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Orthopaedic protraction of the midface in the deciduous dentition
j. Cranio-Max.-Fac.Surg. 17 (1989) J. Cranio-Max.-Fac.Surg. 17 (1989) 17-19 © GeorgThiemeVerlagStuttgart • New York
Orthopaedic Protraction of the Midface in the Deciduous Dentition Results Covering 3 Years out of Treatment Roll S. Tindlund Dept. of Orthodonticsand FacialOrthopaedics(Head:Prof. P. Rygh, D.M.D.), Universityof Bergen,Norway
17
Summary If there is underdevelopment of the upper jaw, the current Bergen concept indicates a period of orthopaedic/orthodontic treatment of cleft lip and palate patients at 6 - 7 years of age. A fixed quad-helix-appliance is used in combination with a facial mask. The result is retained with a fixed palatal arch. A preliminary follow-up study on sagittal growth and development in 30 patients is reported. By treating early, a more basal response is obtained, and several years of more correct function is gained.
Key words Cleft lip and palate - Orthopaedic treatment Growth adaptation - Maxillary protraction
Introduction Modern surgery has greatly reduced the incidence and degree of growth disturbance in patients with cleft lip and palate. But some cases still show maxillary underdevelopment at an early age. In Bergen we find anterior and/or posterior crossbite in the deciduous dentition in about 20 % of the cleft patients. In these cases we advocate a treatment rationale to normalize orofacial function and skeletal deviation at an early age. The aim is that transverse expansion and anterior protraction of the upper jaw should be completed so early that the permanent incisors erupt spontaneously into normal occlusion with secure overjet and overbite (Tindfund, 1987). This should ensure further growth and development under the more favourable influence of normally directed impulses from function and mastication, and in turn reduce detrimental functional disturbances. Postponement of this early interceptive treatment seems to reduce the possibility of influencing the basal parts of the midfacial complex.
Method The treatment rationale was introduced in 1977 (Rygh and Tindlund, 1982). A modified quad-helix appliance is used in combination with a facial mask (Fig. 1). Preformed
Fig. 1
Modified Quad-helix-appliance. Preformed bands with brackets cemented on to deciduous cuspids and molars. The quad-helix-spring is soldered to all four bands. The ends are bent as hooks for elastic traction in the cuspid region. Note that the auxiliary soldered-on-wire palatal to the incisors, is always in passive contact.
Fig.2 "Masque de Delaire". The elastics for protraction are fixed in the cuspid region. The direction of force is inclined downwards about 15 degrees in relation to the occlusal plane,
18
J. Cranio-Max.-Fac. Surg. 17 (1989)
s
N+; SNA=
",
A.O. C-BCI.P b o r n J u l y 1973
N+ ~
"-,
ANB0
R.S. TindIund
'
?
......,"
..... . /
f~tlow-upstudy SNAO.Anlage
p~tm~ion
degrees
n= 3O 0
1/2
d~r~s l "~'-~..... 0 1/2
1 ~11 [ 2
2
3 ~1,'44vea~
1.._.,..!..1/~.._,.a-.-""
...........l"::i~i'~........
.......0.35 3 " years
SNB~Ie
degm~ ...°-"
j r.
.......
~ . . . . 2 + _;.a+o
,
mean111/2 raN. f°ll°w'uP I
]
SNA
SNB
ANB
79.5
80.0
4.5
80.0
75.0
r
before p r o t r a c t i o n 58 I | after p r o t r a c t i o n 78 I
5.0
I
changesin degre~
Fig,3 Changes (in degrees) during and after protraction. The curves to the left side of the vertical axis represent active protraction treatment lasting a mean of 11.5 months. The follow-up study covering 3years begins at year zero (0).
Fig.4 A case demonstrating protraction for 24 months. Note that N-point and A-point have both come forward about 5 mm. Consequently the angle SNA remains approximately unchanged. On the contrary there is a reduction of the angle SNB. (B-CLP; boy; began treatment at age 5 year 8 months).
The anterior protraction is accomplished by a DeIaire mask (Delaire et al., 1973) using elastics with a total force of about 700 grams (Fig. 2). It is important that the elastics are fixed in the cuspid region, and that the direction of force is inclined downwards about 15 degrees in relation to the occlusal plane. Material
Mand-point
ML
Tw o constructed points: Maxillary-point
Mandibular-point
At the Bergen Cleft Centre, about 100 patients have been treated according to the described rationale since 1977, and a group of the first 30 has been followed 3 years after active treatment was complete. All patients were treated to produce a clinically normal overjet and overbite. The mean age at the beginning of treatment was 7 years. The treatment time was a minimum of 6 months and the mean duration 12 months. The longitudinal series of lateral cephalograms were taken before and after active protractiontreatment, and afterwards at 6 months, 1year, 1~, 2, 3 and 5 years.
