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Palatal expansion using a bonded appliance
Palatal expansion appliance
using a bonded
Report of a case Raymond Chelseu,
P. Howe,
D.D.S., MS.*
Mich.
A case involving the design modifications palate free of acrylic. expansion appliance
use of an acrylic-lined bondable palatal expansion appliance is reported. The proposed allow the expansion appliance to be used in patients of any dental age whii keeping the Clinical trial of this appliance suggests that it is an acceptable alternative to conventional designs.
Key words: Palatal expansion, bonded appliance, midpalatal suture, deciduous dentition, maxillary expansion
P
alatal expansion has been accomplished with a variety of fixed expansion appliances, ranging from simple wire configurations, such as the quadhelix, to more complicated designs which include jackscrews, orthodontic bands, and acrylic elements. For example, the quad-helix expander is a single wire which is bent to incorporate four helical loops. It delivers a low force and may be especially effective at an early age.’ As mentioned, other commonly used fixed expansion appliances employ jackscrews and are attached to orthodontic bands. The tissue-borne fixed split acrylic expander contains a jackscrew which is positioned between two palatal blocks of acrylic.“-” These blocks are connected, in turn, to orthodontic bands. Activation of the jackscrew presumably applies a laterally directed force against both the teeth and the palatal mucosa, resulting in widening of the midpalatal suture.3 A second, acrylic-free, jackscrew expander, referred to as the hygienic design, employs heavy wire connectors between the bands and the jackscrew, thus eliminating the midpalatal acrylic. Still another jackscrew expander has been constructed entirely of acrylic except for the jackscrew itself. Development of this all-acrylic expander, which is bonded to the teeth,
This
study
was supported
in part by United
States Public
Health
Service
Grant DE-03610. The author has not filed a patent application for the appliance described in this article and has no affiliation with the manufacturer of this appliance. *Clinical Assistant Professor, Department of Orthodontics, University of Detroit, Detroit, Mich.; Research Investigator at the Center for Human Growth and Development, The University of Michigan, Ann Arbor, Mich; in the private practice of orthodontics in Dexter, Mich.
464
has eliminated the need for orthodontic bands.2 However, it does require that the palatal mucosa be covered with acrylic. Finally, a recent appliance design innovation allows bonding of the expansion appliance and yet clears the palate of acrylic. This appliance,* an acrylic-lined bondable palatal expander (Fig. 1), consists of a midpalatal jackscrew assembly which has four rigid 0.060 inch stainless steel shafts radiating outward from the palate. Each shaft terminates near the free gingival margin, where it connects with one of two 0.040 inch stainless steel wire loops. Each of these loops, one left and one right, has been bent circumferentially at the cervical level to include all the posterior teeth on its respective side (Fig. 2). A portion of this entire rigid wire framework has been encased in a thin collar of acrylic. The acrylic collar surrounds the 0.040 inch wire loops only and contacts the posterior teeth, extending from the free gingival margin to the occlusal surface of each tooth. The collar has been carefully trimmed at the cervical margin of the teeth to avoid gingival coverage, and an occlusal opening has been maintained on each tooth (Fig. 3). CASE REPORT
A 1Zyear-old Caucasian girl had a Class II, Division 1 malocclusion, which was characterizedby mandibular retrognathia, maxillary arch width constriction, and maxillary arch length insufficiency. Dental development had reachedthe late mixed-dentition stage (Fig. 4). *ClearSpan bondable palatal expansion appliance Appliance Works, 1415 West Argyle St., Jackson,
0002-9416/82/120464+05$CtII50/0
0
available from Mich. 49202.
1982 The C.V.
Specialty
Mosby
Co.
Volume 82 Number 6
Fig. 1. Acrylic-lined pliance.
Palatal
bondable
rapid palatal expansion
expansion
with
bonded
appliance
465
apFig. 3. Completed appliance on work model. several times each day. (2) No sugar was to be consumed during the entire time the appliance remained in the mouth. (3) A fluoride rinse was to be used daily. These instructions were intended to minimize the possibility of decalcification of the teeth during treatment. The patient was dismissed and seen at one-week intervals until sufficient expansion was obtained. Removal of the appliance was facilitated by the occlusal openings which were located at the occlusal surface of each tooth on either side of the bonded framework. These openings permitted the use of posterior band-removing pliers in the usual manner to remove the expander. RESULTS
Fig. 2. Rigid wire framework on work model prior to addition of acrylic collar. Following a thorough examination of the appropriate orthodontic records, rapid palatal expansion therapy was indicated. A maxillary alginate impression was taken, and an acrylic-lined bondable palatal expander was fabricated. On the appointed day the patient was given 50 mg. of Banthine, and the maxillary posterior teeth were cleaned and isolated (Fig. 5). The teeth were then etched for 60 seconds with a commercial etching solution, rinsed, and dried. A conventional orthodontic bonding adhesive was injected into each side of the appliance by means of a composite syringe (Fig. 6). The appliance was firmly pressed on the teeth and held in place for 5 minutes. Finally, the appliance was inspected and cleared of excessive bonding material (Fig. 7). Routine instructions were given regarding use of the expansion key to activate the appliance. Particular emphasis was placed on the following instructions: (1) The appliance was to be kept clean at all times; this would require brushing
Palatal expansion treatment was uneventful. The desired goal of midpalatal suture widening was achieved (Fig. 8) and, as expected, a transient dental midline diastema developed during treatment (Figs. 9 and 10). The patient was cooperative and tolerated the appliance well. No decalcification of the teeth was present upon removal of the bonded appliance. DISCUSSION I designed
this acrylic-lined
bondable
palatal
ex-
pander in an effort to provide routinely effective palatal expansion treatment for patients at any stage of dental development without the use of orthodontic bands and without covering the palate with acrylic. While other expansion appliances are effective, each has specific design elements which can affect clinical acceptability. For example, the tissue-borne fixed split acrylic appliance requires considerable care in construction, since it comprises several units. First, orthodontic bands are adapted to the patient’s teeth and an impression is taken. The bands are transferred to a working model and soldered to a wire framework. This framework is
Fig.
