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Factors affecting growth Normal growth changes Skeletal Dental Soft tissues

Clinical evaluation of patients Growth problems & treatment plan Implication of timing,direction & rotation in treatment plan.


SEASONAL CHANGES Growth is faster in spring & summer than in winter CULTURAL CHANGES •In developing countries, city children tend to mature faster than rural ones. •Influence of external stimuli on the gonadotropin –releasing factor.


CRANIOFACIAL GROWTH FROM INFANCY THROUGH ADULTHOOD,Henry W. Fields(Peadiatric clinics of North America oct 1991)

Growth of the cranial structures is far advanced and near its ultimate adult size during infancy and childhood than any other body parts because of the “Cephalocaudal growth gradient.”

Cranial vault growth is completed before maxillary growth,& maxillary growth is completed before mandibular growth.


ď śDimensional differences ď śRegional differences

Growth in three dimensions


1.Transverse dimension 2.Anteroposterior dimension 3.Vertical dimension


•Completed first. •The midpalatal suture fuses before the adolescent growth spurt,& is affected if at all,by adolescent growth changes.

•The mandibular symphysis also is fused at birth or during the first year. •The bases of both the upper and lower jaw are therefore well established early. •Hence palatal expansion should be addressed relatively early.


•Continues well into adolescense & adulthood. •Significant changes occurs in 20-30 years of age . •It appears that boys are more likely to have significant late adolescent and early adult jaw growth that results in forward positioning of the lower jaw than are girls.

VERTICAL DIMENSION •Last dimension to be completed. •Late vertical growth increments are greater in girls than boys & occur in maxilla. •As this occurs mandible if not growing by similar amounts, is forced to translate down & often backward, which lead to a more convex profile.

Treatment delivered when it is more effective and efficient may not be sufficient because the face can continue to change well past the conventional adolescent treatment period.


•The most important region of the cranial vault,in terms of impact on the face & profile, i probably the frontal bone area.

•The appositional changes that take place on the frontal bone & brow ridge tend to make tha area more prominent throughout adolescence & early adult life.

The midsaggital cranial base is a primary cartilaginous structure that undergoes bone growth at the synchondrosis .

The anterior cranial base •The midsphenoidal synchondrosis fuses at birth. •The sphenoethmoidal synchondrosis fuses before the beginning of the mixed dentition (approximately 6 years)

•The frontoethmoidal junction changes little after 2 to 3 years of age.

•Early fusion of the anterior cranial base synchondroses can lead to a retrusive or deficient maxilla.

Posterior cranial base The spheno-occipital synchondrosis is a potential force in posterior & late cranial base growth change.

•This synchondrosis is viable until mid to late adolescence when first bony bridging occurs.

Because a good deal of change in the cranial base takes place from surface apposition on the sphenoid bone( around the pituitary fossa) & at the most anterior & posterior extent of the midline cranial base ( nasion & basion) ,

The anterior cranial base is the most acceptable reference for facial growth.

MAXILLA • Enlarges in the transverse dimensionapposition on its lateral surfaces & growth of the midpalatal suture.

•Anterioinferiorly , relative to the cranial base- apposition at the maxillary tuberosity & along the oral palatal surface.

•Simultaneously , the anterior surface

of the maxilla & the nasal surface of the palate are resorptive.

•The nasal septum moves in synchrony with the maxilla & may provide some guidance of growth & mechanical support.


•Small changes in the chin area accompanied by minimum apposition on the lateral aspects the mandibular body.


•Apposition on the posterior surfaces of the ramus .

•Resorption on the inner surface of the mandibular body & the anterior of the ramus.

•Little change in the size of the anterior mandible,but certainly makes space for the erupting molars , as it lengthens the mandibular body.


•Transverse growth ceases early in both the jaws.

•The width of the anterior portion of both jaws changes by only 2 to 3mm.& occurs during eruption of the permanent incisors.

•Some additional width increase occurs when perm. canines erupt.

•Some arch width also is gained when the premolars erupt between 10 & 12 years

•Crowded front teeth do not spontaneously straighten as the face grows because the space increase on the dentoalveolar ridges is small & not in the area most affected by crowding .

•Facial growth & the obvious increase in the size of the jaws really takes place posteriorly & is most useful in creating space for the molars.


