41994_Australasian_Dentist_100_EMAG

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u e mid-childhood spurt takes place in approximately 50% of children between 6.5 and 8.5 years of age. u e mid-growth spurt tends to occur more frequently and approximately 1 year later for boys than girls. u emore prominent adolescent growth spurt begins with the onset of puberty, at approximately 9 to 10 years of age in females and 11 to 12 years in males. Female and male peak height velocities (PHV) are attained on average at 12 and 14 years of age, respectively. u Girls show ‘juvenile acceleration’ 2 years before the adolescent growth spurt. is should be utilized for ortho dontic purposes. Treatment should not be delayed for girls. u In boys, juvenile acceleration is not very intense compared to girls. e extra years of childhood growth prior to adolescence in males, as well as the slightly greater rates of adolescent growth and the lengthier adolescent period, explain most of the gender di erences in overall body size as well as in craniofacial dimensions.

remains more or less constant, with no distinct adolescent spurt. u Krebs.A (1964) conducted a study on orthopaedic expansion of the palate with the use of implants and con rmed 50% dental movement and 50% skeletal movement in young children. In adolescents, however, only 35% of the movement was skeletal, and 65% was dental. Growth considerations in Mandible u During later childhood and adoles cence, the condyle shows substantially greater amounts of superior than pos terior growth. u For every 1 mm of posterior growth, there is 8 to 9 mm of superior growth. It has been estimated that the condyles of females and males grow 2 to 2.5 and 2.5 to 3.0 mm/yr respectively during childhood and adolescence, with the greatest rates occurring during the ad olescent spurt. u While an adolescent spurt in vertical mandibular growth certainly occurs, a pronounced spurt for the anteroposte rior and transverse growth has not been established. u Mandibular dimorphism increases to 4 to 8 mm by the end of the adolescent growth phase. ere are no gender di erences in vertical rotation during childhood or adolescence. u e most important stages of cervical vertebrae maturity indicators are C2, C3 and C4 because PHV and mandibular growth occur between the times when concavities develop on the inferior borders of C3 and C4. After this point there is a gradual slowing down in adolescent growth.

Because of the growth of craniofacial structures and its correlation with general somatic growth, the timing of peak height velocity (PHV), which occurs at the pinnacle of the adolescent growth spurt, is especially useful for estimating peak maxillary and mandibular growth velocity. Various studies have shown that maxillary growth attains its maximum rate slightly before PHV, while the maximum rate of mandibular growth occurs just after PHV. e entire pubertal period can last 4 to 6 years. Clinical Significance of Growth Spurts e adolescent growth spurt has signi cant clinical implications in orthodontics as follows: u Di erences between the timing of growth spurt in males and females must be kept in mind. u Treatment of skeletal malocclusions by growth modi cation using orthopaedic and functional appliances is more e ective if its use is timed to coincide with the adolescent growth spurt. u Examples: – Chin cup appliance to restrict mandibular advancement in treatment of class III malocclusion, – Frankel Functional Regulator to stimulate mandibular growth in the treatment of class II malocclusion. u It is advisable to continue appliance wearing until the cessation of adolescent growth spurt, to obtain stable results. u Expansion of dental arches (e.g., rapid maxillary expansion) responds well during adolescent growth spurts, and the results are more likely to be stable. u Certain patients with gross skeletal discrepanciesmay requireorthognathic surgical correction, and that surgery is best carried out after the cessation of active growth. Growth considerations in Maxilla u Growth of the nasomaxillary complex continues throughout childhood and adolescence, with substantially greater vertical than anteroposterior growth potential. u In terms of absolute growth, midfacial heights should be expected to increase 10 to 12mm in females and 12 to 14mm in males between 4 and 17 years of age. u Palatal length should be expected to increase 8 to 10 mm over the same time period. e nasion drifts anteriorly at approximately the same rate as the midface is displaced anteriorly. u Although vertical maxillary growth rates peak during adolescence at approximately the same time as stature, anteroposterior maxillary growth

Peak height velocity – Pubertal growth spurt

2. Dental Factors to consider in mixed-dentition examinations are the axial inclination of teeth, molar relation, incisor relation, midlines, arch forms and occlusal line. Along with this, it is better to monitor growth in patients before nal treatment decisions are made. is can be done using serial cephalometric lateral skull radiographs taken a year apart. In late mixed dentition, the clinician must remember that a physiologic space is normally present between the maxillary central incisors until eruption of the canines in adolescent dentition.

Height-velocity curve for a male from birth to 18 years of age. Rapid deceleration of growth during the first three years then a gradual deleceration, briefly interrupted by a juvenile growth spurt at 8 years and the more significant adolescent growth spurt at around 13 years of age.

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