in

muscle mass

Bone & Cartilage : GH increases the length of long bone by using epiphyseal

cartilage mainly in puberty

In late adolescence period no epiphyseal cartilage remaining

for further growth of long bones

THYROID HORMONE

• Basal metabolic rate : Increased by thyroid hormone

• Increase facial skeletal growth

• Needed for tongue growth

• It needed for soft tissue growth

• Needed for dentition and increase eruption

PUBERTY REGULATING AXIS

Initiation of Puberty controlled : Neuroendocrine system

Before Puberty : Hypothalamus - Pituitary - Adrenal Axis

At Puberty : Hypothalamus – Pituitary - Gonadal Axis

HYPOTHALAMUS - PITUITARY - ADRENAL AXIS

· ADRENARCH : Early rise in adrenal androgen

· Adrenal androgen appear to be transformed into oestrogen in the peripheral fatty tissue causing maturation of gonadostat

· Onset of puberty is initiated by the maturation of the hypothalamic pituitary complex and input of CNS is called GONADOSTAT

· Delayed puberty occur in children with Adrenal Insufficiency

- Gonadostat maturation delay

- GH level not increase during puberty

HYPOTHALAMUS - PITUITARY - GONODAL AXIS

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ESTROGEN PROGESTRON CYCLE

GROWTH EFFECT OF ESTROGENS IN FEMALES DUING PUBERTY

EFFECT ON SKELETON

• Estrogen increases osteoblastic activity in bones

• At puberty : Girls growth in height become rapid for several years

• Estrogen cause uniting of epiphyses with shaft of the long bone

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EFFECT ON PROTEIN

• Estrogens cause a slight increase in total body protein

• This mainly results from the growth-promoting effect of estrogen on sexual , organs, bones

• Girls have less increase in Total body protein than boys

• So girls have less muscle mass and strength

GROWTH EFFECT OF TESTOSTERONE IN MALES DUING PUBERTY

EFFECT ON BONE GROWTH AND CALCIUM RETENTION

• Testosterone cause increase in size and strength of bone

• Increases total quantity of bone matrix

• It causes calcium retention

• It cause uniting of epiphyses with shaft of the long bone

EFFECT ON PROTEIN FORMATION AND ON MUSCLE DEVELOPMENT

• During puberty : Development of increasing musculature

• Musculature development of males are more than females

EFFECT ON BASAL METABOLISM

• Basal metabolic rate is increased

REGULATION OF HORMONES

SIGNIFICANCE OF HORMONES DURING PUBERTY

1. GROWTH HORMONE

· Children who received long-term GH therapy showed increased growth of the craniofacial skeleton, especially the maxilla and mandibular ramus.

· These ﬁndings suggest that GH accelerates craniofacial development ,which improves occlusion and the facial proﬁle.

Minayo Funatsua, Koshi Satob,Hideo Mitani Effects of Growth Hormone on Craniofacial Growth: Angle Orthodontist, Vol76, Nov,2006

Growth hormone deficiency cause aberrant facial feature with saddle nose and protubrant frontal bones , retro gnathic maxilla and mandible and reduced facial height and width

• In male overall cranial base size reduction occur

• In females anterior cranial base is normal but posterior cranial base is short

• Small ramal height due to reduction in total mandibular length (Cantu etal 1997)

• Hormone replacement therapy needed for Growth deficient therapy

2. OESTROGEN

• Female who devoid of oestrogen production usually grows several inches taller than the normal mature female : Because her epiphysis do not unite at the normal early time

• Girls who have more fat in their body have more oestrogenic activity so they mature early

• Oestrogen deficiency is a reason for Osteoporosis

₋ Increased bone resorption with normal bone formation

₋ Increased tooth mobility

3. THYROID HORMONES

• Thyroid hormone deficiencies may have profound effect on he proper development of facial skeleton and the dentition

• Thyroid deficiency manifested as short stature with puffy face and dry skin

• Macroglossia

• Delayed dental and skeletal development

• Retarded eruption of permanent teeth

• Short posterior facial height and retruded mandible creating anterior open bite

• Insufficient growth due to hormonal disturbance can negatively affect orthodontic treatment especially with functional appliances

• When a Class II case is not responding satisfactory after a reasonable time period even patient cooperates : One reason may Thyroid hormone deficiency

• Orthodontic Treatment combine with hormone replace therapy so optimum result can achived ( Verna etal 2000 )

CRANIOFACIAL GROWTH CHANGES DURING PUBERTY

Hard tissue changes

· Cranio basal growth changes

· Midfacial growth changes

· Mandibular growth changes

· Dento-alveolar changes

Soft tissue changes

· Lips

· Nose

· Chin

GROWTH OF CRANIAL BASE DURING PUBERTY

· Cranial base shows some increases in growth increments during puberty

· Pubertal growth spurt in the cranial base usually precedes the peak height velocity

· Spurt in the cranial base length is mainly due to growth in_:

Main Growth : Sphenoccipital synchondrosis

Minimum Growth : Foramen magnum + Nasion

During the early postnatal years, the cranial base undergoes a dramatic shift in it growth pattern :

§ Anterior (nasion–sella) cranial base lengths

§ Posterior (sella– basion) cranial base lengths

§ Cranial base angulation ( nasion–sella–basion)

Anterior cranial base grows more mature Posterior cranial base

(closer to its adult size)

Sphenoethmoidal synchondroses

Anterior cranial base has already attained approximately 86% to 87% of its adult size by 4.5 years of age

Spheno-occipital synchondroses

Spheno-occipital synchondrosis fuses at approximately

Females : 16 to 17 years

Males : 18 to 19 years

Ford HER. Growth of the human cranial base. Am J Orthod. 1958;44:498–506

Relative maturity differences between the anterior and posterior cranial base lengths are maintained throughout postnatal growth

Radiographically,

- Spheno-occipital synchondrosis shows active growth until approximately 10 to 13 yrs. age

- Closure time starts superiorly and continues inferiorly : Female - 11 to 14 years

Males - 13 to 16 years

- Hunter was the first one to study about the spurt in cranial base growth during adolescence

- Acceleration of the growth of the Ba-S distance : 12.5 years age

- Increase in the S-N length : 8 to 15 years.

