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Serial extraction
S e ria l e x tr a c tio n , w h ile b e n e fic ia l in s e le c te d c a s e s , is n o t, in its e lf, a n a c c e p ta b le tr e a tm e n t p r o c e d u r e , b u t r e q u ir e s s u p p le m e n ta l a p p lia n c e th e r a p y to c o r r e c t a x ia l in c lin a tio n s , ro ta tio n s , c lo s e e x tr a c tio n s p a c e s , a n d le v e l th e p la n e o f o c c lu s io n .
Serial extraction
H. A d u s s , DDS, C hicago C. J. S chw arz, DDS, Fairlaw n, O hio R. T. M c D a n ie l, DDS, S p rin g fie ld , III S. P ru za n sky, DDS, C hicago T h e se q u e n tia l e x tra c tio n o f p rim a ry and p e rm a n e n t te e th to re d u c e the s e v e rity o f a m a lo c c lu s io n , w ith th e p ro s p e c t th a t lit tle o r no m e ch a n ica l in te rv e n tio n w ill be n e ce ssa ry, has a ttra c te d th o se c o n c e rn e d w ith th e care o f c h ild re n fo r m a n y ye a rs. U n fo rtu n a te ly , se ria l e x tra c tio n has n o t, in its e lf, p ro v id e d s a tis fa c to ry o c c lu s a l re la tio n s h ip s . W h ile b o th a d vantages and d isa d van ta g e s
■ Is th e p a tte rn o f e ru p tio n o f th e p e rm a n e n t te e th a lte re d b y s e ria l e x tra c tio n ? ■ F o r p a tie n ts w ith C la ss I I m a lo c c lu s io n s , w h a t is th e e ffe c t o f h e a d g e a r th e ra p y d u rin g the s e ria l e x tra c tio n p e rio d ? ■ D o e s se ria l e x tra c tio n re d u c e th e c o m p le x it y o f a m a lo c c lu s io n so as to d im in is h th e need f o r o rth o d o n tic a p p lia n c e s a n d /o r re d u c e the tim e re q u ire d f o r w e a rin g o f a p p lia n c e s ?
h a ve been c la im e d fo r se ria l e x tra c tio n , lo n g i tu d in a l d a ta d o c u m e n tin g re s u lts are lim ite d . T o d a y , th e c lin ic ia n e m p lo y in g se ria l e x tra c tio n is c o n c e rn e d w ith q u e s tio n s p e rta in in g to th e sequence a n d tim in g o f e x tra c tio n s , th e v a ria b le e ffe c ts o f g ro w th d u rin g th e se ria l e x tra c tio n p e rio d , and th e n e c e s s ity f o r a p p lia n c e th e ra p y . T h e p u rp o s e o f th is s tu d y w as to d e fin e the p a tte rn o f c ra n io fa c ia l g ro w th and th e p a tte rn o f d e n ta l e ru p tio n , in C la ss I and C la ss I I m a lo c c lu sio ns in p a tie n ts u n d e rg o in g a p la n n e d p ro g ra m o f se ria l e x tra c tio n . S p e c ific a lly , th is s tu d y c o n s id e re d : ■ W h a t e ffe c t does se ria l e x tra c tio n ha ve o n th e p o s itio n o f th e in c is o rs , p a rtic u la rly th e lo w e r in c is o rs ?
R e v ie w o f th e lite ra tu r e S e ria l e x tra c tio n had bee n suggested in th e F re n c h lite ra tu re as e a rly as 1743,1 and a g u id e f o r th e tim in g o f e x tra c tio n s w as re p o rte d b y the E n g lis h m a n , F o x ,2 in 1803. T h e p ro c e d u re ca m e in to vo g u e as th e re s u lt o f p u b lic a tio n b y K je llg r e n o f S w e d e n and H o tz o f S w itz e rla n d in 1948.3 4 K je llg r e n fir s t used th e te rm “ se ria l e x tr a c tio n ,” w h e re a s H o t z 5 p re fe rre d th e p h ra se “ g u id a n c e o f e r u p tio n .” A b o u t th is tim e , H e a th ,6 in A u s tra lia , d e s c rib e d a p ro g ra m o f “ p la n n e d m in im a l o rth o d o n tic JADA, Vol. 95, Septem ber 1977 ■ 573
tre a tm e n t.” F o r a ll in te n ts and p u rp o s e s , th e p ro posals w e re a ll v a ria b le s o f s e ria l e x tra c tio n as it is p ra c tic e d to d a y . O f p a rtic u la r in te re s t w as th e shared o b je c tiv e th a t e a rly re m o v a l o f c ro w d e d te e th and sub se q u e n t a lig n m e n t o f e ru p tin g te e th w o u ld p ro v id e th e g re a te st b e n e fit fo r th o se w h o c o u ld n o t a ffo rd o rth o d o n tic tre a tm e n t o r fo r th o se fo r w h o m o rth o d o n tic se rvice s w e re n o t a v a ila b le . T h e s im u lta n e o u s re d is c o v e ry o f s e ria l e x tr a c tio n in d iffe re n t p a rts o f th e w o rld ca n be a s c rib e d to a ch a n g in g c lim a te o f ideas. F o r a b o u t th is tim e , e x tra c tio n becam e an a cce p te d p ro ce d u re in o rth o d o n tic p ra c tic e . T w e e d ’ s7 re p o rt o n fa ilu re s in o rth o d o n tic tre a tm e n t as a re s u lt o f a rc h le n g th d e fic ie n c y had a se m in a l in flu e n c e .7 S im ila rly , H o w e s ,8 C a re y ,9 and N a n c e 10 c o n tr ib u te d to th e in te re s t w ith th e ir re p o rts f o r es tim a tin g and p re d ic tin g a rch le n g th a d e q u a c y re l a tiv e to s u p p o rtin g bone. D u r in g th e subse q u e n t decade, a ra tio n a le fo r th e u tiliz a tio n o f s e ria l e x tra c tio n e v o lv e d . T h is in c lu d e d : ■ S om e in d iv id u a ls p re s e n t a d is c re p a n c y be tw e e n to o th m a te ria l and s u p p o rtin g b o n e th a t does n o t im p ro v e w ith g r o w th .11 ■ A f t e r e ru p tio n o f th e fir s t m o la rs , th e re is no in cre a se in a rch le n g th , and ia tro g e n ic a lly p ro d u ce d a rc h le n g th is n o t s ta b le .3 ■ E a rly re m o v a l o f te e th a llo w s p h y s io lo g ic u n a ssiste d m o v e m e n t o f a d ja c e n t te e th in to m o re fa v o ra b le p o s itio n s .12 In c lu d e d am o n g th e b e n e fits to be d e riv e d fr o m s e ria l e x tra c tio n w e re :
■ S p o n ta n e o u s te e th .3
a lig n m e n t
of
th e
a n te rio r
■ A re d u c tio n in tim e a n d c o m p le x ity o f ac tiv e a p p lia n c e th e r a p y .3 ■ P re s e rv a tio n o f th e p e rio d o n tiu m o f th e an te r io r te e th , since th e y w ill n o t be d is p la c e d b y c r o w d in g .10 T h e lim ita tio n s o f se ria l e x tra c tio n also w e re d e fin e d : ■ A p o s s ib le in cre a se in o v e rb ite .13 ■ M a n d ib u la r in c is o rs m a y tip lin g u a lly and th e re b y decrease a rc h le n g th .10,14-15 ■ E x c e s s iv e c o n c a v ity o f th e c irc u m o ra l area as a re s u lt o f c o lla p s e o f th e d e n titio n .10,16 ■ F u ll a p p lia n c e th e ra p y is n ecessary to c o m p le te tre a tm e n t, eve n a fte r a lo n g p e rio d o f o b s e rv a tio n .13 T h e 1960s w e re m a rk e d b y an im p o rta n t ser ies o f p a p e rs b y G r o n ,17 F a n n in g ,18 and M o o r re e s .19 T h e s e in v e s tig a to rs d o c u m e n te d “ n o r m a l” d e n ta l d e v e lo p m e n t, e ru p tio n , and e x fo lia tio n and p ro v id e d g u id e lin e s fo r th e tim in g o f e x tra c tio n s in a p la n n e d p ro g ra m o f se ria l e x tra c tio n . A ls o in th e 60s, se ve ra l theses a t S a in t L o u is U n iv e r s ity d o c u m e n te d th e p a tte rn o f c ra n io fa c ia l g ro w th a n d th e changes in in c is o r p o s itio n d u rin g th e age p e rio d o f s e ria l e x tra c tio n . T h is w o rk w as b ro u g h t to g e th e r in R in g e n b e rg ’ s20 p a p e r, “ S e ria l e x tra c tio n : s to p , lo o k and be c e r ta in .” In 1969, D e w e l,21 in c o m m e n tin g o n his e x p e rie n c e and o b s e rv a tio n s w ith se ria l e x tra c tio n w ro te , “ i t has been d is illu s io n in g to le a rn th a t
THE AUTHORS
ADUSS
SCHWARZ
Drs. Aduss and Pruzansky are in the private practice o f orthodontics. In addition, Dr. Aduss is professor of orthodontics, Center fo r Cra niofacial Anomalies, and Dr. Pruzansky is d ir ector of the Center and professor of orthodon tics in the D epartment o f Pediatrics, Abraham Lincoln School of Medicine, University of
574 ■ JADA, Vol. 95, September 1977
MCDANIEL
PRUZANSKY
Illinois Medical Center. Dr. McDaniel is In the private practice o f orthod ontics and Dr. Schwarz is in the private practice o f orthod on tics. Address requests fo r reprints to Dr. Aduss, Center fo r C raniofacial Anomalies, University of Illinois Medical Center, PO Box 6998, Chi cago, 60680.
serial extraction, in itself, rarely creates accep table occlusal relations and that certain diverse reactions will result if the procedure is not fol lowed by comprehensive orthodontic treat ment.” Now, in the 70s, three guidelines deserve em phasis: ■ The timing of serial extraction cannot be related to chronologic age, but must be consid ered relative to dental age among other develop mental yardsticks. ■ Serial extraction, in itself, is not an accept able treatment procedure, but requires supple mentary appliance therapy. ■ Each patient, in a planned program of serial extraction, requires continual monitoring of his pattern of craniofacial growth and dental devel opment. Although these guidelines evolved from 30 years of observation and study, to date there is only limited documentation of what actually hap pens during the serial extraction period.