•Existing pattern will prevail in most of the cases •Orthopedic correction should include the use of extraoral high pull force to the molars or any other appropriate appliance


Assume the “worst case scenario” For the milder version of the case described the assumption is that growth is going to proceed in an unfavourable direction relative to the needed correction


Facial & dental changes in adolescents & their clinical implications(Samir E.Bishara AO,2000) Terminal plane relationship in the primary dentition and its clinical implication



MESIAL STEP ďƒ˜61.1% of individuals.









The greater the mesial step the greater the probability for the molar relationship to develop into a class III occlusion.

DISTAL STEP ďƒ˜9.5% of individuals

Disto occlusion in the primary or mixed dentitions will not self – correct with growth

FLUSH TERMINAL PLANE ďƒ˜29.4% of individuals


44% - CLASS II

Closely observe these cases and initiate treatment when needed at the appropriate time


The combined width of the deciduous cuspid,first deciduous & second deciduous molars

is on the average 1.7mm greater than the permanent successors in the mandibular arch and 0.9mm greater in the maxillary arch.

If the clinician finds that the loss of the deciduous first molar is indeed a sign of lack of space, we know that ordinary growth procedures will not make up that space. Though the leeway space of nance is present adjustive changes following the loss of a tooth can quickly dissipate this advantage. Thereafter the clinician may plan to maintain the space by placing a lower lingual arch or any other space maintainer

In the 56.4% of individuals with a flush terminal plane,placing a lower lingual arch to maintain the space may have the adverse affect.

End to end molar relationship – lingual arch is placed, consider using headgear or other appliances to obtain a class I occlusion.

EXCESSIVE OVERBITE IN DECIDUOUS DENTITION Many deciduous dentitions present with excessive overbite In the deciduous dentition, the teeth are more vertical & the angle formed by the intersection of the long axis is greater In the permanent dentition the long axis of the upper & lower incisors form a more acute angle.

ď śThe more upright the incisors the greater the likelihood of excessive overbite ď śA combination of the more acute axial inclination of the permanent incisors as they erupt & simultaneous vertical alveolar growth often reduces the temporarily excessive overbite

INTERCANINE DIMENSION ďƒ˜The mandibular intercanine dimension is completed at 9 years- girls at 10 years- boys ďƒ˜The maxillary arch,intercanine dimension is completed at 12 years-girls at 18 years- boys

“Safety valve mechanism” In both male & female the maxillary intercanine dimension serves as a “safety valve”for pubertal growth spurts,where there is a basal horizontal mandibular growth,partly unmatched by the maxilla,as the mandible grows downward & forward.

UGLY DUCKLING PATTERN •The maxillary lateral incisors erupt into the oral cavity with a strong inclination of their crowns •This tends to force the apices of these teeth toward the midline,while the crowns tend to flare laterally.

•As the lateral erupt, the canines higher up in the alveolar process are also erupting but are literally sliding down the developing roots of lateral incisors.

•As the canine continues to erupt however, there is an autonomous straightening up of the lateral incisors. •The temporary spacing that often occurs between the central incisors & the lateral incisors is usually closed as the canines erupt into complete occlusion. •Hence it would be most hazardous to place appliances at this critical stage.


Soft tissue changes ď śGrowth in the length of the face is significant & can greatly influence the balance between the nose, lips,& the chin. ď śThere is a tendency for the lips to thin & become more retrusive with age in the absence of treatment.

ď śThis natural process makes the nose & chin more prominent in relative terms. ď śThis means that more children have lips that approximate at rest simply because of normal growth changes.

ď śThese changes combined with the average forward mandibular rotation in boys,produce considerable flattening of the profile. ď śFor girls, the profile flattening is less dramatic becoz, although all the changes in the soft tissue are similar, they are less magnitude than those in boys & the average backward rotation mitigates the flattening.



•Anterior posterior •Vertical •Transverse •Problems occur simultaneously.

Look at them from the side.

Seat the patient ,& ask them to look at a distant object One tries to visualize the anterior extent of the cranial base, the maxilla, & the mandible-relationship between the three can be evaluated The soft tissue landmarks overlying these skeletal points are connected mentally

ď śTwo line segments describe the facial profile ď śThe bridge of the nose to the base of the nose to the point of the chin


ďƒ˜Patients who have no convexity, in other words ,a straight facial profile where the bridge of the nose,& the chin point are in straight line are of concern in the preschool & early childhood years. ďƒ˜Ideally the base of the nose & the chin point should begin to approximate a vertical line dropped from the bridge of the nose as a child nears adolescence.