GROWTH OF CRANIAL BASE OF BOYS DURING PUBERTY

· Acceleration in the growth of the lengths S-N, Ba-N, Ba-S was seen ; (within 2 years of peak height velocity )

· Spurt larger for Ba-N than S-N and Ba-S

· Elongation of S-N, Ba-N , Ba-S continued : till 17.5 yrs.

· Spurt in Ba-N length is smaller than S-N in early maturing boys

· Ba-S has greater spurt in shorter boys but the Ba-S length is greater in taller boys

Cranial Base Elongation in boys during pubescence : Arther B Lewis etal ( AO 1974 )

GROWTH OF CRANIAL BASE OF GIRLS DURING PUBERTY

- Acceleration in the growth of the lengths S-N, Ba-N, Ba-S was seen

- Elongation of S-N, Ba-N , Ba-S continued : till 17.5 yrs.

- Elongation of Ba-S continued : till 16.5 yrs.

- Spurt larger for Ba-N than S-N and Ba-S

Cranial Base Elongation in Girls during pubescence : Arther B Lewis etal (AO 1972)

SEX DIFFERENCES IN THE ELONGATION OF THE CRANIAL BASE

Pubertal growth spurt in cranial base is

- Much earlier in girls than in boys

- Greater in boys than in girls.

Sex differences in the elongation of the Cranial base : Arther B Lewis etal (AO 1972)

Conclusions

This study found the following:

• Linear measurements of cranial base length showed significant growth during all pubertal stages (pre-peak, peak and post-peak stages).

• No significant differences were found between genders in any cephalometric measures during the pubertal stages.

- Luciana Abra Malta , Cristina F Ortolani , Kurt Faltin. Quantification of cranial base growth during pubertal growth : J O ,Vol.36,2009,229–235

SIGNIFICANCE OF CRANIAL BASE LENGTH CHANGE DURING PUBERTY

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GROWTH OF MIDFACIAL STRUCTURES DURING PUBERTY

FACIAL GROWTH DURING PUBERTY

· Growth of jaws usually correlate with body height growth and events in puberty

· Adolescent growth spurt in the length of the mandible and body height are almost same modest though discernible increase in growth at the sutures of the maxilla.

Jaw growth follows the curve for general body growth, the correlation is not perfect. Longitudinal data from studies of craniofacial growth indicate that a significant number of individuals, especially among the girls, have a "juvenile acceleration" in jaw growth that occurs 1 to 2 years before the adolescent growth spurt (Figure 4-6). growth acceleration at puberty

GROWTH OF MIDFACIAL STRUCTURES DURING PUBERTY

Only modest increase in the growth of maxilla during puberty

Postnatal development of the naso-maxillary complex

• Intramembranous ossification

• Sutural growth

• Extensive surface remodelling (especially along its posterior and superior aspects)

• Displacement

Postnatal development of the naso-maxillary complex

• Intramembranous ossification

• Sutural growth

• Extensive surface remodelling (especially along its posterior and superior aspects)

• Displacement

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• Entire period between ages 7 and 15 :

1. One third of the total forward movement of the maxilla can be : Passive displacement

2. Rest is the result of active growth of the maxillary sutures in response to stimuli from the

• Enveloping soft tissues

• When active growth of the maxilla is considered : Effect of surface remodelling occur by apposition or resorption

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Enlow DH, Bang S. Growth and remodelling of the human maxilla. Am J Orthod. 1965;51:446–464

Growth of the nasomaxillary complex continues throughout childhood and adolescence, with substantially greater vertical than anteroposterior growth potential

MID FACIAL HEIGHT

Mid facial heights should be expected to increase 10 to 12 mm in females and 12 to 14 mm in males between 4 and 17 years of age.

PALATAL LENGTH

Palatal length should be expected to increase 8 to 10 mm over the same time period

SNA ANGLE

SNA angle shows little or no change during childhood or adolescence because nasion drifts anteriorly at approximately the same rate as the midface is displaced anteriorly

GROWTH OF MAXILLA DURING PUBERTY

· Singh and Savara, and Bjork who made longitudinal cephalometric studies regarding the growth of maxilla.

· O' Rielly used the data from the studies of Bjork to calculate the increase in the length of maxilla during puberty

His Conclusion :

• No significant difference in the amount of growth of maxillary length before or after menarche

• Timing of maximum increment in maxillary length was weakly correlated with the onset of epiphyseal- diaphyseal fusion and menarche

SEX DIFFERENCES IN MAXILLARY GROWTH THROUGHOUT CHILDHOOD AND ADOLESCENCE

• Males being larger and growing maxillary growth more than females.

• Size differences, averaging between 1 and 1.5 mm, are small but consistent during childhood.

• Sexual dimorphism increases substantially throughout the midfacial complex during adolescence,

• Differences of approx 4 mm in maxillary length ( ANS-PNS) and upper facial height (N-ANS) at 17 years of age.

ROTATION OF MIDFACE DURING PUBERTY

• Most children undergo true forward or counter-clockwise (subject facing to the right) rotation of the mid face , due to greater inferior displacement of the posterior than anterior maxilla.