Fig. view
4. Pretreatment
5. Pretreatment intraoral photograph. just prior to appliance placement.
Maxillary
photographs
occlusal
of the patient,
a 12-year-old
Fig. 6. Injection of the appliance.
girl.
of the bonding
adhesive
into the acrylic
collars
Palatal expansion with bonded appliance
Vohme 82 Number 6
Fig.
7. Expander
Fig. 8. Occlusal during activation
bonded
in place
prior
x-ray view of the midpalatal of the appliance.
to activation.
suture
separation
embedded in blocks of palatal acrylic which connect, in turn, to the midpalatal jackscrew. Occasional failures in delivery may result from inaccurate band placement prior to the model-pouring and soldering steps. Potential difficulty in speech accommodation and the possibility of food entrapment between the acrylic and palatal mucosa are present. Also, painful ulceration of the palatal mucosa, which can occur during activation, requires removal of the appliance and interruption of the expansion treatment. An advantage of this appliance could be the possibility that it minimizes dent2 tipping during activation. The hygienic type, acrylic-free expansion appliance requires less construction effort than the tissue-borne fixed split acrylic appliance, since the palatal acrylic is omitted. Once again, however, accurate band placement in the impression, prior to the pouring and soldering steps, is critical in obtaining an acceptable clinical fit. The principal limitation of this design is that the appliance must be connected to orthodontic bands. Many patients have adequate numbers of erupted permanent teeth which are sufficiently parallel to allow
Fig.
9. Occlusal
photograph
Fig. 10. Transient midline palatal suture separation.
during
diastema
activation
which
resuits
467
stage.
from
mid-
insertion of this rigid appliance. Howev;7r, a significant number of patients have malposed teeth, making parallel insertion of the appliance difficult. Furthermore, fitting bands and keeping banded appliances cemented in the mouth can be a problem for patients whose dentitions are in either the deciduous or mixed-dentition stages. An advantage of the hygienic design is that the acrylic is omitted from the palate. Therefore, the likelihood of ulceration is minimized and hygiene is improved. The all-acrylic bonded expander is easily fabricated. Unlike the tissue-borne fixed split expander or the acrylic-free hygienic type of expander, it requires no orthodontic bands and is applied by conventional bonding techniques. Some difficulty can be experienced in removing the appliance after treatment and, like the tissue-borne fixed split acrylic expander, the all-acrylic appliance has the potential for palatal mucosa ulceration. Use of a bonded appliance which has an acrylic-free palate may overcome some of the limitations of the previously mentioned appliances. Unlike the tissue- ’
borne fixed split acrylic expander and the hygienic expander, this appliance does not rely on orthodontic bands. Therefore, it can be used in patients with deciduous dentitions and in patients with severely malposed teeth. Yet, unlike the tissue-borne fixed split acrylic appliance and the all-acrylic bonded appliance, both of which cover the palate, the current design eliminates the palatal acrylic. This may reduce the likelihood of food entrapment as well as mucosal ulceration. As with any fixed appliance, it is prudent to minimize the possbility of decalcification by careful hygiene and dietary instruction. I have not collected sufficient data to compare stability of the treatment result achieved with this type of expansion appliance with that achieved with other appliances. This may be a fruitful area of investigation.
The author would like to thank Dr. James A. McNamam. Jr.. for William
his review L. Rrudon.
of
this
manuscript.
Illustrations
are
bj
REFERENCES I. Bell, R. A.: A review of maxillary expansion in relation to rate of expansion and patient’s age, AM. J. ORTHOD. 81: 32, 1982. 2. Genecov, E. R.: Personal communication. 1982. 3. Greenbaum, K. R., and Zachrisson, B. U.: The effect of palatal expansion therapy on the periodontal supporting tissues, AM. J. ORTHOD.
81:
13, 1982.