• represent the more basal part of the jaws • easily reproduced • variables measured as coordinates in relation to NS-line and sella as origo
Fig.5 Constructed maxillary-pointand mandibular-point. Changes are measured in ram,
bands with tubes or brackets are adapted to the deciduous second molars and canines. The quad-helix is soldered to all four bands. There are hooks for elastics mesio-lingually to the cuspid bands. The preferred treatment time is at the age of 6-7years. All posterior crossbites are corrected first by transverse expansion, usually within 2-3 months of treatment commencing.
Results and Discussion Almost all conventionally-used cephalometric variables showed significant changes during the active protractionperiod, the majority at the 1 % level. But there was considerable variation, for example the mean change of angle ANB was+ 2.5 degrees with a range from 0 to 7.5 degrees. During protraction there was a mean increase in the SNAangle and a decrease in the SNB-angle (Fig. 3, left side of the vertical axis). The follow-up-study starts at year zero (Fig. 3, right side of the vertical axis). After finishing the protraction the SNA-angle decreases by 1.3 degrees within 3 years, and
Orthopaedic Protraction of the Midface in the Deciduous Dentition
J. Cranio-Max.-Fac. Surg. 17 (1989) protraction degrees
19
follow-up-study
H°-angle n = 30
0.96
-] - 0 1/2 1 , w ,,L protraction mean 11 1/2 m t s . ~ follow-up protraction mm
follow-up-st udy
1 1/2
2
3
years
changes in degrees
n = 30 .....- 1.66
Max.-point 0 mm
1
1/2
1 1/2
2
3 ~" years
. . " " Y " ...............................y...-" 2.83
/"
...... •..,.......,...
../
1/2/ ....."'~0.94
protraction mean 11 1/2 rnts
1
11/2
Mand.-point 2
L.. 3
'-~
~!G uL
years
n = 30
) follow-up
changes in rnm measured parallel 1:o SN-]ine
Fig. 6 Changes (in mm) during and after protraction. The curves to the left side of the vertical axis represent active protraction treatment lasting a mean of 11.5 months. The follow-up-study covering 3 years begins at year zero (0). The maxillary-point remains stable.
Fig. 7 Changes (in degrees) during and after protraction. The Hangle indicates a postive influence on the soft-tissue-profile.
the SNB-angle increases by 1.5 degrees, resulting in a mean growth-change of the angle ANB of 2.8 degrees. Individual cases, however, show clearly that the point N (nasion), during active protraction, may come forward in the same magnitude as the point A (subspinale) resulting in little or no change of the angle SNA (Fig. 4). On the contrary we find a reduction of the angle SNB. The SNA, SNB and ANB-angles thus, when interpreted in isolation, do not give adequate information about the longitudinal changes. And the traditional points A and B are difficult to locate in this patient-group and at this age. Two constructed points, the maxillary-point and the mandibular-point are chosen (Fig. 5). They represent a more basal part of the jaws, and are easily reproduced. The variables are measured to a coordinate-system related to the NS-line and a vertical through the Sella. Based on this, the follow-up-study shows that the maxillary-point remains stable, or in fact increases slightly, while the mandibular-point comes forward by a mean of 3.7 mm (Fig. 6). It seems thus clear that the registered reduction of the ANB-angle is due to forward growth of the mandible rather than relapse of the position of the maxilla. The H-angle indicates a marked positive and lasting influence on the soft-tissue-profile (Fig. 7). Both clinically and cephalometrically there is considerable variation. Apart from the specific growth inhibition related to early surgery in cleft lip and palate, it is likely that inherited growth pattern and facial type are of great im-
portance, both for the outcome of the protraction and subsequently for clinical stability. Conclusions By treating early, at about 6 years of age, we obtain more basal response and several years of more correct function. The follow-up-study revealed that after active treatment the maxilla and mandible revert to the original growth pattern. In cases with moderate underdevelopment of the maxilla, the early period of protraction has been sufficient to keep the occlusion normalized. References
Delaire, J., P. Verdon, M.-C. K~n~si:Extraorale Zugkriifte mit StirnKinn-Abst~tzung zur Behandlung der Oberkieferdeformierungen als Folge von Lippen-Kiefer-Gaumenspalten.Fortschr. Kieferorthop. 34 (1973) 225-237 Rygh, P., R. Tindlund: Orthopaedic expansion and protraction of the maxilla in cleft palate patients - A new treatment rationale. Cleft Palate J. 19 (1982) 104-112 Tindlund, IL: Treatment of cleft lip and palate in Bergen - Teamwork. Nor. Tannlegefor Tid 97 (1987) 360-369 Dr. R. S. Tindlund, D.D.S. Dept. of Orthodontics and Facial Orthopaedics Arstadtveien 17 N-5009 Bergen Norway
Orthopaedic Protraction of the Midface in the Deciduous Dentition Results Covering 3 Years out of Treatment Roll S. Tindlund Dept. of Orthodonticsand FacialOrthopaedics(Head:Prof. P. Rygh, D.M.D.), Universityof Bergen,Norway
17
Summary If there is underdevelopment of the upper jaw, the current Bergen concept indicates a period of orthopaedic/orthodontic treatment of cleft lip and palate patients at 6 - 7 years of age. A fixed quad-helix-appliance is used in combination with a facial mask. The result is retained with a fixed palatal arch. A preliminary follow-up study on sagittal growth and development in 30 patients is reported. By treating early, a more basal response is obtained, and several years of more correct function is gained.