• True rotation that occurs tends to be covered up or hidden by the resorption that occurs on the nasal floor.

• True forward rotation is associated with greater resorption in the anterior than posterior aspect of the nasal floor.

• Due to greater transverse displacements posteriorly than anteriorly, the midfacial complex also exhibits transverse rotation around the midpalatal suture

• As a result, there is greater sutural growth in the posterior than anterior aspect of the midpalatal suture

• Cephalometric analyses using metallic implants have shown that

• Posterior maxilla expands : 0.27 to 0.43 mm/yr., with greater expansion occurring during childhood than during adolescence

• Males also have a significantly wider midfaces than females, with differences approximating 5 to 7 mm during late adolescence

SIGNIFICANCE OF MIDFACE GROWTH

EYE BALL AND MIDFACE

• Growth of the eyeball is associated with both the anterior and lateral displacements of the midface

• Enucleation of the eyeball during growth results in deficiencies in the anterior and lateral growth of the midface

GROWTH OF MAXILLA

• If maxillary growth is deficient than normal cause Retrognatic Maxilla

• If maxillary growth is more than normal caause Prognathic Maxilla

ROTATION OF MAXILLA

• Skeletal Open bite chance is more in anticlockwise rotation of maxilla

• Skeletal Deep bite chance is more in Clockwise rotation of maxilla

HEAD GEAR AND FACE MASK USE

• Maxillary horizontal growth is completed much earlier than mandible and so the use of headgear to restrict or redirect its growth should be started much before pubertal growth spurt in mixed dentition period.

MANDIBULAR GROWTH DURING PUBERTY

• Mandible has the greatest postnatal growth potential of any component of the craniofacial complex

• Mandible follows Cephalocaudal gradient of growth and follows the growth of the body height is dramatically evident at puberty.

•

Mandible shown against the background of Scammon's curve

• Between 4 and 17 years of age

1. Total mandibular length [Co–Me]) : Male - 30 mm Female - 25 mm

2. Corpus length (Go–Pg ) : Male - 22 mm Female – 18mm

3. Ramus height ( Co–Go) : Male -17mm Female - 14

• Greatest increases in length can be seen in TOTAL MANDIBULAR LENGTH

• Longitudinal cephalometric study of Nanda :

- Significant increase in size of mandible : 13 -16 yrs.

- Se-Go shows greater proportionate increase than Go-Gn

- Go-Gn growth stop at age (19 yrs. ) but Se-Go continue to grow

• Bjork’s Mandibular condyle study conclusions

- Indicate that there was a discernible but not significant spurt in mandibular growth during puberty

- There was no relationship between the intensity and direction of growth.

- Michigan growth studies and Bolton growth studies showed only gradual increase in size of the mandible with age.

• In the Iowa growth samples,

• 3 Groups : Each of 2 year duration

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• There Is significant growth of the mandible which takes place over a longer period during adolescence

• But this does not assign a specific time for early and late treatment as the timing of treatment is also affected by numerous other factors.

VERTICAL GROWTH

• Annual rates of vertical growth of mandible

• Range between 0.9 mm per year for the lingual incisor contact point to -0.2 mm per year for gnathion

• Males showed significantly greater rates of vertical growth than females, especially for the upper half of the symphysis

• Vertical growth rates were also greater during puberty than during childhood

HORIZONTAL GROWTH

• Horizontal growth changes indicated lingual movement of most symphyseal landmarks

• Annual rates of growth were greatest for landmarks located in the upper half of the symphysis.

• B-point showed the greatest lingual drift

• During puberty, the mandibular incisors in females moved lingually as the upper anterior half of the symphysis was remodeled

• In males, the incisors maintained their horizontal position while the labial sulcus developed.

• Between 7 and 15 years of age,

- Biantegonial width : 10 mm

- Bigonial widths : 12mm

• Importantly, mandibular width continues to increase throughout childhood and adolescence.

• While an adolescent spurt in vertical mandibular growth certainly occurs, a pronounced spurt for the anteroposterior and transverse growth has not been established.

• Growth changes that occur are closely associated with the functional processes that comprise the mandible, including

1. Gonial process

Major sites of postnatal remodelling

Coronoid process

3. Alveolar process

4. Bony attachments of the

suprahyoid muscles

• Condylar growth is often assumed to be the mandible’s primary growth site

• It is important to note that the entire superior aspect of the ramus displays approximately the same amount of growth.

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CONDYLAR GROWTH

• Greatest growth rate of condyle rates occurring during the earlier childhood years and during the adolescent spurt

• Posterior growth ( every 1 mm ) : Superior growth ( 8 to 9 mm )

• Condyles Growth : Male - 2.5 to 3.0 mm/yr.

Females - 2 to 2.5 mm/yr.,

• During later childhood and adolescence, : condyle shows substantially greater amounts of superior than posterior growth.

CORNOID PROCESS AND GONION GROWTH

• Coronoid process and sigmoid notch follow similar growth patterns

• Due to the resorption of bone that normally occurs in the gonial region, ramus height substantially underestimates the actual amount of growth that occurs at the condyle

• 1 mm of resorption at gonion for every 3 mm of superior condylar growth

MANDIBULAR ROTATION

• Mandible undergoes substantial amounts of true vertical rotation and less transverse rotation.

• Mandible exhibits more vertical rotation than the maxilla

• Typical pattern of rotation is forward (counter-clockwise with the profile facing to the right), due to greater inferior displacements of the posterior than anterior aspects of the mandible.