Young children up to school age usually have some facial convexity in their profiles It continues into the early childhood years and upto adolescence in girls. Boys may have slightly straighter facial profiles,but minor convexity even at maturity is normal. Either excess convexity or concavity is an indication of a jaw problem



VERTICAL FACIAL RELATIONS Most well balanced face have half the face below the base of the nose. These individuals normally have a overbite of 1-5mm. Patients with increased lower facial height often have a open-bite occlusion.

Anterior open-bite is often seen as a normal transition from the primary to early mixed dentition years and does not always confirm skeletal problem . Patients with decreased lower facial height often have excessive overbite of more than 6mm. Again these dental relationships do not always confirm a skeletal problem but certainly are suggestive of a discrepancy.







FACIAL ASYMMETRY ď śExamine the patient from posterosuperior view

Determine if the center of the chin point lies on the facial midline. Should be accomplished when the patient is biting the teeth together. Minor facial asymmetry is common More than 2- 3mm of asymmetry or facial asymmetry with a history of trauma, is of concern.

MAXILLARY SKELETAL CONSTRICTION ďƒźObserved by the presence of posterior cross-bite when the patient is biting the teeth together.


Excess facial convexity or concavity, significantly increased or decreased lower face height, facial asymmetry & posterior crossbite need to be referred for further evaluation.


•Caused by unfavourable jaw size or position.

•Indicated as extreme overjet


•If this is the predominant cause of the problem headgear is used

•Headgear acts to restrain forward growth while the lower jaw continues to grow.

•These compressive headgear forces are

transmitted to the sutures through appliances on the teeth.

•Dental changes accompany headgear treatment.

RETRUSIVE MAXILLA There appears to be reasonable evidence to indicate that maxillas that are positioned posteriorly can be successfully moved anteriorly in young growing children between the ages of 6 – 8 years.


•Treatment aimed at the mandible – functional appliance.

•They accentuate mandibular growth,possibly by unloading the condyle & stretching the associated mandibular muscles.

•Muscle forces transmitted to the maxilla have a

restraining effect or headgear effect on the maxilla.

•They also have a tooth moving effect & tip the

upper teeth backwards & the lower teeth forwards.


•More difficult problem to treat •The mandible undergoes accelerated growth to a greater extent than the maxilla during the adolescent growth spurt.

•Because growth modification for this type

of malocclusion is routinely unsuccessful, camouflage treatment is often attempted

ďƒ˜Headgears have more effect on the maxilla & functional appliances have more effect on the mandible.In both types of treatment there are related dental changes. ďƒ˜To achieve the kind of growth changes that are most desirable,the patient should be growing reasonably rapidly & certainly not past the peak adolescent growth spurt.

•Unfortunately comouflage is usually only acceptable for male patients who can tolerate a more prominent mandible.

•Ultimately many patients need to be

treated surgically to either move the maxilla forward ,the mandible backward, or a combination of the two procedures.


•Patients with vertical facial problems comprise less than 5% of all malocclusions.

•Those with excessive lower face height are difficult to treat & often require surgical intervention.

•In all of these patients ,there is

overdevelopment of the lower face that is often accompanied by exaggerated tooth eruption.

•The mandible appears to be rotated downward and posteriorly.

•Treatment for this type of problem can include headgears or functional appliances to restrict downward growth of the upper jaw & tooth eruption.

•The mandible then has a growth expressed in a

forward direction with limited increases in the facial and dental height.

•But because of the long duration of vertical

facial growth, this type of treatment may need to be continued into late adolescence& may still prove unsuccessful.

•Hence this type of malocclusion should be camouflaged or treated surgically

•The surgical treatment to correct this type of malocclusion often involves superior repositioning of the maxilla, forward & upward autorotation of the mandible, as well as repositioning of the mandible.

•This type of surgical treatment after the completion of growth is usually successful.


•The most common transverse problem is maxillary constriction.

•Posterior crossbite can occur in

approximately 5% of the population.

•Palatal expansion can be accomplished in the primary or early mixed dentition


•Appliances that apply moderate to high forces to the teeth that are transmitted to the maxilla & midpalatal sutures.