Materials The patients studied were derived entirely from the private practice of two authors (H. A. and S. P.), and were divided into two groups accord ing to their malocclusion. There were 15 children (7 boys, 8 girls) with a Class I molar occlusion and 16 (6 boys, 10 girls) with a Class II molar oc clusion. Selection for inclusion in this study was based solely on the completeness of the diagnos tic and interim records, which included dental casts, facial photographs, and cephalometric radiographs in the lateral, posteroanterior, and right and left 45° oblique projections (Fig 1, 2). For each patient, a planned program of serial extraction was instituted because of a bimaxil lary arch length deficit, or a bimaxillary protru sion and/or an unfavorable pattern of facial growth. The sequence of serial extraction used fol lowed the procedure described by Heath 6 and involved extraction of the primary first molars and, whenever possible, maintenance of pri mary canines. The primary first molars were ex tracted, as suggested by Gron ,17 when at least half of the premolar root had formed. First pre molars were removed when they erupted. For the patients with a Class I malocclusion, no active orthodontic therapy was instituted
during the serial extraction period. For those who had a Class II malocclusion, cervical headgear was employed to correct the Class II molar relation during the serial extrac tion period. In eight of the 16 patients with Class II occlusal relationships, anterior bands and an arch wire were utilized for varying periods to retract markedly protrusive incisors and thereby reduce susceptibility to trauma and improve lip posture and function. Although there was a range in chronologic age at the initiation of treatment, the application of extraction procedures, based on dental develop ment, resulted in a sample of relatively homog enous dental age. After serial extraction, and with the eruption of the permanent dentition, all patients were treated with a full edgewise appliance.
M ethods
The serial oblique cephalometric radiograph served as the most important documentary tool for this study. It provided a reproducible radiographic projection controlled for enlargement and distortion. The accuracy of the technique and its applicability to serial extraction had al ready been demonstrated .22 Various reference planes for the superimposition of serial 45° oblique cephalometric radiographs had been de fined on both dry skulls and on longitudinal films of children.23 The technique had been used to document the effect of pulpotomy and caries on the rate of root resorption of primary teeth and the eruption of the permanent dentition.24 Con trol data for this study was provided, in part, by a previous study that used the 45° oblique roentgencephalogram to analyze symmetry of tooth eruption in the mandibular buccal segments of children not subjected to serial extraction or orthodontic treatment.25 The serial oblique films were evaluated initially (before extraction of the primary first molar); intermediate (before extraction of the erupted first premolars); and preappliance (after erup tion of the second premolar and/or canine and before placement of a full edgewise appliance). Each oblique film was analyzed to determine the change in pattern and/or path of eruption of the succedaneous teeth during the serial extrac tion period. The landmarks used are identified in Figure 3 . Lateral cephalometric radiographs obtained Aduss—others: SERIAL EXTRACTIONS ■ 575
Fig 1 ■ Serial 45° oblique cephalom etric radiographs. At age 8 years, 11 months, obtained prio r to extraction o f firs t prim ary molar. At age 9-4, interm ediate film , preceding the extraction of erupted firs t premolar. At age 11-2, prelim inary to appliance placem ent and fo llo w in g eruption of second prem olar and canine. At age 12-9, at tim e of removal of o rthod ontic appliance.
576 ■ JADA, Vol. 95, September 1977
Fig 2 ■ Longitudinal lateral cephalom etric radiographs obtained d u ring the serial extraction period and subse quent phase o f o rth o d o n tic treatm ent. Cervical headgear was used to correct m olar occlusio n d u rin g serial extraction period.
Fig 3 ■ Analysis of 45° oblique cephalom etric radiographs. A-B (palatal plane); C-D (m andibular plane); JIH-(gabling angle) form ed by connecting tip s of unerupted mandibular canine and prem olars. Axial inclina tion of each m axillary to o th was determ ined by m easuring a n te ro in fe rio r angle at junctio n of tooth and palatal plane, fo r example, axial inclina tion of canine is the a n tero in ferio r angle at junctio n of AB and EF planes. In mandible, anterosuperior angle was recorded to define axial inclina tion, fo r example, axial Inclina tion fo r m andibular canine is the anterosuperior angle at ju n c tio n o f CD and FG planes.
Aduss— others: SERIAL EXTRACTIONS ■ 577
Fig 4 ■ A nalysis o f lateral cephalom etric radiographs. Landm arks used in analysis of lateral projection in clud ed:S -ce nter of sella tu rcica ; O-orbital; P-porion; F.H.-Frankfort ho rizonta l; P tm -pterygom axillary fissure; A -po in t A; OP-occlusal plane; M P-m andlbular plane; G o-gon io n; M -m enton; Po-pogonlon; B -point B; (i-m axillary firs t m olar; and N-nasion.
at each o f th e p re v io u s ly m e n tio n e d stages also w e re a n a ly z e d to d e te rm in e th e p a tte rn o f c ra n io fa c ia l g ro w th d u rin g th e serial e x tra c tio n p e rio d ; h o w e v e r, o n ly th o se m easures e m p lo y e d to d o c u m e n t th e changes in th e p o s itio n o f th e in c is o rs and m o la rs w ill b e co n s id e re d in th is re p o rt. T h e la n d m a rk s u tiliz e d in th e a n a ly sis a re id e n tifie d in F ig u re 4.
R e s u lts a n d d is c u s s io n
te e th a t th e in c is o rs w o u ld n o t tip lin g u a lly , so th a t in n e ith e r C la ss I n o r C la ss I I m a lo c c lu sio n s w as th e change in in c is o r p o s itio n p re d ic t ab le . ■ Is th e p a tte rn o f e ru p tio n o f th e p e rm a n e n t te e th a lte re d b y s e ria l e x tra c tio n ? T o a n s w e r th is , th e “ g a b lin g a n g le ” w as u s e d .25 T h is is th e angle fo rm e d b y c o n n e c tin g the tip s o f th e u n e ru p te d m a n d ib u la r c a n in e and p re m o la rs (F ig 3). T h e angle d e fin e s th e re la tiv e b o n y p o s itio n o f th e th re e te e th and w as used in th is s tu d y to de-
R e s u lts o f th is in v e s tig a tio n a re segregated in te rm s o f th e q u e s tio n s posed. ■ W h a t e ffe c t does se ria l e x tra c tio n h a v e o n th e p o s itio n o f th e in c is o rs , p a rtic u la rly th e lo w e r in c is o rs ? T h e m ea n p o s itio n o f th e lo w e r in c is o r re m a in e d u n ch a n g e d d u rin g th e s e ria l e x tra c tio n p e rio d . T h e m e a n , h o w e v e r, d id n o t m ir r o r in d i v id u a l v a ria tio n w h e re th e p o s itio n o f th e lo w e r in c is o r tip p e d la b ia lly o r lin g u a lly d u rin g th e se r ia l e x tr a c tio n p e rio d . T h e v a rie d re sp o n se o f th e lo w e r in c is o r w as re fle c te d in th e r e la tiv e ly la rg e
In itia l
Age
C lass 11
11 2 .9 *9 .9
110.0*9.3
R ight M a x illa 3 4 5 6
s ta n d a rd d e v ia tio n s fo r th o se v a lu e s used to de fin e th e p o s itio n o f th e in c is o r (T a b le 1). I n a d d i tio n , th e change in a n g u la tio n o f th e lo w e r in c i
M andible 3 4 5 6
s o r d id n o t c o rre la te w ith th e p re se n ce o r ab sence o f th e p rim a ry c a n in e . I n o th e r w o rd s , th e p re se n ce o f th e p rim a ry ca n in e d id n o t g u a ra n
Gabl ing Angle
578 ■ JADA, Vol. 95, S eptem ber 1977
C lass I
L e ft
R ight
73. 1±14.3 8 4 .3± 9 .0 8 8 .2 * 9 .7 111. 1± 4.1
7 4 .6 *1 2 .4 8 8 .8 * 8 .9 9 8 .6 *1 1 .0 11 3.0* 4 .7
9 3 .7 * 9.3 9 6 .6± 8.8 9 9 .3 ± 1 0 .8 8 6 .8 * 6 .1
9 3 .8 * « .8 9 4 .6 * 7.4 9 5 .5 *1 1 .4 8 2 .8 * 2 .6
9 4 .7 * 9.9 9 5 .8 * 7.3 9 1 .6 *1 2 .3 86. 1* 4.1
143.5*26.5
150.1*24.8
149.3*19.3
8 0 .0 * 8 6 .9 * 9 2 .1 * 10 6.4*
6 .9 7.4 7.7 7.3
L e ft
8 1 .3 * 7 .4 8 9 .4 * 8.1 9 6 .5 *1 0 .7 10 8.6* 6 .3
9 7 .2 * 9 6 .9 * 9 2 .0 * 8 6 .9 *
9.6 8 .7 8.3 3 .7
153.7*29.2
Initial
Age FA Convexity ANB SNPo MP1 Y-Axis
T a b le 1 ■ Measurements
derived fro m the lateral cephalom etric radiographs.