• Rates of vertical mandibular rotation 0.4 and 1.3 deg/yr., with significantly greater rates of rotation during childhood than adolescence

SEX DIFFERENCES IN MANDIBULAR GROWTH

• Sex differences in mandibular growth are more pronounced during adolescence

•

Sex differences, which are

• Greatest for overall length Corpus length Ramus height,

• 0 to 2 mm difference between 1 and 12 years of age, when males initiate their adolescent phase of growth

• Mandibular dimorphism increases to 4 to 8 mm by the end of adolescent growth phase (Figure 8-35).

• No sex differences I : vertical rotation during childhood or adolescence.

•

SIGNIFICANCE OF MANDIBLUR GROWTH DURING PUBERTY

ABNORMAL GROWTH

• If mandibular growth is deficient than normal then mandible become Retrognathic

• If mandibular growth is more than normal then mandible become Prognathic

ROTATION OF MANDIBLE

• Skeletal Open bite seen in Clockwise rotation of mandible

• Skeletal Deep bite seen in Anti-clockwise rotation of mandible

FACE MASK AND CHINCUP

• Orthopaedic appliances like facemask and chin cup are used for the treatment of skeletal class III malocclusions early during the mixed dentition period

• But , continuing growth of mandible and its pubertal growth spurt can lead to development of malocclusion after early interventions.

FUNCTIONAL APPLIANCES

• Effectiveness of functional appliances to modify skeletal growth is minimal after pubertal growth spurt

ARCH DEVELOPMENT, TOOTH MIGRATION, AND ERUPTION

ARCH WIDTH

Intercanine Width

• Maxillary inter-canine width

• Transition to Early mixed dentition : 3 mm

• Emergence of permanent canines : 2mm

• Mandibular intercanine width increases approximately 3 mm during initial transition but shows little or no change with the eruption of the permanent canine

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Intermolar width

• Intermolar widths progressively increase during childhood and adolescence, approximately 4 to 5 mm for the maxilla and 2 to 3 mm for the mandible between 6 and 16 years of age

ARCH LENGTH

• Maxillary arch length (incisors to molars) decreases slightly during the transition to the early mixed dentition, increases 1 to 2 mm with emergence of permanent incisors, and then decreases approximately 2 mm with loss of the deciduous first and second molars.

• Mandibular arch length decreases slightly during the transition to mixed dentition, maintains its dimension during most of the mixed dentition, and then decreases 2 to 3 mm with the loss of the deciduous first and second molars.

• Arch length decreases during adolescence

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ARCH PERIMETER

Maxillary arch perimeter

• Arch Perimeter from first molars to first molars increases 4 to 5 mm during early mixed dentition and then decreases approximately 4 mm during late mixed dentition

• Resulting in only a slight overall increase between 5 and 18 years of age

Mandibular arch perimeter

• Mandibular arch perimeter, from first molar to first molar, on the other hand, increases approximately 2 mm during early mixed dentition and decreases 4 to 6 mm during late mixed dentition

• Resulting in overall decreases of 3.5 and 4.5 mm in males and females, respectively.

ANTERIOR MIGRATION OF TOOTH DURING PUBERTY

• Childhood (6-12 yr. of age )

Maxillary Incisor > Maxillary molar

( 0.8 mm/yr.) ( 0.6 mm/yr.)

• Age ( 10-12 yr. )

Maxillary Incisor < Maxillary Molar

( 0.3 mm/yr. ) ( 0.5/0.6 mm/yr.)

Mandibular Incisor < Mandibular Molar

( 0.2/0.3 mm/yr. ) ( 0.7 mm/yr.)

TOOTH ERUPTION DURING PUBERTY

During childhood,

Maxillary 1^st molars Mandibular 1^stMolar

Maxillary 1^st Incisor Mandibular 1^stIncisor

( 1.0 mm/yr. ) ( 0.5 mm/yr. )

During Adolescence

Maxillary Incisor < Maxillary Molar

( 0.9 mm/yr. ) ( 1.2-1.4 mm/yr.)

Mandibular Incisor and Mandibular Molar 0.5 to 0.9 mm/yr.

SEXUAL DIMORPHISM IN THE MIGRATION AND ERUPTION OF TEETH

• Childhood : No Sexual dimorphism seen

• Adolescence : Sexual dimorphism seen

• Mandibular teeth eruption : BOYS > Girls

• Maxillary teeth show only limited sex differences pertaining primarily to the molars

SIGNIFICANCE

• Most important from a clinical perspective, the teeth continue to migrate and erupt throughout childhood and adolescence, even after they have attained functional occlusion.

SOFT TISSUE PROFILE CHANGES

CHANGES IN LIPS

•

Lips trail behind the growth of the jaws prior to adolescence, then undergo a growth spurt to catch up.

• Lip height : Lip incompetence

• Lip incompetence : High during mixed dentition

: Decreases during adolescence period

Age : 11yr 9 m Age : 14yr 8 m Age : 16yr 11 m Age : 18yr 6 m

- When lips height increase gingival display decreases

- What looks like too much display of gingiva prior to and in adolescence can look perfectly normal in a young adult

Age : 12y Age : 14y Age : 24y

Lip thickness reaches its maximum during adolescence, then decreases some women consider loss of lip thickness a problem and seek treatment to increase it.

• Lips are framed by the nose above and chin below, both of which become more prominent with adolescent and post-adolescent growth while the lips do not, so the relative prominence of the lips decreases.