Key words Cleft lip and palate - Orthopaedic treatment Growth adaptation - Maxillary protraction
Introduction Modern surgery has greatly reduced the incidence and degree of growth disturbance in patients with cleft lip and palate. But some cases still show maxillary underdevelopment at an early age. In Bergen we find anterior and/or posterior crossbite in the deciduous dentition in about 20 % of the cleft patients. In these cases we advocate a treatment rationale to normalize orofacial function and skeletal deviation at an early age. The aim is that transverse expansion and anterior protraction of the upper jaw should be completed so early that the permanent incisors erupt spontaneously into normal occlusion with secure overjet and overbite (Tindfund, 1987). This should ensure further growth and development under the more favourable influence of normally directed impulses from function and mastication, and in turn reduce detrimental functional disturbances. Postponement of this early interceptive treatment seems to reduce the possibility of influencing the basal parts of the midfacial complex.
Method The treatment rationale was introduced in 1977 (Rygh and Tindlund, 1982). A modified quad-helix appliance is used in combination with a facial mask (Fig. 1). Preformed
Fig. 1
Modified Quad-helix-appliance. Preformed bands with brackets cemented on to deciduous cuspids and molars. The quad-helix-spring is soldered to all four bands. The ends are bent as hooks for elastic traction in the cuspid region. Note that the auxiliary soldered-on-wire palatal to the incisors, is always in passive contact.
Fig.2 "Masque de Delaire". The elastics for protraction are fixed in the cuspid region. The direction of force is inclined downwards about 15 degrees in relation to the occlusal plane,
18
J. Cranio-Max.-Fac. Surg. 17 (1989)
s
N+; SNA=
",
A.O. C-BCI.P b o r n J u l y 1973
N+ ~
"-,
ANB0
R.S. TindIund
'
?
......,"
..... . /
f~tlow-upstudy SNAO.Anlage
p~tm~ion
degrees
n= 3O 0
1/2
d~r~s l "~'-~..... 0 1/2
1 ~11 [ 2
2
3 ~1,'44vea~
1.._.,..!..1/~.._,.a-.-""
...........l"::i~i'~........
.......0.35 3 " years
SNB~Ie
degm~ ...°-"
j r.
.......
~ . . . . 2 + _;.a+o
,
mean111/2 raN. f°ll°w'uP I
]
SNA
SNB
ANB
79.5
80.0
4.5
80.0
75.0
r
before p r o t r a c t i o n 58 I | after p r o t r a c t i o n 78 I
5.0
I
changesin degre~
Fig,3 Changes (in degrees) during and after protraction. The curves to the left side of the vertical axis represent active protraction treatment lasting a mean of 11.5 months. The follow-up study covering 3years begins at year zero (0).
Fig.4 A case demonstrating protraction for 24 months. Note that N-point and A-point have both come forward about 5 mm. Consequently the angle SNA remains approximately unchanged. On the contrary there is a reduction of the angle SNB. (B-CLP; boy; began treatment at age 5 year 8 months).
The anterior protraction is accomplished by a DeIaire mask (Delaire et al., 1973) using elastics with a total force of about 700 grams (Fig. 2). It is important that the elastics are fixed in the cuspid region, and that the direction of force is inclined downwards about 15 degrees in relation to the occlusal plane. Material
Mand-point
ML
Tw o constructed points: Maxillary-point
Mandibular-point
At the Bergen Cleft Centre, about 100 patients have been treated according to the described rationale since 1977, and a group of the first 30 has been followed 3 years after active treatment was complete. All patients were treated to produce a clinically normal overjet and overbite. The mean age at the beginning of treatment was 7 years. The treatment time was a minimum of 6 months and the mean duration 12 months. The longitudinal series of lateral cephalograms were taken before and after active protractiontreatment, and afterwards at 6 months, 1year, 1~, 2, 3 and 5 years.