C las s I
C lass II
C lass I
Clas s II
C lass I
C las s II
112.9 ± 9.9
110.0 i 9.3
1 31 .3 113,2
123.5+10.1
147.4 +13.2
139.3 + 11.7
8 4.8 9 .7 5.4 74.9 30.2 60.5
± ± ± * * *
84.6 11.8 6.3 73.7 27.5 59.7
1.9 4.2 1.7 2.7 5.0 2.5
U1-LI 130.8 ±10.2 U 1-APo (mm. 1 6 .9 * 2.9 L l-M P 87.6 ± 6.9 L l- A P o (mm. I 0 . 47± 2.0
+ * + ± -t +
1.5 4.0 1.4 2.7 4. 1 1.6
130.0 ±11,8 7.8 ± 2.8 91.3 ± 9. 1 . 56± 2.5
te rm in e th e e ffe c t o f e x tra c tio n o f th e p rim a ry fir s t m o la r on th e e ru p tio n o f th e u n d e rly in g p re
85.8+ 8. 5+ 4. 5t 75.8* 29.8+ 60.0+
2.0 5.0 2.2 2.6 5.4 2.6
132,7*10.4 7.0± 2.8 8 7 .8± 7.8 1.0± 2.5
8 4 .3± 11.0* 5.6+ 74.0+ 26.8* 60.1*
1.9 3.4 1.7 2.9 3.6 1.2
131.8+10.9 7.2+ 2 .8 91.4* 9.9 - 0.1 * 2.3
* 1.9 +6.1 * 2.4 * 2.8 * 3.7 * 2.0
85.4* 9.7* 5. 1* 74.9* 25.9* 59.7*
1.7 4. 1 1.6 2.8 3.6 1.1
134.2 ±10.8 6 .2 ± 2.5 86.7 ± 7.4 0.71* 2.0
131.2* 7.3* 91. 7± -0 .2 ±
9.4 2.4 7. 1 2.3
86.6 7.6 4.4 75.9 27.4 58.8
lo ss o f th e p rim a ry c a n in e , m e re ly o u td is ta n c e d th e e ru p tin g fir s t p re m o la r, d e s p ite e x tr a c tio n o f th e p rim a ry f ir s t m o la r (F ig 5 C ).
m o la r (T a b le 2). O n an a p r io r i ba sis, e x tra c tio n o f th e m a n d ib u la r p rim a ry f ir s t m o la r s h o u ld h a ste n e ru p tio n
I n c o n tra s t to th e p a tie n ts w ith C la ss I m a lo c c lu s io n s , w h e re th e g a b lin g angle in 13 o f 21 o b s e rv a tio n s b e ca m e m o re o b tu s e , th e g a b lin g angle in 22 o f 30 p a tie n ts w ith C la ss I I m a lo c c lu s io n s b e ca m e m o re a cu te . T h a t th is d iffe re n c e w a s in d ir e c tly re la te d to th e e ffe c ts o f h e a d g e a r th e ra p y w a s suggested b y th e fo llo w in g : In th e p a tie n ts w ith C la ss I o c c lu s io n s , a fte r e x tra c tio n o f the m a n d ib u la r p rim a ry f ir s t m o la r,
o f th e fir s t p re m o la r and th e re b y in cre a se th e g a b lin g angle. T h is re a s o n in g d id n o t a lw a y s h o ld . F o r e x a m p le , in th e C la ss I se rie s, 13 o f th e 2 1 angles m easured b e ca m e m o re o b tu s e fo llo w in g e x tra c tio n o f th e p rim a ry fir s t m o la r, w h ile e ig h t be cam e m o re a c u te . W h e re th e angle be cam e m o re a cu te , th e e ru p tin g fir s t m o la r had an u n o b s tru c te d v e rtic a l p a th o f e ru p tio n . I n th o se cases w h e re th e angle b e ca m e m o re o b tu s e , one o f th e fo llo w in g c o n d itio n s w as o b s e rv e d : A . T h e m a n d ib u la r f ir s t p re m o la r b e ca m e im
17 o f 25 m a n d ib u la r p e rm a n e n t f ir s t m o la rs and th e ir c o n tig u o u s u n e ru p te d se co n d p re m o la rs te n d e d to tip m e s ia lly , p o s s ib ly im p e d in g th e e ru p tio n o f th e f ir s t p re m o la r. I n th o s e w ith C la s s I I m a lo c c lu s io n s f o r w h o m h e a d g e a r w as u s e d , 16 o f 31 m a n d ib u la r p e rm a n e n t f ir s t m o
p a c te d a gainst th e m e sia l ro o t o f th e p rim a ry sec on d m o la r (F ig 5 A ). B . T h e p e rm a n e n t m a n d ib u la r c a n in e , w h ic h in c e rta in in sta n ce s w a s e ru p tin g ahead o f th e fir s t p re m o la r, tip p e d d is ta lly , a n d im p e d e d e ru p tio n o f th e fir s t p re m o la r (F ig 5 B ). C . T h e p e rm a n e n t m a n d ib u la r c a n in e , u p o n
la rs a n d th e u n e ru p te d p re m o la rs te n d e d to re m a in u p rig h t. A f t e r e x tra c tio n o f th e fir s t p re m o la r, th e sec o n d p re m o la r in th e p a tie n ts w ith C la s s I I m a l o c c lu s io n s c o n tin u e d to re m a in u p rig h t; w h ile in
Preappliance
Intermediate C las s I
C l a s s II
Class I
C l a s s II
131.3*13.2
123.5*10.1
147.4 ±13.2
139.3*11.7
Left
Right
Left
Right
Left
Right
Left
8.7 6.7 9.9 6.4
80.6*11.5 90.4* 8.8 91.8*11.9 110.8* 5 .0
84.8*10.3 88.2* 8.9 92.8*1 0.9 102.6* 6.2
86.4* 9 .9 93.0* 8.2 94.0*11.7 104.8* 5 .7
93.0 *8.9
93.5*12.4
9 2 .5* 8.1
9 6.5 *4 .4
91.3 *7.7 102.8*3.0
93.7*12.1 106.7* 4 .1
9 3 .2* 5.1 9 8.0 * 5 .4
9 5 .6 * 5 .7 9 9 .8 * 6 .2
98 .6* 7.4 9 5 . 7± 7.3 99.0±10.0 9 0 . 0± 7.0
101.7* 9 . 7 101.9* 8.3 95.7*10.4 85.4* 4 .6
97.8* 98.6* 89.9* 88.0*
106.5*5.1
108.1* 5 .7
107.4*4.8
10 5.9*6.0
92 .6 *7.7 8 6.1*5.2
91.8* 5.4 84.0* 5 .5
91. 1*6. 1 87.4 *6 .4
9 2 .0 * 5 .7 88.0 *4 .5
145.6±40. 3
148.7*39.4
133.5*33.5
Right
Preappliance
Intermediate
T a b le 2 ■ M easurements
82.9* 87.7* 86.8* 109.2*
6 .8 8.2 7.9 5.2
98.8* 100.2* 90.6* 88.6*
8.1 9.3 7 .8 4 .4
derived from the 45° oblique cephalom etric radiographs.
144.2*30.7
A duss—others: SERIAL EXTRACTIONS ■ 579
th e C la ss I g ro u p , th e second p re m o la r tip p e d m e s ia lly and fo llo w e d a p a th o f e ru p tio n in to th e e x tra c tio n site . W as th is d iffe re n c e b e tw e e n th e C la ss I and C la ss I I cases an in d ire c t re s u lt o f
headgear? T h e a n s w e r, a t th is tim e , is a m a tte r o f s p e c u la tio n . V e r y e a rly in th is s tu d y i t w as a p p a re n t th a t th e to o th m o s t fa v o ra b ly a ffe c te d b y se ria l e x tra c tio n w as th e c a n in e . I f s e ria l e x tra c tio n is c o n s id e re d a c o m p e titio n fo r space w h e re th e c lin ic ia n trie s to p ro v id e a b e tte r tr a c k fo r c e r ta in te e th , th e n th e u ltim a te w in n e r, in a ll cases, was th e ca n in e. I n b o th th e C la ss I and C la ss I I g ro u p s , in b o th th e m a n d ib le and m a x illa , th e p a th o f e ru p tio n o f th e ca n in e w as in it ia lly a lte re d a fte r e x tra c tio n o f th e p rim a ry fir s t m o la r, and m o d ifie d eve n fu r th e r a fte r e x tra c tio n o f th e fir s t p re m o la r. T h u s , b y th e tim e th e p a tie n t w as re a d y fo r ap p lia n c e s , th e g re a te s t p o rtio n o f th e e x tra c tio n site w as o c c u p ie d b y th e c a n in e . A t th is p o in t, a n o te o f c a u tio n is in o rd e r. In c o n s id e rin g changes in a x ia l in c lin a tio n , i t sh o u ld be re m e m b e re d th a t th e size o f o u r sam ple was r e la tiv e ly s m a ll, and th a t w h ile th e re w as n o sig n ific a n t change in th e m ean a x ia l in c lin a tio n o f a to o th , som e te e th d e m o n s tra te d m e sia l tip p in g , som e d is ta l tip p in g , and som e n o change. F o r e x a m p le , th e m a x illa ry second p re m o la r in the p a tie n ts w ith C la ss I m a lo c c lu s io n s , ta k e n o n an in d iv id u a l basis, d e m o n s tra te d th a t 13 o f 22 p re m o la rs had tip p e d m e s ia lly , s ix had tip p e d d ista lly , and th re e d id n o t change. T h e m a x illa ry second p re m o la r in th e p a tie n ts w ith C la ss I I m a lo c c lu s io n s , ta k e n o n an in d iv id u a l basis, d e m o n s tra te d 16 cases w h e re th e lo n g axes tip p e d d is ta lly , 12 m e s ia lly , a n d th re e w h e re no change o c c u rre d . T h e p ro m in e n t degree o f in d i v id u a l v a ria tio n em phasizes th e n eed f o r a v o id in g c o o k b o o k ro u tin e and th e n e c e s s ity o f m o n ito r in g each in d iv id u a l case fr o m th e b e g in n in g th ro u g h c o m p le tio n o f th e s e ria l e x tra c tio n p ro g ram . ■ F o r p a tie n ts w ith C la ss I I m a lo c c lu s io n s , w h a t is th e e ffe c t o f h e a d g e a r th e ra p y d u rin g the s e ria l e x tra c tio n p e rio d ? M o la r re la tio n s w e re c o rre c te d to C la ss I o c c lu s io n , and th e m a x il la ry m o la r w as u p rig h t o r eve n tip p e d d is ta lly b y th e tim e th e p a tie n t w as re a d y f o r fu ll a p p lia n c es. In c o n tra s t, th e m a x illa ry fir s t m o la r f o r pa
Fig 5 ■ Inh ib itio n o f first prem olar along its path of eruption. 580 ■ JADA, Vol. 95, September 1977
tie n ts w ith C la ss I m o la r o c c lu s io n s (w ith o u t headgear) te n d e d to tip m e s ia lly d u rin g th e serial e x tra c tio n p e rio d (T a b le 2). In te rm s o f re d u c in g tre a tm e n t tim e , it w o u ld ha ve been id e a l to c o rre la te th e b e g in n in g o f headgear th e ra p y w ith th e a c tiv e phase o f fa c ia l g ro w th . In th e p a tie n ts u n d e r s tu d y , headgear w as g e n e ra lly s ta rte d a fte r th e re m o v a l o f the
First remolar Extraetions 132.8 14. 2 mo.
Months 108 nyL i Years
120 10
Initi il 112. 9 ± 9.9 mo.
Full Appliances 155.7 ± 15. 5 mo.
132 11
144 12
Intermediate 131 3 ± 13. 2 mo.