CHANGES IN NOSE

Growth of the nasal bone is complete at about age 10

• Growth of the nasal cartilage and soft tissues, both of which undergo a considerable adolescent spurt

• Result is that the nose becomes much more prominent at adolescence, especially in boys

Age : 4y 9 m Age : 12y 4 m Age : 14y 8 m Age : 17y 8m

After age of 12 ,

Girls shows decline in nasal growth , but boys shows increased growth velocity

NASOLABIAL ANGLE

• Larger in girls than in boys

• Decreases with age more in girls than in boys

CHANGES IN CHIN

• Maturing face becomes less convex as the mandible and chin become more prominent

• Prominence of chin is more in males than female

• Chin prominence increased at rate : 0.2-0.7 mm per year

FACIAL SOFT TISSUE CHANGES DURING THE PRE-PUBERTAL AND PUBERTAL GROWTH PHASE: A MIXED LONGITUDINAL LASER-SCANNING STUDY

• Aim of this mixed longitudinal study was to assess facial growth among pre-pubertal and pubertal subjects without malocclusion using a non-invasive three-dimensional laser scanning system.

• Conclusions:

• Soft tissue facial growth has generally similar amounts and rates irrespective of the pubertal growth spurt. Pre-pubertal subjects show greater annual rates of facial middle third height changes while pubertal subjects show greater annual rates of chin protrusion.

Jasmina Primozic, Giuseppe Perinetti, Luca Contardo, Maja Ovsenik . Facial soft tissue changes during the pre-pubertal and pubertal growth phase: a mixed longitudinal laser-scanning study

EJO 17 February 2016

SIGNIFICANCE OF SOFT TISSUE DURING PUBERTY

• Soft tissue growth and other factors leading to the expansion of the oro-nasal capsule are relatively more important in explaining the mid facial rotation and displacement during later childhood and adolescence.

• Determining how much lip support should be provided by the teeth at the time orthodontic treatment typically ends in late adolescence.

• Chin is an important part of profile that leads to straightening of profile

• Changes in the facial soft tissues with aging, which also must be taken into consideration in planning orthodontic treatment

OTHER SIGNIFICANCE OF PUBERTY IN ORTHODONTICS

SIGNIFICANCE OF PUBERTY IN ORTHODONTICS

• Pubertal increments offers best time for, determining the predictability, growth direction, patient management and total treatment time.

DIAGNOSIS AND TREATMENT PLANNING

Assessment of Developmental Age.

• In a step particularly important for children around the age of puberty when most orthodontic treatment is carried out, the patient's developmental age should be assessed.

• Everyone becomes a more or less accurate judge of other people's ages-we expect to come within a year or two simply by observing the other person's facial appearance.

• Occasionally, we are fooled, as when we say that a l2-year-oId girl looks 15, or a l5-year- old boy looks 12. With adolescents, the judgment is of physical maturity.

• Tendency for a clinically useful acceleration in jaw growth to precede the adolescent spurt, particularly in girls

• Major reason for careful assessment of physiologic age in planning orthodontic treatment is If treatment is delayed too long, the opportunity to utilize the growth spurt is missed

NORMAL OR ABNORMAL GROWTH DURING PUBERTYT

• It is important to assess the general growth status of adolescent child reporting for orthodontic treatment.

• Percentile growth charts can be used for the purpose.

• It helps in assessing whether the child’s growth is normal or abnormal

• Highly abnormal growth needs medical attention to rule out any systemic or hormonal imbalance.

GROWTH MODIFICATION

Functional appliances

• Functional jaw orthodontic therapy takes advantages of redirection of remaining growth of craniofacial region.

• Twin block, bionator, Frankel appliances are given for class II skeletal correction.

• Effectiveness of these appliances to modify skeletal growth is minimal after pubertal growth spurt.

Orthopaedics appliances

• Orthopaedic appliances like headgears are also advantageous to correct maxillary prognathism during growing stage of the patient.

• Orthopaedic appliances like facemask and chin cup are used for the treatment of skeletal class III malocclusions early during the mixed dentition period

• But , continuing growth of mandible and its pubertal growth spurt can lead to development of malocclusion after early interventions.

MAXILLARY EXPANSION

• Maxillary expansion procedures in cases of jaw constriction should be carried out during early mixed dentition.

• Growth in width of maxilla occurs by sutural growth in interpalatine and intermaxillary sutures. Maximum growth occurs in first 5 years.

• The skeletal expansion procedures should be carried out before the fusion of palatal sutures by 10 years

ORTHOGNATHIC SURGERY

• Active growth cessation is prerequisite for orthognathic surgery

• Particularly in cases with mandibular prognathism

PLANNING OF RETENTION REGIME

• It is extremely important to pay attention to the person's growth pattern, and a distinction must be made in the selection of retention devices on the basis of the nature and the extent of dentofacial dysplasia (growth pattern). The nature and duration of retention should depend on the maturation status of the patient and on anticipated future growth. Retention guidance is necessary for adjustment of the dentition to late growth changes and maturation of neuromuscular balance. "Active retention" is a concept we accept as readily as the orthopaedic surgeon does for his scoliosis patients.

Considerations of dentofacial growth in long-term retention and stability : Is active retention needed ?

RamS.Nanda and Surender K.Nanda

CAN ALVEOLAR GROWTH AFFECT THE PLACEMENT OF IMPLANTS?

Patients missing central incisor due to trauma or a congenitally missing lateral incisor, the treatment options for replacing the lost tooth following orthodontic treatment may placing a single tooth implant.

• In a 1996 study, Iseri and Solow evaluated cephalograms on Patients from the original Bjork material with metallic implants placed in the maxilla and mandible.