•Several forms of surgical intervention for trasverse problems are possible for older patients.

•Palate expansion combined with surgical treatment or surgical treatment alone.

•Treatment for mandibular facial asymmetry

may initially include functional appliances to modify or increase the growth on the deficient side & adjust the eruption of the teeth or surgical intervention.



PUBERTAL SPURTS 1st peak – 3 year age level 2nd peak – girls- 6 to 7 years boys- 7to 9 years 3rd peak - girls - 11 to 12 years boys- 14 to 15 years

Growth stages

1. Infancy to early childhood –birth to 6 years(the primary dentition years) 2. Late childhood or the preadolescent period– 5 or 6 years to onset of puberty(the mixed dentition years).

3. Adolescence – period of life when sexual maturity is attained( early permanent dentition years) 4. Adults.

Infancy & early childhood

Growth of brain case, gets completed by the age of 6

Extra oral orthopedic forces can be used to our advantage

 Rapid growth is exhibited during this period (ie)4-6 years

Growth modification using functional appliances for jaw discrepancies should be successful at this stage.

Unfortunately relapse occurs because of continued growth in the original disproportionate pattern due to a phenomenon known as “predominance of morphogenetic pattern�

Growth modification therapy for skeletal discrepancies is best attempted until the preadolescent years when growth modification results are more stable

Juvenile period or preadolescent

“Juvenile acceleration” occurs 1- 2 years before the adolescent growth spurt ,more particular in girls

•This juvenile acceleration can equal or exceed the jaw growth that accompanies the secondary sexual maturation.

•Careful assessment of physical growth is clinically important

•If treatment is delayed too long in girls we may miss this juvenile spurt.

Class II correction – preadolescent period is more effective

REASONS ďƒ˜The bones are less minerlized & therefore more easily deformed ďƒ˜Sutures & ligaments are more cellular resulting in more rapid biological responses

ďƒ˜Growing tissues are more responsive to external forces ďƒ˜Best orthopaedic results are obtained when growth is more active ďƒ˜The juvenile period has greater growth on the average at its beginning

Adolescent period

Girls’ physical and facial growth occurs before boys’and demonstrates less intensity. In boys generally puberty begins later & extends for a longer period which is 5 years in boys as compared to 3 & half in girls

Girls – adolescent facial growth spurt- between the ages of 9 to 11, or possibly 12. Boys – accelerated facial growth – between 11 to13,or possibly 14.

During the adolescent growth spurt,growth modification & definitive treatment can be combined ďƒźResults are stable,unlike the deciduous dentition period


Early maturing girls ďƒźThe adolescent growth spurt precedes the final transition of the dentition ďƒź if girls are to receive orthodontic treatment it is best during the mixed dentition rather than in the permanent dentition

Slow maturing boys ďƒźA considerable amount of physical growth remains even after transition of the dentition

TYPICAL TREATMENT PLAN FOR JAW DISCREPANCIES STAGE I – during mixed dentition stage ,focus on skeletal problem( ie 1- 2 years before the peak of the adolescent growth spurt) STAGE II – comprehensive fixed appliance treatment during the early permanent for stability.


Factors affecting the directions of growth


•The formation of bone at the muscle attachments depends upon the activity of the muscles. •The musculature is important for the soft tissue matrix,whose growth normally carries the jaw downward & forward •The loss of musculature could occur in utero or due to birth injury as a damage to the motor nerves

ďƒźExcessive muscle contractions can cause restriction of growth.this is seen in Torticollis where growth is restricted on the affected side, ďƒźDecrease in muscle activity in conditions like cerebral palsy or muscular dystrophy can cause displacement of the jaws.this results in a vertical rotation & even open bite

Ingerwall & Muller in their studies have said that in high angle cases , there is a weaker musculature which supports the supra eruption of the posteriors & in low angle cases the musculature is strong which prevents the supra eruption of the posteriors.



 the most common,non nutritive habit In general habits during primary dentition have little effect If habit persists during permanent dentition this could lead to malocclusions & also vertical rotation of the mandible due to extrusion of molars If a child stops the habit by 3-4 years then there would be no deletrious effect.