156 1*3
168 l'4
180 l'5
Pos Extraction 147. 4 ± 13. 2 mo.
192 16
Rete ntion 185. 2 ± 17. 9 mo.
Fig 6 ■ C hronology o f serial extraction— Class I occlusion.
p rim a ry fir s t m o la r. O n th e b asis o f th e a n a ly sis o f th e la te ra l ra d io g ra p h s , th e e rr o r w as u s u a lly in s ta rtin g to o e a rly . T o a v o id w h a t has been ca lle d th e “ s a tu ra tio n p o in t” 26 in p a tie n t c o o p e ra tio n , h e a dg ear w as d is c o n tin u e d w h e n m o la r re la tio n s w e re c o rre c te d a n d , w h e n n e c e ssa ry, in c is o rs re tra c te d . ■ D o e s s e ria l e x tra c tio n re d u c e th e c o m p le x it y o f a m a lo c c lu s io n and th e re b y re d u c e th e tim e re q u ire d f o r fu ll a p p lia n ce s? P a rt o f th is q u e s tio n has a lre a d y been a n s w e re d . C a n in e s , w h ic h m a y have been im p a c te d o r b lo c k e d -o u t, e ru p te d in to space fo r m e r ly o c c u p ie d b y fir s t p re m o la rs . A l l in a ll, th e te e th w e re c lo s e r to th e ir fin a l p o s i tio n s an d th e c o m p le x ity o f th e m a lo c c lu s io n w as re d u ce d . H o w e v e r, th e p a tie n ts s till re q u ire d fu ll a p p li ances to c o m p le te c lo s u re o f e x tra c tio n spaces, c o rre c t ro ta tio n s and a x ia l in c lin a tio n s , and le v e l th e p la n e o f o c c lu s io n . T h e re fo re , th e to ta l tim e in v o lv e d in a p la n n e d p ro g ra m o f se ria l e x tra c tio n appeared to be g re a te r th a n th a t e xp e n d e d on o th e r p a tie n ts (F ig 6, 7). I t s h o u ld be re m e m b e re d th a t tre a tm e n t tim e is d ir e c tly d e p e n d e n t on th e sta n d a rd s and s k ills o f th e in d iv id u a l c lin ic ia n . F o r th e p a tie n ts w it h in th is s tu d y , th e m ean a p p lia n c e tim e f o r th e C lass I g ro u p w as 29.5 m o n th s and f o r th e C la ss I I g ro u p , 23.1 m o n th s . W h ile th is m a y be ac c e p ta b le to on e c lin ic ia n , it m a y seem o v e r ly lo n g to a n o th e r.
A m o re im p o rta n t le sso n to b e le a rn e d fr o m a re v ie w o f th e c h ro n o lo g y o f se ria l e x tr a c tio n c o n ce rn s o v e ra ll in v o lv e m e n t w ith th e p a tie n t. F ro m th e tim e the in itia l re c o rd s w e re o b ta in e d , th e m ean tim e w as s lig h tly m o re th a n s ix y e a rs fo r th e C la ss I g ro u p and a p p ro x im a te ly fiv e ye a rs f o r th e C lass I I g ro u p . I t w o u ld a p p e a r th a t i r re s p e c tiv e o f d iffe re n c e s a ttrib u ta b le to v a ria b le o rth o d o n tic s k ills , s e ria l e x tr a c tio n , w h ile re d u c in g th e c o m p le x ity o f a m a lo c c lu s io n , g re a tly e x te n d e d th e d u ra tio n o f th e o r th o d o n tis t’ s o b li g a tio n . T h e e c o n o m ic s and p o s s ib le e ffe c t o n p a tie n t m o tiv a tio n o f su c h e x te n d e d tre a tm e n t tim e w a rra n t c a re fu l c o n s id e ra tio n b e fo re b e g in n in g a p la n n e d p ro g ra m o f s e ria l e x tr a c tio n .
C o n c lu s io n S e ria l e x tra c tio n is o f s u ffic ie n t b e n e fit to th e p a tie n t to m e rit c o n tin u e d a p p lic a tio n in c a re fu l ly se le cte d cases. P a tie n t s e le c tio n a n d th e tim in g o f tre a tm e n t re q u ire e v a lu a tio n o f a v a rie ty o f d e v e lo p m e n ta l g u id e lin e s n o t a lw a y s used in d ia g n o s is and tre a tm e n t p la n n in g f o r th e p e rm a n e n t d e n titio n . L o n g itu d in a l re c o rd s , as th o s e use d in th is s tu d y , and p a rtic u la rly th e 45° o b liq u e c e p h a lo m e tric ra d io g ra p h , a id in m o n ito rin g d e v e lo p m e n t and th e re s u lts o f tre a tm e n t o n an in d iv id u a liz e d basis. In te r im re c o rd s , p a r tic u la r ly th o se
Fig 7 ■ C hronology o f serial extraction— Class II m alocclusion.
Headgear started 117.6 ± 9.0 mo.
Fir st Premolar Ext ractions 126 ± 10 mo.
Full Appliances 14b. 3 ± 13. 2 mo.
Months
108
120
132
144
156
Years
9
10
11
12
13
In tial 110 ± 9. 3 mo.
Int ^rmediate 123. 5 ± 10.1 mo.
Post Extraction 139.3 ± 11.7 mo.
168 14 Retention 167.6 ± 13. 4 mo.
Aduss— others: SERIAL EXTRACTIONS ■ 581
Fig 8 ■ The a p plication of longitudinal records to serial extrac tion.
o b ta in e d d u rin g th e n o n a p p lia n c e phase o f tre a t m e n t, are in v a lu a b le f o r p a re n t and p a tie n t c o u n s e lin g a n d to re in fo rc e m o tiv a tio n (F ig 8). T h e re s u lts o f th is s tu d y c o n firm p re v io u s re p o rts th a t s e ria l e x tra c tio n , in its e lf, does n o t c o n s titu te a lo g ic a l end p o in t in tre a tm e n t. In v a r ia b ly , a p e rio d o f fu ll-a p p lia n c e th e ra p y m u st fo llo w to c o rr e c t a x ia l in c lin a tio n s , ro ta tio n s , clo s e e x tr a c tio n spaces, and le v e l th e p la n e o f o c c lu s io n . W h ile th e c o m p le x ity o f a m a lo c c lu s io n is re d u c e d in a p la n n e d p ro g ra m o f s e ria l e x tr a c tio n , th e c lin ic ia n ’ s o b lig a tio n is e x te n d e d .
S upported in part by grants fro m the National Institutes of Health (DE 02872) and Maternal and Child Health Services, De pa rtm ent o f Health, Education and Welfare. 1. B unon, R. Essay s u r les maladies des dents ou l'on propose les moyens de le lr procurer une donne con firm atio n des las plus ten dre enfance, et d'eu assurer la conservation pendant to u t le cou rs de la vie. Paris, 1743. 2. Fox, J. The natural history o f the human teeth, includ ing a p a rtic u la r e lucid ation o f the changes w hich take place d u ring the second de n titio n and describing the proper mode o f treatm ent to prevent irre gula rities o f the teeth. London, Thomas Cox, 1803. 3. K jellgren, B. Serial extraction as a corrective procedure in dental orthop edic therapy. Trans Europ Orthod Soc 1947-1948, p 134.
582 ■ JADA, Vol. 95, September 1977
4. Hotz, R.P. Active supervision o f the eruption of the teeth by extraction. Trans Europ O rthod Soc 1947-1948, p 34. 5. Hotz, R.P. G uidance o f eruption versus serial extraction, Am J O rthod 58:1 July 1970. 6. Heath, J.S.R. Planned minim al orthod ontic treatment. A ustral J Dent 53:285 Sept 1949. 7. Tweed, C.H. Indications fo r the extraction o f teeth in o rth od o n tic procedure. Am J O rthod and Oral Surg 30:405 Aug 1944. 8. Howes, A.E. Case analysis and treatm ent planning based upon the relationship o f the too th material to its s up portin g bone. Am J O rthod and Oral Surg 33:499 Aug 1947. 9. Carey, C.W. Linear arch dim ension and tooth size. Am J O rthod 35:762 O ct 1949. 10. Nance, H.N. Lim itations of orth o d o n tic treatm ent. I. Mixed d e ntition diagnosis and treatm ent. Am J O rthod and Oral Surg 33:117 May 1947. 11. Dewel, B.F. Serial extraction in o rthod ontics: indications, objectives, and treatm ent procedures. Am J Orthod 40:906 1954. 12. Lloyd, B.Z. Serial extraction as a treatm ent procedure. Am J O rthod 42:728, 1956. 13. Heath, J. The dangers and pitfa lls o f serial extractions. Trans Europ O rthod Soc 1961, p 60. 14. Jacobs, J. C ephalom etric and clinical evaluation o f Class I discrepancy cases treated by serial extraction procedures, thesis. Saint Louis University, 1959. 15. Stockhouse, B.E. A cephalom etric evaluation o f Class II Division I discrepancy cases treated by serial extraction proce dures, thesis. Saint Louis University, 1966. 16. Dewel, B.F Serial e xtraction : its lim itations and con tra indica tions in o rth o d o n tic treatment. Am J Orthod 53:904 Dec 1967. 17. Gron, A.M. P rediction o f tooth emergence. J Dent Res 41: 573, 1962. 18. Fanning, E.A. Effects o f extraction o f deciduous molars on the form ation and eruption o f their successors. A ngle Orthod 33:44, 1962. 19. Moorrees, C.F.A.; Fanning, E.A.; and Gron, A. Considera tio n of dental developm ent in serial extraction. A ngle Orthod 33:44, 1963. 20. Ringenberg, Q.M. Serial extraction: stop, look and be cer tain. Am J Orthod 50:327, 1964. 21. Dewel, B.F. Prerequisites in serial extraction. Am J Orthod 55:633, 1969. 22. Barber, T.K.; Pruzansky, S; and Kindelsperger, R. An eval uation o f the oblique cephalom etric film . J Dent Child 28:94, 1961. 23. Pruzansky, S. The o b liq ue cephalom etric radiographic p ro jection, unpublished thesis. American Board o f O rthodontics, 1967. 24. Lauterstein, A.M.; Pruzansky, S.; and Barber, T.K. Effect o f deciduous m andibular m olar pulpotom y on the eruption of succedaneous prem olar. J Dent Res 41:1367 Nov-Dee 1962. 25. Lauterstein, A.M.; Pruzansky, S.; and Levine, N.L. Bilateral asym metry in m andibular tooth development. J Dent Res 46:279 Jan-Feb 1967. 26. Ketterhagen, D. Taking a second look at headcap treat ment. A ngle Orthod 27:93 A pril 1957.