• They found signiﬁcant anterior alveolar growth that continued in to late adolescence and early adulthood

SamirE.Bishara Facial and Dental Changes in Adolescents and Their Clinical Implications : AO 2000;70:000–000

• Clinicians should postpone placing an implant in younger patients until alveolar growth is completed

• Such growth could cause the implant to become progressively in infra occlusion

Haluk Iseri* and Beni Solow Continued eruption of maxillary incisors and first molars in girls from 9 to 25 years, studied by the implant method : EJO 18 ( 1996) 245-256

CLEFT PALATE AND PUBERTY

- In cleft palate patient during puberty time :

- Skeletal discrepancy becomes accentuated, and facial appearance and occlusal relationships deteriorate

• These changes occur at a time when individuals are most self-conscious about their body image and facial appearance

• Facial scars already detract from the cosmetic appearance, and derogatory comments by peers may have a profound psychological effect

• With a decline in cosmetic appearance , many patients have a special need for early intervention by the surgeons, orthodontists this time

CONCLUSION

Puberty period is very important period in a human life because many changes like physical , mental , phsycosocial and cognitive changes occur during this time .Also this period is important for Orthodontist in treatment planning and he can modulate the growth in certain situation , and other situation he have to know when the growth ceases to plan for orthodontic surgery as

“ Only what the mind knows that the Eye See ”So better understanding about puberty and its role in orthodontics is important for an Orthodontist

REFERENCES

1. Contemporary Orthodontics 4^th Edition : William . R. Proffit

2. Orthodontics current principle and technique : Xubair , Graber , Vanarsdall , Vig

3. Orthodontics in Daily Practice : J A Salzmann

4. Textbook of craniofacial Growth : Sridhar Pream Kumar

5. Biomechanics of tooth movement : Vinod Krishnan

6. Effects of Growth Hormone on Craniofacial Growth : Minayo Funatsua, Koshi Satob,Hideo Mitani : Angle Orthodontist, Vol76, Nov,2006

7. Ford HER. Growth of the human cranial base. Am J Orthod. 1958;44:498–506

8. Cranial Base Elongation in boys during pubescence : Arther B Lewis etal( AO 1974 )

9. Cranial Base Elongation in girls during pubescence : Arther B Lewis etal ( AO 1972)

10. Sex differences in the elongation of the Cranial base : Arther B Lewis ( AO 1972)

11. Quantification of cranial base growth during pubertal growth Luciana Abra Malta , Cristina F Ortolani , Kurt Faltin: J O ,Vol.36,2009,229–235

12. Enlow DH, Bang S. Growth and remodelling of the human maxilla. Am J Orthod. 1965;51:446–464.

13. Jasmina Primozic, Giuseppe Perinetti, Luca Contardo, Maja Ovsenik . Facial soft tissue changes during the pre-pubertal and pubertal growth phase: a mixed longitudinal laser-scanning study - EJO 17 February 2016

14. Considerations of dentofacial growth in long-term retention and stability : Is active retention needed ? - RamS.Nanda and Surender K.Nanda

15. Facial and Dental Changes in Adolescents and Their Clinical Implications : AO 2000; 70:000–000-SamirE.Bishara

Continued eruption of maxillary incisors and first molars in girls from 9 to 25 years, studied by the implant method : EJO 18 ( 1996) 245-256

- Haluk Iseri* and Beni Solow

Role of Puberty in Orthodontics

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INTRODUCTION

Adolescence is characterised by increased growth rate in practically all the bones and muscles of the body . Composition of body and face changes dramatically during adolescence

Clinical orthodontic considerations associated with pubertal growth spurt are concerned with amount of growth and its effect on the outcome of treatment

GROWTH SPURTS

Defined as periods of growth acceleration

Normal spurts are

· Infantile spurt : at 3 years age

· Juvenile spurt : 7-8 years (females)

8-10 years (males)

· Pubertal spurt : 10-11 years(females)

14-15 years (males)

TIMING OF PUBERTY

Timing of puberty in both males and females shows greater variation

• Adolescent growth spurt generally occur earlier in females than in males

• Female precedes males by 2 years in pubertal growth spurts

Boys are

1. Slow growers

2. Longer period of adolescence ( 5 years )

3. Cut offing time puberty not well defined compared to female

4. Cartilage to bone transformation less prominent

Girls are

1. Fast growers

2. Short period of adolescence ( 3 ½ years)

3. Cut offing time puberty well defined compared to male

4. Cartilage to bone transformation more prominent

FACTORS AFFECTING TIMING OF PUBERTY

1. Genetic Factor : Early maturing and late maturing families

2. Environmental Factor

3. Ethnic Factor

4. Body Type : Girls with slender body type maturing late ( E g : Athletic girls)

5. Amount of Fat : Girls with more fat mature early

6. Seasonal Factor (Spring and Summer season : Growth faster )

7. Hormone ( GH , Oestrogen , Adrenal hormones , Thyroid hormones )

CHANGES DURING PUBERTY

· Physical changes

· Psycological changes

· Hormonal changes

· Cranio facial changes

PHYSICAL CHANGES DURING PUBERTY

1. Increase in body Stature

2. Increased Weight

3. Longer arms and Legs

4. Bigger hands and feet

5. Face look less child like

6. Appearance of secondary sexual characteristics

7. Menarche seen in Girls

PSYCOLOGICAL CHANGES DURING PUBERTY

1. Puberty may bring on powerful emotions

2. Mood swings occur due to hormonal changes ; fluctuations in your emotions are signs that you are maturing emotionally

3. More self conscious about Beauty

4. Teenagers make decisions with their emotions rather than logic

They are highly influenced by PEER GROUP in this time

If the adolescent patient comes for treatment alone or with a friend and not escorted by mother/father