TONGUE THRUST  the position of tongue in children & adult varies Tongue is interposed between lips in infancy which is normal If this persists , it may lead to an open bite & vertical rotatin of the jaws & cause malocclusion

MOUTH BREATHING Partial obstrution of nasal airway is due to enlarges adenoid & tonsils and may lead to mouth breathing. Solow & Kreiboig (1977) confirmed in several studies that factors affecting adequacy of the nasal airway can result in a posterior tilt of the head. When the head tilted back,the face was retrognathic & the mandibular plane angle as well the total & anterior face heights were large.


This is a condition which is characterized by a deficient mandible & cleft palate due to the pressures that restrict growth during intrauterine life. After birth one can expect normal growth. In some cases there has been a restriction which is caused by the pressure that have injured the TMJ.


Mandibular growth rotations – thier mechanisms & importance W.J.B.Houston EJO ,1988. MANDIBULAR GROWTH ROTATIONS: Reflection or imbalance of differential growth in anterior & posterior face heights

GROWTH IN POSTERIOR FACE HEIGHT: Depends on vertical components of growth at the middle cranial fossa& at the condyle. GROWTH IN ANTERIOR FACE HEIGHT: Is greatly influenced by growth of the cervical column & the resulting differential growth of the muscles,fascia,& other soft tissues, that pass between cranium, mandible,hyoid bone & shoulder girdle.

ď ś(-ve) or forward Counterclockwise(facing right) Clockwise(facing left) ď ś(+ve) or backward Clockwise( facing right) Counterclockwise(facing left)

Growth of the anterior & posterior face heights are determined in different ways, & so it is not surprising that there can be minor discrepancies in the amount of their growth Since growth in the AFH is determined primarily by growth in the length of the cervical column & the associated stretch of the cranio-cervical fascia & musculature Treatment induced changes in the AFH will be unstable unless they are associated with adaptive changes in head posture or in the musculo-fascial balance of the mandible.

Clinical significance of growth rotation

FORWARD ROTATION/DECREASED AFH In forward rotation of jaws the fulcrum point is located at the incisors STABLE:the overbite remains unchanged UNSTABLE:the fulcruming point is located further back along the occlusal plane, resulting in deepening of the bite combined with greater increase of the posterior facial height.

This deterioration of the occlusion is not pronounced during puberty when growth intensity is at its greatest, but continues throughout the growth periods. Therfore deep bite should be treated early & the occlusion supported throughout the growth period. Retention should be maintained untill the mandibular growth is completed.

POSTERIOR ROTATION OF MANDIBLE/INCREASED AFH The centre of growth rotation ( fulcrum point) is located near the mandibular condyles. Here early interception is needed to maximise the dentoalveolar compensation

ďƒ˜In cases where extractions are necessary, treatment should be postponed until after puberty. REASONS:

a. After puberty there is less active growth b. Potential for backward or posterior rotation is reduced c. Tendency to extrude the posterior teeth decreases when there is less active growth. d. Mesial migration & uprighting of the anterior teeth are minimal.


Problems with facial growth can result in aesthetic & functional complaints. Using a simple method of clinical evaluation the orthodontist can identify facial growth ploblems in the anteroposterior,vertical & transverse dimensions. These problems can then be referred for evaluation & treatment by a variety of means.

By adopting a contemporary view that facial growth is the result of genetic & environmental factors,growth modification becomes a real possibility. Unfortunately some problems must be camouflaged or treated by combined surgical & orthodontic means Continued growth in early childhood can enhance or detract from treatment results obtained in childhood or adolescence

These dynamic properties of the face make management of facial growth challenging but generally rewarding & successful because of substantial aesthetic & functional improvements

Guided by:Dr.Uma

Facial & dental changes in adolescents & their clinical implications Samir Bishara(A.O.,2000) Skieller,Bjork,and Linde hansen Found that the combination of 4 variables gave the best prognostic estimate of future mandibular growth direction.

1.Mandibular plane inclination to the anterior cranial base –(MP:Sn angle) or the ratio of PFH/AFH. 2.Intermolar angle

3. Shape of the lower border of the mandible measured as the angle – Go–Me and a tangent to the lower border of the mandible 4. The inclination of the symphysis measured as the angle between the tangent of the anterior surface of the symphysis and SN

Steep MP Obtuse gonial angle Open bite tendency Severly retrognathic or prognathic mandible Future growth will be unfavourable

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