Serial extraction
H. A d u s s , DDS, C hicago C. J. S chw arz, DDS, Fairlaw n, O hio R. T. M c D a n ie l, DDS, S p rin g fie ld , III S. P ru za n sky, DDS, C hicago T h e se q u e n tia l e x tra c tio n o f p rim a ry and p e rm a n e n t te e th to re d u c e the s e v e rity o f a m a lo c c lu s io n , w ith th e p ro s p e c t th a t lit tle o r no m e ch a n ica l in te rv e n tio n w ill be n e ce ssa ry, has a ttra c te d th o se c o n c e rn e d w ith th e care o f c h ild re n fo r m a n y ye a rs. U n fo rtu n a te ly , se ria l e x tra c tio n has n o t, in its e lf, p ro v id e d s a tis fa c to ry o c c lu s a l re la tio n s h ip s . W h ile b o th a d vantages and d isa d van ta g e s
■ Is th e p a tte rn o f e ru p tio n o f th e p e rm a n e n t te e th a lte re d b y s e ria l e x tra c tio n ? ■ F o r p a tie n ts w ith C la ss I I m a lo c c lu s io n s , w h a t is th e e ffe c t o f h e a d g e a r th e ra p y d u rin g the s e ria l e x tra c tio n p e rio d ? ■ D o e s se ria l e x tra c tio n re d u c e th e c o m p le x it y o f a m a lo c c lu s io n so as to d im in is h th e need f o r o rth o d o n tic a p p lia n c e s a n d /o r re d u c e the tim e re q u ire d f o r w e a rin g o f a p p lia n c e s ?
h a ve been c la im e d fo r se ria l e x tra c tio n , lo n g i tu d in a l d a ta d o c u m e n tin g re s u lts are lim ite d . T o d a y , th e c lin ic ia n e m p lo y in g se ria l e x tra c tio n is c o n c e rn e d w ith q u e s tio n s p e rta in in g to th e sequence a n d tim in g o f e x tra c tio n s , th e v a ria b le e ffe c ts o f g ro w th d u rin g th e se ria l e x tra c tio n p e rio d , and th e n e c e s s ity f o r a p p lia n c e th e ra p y . T h e p u rp o s e o f th is s tu d y w as to d e fin e the p a tte rn o f c ra n io fa c ia l g ro w th and th e p a tte rn o f d e n ta l e ru p tio n , in C la ss I and C la ss I I m a lo c c lu sio ns in p a tie n ts u n d e rg o in g a p la n n e d p ro g ra m o f se ria l e x tra c tio n . S p e c ific a lly , th is s tu d y c o n s id e re d : ■ W h a t e ffe c t does se ria l e x tra c tio n ha ve o n th e p o s itio n o f th e in c is o rs , p a rtic u la rly th e lo w e r in c is o rs ?
R e v ie w o f th e lite ra tu r e S e ria l e x tra c tio n had bee n suggested in th e F re n c h lite ra tu re as e a rly as 1743,1 and a g u id e f o r th e tim in g o f e x tra c tio n s w as re p o rte d b y the E n g lis h m a n , F o x ,2 in 1803. T h e p ro c e d u re ca m e in to vo g u e as th e re s u lt o f p u b lic a tio n b y K je llg r e n o f S w e d e n and H o tz o f S w itz e rla n d in 1948.3 4 K je llg r e n fir s t used th e te rm “ se ria l e x tr a c tio n ,” w h e re a s H o t z 5 p re fe rre d th e p h ra se “ g u id a n c e o f e r u p tio n .” A b o u t th is tim e , H e a th ,6 in A u s tra lia , d e s c rib e d a p ro g ra m o f “ p la n n e d m in im a l o rth o d o n tic JADA, Vol. 95, Septem ber 1977 ■ 573
tre a tm e n t.” F o r a ll in te n ts and p u rp o s e s , th e p ro posals w e re a ll v a ria b le s o f s e ria l e x tra c tio n as it is p ra c tic e d to d a y . O f p a rtic u la r in te re s t w as th e shared o b je c tiv e th a t e a rly re m o v a l o f c ro w d e d te e th and sub se q u e n t a lig n m e n t o f e ru p tin g te e th w o u ld p ro v id e th e g re a te st b e n e fit fo r th o se w h o c o u ld n o t a ffo rd o rth o d o n tic tre a tm e n t o r fo r th o se fo r w h o m o rth o d o n tic se rvice s w e re n o t a v a ila b le . T h e s im u lta n e o u s re d is c o v e ry o f s e ria l e x tr a c tio n in d iffe re n t p a rts o f th e w o rld ca n be a s c rib e d to a ch a n g in g c lim a te o f ideas. F o r a b o u t th is tim e , e x tra c tio n becam e an a cce p te d p ro ce d u re in o rth o d o n tic p ra c tic e . T w e e d ’ s7 re p o rt o n fa ilu re s in o rth o d o n tic tre a tm e n t as a re s u lt o f a rc h le n g th d e fic ie n c y had a se m in a l in flu e n c e .7 S im ila rly , H o w e s ,8 C a re y ,9 and N a n c e 10 c o n tr ib u te d to th e in te re s t w ith th e ir re p o rts f o r es tim a tin g and p re d ic tin g a rch le n g th a d e q u a c y re l a tiv e to s u p p o rtin g bone. D u r in g th e subse q u e n t decade, a ra tio n a le fo r th e u tiliz a tio n o f s e ria l e x tra c tio n e v o lv e d . T h is in c lu d e d : ■ S om e in d iv id u a ls p re s e n t a d is c re p a n c y be tw e e n to o th m a te ria l and s u p p o rtin g b o n e th a t does n o t im p ro v e w ith g r o w th .11 ■ A f t e r e ru p tio n o f th e fir s t m o la rs , th e re is no in cre a se in a rch le n g th , and ia tro g e n ic a lly p ro d u ce d a rc h le n g th is n o t s ta b le .3 ■ E a rly re m o v a l o f te e th a llo w s p h y s io lo g ic u n a ssiste d m o v e m e n t o f a d ja c e n t te e th in to m o re fa v o ra b le p o s itio n s .12 In c lu d e d am o n g th e b e n e fits to be d e riv e d fr o m s e ria l e x tra c tio n w e re :
■ S p o n ta n e o u s te e th .3
a lig n m e n t
of
th e
a n te rio r
■ A re d u c tio n in tim e a n d c o m p le x ity o f ac tiv e a p p lia n c e th e r a p y .3 ■ P re s e rv a tio n o f th e p e rio d o n tiu m o f th e an te r io r te e th , since th e y w ill n o t be d is p la c e d b y c r o w d in g .10 T h e lim ita tio n s o f se ria l e x tra c tio n also w e re d e fin e d : ■ A p o s s ib le in cre a se in o v e rb ite .13 ■ M a n d ib u la r in c is o rs m a y tip lin g u a lly and th e re b y decrease a rc h le n g th .10,14-15 ■ E x c e s s iv e c o n c a v ity o f th e c irc u m o ra l area as a re s u lt o f c o lla p s e o f th e d e n titio n .10,16 ■ F u ll a p p lia n c e th e ra p y is n ecessary to c o m p le te tre a tm e n t, eve n a fte r a lo n g p e rio d o f o b s e rv a tio n .13 T h e 1960s w e re m a rk e d b y an im p o rta n t ser ies o f p a p e rs b y G r o n ,17 F a n n in g ,18 and M o o r re e s .19 T h e s e in v e s tig a to rs d o c u m e n te d “ n o r m a l” d e n ta l d e v e lo p m e n t, e ru p tio n , and e x fo lia tio n and p ro v id e d g u id e lin e s fo r th e tim in g o f e x tra c tio n s in a p la n n e d p ro g ra m o f se ria l e x tra c tio n . A ls o in th e 60s, se ve ra l theses a t S a in t L o u is U n iv e r s ity d o c u m e n te d th e p a tte rn o f c ra n io fa c ia l g ro w th a n d th e changes in in c is o r p o s itio n d u rin g th e age p e rio d o f s e ria l e x tra c tio n . T h is w o rk w as b ro u g h t to g e th e r in R in g e n b e rg ’ s20 p a p e r, “ S e ria l e x tra c tio n : s to p , lo o k and be c e r ta in .” In 1969, D e w e l,21 in c o m m e n tin g o n his e x p e rie n c e and o b s e rv a tio n s w ith se ria l e x tra c tio n w ro te , “ i t has been d is illu s io n in g to le a rn th a t
THE AUTHORS
ADUSS
SCHWARZ
Drs. Aduss and Pruzansky are in the private practice o f orthodontics. In addition, Dr. Aduss is professor of orthodontics, Center fo r Cra niofacial Anomalies, and Dr. Pruzansky is d ir ector of the Center and professor of orthodon tics in the D epartment o f Pediatrics, Abraham Lincoln School of Medicine, University of
574 ■ JADA, Vol. 95, September 1977
MCDANIEL
PRUZANSKY
Illinois Medical Center. Dr. McDaniel is In the private practice o f orthod ontics and Dr. Schwarz is in the private practice o f orthod on tics. Address requests fo r reprints to Dr. Aduss, Center fo r C raniofacial Anomalies, University of Illinois Medical Center, PO Box 6998, Chi cago, 60680.
serial extraction, in itself, rarely creates accep table occlusal relations and that certain diverse reactions will result if the procedure is not fol lowed by comprehensive orthodontic treat ment.” Now, in the 70s, three guidelines deserve em phasis: ■ The timing of serial extraction cannot be related to chronologic age, but must be consid ered relative to dental age among other develop mental yardsticks. ■ Serial extraction, in itself, is not an accept able treatment procedure, but requires supple mentary appliance therapy. ■ Each patient, in a planned program of serial extraction, requires continual monitoring of his pattern of craniofacial growth and dental devel opment. Although these guidelines evolved from 30 years of observation and study, to date there is only limited documentation of what actually hap pens during the serial extraction period.