Better for Orthodontist – Patient relationship

ENDOCRINOLOGY OF ADOLESCENCE

Puberty is a period during which many dramatic hormonal changes occur

Growth is controlled by many hormones during puberty

1. Growth hormone

2. Anterior pituitary hormones

3. Thyroid hormone

4. Gonadal hormones : Oestrogen , Progestron and Testosterone

5. Adrenal androgens

6. Releasing and Inhibiting hormones of hypothalamas

GROWTH HORMONE

Protein : Stimulate protein synthesis and protein deposit cause increase in

muscle mass

Bone & Cartilage : GH increases the length of long bone by using epiphyseal

cartilage mainly in puberty

In late adolescence period no epiphyseal cartilage remaining

for further growth of long bones

THYROID HORMONE

• Basal metabolic rate : Increased by thyroid hormone

• Increase facial skeletal growth

• Needed for tongue growth

• It needed for soft tissue growth

• Needed for dentition and increase eruption

PUBERTY REGULATING AXIS

Initiation of Puberty controlled : Neuroendocrine system

Before Puberty : Hypothalamus - Pituitary - Adrenal Axis

At Puberty : Hypothalamus – Pituitary - Gonadal Axis

HYPOTHALAMUS - PITUITARY - ADRENAL AXIS

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· ADRENARCH : Early rise in adrenal androgen

· Adrenal androgen appear to be transformed into oestrogen in the peripheral fatty tissue causing maturation of gonadostat

· Onset of puberty is initiated by the maturation of the hypothalamic pituitary complex and input of CNS is called GONADOSTAT

· Delayed puberty occur in children with Adrenal Insufficiency

- Gonadostat maturation delay

- GH level not increase during puberty

HYPOTHALAMUS - PITUITARY - GONODAL AXIS

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ESTROGEN PROGESTRON CYCLE

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GROWTH EFFECT OF ESTROGENS IN FEMALES DUING PUBERTY

EFFECT ON SKELETON

• Estrogen increases osteoblastic activity in bones

• At puberty : Girls growth in height become rapid for several years

• Estrogen cause uniting of epiphyses with shaft of the long bone

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EFFECT ON PROTEIN

• Estrogens cause a slight increase in total body protein

• This mainly results from the growth-promoting effect of estrogen on sexual , organs, bones

• Girls have less increase in Total body protein than boys

• So girls have less muscle mass and strength

GROWTH EFFECT OF TESTOSTERONE IN MALES DUING PUBERTY

EFFECT ON BONE GROWTH AND CALCIUM RETENTION

• Testosterone cause increase in size and strength of bone

• Increases total quantity of bone matrix

• It causes calcium retention

• It cause uniting of epiphyses with shaft of the long bone

EFFECT ON PROTEIN FORMATION AND ON MUSCLE DEVELOPMENT

• During puberty : Development of increasing musculature

• Musculature development of males are more than females

EFFECT ON BASAL METABOLISM

• Basal metabolic rate is increased

REGULATION OF HORMONES

SIGNIFICANCE OF HORMONES DURING PUBERTY

1. GROWTH HORMONE

· Children who received long-term GH therapy showed increased growth of the craniofacial skeleton, especially the maxilla and mandibular ramus.

· These ﬁndings suggest that GH accelerates craniofacial development ,which improves occlusion and the facial proﬁle.

Minayo Funatsua, Koshi Satob,Hideo Mitani Effects of Growth Hormone on Craniofacial Growth: Angle Orthodontist, Vol76, Nov,2006

Growth hormone deficiency cause aberrant facial feature with saddle nose and protubrant frontal bones , retro gnathic maxilla and mandible and reduced facial height and width

• In male overall cranial base size reduction occur

• In females anterior cranial base is normal but posterior cranial base is short

• Small ramal height due to reduction in total mandibular length (Cantu etal 1997)

• Hormone replacement therapy needed for Growth deficient therapy

2. OESTROGEN

• Female who devoid of oestrogen production usually grows several inches taller than the normal mature female : Because her epiphysis do not unite at the normal early time

• Girls who have more fat in their body have more oestrogenic activity so they mature early

• Oestrogen deficiency is a reason for Osteoporosis

₋ Increased bone resorption with normal bone formation

₋ Increased tooth mobility

3. THYROID HORMONES

• Thyroid hormone deficiencies may have profound effect on he proper development of facial skeleton and the dentition

• Thyroid deficiency manifested as short stature with puffy face and dry skin

• Macroglossia

• Delayed dental and skeletal development

• Retarded eruption of permanent teeth

• Short posterior facial height and retruded mandible creating anterior open bite

• Insufficient growth due to hormonal disturbance can negatively affect orthodontic treatment especially with functional appliances

• When a Class II case is not responding satisfactory after a reasonable time period even patient cooperates : One reason may Thyroid hormone deficiency

• Orthodontic Treatment combine with hormone replace therapy so optimum result can achived ( Verna etal 2000 )

CRANIOFACIAL GROWTH CHANGES DURING PUBERTY

Hard tissue changes

· Cranio basal growth changes

· Midfacial growth changes

· Mandibular growth changes

· Dento-alveolar changes

Soft tissue changes

· Lips

· Nose

· Chin

GROWTH OF CRANIAL BASE DURING PUBERTY

· Cranial base shows some increases in growth increments during puberty

· Pubertal growth spurt in the cranial base usually precedes the peak height velocity

· Spurt in the cranial base length is mainly due to growth in_:

Main Growth : Sphenoccipital synchondrosis

Minimum Growth : Foramen magnum + Nasion

During the early postnatal years, the cranial base undergoes a dramatic shift in it growth pattern :