• represent the more basal part of the jaws • easily reproduced • variables measured as coordinates in relation to NS-line and sella as origo
Fig.5 Constructed maxillary-pointand mandibular-point. Changes are measured in ram,
bands with tubes or brackets are adapted to the deciduous second molars and canines. The quad-helix is soldered to all four bands. There are hooks for elastics mesio-lingually to the cuspid bands. The preferred treatment time is at the age of 6-7years. All posterior crossbites are corrected first by transverse expansion, usually within 2-3 months of treatment commencing.
Results and Discussion Almost all conventionally-used cephalometric variables showed significant changes during the active protractionperiod, the majority at the 1 % level. But there was considerable variation, for example the mean change of angle ANB was+ 2.5 degrees with a range from 0 to 7.5 degrees. During protraction there was a mean increase in the SNAangle and a decrease in the SNB-angle (Fig. 3, left side of the vertical axis). The follow-up-study starts at year zero (Fig. 3, right side of the vertical axis). After finishing the protraction the SNA-angle decreases by 1.3 degrees within 3 years, and
Orthopaedic Protraction of the Midface in the Deciduous Dentition
J. Cranio-Max.-Fac. Surg. 17 (1989) protraction degrees
19
follow-up-study
H°-angle n = 30
0.96
-] - 0 1/2 1 , w ,,L protraction mean 11 1/2 m t s . ~ follow-up protraction mm
follow-up-st udy
1 1/2
2
3
years
changes in degrees
n = 30 .....- 1.66
Max.-point 0 mm
1
1/2
1 1/2
2
3 ~" years
. . " " Y " ...............................y...-" 2.83
/"
...... •..,.......,...
../
1/2/ ....."'~0.94
protraction mean 11 1/2 rnts
1
11/2
Mand.-point 2
L.. 3
'-~
~!G uL
years
n = 30
) follow-up
changes in rnm measured parallel 1:o SN-]ine
Fig. 6 Changes (in mm) during and after protraction. The curves to the left side of the vertical axis represent active protraction treatment lasting a mean of 11.5 months. The follow-up-study covering 3 years begins at year zero (0). The maxillary-point remains stable.
Fig. 7 Changes (in degrees) during and after protraction. The Hangle indicates a postive influence on the soft-tissue-profile.
the SNB-angle increases by 1.5 degrees, resulting in a mean growth-change of the angle ANB of 2.8 degrees. Individual cases, however, show clearly that the point N (nasion), during active protraction, may come forward in the same magnitude as the point A (subspinale) resulting in little or no change of the angle SNA (Fig. 4). On the contrary we find a reduction of the angle SNB. The SNA, SNB and ANB-angles thus, when interpreted in isolation, do not give adequate information about the longitudinal changes. And the traditional points A and B are difficult to locate in this patient-group and at this age. Two constructed points, the maxillary-point and the mandibular-point are chosen (Fig. 5). They represent a more basal part of the jaws, and are easily reproduced. The variables are measured to a coordinate-system related to the NS-line and a vertical through the Sella. Based on this, the follow-up-study shows that the maxillary-point remains stable, or in fact increases slightly, while the mandibular-point comes forward by a mean of 3.7 mm (Fig. 6). It seems thus clear that the registered reduction of the ANB-angle is due to forward growth of the mandible rather than relapse of the position of the maxilla. The H-angle indicates a marked positive and lasting influence on the soft-tissue-profile (Fig. 7). Both clinically and cephalometrically there is considerable variation. Apart from the specific growth inhibition related to early surgery in cleft lip and palate, it is likely that inherited growth pattern and facial type are of great im-
portance, both for the outcome of the protraction and subsequently for clinical stability. Conclusions By treating early, at about 6 years of age, we obtain more basal response and several years of more correct function. The follow-up-study revealed that after active treatment the maxilla and mandible revert to the original growth pattern. In cases with moderate underdevelopment of the maxilla, the early period of protraction has been sufficient to keep the occlusion normalized. References
Delaire, J., P. Verdon, M.-C. K~n~si:Extraorale Zugkriifte mit StirnKinn-Abst~tzung zur Behandlung der Oberkieferdeformierungen als Folge von Lippen-Kiefer-Gaumenspalten.Fortschr. Kieferorthop. 34 (1973) 225-237 Rygh, P., R. Tindlund: Orthopaedic expansion and protraction of the maxilla in cleft palate patients - A new treatment rationale. Cleft Palate J. 19 (1982) 104-112 Tindlund, IL: Treatment of cleft lip and palate in Bergen - Teamwork. Nor. Tannlegefor Tid 97 (1987) 360-369 Dr. R. S. Tindlund, D.D.S. Dept. of Orthodontics and Facial Orthopaedics Arstadtveien 17 N-5009 Bergen Norway