Materials The patients studied were derived entirely from the private practice of two authors (H. A. and S. P.), and were divided into two groups accord ing to their malocclusion. There were 15 children (7 boys, 8 girls) with a Class I molar occlusion and 16 (6 boys, 10 girls) with a Class II molar oc clusion. Selection for inclusion in this study was based solely on the completeness of the diagnos tic and interim records, which included dental casts, facial photographs, and cephalometric radiographs in the lateral, posteroanterior, and right and left 45° oblique projections (Fig 1, 2). For each patient, a planned program of serial extraction was instituted because of a bimaxil lary arch length deficit, or a bimaxillary protru sion and/or an unfavorable pattern of facial growth. The sequence of serial extraction used fol lowed the procedure described by Heath 6 and involved extraction of the primary first molars and, whenever possible, maintenance of pri mary canines. The primary first molars were ex tracted, as suggested by Gron ,17 when at least half of the premolar root had formed. First pre molars were removed when they erupted. For the patients with a Class I malocclusion, no active orthodontic therapy was instituted
during the serial extraction period. For those who had a Class II malocclusion, cervical headgear was employed to correct the Class II molar relation during the serial extrac tion period. In eight of the 16 patients with Class II occlusal relationships, anterior bands and an arch wire were utilized for varying periods to retract markedly protrusive incisors and thereby reduce susceptibility to trauma and improve lip posture and function. Although there was a range in chronologic age at the initiation of treatment, the application of extraction procedures, based on dental develop ment, resulted in a sample of relatively homog enous dental age. After serial extraction, and with the eruption of the permanent dentition, all patients were treated with a full edgewise appliance.
M ethods
The serial oblique cephalometric radiograph served as the most important documentary tool for this study. It provided a reproducible radiographic projection controlled for enlargement and distortion. The accuracy of the technique and its applicability to serial extraction had al ready been demonstrated .22 Various reference planes for the superimposition of serial 45° oblique cephalometric radiographs had been de fined on both dry skulls and on longitudinal films of children.23 The technique had been used to document the effect of pulpotomy and caries on the rate of root resorption of primary teeth and the eruption of the permanent dentition.24 Con trol data for this study was provided, in part, by a previous study that used the 45° oblique roentgencephalogram to analyze symmetry of tooth eruption in the mandibular buccal segments of children not subjected to serial extraction or orthodontic treatment.25 The serial oblique films were evaluated initially (before extraction of the primary first molar); intermediate (before extraction of the erupted first premolars); and preappliance (after erup tion of the second premolar and/or canine and before placement of a full edgewise appliance). Each oblique film was analyzed to determine the change in pattern and/or path of eruption of the succedaneous teeth during the serial extrac tion period. The landmarks used are identified in Figure 3 . Lateral cephalometric radiographs obtained Aduss—others: SERIAL EXTRACTIONS ■ 575
Fig 1 ■ Serial 45° oblique cephalom etric radiographs. At age 8 years, 11 months, obtained prio r to extraction o f firs t prim ary molar. At age 9-4, interm ediate film , preceding the extraction of erupted firs t premolar. At age 11-2, prelim inary to appliance placem ent and fo llo w in g eruption of second prem olar and canine. At age 12-9, at tim e of removal of o rthod ontic appliance.
576 ■ JADA, Vol. 95, September 1977
Fig 2 ■ Longitudinal lateral cephalom etric radiographs obtained d u ring the serial extraction period and subse quent phase o f o rth o d o n tic treatm ent. Cervical headgear was used to correct m olar occlusio n d u rin g serial extraction period.
Fig 3 ■ Analysis of 45° oblique cephalom etric radiographs. A-B (palatal plane); C-D (m andibular plane); JIH-(gabling angle) form ed by connecting tip s of unerupted mandibular canine and prem olars. Axial inclina tion of each m axillary to o th was determ ined by m easuring a n te ro in fe rio r angle at junctio n of tooth and palatal plane, fo r example, axial inclina tion of canine is the a n tero in ferio r angle at junctio n of AB and EF planes. In mandible, anterosuperior angle was recorded to define axial inclina tion, fo r example, axial Inclina tion fo r m andibular canine is the anterosuperior angle at ju n c tio n o f CD and FG planes.
Aduss— others: SERIAL EXTRACTIONS ■ 577
Fig 4 ■ A nalysis o f lateral cephalom etric radiographs. Landm arks used in analysis of lateral projection in clud ed:S -ce nter of sella tu rcica ; O-orbital; P-porion; F.H.-Frankfort ho rizonta l; P tm -pterygom axillary fissure; A -po in t A; OP-occlusal plane; M P-m andlbular plane; G o-gon io n; M -m enton; Po-pogonlon; B -point B; (i-m axillary firs t m olar; and N-nasion.
at each o f th e p re v io u s ly m e n tio n e d stages also w e re a n a ly z e d to d e te rm in e th e p a tte rn o f c ra n io fa c ia l g ro w th d u rin g th e serial e x tra c tio n p e rio d ; h o w e v e r, o n ly th o se m easures e m p lo y e d to d o c u m e n t th e changes in th e p o s itio n o f th e in c is o rs and m o la rs w ill b e co n s id e re d in th is re p o rt. T h e la n d m a rk s u tiliz e d in th e a n a ly sis a re id e n tifie d in F ig u re 4.
R e s u lts a n d d is c u s s io n
te e th a t th e in c is o rs w o u ld n o t tip lin g u a lly , so th a t in n e ith e r C la ss I n o r C la ss I I m a lo c c lu sio n s w as th e change in in c is o r p o s itio n p re d ic t ab le . ■ Is th e p a tte rn o f e ru p tio n o f th e p e rm a n e n t te e th a lte re d b y s e ria l e x tra c tio n ? T o a n s w e r th is , th e “ g a b lin g a n g le ” w as u s e d .25 T h is is th e angle fo rm e d b y c o n n e c tin g the tip s o f th e u n e ru p te d m a n d ib u la r c a n in e and p re m o la rs (F ig 3). T h e angle d e fin e s th e re la tiv e b o n y p o s itio n o f th e th re e te e th and w as used in th is s tu d y to de-
R e s u lts o f th is in v e s tig a tio n a re segregated in te rm s o f th e q u e s tio n s posed. ■ W h a t e ffe c t does se ria l e x tra c tio n h a v e o n th e p o s itio n o f th e in c is o rs , p a rtic u la rly th e lo w e r in c is o rs ? T h e m ea n p o s itio n o f th e lo w e r in c is o r re m a in e d u n ch a n g e d d u rin g th e s e ria l e x tra c tio n p e rio d . T h e m e a n , h o w e v e r, d id n o t m ir r o r in d i v id u a l v a ria tio n w h e re th e p o s itio n o f th e lo w e r in c is o r tip p e d la b ia lly o r lin g u a lly d u rin g th e se r ia l e x tr a c tio n p e rio d . T h e v a rie d re sp o n se o f th e lo w e r in c is o r w as re fle c te d in th e r e la tiv e ly la rg e
In itia l
Age
C lass 11
11 2 .9 *9 .9
110.0*9.3
R ight M a x illa 3 4 5 6
s ta n d a rd d e v ia tio n s fo r th o se v a lu e s used to de fin e th e p o s itio n o f th e in c is o r (T a b le 1). I n a d d i tio n , th e change in a n g u la tio n o f th e lo w e r in c i
M andible 3 4 5 6
s o r d id n o t c o rre la te w ith th e p re se n ce o r ab sence o f th e p rim a ry c a n in e . I n o th e r w o rd s , th e p re se n ce o f th e p rim a ry ca n in e d id n o t g u a ra n
Gabl ing Angle
578 ■ JADA, Vol. 95, S eptem ber 1977
C lass I
L e ft
R ight
73. 1±14.3 8 4 .3± 9 .0 8 8 .2 * 9 .7 111. 1± 4.1
7 4 .6 *1 2 .4 8 8 .8 * 8 .9 9 8 .6 *1 1 .0 11 3.0* 4 .7
9 3 .7 * 9.3 9 6 .6± 8.8 9 9 .3 ± 1 0 .8 8 6 .8 * 6 .1
9 3 .8 * « .8 9 4 .6 * 7.4 9 5 .5 *1 1 .4 8 2 .8 * 2 .6
9 4 .7 * 9.9 9 5 .8 * 7.3 9 1 .6 *1 2 .3 86. 1* 4.1
143.5*26.5
150.1*24.8
149.3*19.3
8 0 .0 * 8 6 .9 * 9 2 .1 * 10 6.4*
6 .9 7.4 7.7 7.3
L e ft
8 1 .3 * 7 .4 8 9 .4 * 8.1 9 6 .5 *1 0 .7 10 8.6* 6 .3
9 7 .2 * 9 6 .9 * 9 2 .0 * 8 6 .9 *
9.6 8 .7 8.3 3 .7
153.7*29.2
Initial
Age FA Convexity ANB SNPo MP1 Y-Axis
T a b le 1 ■ Measurements
derived fro m the lateral cephalom etric radiographs.
C las s I
C lass II
C lass I
Clas s II
C lass I
C las s II
112.9 ± 9.9
110.0 i 9.3
1 31 .3 113,2
123.5+10.1
147.4 +13.2
139.3 + 11.7
8 4.8 9 .7 5.4 74.9 30.2 60.5
± ± ± * * *
84.6 11.8 6.3 73.7 27.5 59.7
1.9 4.2 1.7 2.7 5.0 2.5
U1-LI 130.8 ±10.2 U 1-APo (mm. 1 6 .9 * 2.9 L l-M P 87.6 ± 6.9 L l- A P o (mm. I 0 . 47± 2.0
+ * + ± -t +
1.5 4.0 1.4 2.7 4. 1 1.6
130.0 ±11,8 7.8 ± 2.8 91.3 ± 9. 1 . 56± 2.5
te rm in e th e e ffe c t o f e x tra c tio n o f th e p rim a ry fir s t m o la r on th e e ru p tio n o f th e u n d e rly in g p re
85.8+ 8. 5+ 4. 5t 75.8* 29.8+ 60.0+
2.0 5.0 2.2 2.6 5.4 2.6
132,7*10.4 7.0± 2.8 8 7 .8± 7.8 1.0± 2.5
8 4 .3± 11.0* 5.6+ 74.0+ 26.8* 60.1*
1.9 3.4 1.7 2.9 3.6 1.2
131.8+10.9 7.2+ 2 .8 91.4* 9.9 - 0.1 * 2.3
* 1.9 +6.1 * 2.4 * 2.8 * 3.7 * 2.0
85.4* 9.7* 5. 1* 74.9* 25.9* 59.7*
1.7 4. 1 1.6 2.8 3.6 1.1
134.2 ±10.8 6 .2 ± 2.5 86.7 ± 7.4 0.71* 2.0
131.2* 7.3* 91. 7± -0 .2 ±
9.4 2.4 7. 1 2.3
86.6 7.6 4.4 75.9 27.4 58.8
lo ss o f th e p rim a ry c a n in e , m e re ly o u td is ta n c e d th e e ru p tin g fir s t p re m o la r, d e s p ite e x tr a c tio n o f th e p rim a ry f ir s t m o la r (F ig 5 C ).