§ Anterior (nasion–sella) cranial base lengths

§ Posterior (sella– basion) cranial base lengths

§ Cranial base angulation ( nasion–sella–basion)

Anterior cranial base grows more mature Posterior cranial base

(closer to its adult size)

Sphenoethmoidal synchondroses

Anterior cranial base has already attained approximately 86% to 87% of its adult size by 4.5 years of age

Spheno-occipital synchondroses

Spheno-occipital synchondrosis fuses at approximately

Females : 16 to 17 years

Males : 18 to 19 years

Ford HER. Growth of the human cranial base. Am J Orthod. 1958;44:498–506

Relative maturity differences between the anterior and posterior cranial base lengths are maintained throughout postnatal growth

Radiographically,

- Spheno-occipital synchondrosis shows active growth until approximately 10 to 13 yrs. age

- Closure time starts superiorly and continues inferiorly : Female - 11 to 14 years

Males - 13 to 16 years

- Hunter was the first one to study about the spurt in cranial base growth during adolescence

- Acceleration of the growth of the Ba-S distance : 12.5 years age

- Increase in the S-N length : 8 to 15 years.

GROWTH OF CRANIAL BASE OF BOYS DURING PUBERTY

· Acceleration in the growth of the lengths S-N, Ba-N, Ba-S was seen ; (within 2 years of peak height velocity )

· Spurt larger for Ba-N than S-N and Ba-S

· Elongation of S-N, Ba-N , Ba-S continued : till 17.5 yrs.

· Spurt in Ba-N length is smaller than S-N in early maturing boys

· Ba-S has greater spurt in shorter boys but the Ba-S length is greater in taller boys

Cranial Base Elongation in boys during pubescence : Arther B Lewis etal ( AO 1974 )

GROWTH OF CRANIAL BASE OF GIRLS DURING PUBERTY

- Acceleration in the growth of the lengths S-N, Ba-N, Ba-S was seen

- Elongation of S-N, Ba-N , Ba-S continued : till 17.5 yrs.

- Elongation of Ba-S continued : till 16.5 yrs.

- Spurt larger for Ba-N than S-N and Ba-S

Cranial Base Elongation in Girls during pubescence : Arther B Lewis etal (AO 1972)

SEX DIFFERENCES IN THE ELONGATION OF THE CRANIAL BASE

Pubertal growth spurt in cranial base is

- Much earlier in girls than in boys

- Greater in boys than in girls.

Sex differences in the elongation of the Cranial base : Arther B Lewis etal (AO 1972)

Conclusions

This study found the following:

• Linear measurements of cranial base length showed significant growth during all pubertal stages (pre-peak, peak and post-peak stages).

• No significant differences were found between genders in any cephalometric measures during the pubertal stages.

- Luciana Abra Malta , Cristina F Ortolani , Kurt Faltin. Quantification of cranial base growth during pubertal growth : J O ,Vol.36,2009,229–235

SIGNIFICANCE OF CRANIAL BASE LENGTH CHANGE DURING PUBERTY

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GROWTH OF MIDFACIAL STRUCTURES DURING PUBERTY

FACIAL GROWTH DURING PUBERTY

· Growth of jaws usually correlate with body height growth and events in puberty

· Adolescent growth spurt in the length of the mandible and body height are almost same modest though discernible increase in growth at the sutures of the maxilla.

GROWTH OF MIDFACIAL STRUCTURES DURING PUBERTY

Only modest increase in the growth of maxilla during puberty

Postnatal development of the naso-maxillary complex

• Intramembranous ossification

• Sutural growth

• Extensive surface remodelling (especially along its posterior and superior aspects)

• Displacement

Postnatal development of the naso-maxillary complex

• Intramembranous ossification

• Sutural growth

• Extensive surface remodelling (especially along its posterior and superior aspects)

• Displacement

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• Entire period between ages 7 and 15 :

1. One third of the total forward movement of the maxilla can be : Passive displacement

2. Rest is the result of active growth of the maxillary sutures in response to stimuli from the

• Enveloping soft tissues

• When active growth of the maxilla is considered : Effect of surface remodelling occur by apposition or resorption

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Enlow DH, Bang S. Growth and remodelling of the human maxilla. Am J Orthod. 1965;51:446–464

Growth of the nasomaxillary complex continues throughout childhood and adolescence, with substantially greater vertical than anteroposterior growth potential

MID FACIAL HEIGHT

Mid facial heights should be expected to increase 10 to 12 mm in females and 12 to 14 mm in males between 4 and 17 years of age.

PALATAL LENGTH

Palatal length should be expected to increase 8 to 10 mm over the same time period

SNA ANGLE

SNA angle shows little or no change during childhood or adolescence because nasion drifts anteriorly at approximately the same rate as the midface is displaced anteriorly

GROWTH OF MAXILLA DURING PUBERTY

· Singh and Savara, and Bjork who made longitudinal cephalometric studies regarding the growth of maxilla.

· O' Rielly used the data from the studies of Bjork to calculate the increase in the length of maxilla during puberty

His Conclusion :

• No significant difference in the amount of growth of maxillary length before or after menarche

• Timing of maximum increment in maxillary length was weakly correlated with the onset of epiphyseal- diaphyseal fusion and menarche

SEX DIFFERENCES IN MAXILLARY GROWTH THROUGHOUT CHILDHOOD AND ADOLESCENCE

• Males being larger and growing maxillary growth more than females.

• Size differences, averaging between 1 and 1.5 mm, are small but consistent during childhood.

• Sexual dimorphism increases substantially throughout the midfacial complex during adolescence,

• Differences of approx 4 mm in maxillary length ( ANS-PNS) and upper facial height (N-ANS) at 17 years of age.