m o la r (T a b le 2). O n an a p r io r i ba sis, e x tra c tio n o f th e m a n d ib u la r p rim a ry f ir s t m o la r s h o u ld h a ste n e ru p tio n
I n c o n tra s t to th e p a tie n ts w ith C la ss I m a lo c c lu s io n s , w h e re th e g a b lin g angle in 13 o f 21 o b s e rv a tio n s b e ca m e m o re o b tu s e , th e g a b lin g angle in 22 o f 30 p a tie n ts w ith C la ss I I m a lo c c lu s io n s b e ca m e m o re a cu te . T h a t th is d iffe re n c e w a s in d ir e c tly re la te d to th e e ffe c ts o f h e a d g e a r th e ra p y w a s suggested b y th e fo llo w in g : In th e p a tie n ts w ith C la ss I o c c lu s io n s , a fte r e x tra c tio n o f the m a n d ib u la r p rim a ry f ir s t m o la r,
o f th e fir s t p re m o la r and th e re b y in cre a se th e g a b lin g angle. T h is re a s o n in g d id n o t a lw a y s h o ld . F o r e x a m p le , in th e C la ss I se rie s, 13 o f th e 2 1 angles m easured b e ca m e m o re o b tu s e fo llo w in g e x tra c tio n o f th e p rim a ry fir s t m o la r, w h ile e ig h t be cam e m o re a c u te . W h e re th e angle be cam e m o re a cu te , th e e ru p tin g fir s t m o la r had an u n o b s tru c te d v e rtic a l p a th o f e ru p tio n . I n th o se cases w h e re th e angle b e ca m e m o re o b tu s e , one o f th e fo llo w in g c o n d itio n s w as o b s e rv e d : A . T h e m a n d ib u la r f ir s t p re m o la r b e ca m e im
17 o f 25 m a n d ib u la r p e rm a n e n t f ir s t m o la rs and th e ir c o n tig u o u s u n e ru p te d se co n d p re m o la rs te n d e d to tip m e s ia lly , p o s s ib ly im p e d in g th e e ru p tio n o f th e f ir s t p re m o la r. I n th o s e w ith C la s s I I m a lo c c lu s io n s f o r w h o m h e a d g e a r w as u s e d , 16 o f 31 m a n d ib u la r p e rm a n e n t f ir s t m o
p a c te d a gainst th e m e sia l ro o t o f th e p rim a ry sec on d m o la r (F ig 5 A ). B . T h e p e rm a n e n t m a n d ib u la r c a n in e , w h ic h in c e rta in in sta n ce s w a s e ru p tin g ahead o f th e fir s t p re m o la r, tip p e d d is ta lly , a n d im p e d e d e ru p tio n o f th e fir s t p re m o la r (F ig 5 B ). C . T h e p e rm a n e n t m a n d ib u la r c a n in e , u p o n
la rs a n d th e u n e ru p te d p re m o la rs te n d e d to re m a in u p rig h t. A f t e r e x tra c tio n o f th e fir s t p re m o la r, th e sec o n d p re m o la r in th e p a tie n ts w ith C la s s I I m a l o c c lu s io n s c o n tin u e d to re m a in u p rig h t; w h ile in
Preappliance
Intermediate C las s I
C l a s s II
Class I
C l a s s II
131.3*13.2
123.5*10.1
147.4 ±13.2
139.3*11.7
Left
Right
Left
Right
Left
Right
Left
8.7 6.7 9.9 6.4
80.6*11.5 90.4* 8.8 91.8*11.9 110.8* 5 .0
84.8*10.3 88.2* 8.9 92.8*1 0.9 102.6* 6.2
86.4* 9 .9 93.0* 8.2 94.0*11.7 104.8* 5 .7
93.0 *8.9
93.5*12.4
9 2 .5* 8.1
9 6.5 *4 .4
91.3 *7.7 102.8*3.0
93.7*12.1 106.7* 4 .1
9 3 .2* 5.1 9 8.0 * 5 .4
9 5 .6 * 5 .7 9 9 .8 * 6 .2
98 .6* 7.4 9 5 . 7± 7.3 99.0±10.0 9 0 . 0± 7.0
101.7* 9 . 7 101.9* 8.3 95.7*10.4 85.4* 4 .6
97.8* 98.6* 89.9* 88.0*
106.5*5.1
108.1* 5 .7
107.4*4.8
10 5.9*6.0
92 .6 *7.7 8 6.1*5.2
91.8* 5.4 84.0* 5 .5
91. 1*6. 1 87.4 *6 .4
9 2 .0 * 5 .7 88.0 *4 .5
145.6±40. 3
148.7*39.4
133.5*33.5
Right
Preappliance
Intermediate
T a b le 2 ■ M easurements
82.9* 87.7* 86.8* 109.2*
6 .8 8.2 7.9 5.2
98.8* 100.2* 90.6* 88.6*
8.1 9.3 7 .8 4 .4
derived from the 45° oblique cephalom etric radiographs.
144.2*30.7
A duss—others: SERIAL EXTRACTIONS ■ 579
th e C la ss I g ro u p , th e second p re m o la r tip p e d m e s ia lly and fo llo w e d a p a th o f e ru p tio n in to th e e x tra c tio n site . W as th is d iffe re n c e b e tw e e n th e C la ss I and C la ss I I cases an in d ire c t re s u lt o f
headgear? T h e a n s w e r, a t th is tim e , is a m a tte r o f s p e c u la tio n . V e r y e a rly in th is s tu d y i t w as a p p a re n t th a t th e to o th m o s t fa v o ra b ly a ffe c te d b y se ria l e x tra c tio n w as th e c a n in e . I f s e ria l e x tra c tio n is c o n s id e re d a c o m p e titio n fo r space w h e re th e c lin ic ia n trie s to p ro v id e a b e tte r tr a c k fo r c e r ta in te e th , th e n th e u ltim a te w in n e r, in a ll cases, was th e ca n in e. I n b o th th e C la ss I and C la ss I I g ro u p s , in b o th th e m a n d ib le and m a x illa , th e p a th o f e ru p tio n o f th e ca n in e w as in it ia lly a lte re d a fte r e x tra c tio n o f th e p rim a ry fir s t m o la r, and m o d ifie d eve n fu r th e r a fte r e x tra c tio n o f th e fir s t p re m o la r. T h u s , b y th e tim e th e p a tie n t w as re a d y fo r ap p lia n c e s , th e g re a te s t p o rtio n o f th e e x tra c tio n site w as o c c u p ie d b y th e c a n in e . A t th is p o in t, a n o te o f c a u tio n is in o rd e r. In c o n s id e rin g changes in a x ia l in c lin a tio n , i t sh o u ld be re m e m b e re d th a t th e size o f o u r sam ple was r e la tiv e ly s m a ll, and th a t w h ile th e re w as n o sig n ific a n t change in th e m ean a x ia l in c lin a tio n o f a to o th , som e te e th d e m o n s tra te d m e sia l tip p in g , som e d is ta l tip p in g , and som e n o change. F o r e x a m p le , th e m a x illa ry second p re m o la r in the p a tie n ts w ith C la ss I m a lo c c lu s io n s , ta k e n o n an in d iv id u a l basis, d e m o n s tra te d th a t 13 o f 22 p re m o la rs had tip p e d m e s ia lly , s ix had tip p e d d ista lly , and th re e d id n o t change. T h e m a x illa ry second p re m o la r in th e p a tie n ts w ith C la ss I I m a lo c c lu s io n s , ta k e n o n an in d iv id u a l basis, d e m o n s tra te d 16 cases w h e re th e lo n g axes tip p e d d is ta lly , 12 m e s ia lly , a n d th re e w h e re no change o c c u rre d . T h e p ro m in e n t degree o f in d i v id u a l v a ria tio n em phasizes th e n eed f o r a v o id in g c o o k b o o k ro u tin e and th e n e c e s s ity o f m o n ito r in g each in d iv id u a l case fr o m th e b e g in n in g th ro u g h c o m p le tio n o f th e s e ria l e x tra c tio n p ro g ram . ■ F o r p a tie n ts w ith C la ss I I m a lo c c lu s io n s , w h a t is th e e ffe c t o f h e a d g e a r th e ra p y d u rin g the s e ria l e x tra c tio n p e rio d ? M o la r re la tio n s w e re c o rre c te d to C la ss I o c c lu s io n , and th e m a x il la ry m o la r w as u p rig h t o r eve n tip p e d d is ta lly b y th e tim e th e p a tie n t w as re a d y f o r fu ll a p p lia n c es. In c o n tra s t, th e m a x illa ry fir s t m o la r f o r pa
Fig 5 ■ Inh ib itio n o f first prem olar along its path of eruption. 580 ■ JADA, Vol. 95, September 1977
tie n ts w ith C la ss I m o la r o c c lu s io n s (w ith o u t headgear) te n d e d to tip m e s ia lly d u rin g th e serial e x tra c tio n p e rio d (T a b le 2). In te rm s o f re d u c in g tre a tm e n t tim e , it w o u ld ha ve been id e a l to c o rre la te th e b e g in n in g o f headgear th e ra p y w ith th e a c tiv e phase o f fa c ia l g ro w th . In th e p a tie n ts u n d e r s tu d y , headgear w as g e n e ra lly s ta rte d a fte r th e re m o v a l o f the
First remolar Extraetions 132.8 14. 2 mo.
Months 108 nyL i Years
120 10
Initi il 112. 9 ± 9.9 mo.
Full Appliances 155.7 ± 15. 5 mo.
132 11
144 12
Intermediate 131 3 ± 13. 2 mo.
156 1*3
168 l'4
180 l'5
Pos Extraction 147. 4 ± 13. 2 mo.
192 16
Rete ntion 185. 2 ± 17. 9 mo.
Fig 6 ■ C hronology o f serial extraction— Class I occlusion.
p rim a ry fir s t m o la r. O n th e b asis o f th e a n a ly sis o f th e la te ra l ra d io g ra p h s , th e e rr o r w as u s u a lly in s ta rtin g to o e a rly . T o a v o id w h a t has been ca lle d th e “ s a tu ra tio n p o in t” 26 in p a tie n t c o o p e ra tio n , h e a dg ear w as d is c o n tin u e d w h e n m o la r re la tio n s w e re c o rre c te d a n d , w h e n n e c e ssa ry, in c is o rs re tra c te d . ■ D o e s s e ria l e x tra c tio n re d u c e th e c o m p le x it y o f a m a lo c c lu s io n and th e re b y re d u c e th e tim e re q u ire d f o r fu ll a p p lia n ce s? P a rt o f th is q u e s tio n has a lre a d y been a n s w e re d . C a n in e s , w h ic h m a y have been im p a c te d o r b lo c k e d -o u t, e ru p te d in to space fo r m e r ly o c c u p ie d b y fir s t p re m o la rs . A l l in a ll, th e te e th w e re c lo s e r to th e ir fin a l p o s i tio n s an d th e c o m p le x ity o f th e m a lo c c lu s io n w as re d u ce d . H o w e v e r, th e p a tie n ts s till re q u ire d fu ll a p p li ances to c o m p le te c lo s u re o f e x tra c tio n spaces, c o rre c t ro ta tio n s and a x ia l in c lin a tio n s , and le v e l th e p la n e o f o c c lu s io n . T h e re fo re , th e to ta l tim e in v o lv e d in a p la n n e d p ro g ra m o f se ria l e x tra c tio n appeared to be g re a te r th a n th a t e xp e n d e d on o th e r p a tie n ts (F ig 6, 7). I t s h o u ld be re m e m b e re d th a t tre a tm e n t tim e is d ir e c tly d e p e n d e n t on th e sta n d a rd s and s k ills o f th e in d iv id u a l c lin ic ia n . F o r th e p a tie n ts w it h in th is s tu d y , th e m ean a p p lia n c e tim e f o r th e C lass I g ro u p w as 29.5 m o n th s and f o r th e C la ss I I g ro u p , 23.1 m o n th s . W h ile th is m a y be ac c e p ta b le to on e c lin ic ia n , it m a y seem o v e r ly lo n g to a n o th e r.
A m o re im p o rta n t le sso n to b e le a rn e d fr o m a re v ie w o f th e c h ro n o lo g y o f se ria l e x tr a c tio n c o n ce rn s o v e ra ll in v o lv e m e n t w ith th e p a tie n t. F ro m th e tim e the in itia l re c o rd s w e re o b ta in e d , th e m ean tim e w as s lig h tly m o re th a n s ix y e a rs fo r th e C la ss I g ro u p and a p p ro x im a te ly fiv e ye a rs f o r th e C lass I I g ro u p . I t w o u ld a p p e a r th a t i r re s p e c tiv e o f d iffe re n c e s a ttrib u ta b le to v a ria b le o rth o d o n tic s k ills , s e ria l e x tr a c tio n , w h ile re d u c in g th e c o m p le x ity o f a m a lo c c lu s io n , g re a tly e x te n d e d th e d u ra tio n o f th e o r th o d o n tis t’ s o b li g a tio n . T h e e c o n o m ic s and p o s s ib le e ffe c t o n p a tie n t m o tiv a tio n o f su c h e x te n d e d tre a tm e n t tim e w a rra n t c a re fu l c o n s id e ra tio n b e fo re b e g in n in g a p la n n e d p ro g ra m o f s e ria l e x tr a c tio n .
C o n c lu s io n S e ria l e x tra c tio n is o f s u ffic ie n t b e n e fit to th e p a tie n t to m e rit c o n tin u e d a p p lic a tio n in c a re fu l ly se le cte d cases. P a tie n t s e le c tio n a n d th e tim in g o f tre a tm e n t re q u ire e v a lu a tio n o f a v a rie ty o f d e v e lo p m e n ta l g u id e lin e s n o t a lw a y s used in d ia g n o s is and tre a tm e n t p la n n in g f o r th e p e rm a n e n t d e n titio n . L o n g itu d in a l re c o rd s , as th o s e use d in th is s tu d y , and p a rtic u la rly th e 45° o b liq u e c e p h a lo m e tric ra d io g ra p h , a id in m o n ito rin g d e v e lo p m e n t and th e re s u lts o f tre a tm e n t o n an in d iv id u a liz e d basis. In te r im re c o rd s , p a r tic u la r ly th o se
Fig 7 ■ C hronology o f serial extraction— Class II m alocclusion.
Headgear started 117.6 ± 9.0 mo.
Fir st Premolar Ext ractions 126 ± 10 mo.
Full Appliances 14b. 3 ± 13. 2 mo.
Months
108
120
132
144
156
Years
9
10
11
12
13
In tial 110 ± 9. 3 mo.
Int ^rmediate 123. 5 ± 10.1 mo.
Post Extraction 139.3 ± 11.7 mo.
168 14 Retention 167.6 ± 13. 4 mo.
Aduss— others: SERIAL EXTRACTIONS ■ 581
Fig 8 ■ The a p plication of longitudinal records to serial extrac tion.
o b ta in e d d u rin g th e n o n a p p lia n c e phase o f tre a t m e n t, are in v a lu a b le f o r p a re n t and p a tie n t c o u n s e lin g a n d to re in fo rc e m o tiv a tio n (F ig 8). T h e re s u lts o f th is s tu d y c o n firm p re v io u s re p o rts th a t s e ria l e x tra c tio n , in its e lf, does n o t c o n s titu te a lo g ic a l end p o in t in tre a tm e n t. In v a r ia b ly , a p e rio d o f fu ll-a p p lia n c e th e ra p y m u st fo llo w to c o rr e c t a x ia l in c lin a tio n s , ro ta tio n s , clo s e e x tr a c tio n spaces, and le v e l th e p la n e o f o c c lu s io n . W h ile th e c o m p le x ity o f a m a lo c c lu s io n is re d u c e d in a p la n n e d p ro g ra m o f s e ria l e x tr a c tio n , th e c lin ic ia n ’ s o b lig a tio n is e x te n d e d .
S upported in part by grants fro m the National Institutes of Health (DE 02872) and Maternal and Child Health Services, De pa rtm ent o f Health, Education and Welfare. 1. B unon, R. Essay s u r les maladies des dents ou l'on propose les moyens de le lr procurer une donne con firm atio n des las plus ten dre enfance, et d'eu assurer la conservation pendant to u t le cou rs de la vie. Paris, 1743. 2. Fox, J. The natural history o f the human teeth, includ ing a p a rtic u la r e lucid ation o f the changes w hich take place d u ring the second de n titio n and describing the proper mode o f treatm ent to prevent irre gula rities o f the teeth. London, Thomas Cox, 1803. 3. K jellgren, B. Serial extraction as a corrective procedure in dental orthop edic therapy. Trans Europ Orthod Soc 1947-1948, p 134.
582 ■ JADA, Vol. 95, September 1977
4. Hotz, R.P. Active supervision o f the eruption of the teeth by extraction. Trans Europ O rthod Soc 1947-1948, p 34. 5. Hotz, R.P. G uidance o f eruption versus serial extraction, Am J O rthod 58:1 July 1970. 6. Heath, J.S.R. Planned minim al orthod ontic treatment. A ustral J Dent 53:285 Sept 1949. 7. Tweed, C.H. Indications fo r the extraction o f teeth in o rth od o n tic procedure. Am J O rthod and Oral Surg 30:405 Aug 1944. 8. Howes, A.E. Case analysis and treatm ent planning based upon the relationship o f the too th material to its s up portin g bone. Am J O rthod and Oral Surg 33:499 Aug 1947. 9. Carey, C.W. Linear arch dim ension and tooth size. Am J O rthod 35:762 O ct 1949. 10. Nance, H.N. Lim itations of orth o d o n tic treatm ent. I. Mixed d e ntition diagnosis and treatm ent. Am J O rthod and Oral Surg 33:117 May 1947. 11. Dewel, B.F. Serial extraction in o rthod ontics: indications, objectives, and treatm ent procedures. Am J Orthod 40:906 1954. 12. Lloyd, B.Z. Serial extraction as a treatm ent procedure. Am J O rthod 42:728, 1956. 13. Heath, J. The dangers and pitfa lls o f serial extractions. Trans Europ O rthod Soc 1961, p 60. 14. Jacobs, J. C ephalom etric and clinical evaluation o f Class I discrepancy cases treated by serial extraction procedures, thesis. Saint Louis University, 1959. 15. Stockhouse, B.E. A cephalom etric evaluation o f Class II Division I discrepancy cases treated by serial extraction proce dures, thesis. Saint Louis University, 1966. 16. Dewel, B.F Serial e xtraction : its lim itations and con tra indica tions in o rth o d o n tic treatment. Am J Orthod 53:904 Dec 1967. 17. Gron, A.M. P rediction o f tooth emergence. J Dent Res 41: 573, 1962. 18. Fanning, E.A. Effects o f extraction o f deciduous molars on the form ation and eruption o f their successors. A ngle Orthod 33:44, 1962. 19. Moorrees, C.F.A.; Fanning, E.A.; and Gron, A. Considera tio n of dental developm ent in serial extraction. A ngle Orthod 33:44, 1963. 20. Ringenberg, Q.M. Serial extraction: stop, look and be cer tain. Am J Orthod 50:327, 1964. 21. Dewel, B.F. Prerequisites in serial extraction. Am J Orthod 55:633, 1969. 22. Barber, T.K.; Pruzansky, S; and Kindelsperger, R. An eval uation o f the oblique cephalom etric film . J Dent Child 28:94, 1961. 23. Pruzansky, S. The o b liq ue cephalom etric radiographic p ro jection, unpublished thesis. American Board o f O rthodontics, 1967. 24. Lauterstein, A.M.; Pruzansky, S.; and Barber, T.K. Effect o f deciduous m andibular m olar pulpotom y on the eruption of succedaneous prem olar. J Dent Res 41:1367 Nov-Dee 1962. 25. Lauterstein, A.M.; Pruzansky, S.; and Levine, N.L. Bilateral asym metry in m andibular tooth development. J Dent Res 46:279 Jan-Feb 1967. 26. Ketterhagen, D. Taking a second look at headcap treat ment. A ngle Orthod 27:93 A pril 1957.