4. Haas, A. J.: Rapid expansion of the maxillary dental arch and nasal cavity by opening of the midpalatal suture. Angle Orthod. 31: 73, 1961. 5. Haas, A. J.: Palatal expansion: Just the beginning of dentofacial orthopedics, AM. J. ORTHOD. 57: 219, 1970. 6. Haas. A. J.: Long-term posttreatment evaluation of rapid palatal expansion, Angle Orthod. 50: 189, 1980.
using a bonded
Report of a case Raymond Chelseu,
P. Howe,
D.D.S., MS.*
Mich.
A case involving the design modifications palate free of acrylic. expansion appliance
use of an acrylic-lined bondable palatal expansion appliance is reported. The proposed allow the expansion appliance to be used in patients of any dental age whii keeping the Clinical trial of this appliance suggests that it is an acceptable alternative to conventional designs.
Key words: Palatal expansion, bonded appliance, midpalatal suture, deciduous dentition, maxillary expansion
P
alatal expansion has been accomplished with a variety of fixed expansion appliances, ranging from simple wire configurations, such as the quadhelix, to more complicated designs which include jackscrews, orthodontic bands, and acrylic elements. For example, the quad-helix expander is a single wire which is bent to incorporate four helical loops. It delivers a low force and may be especially effective at an early age.’ As mentioned, other commonly used fixed expansion appliances employ jackscrews and are attached to orthodontic bands. The tissue-borne fixed split acrylic expander contains a jackscrew which is positioned between two palatal blocks of acrylic.“-” These blocks are connected, in turn, to orthodontic bands. Activation of the jackscrew presumably applies a laterally directed force against both the teeth and the palatal mucosa, resulting in widening of the midpalatal suture.3 A second, acrylic-free, jackscrew expander, referred to as the hygienic design, employs heavy wire connectors between the bands and the jackscrew, thus eliminating the midpalatal acrylic. Still another jackscrew expander has been constructed entirely of acrylic except for the jackscrew itself. Development of this all-acrylic expander, which is bonded to the teeth,
This
study
was supported
in part by United
States Public
Health
Service
Grant DE-03610. The author has not filed a patent application for the appliance described in this article and has no affiliation with the manufacturer of this appliance. *Clinical Assistant Professor, Department of Orthodontics, University of Detroit, Detroit, Mich.; Research Investigator at the Center for Human Growth and Development, The University of Michigan, Ann Arbor, Mich; in the private practice of orthodontics in Dexter, Mich.
464
has eliminated the need for orthodontic bands.2 However, it does require that the palatal mucosa be covered with acrylic. Finally, a recent appliance design innovation allows bonding of the expansion appliance and yet clears the palate of acrylic. This appliance,* an acrylic-lined bondable palatal expander (Fig. 1), consists of a midpalatal jackscrew assembly which has four rigid 0.060 inch stainless steel shafts radiating outward from the palate. Each shaft terminates near the free gingival margin, where it connects with one of two 0.040 inch stainless steel wire loops. Each of these loops, one left and one right, has been bent circumferentially at the cervical level to include all the posterior teeth on its respective side (Fig. 2). A portion of this entire rigid wire framework has been encased in a thin collar of acrylic. The acrylic collar surrounds the 0.040 inch wire loops only and contacts the posterior teeth, extending from the free gingival margin to the occlusal surface of each tooth. The collar has been carefully trimmed at the cervical margin of the teeth to avoid gingival coverage, and an occlusal opening has been maintained on each tooth (Fig. 3). CASE REPORT
A 1Zyear-old Caucasian girl had a Class II, Division 1 malocclusion, which was characterizedby mandibular retrognathia, maxillary arch width constriction, and maxillary arch length insufficiency. Dental development had reachedthe late mixed-dentition stage (Fig. 4). *ClearSpan bondable palatal expansion appliance Appliance Works, 1415 West Argyle St., Jackson,
0002-9416/82/120464+05$CtII50/0
0
available from Mich. 49202.
1982 The C.V.
Specialty
Mosby
Co.
Volume 82 Number 6
Fig. 1. Acrylic-lined pliance.
Palatal
bondable
rapid palatal expansion
expansion
with
bonded
appliance
465
apFig. 3. Completed appliance on work model. several times each day. (2) No sugar was to be consumed during the entire time the appliance remained in the mouth. (3) A fluoride rinse was to be used daily. These instructions were intended to minimize the possibility of decalcification of the teeth during treatment. The patient was dismissed and seen at one-week intervals until sufficient expansion was obtained. Removal of the appliance was facilitated by the occlusal openings which were located at the occlusal surface of each tooth on either side of the bonded framework. These openings permitted the use of posterior band-removing pliers in the usual manner to remove the expander. RESULTS
Fig. 2. Rigid wire framework on work model prior to addition of acrylic collar. Following a thorough examination of the appropriate orthodontic records, rapid palatal expansion therapy was indicated. A maxillary alginate impression was taken, and an acrylic-lined bondable palatal expander was fabricated. On the appointed day the patient was given 50 mg. of Banthine, and the maxillary posterior teeth were cleaned and isolated (Fig. 5). The teeth were then etched for 60 seconds with a commercial etching solution, rinsed, and dried. A conventional orthodontic bonding adhesive was injected into each side of the appliance by means of a composite syringe (Fig. 6). The appliance was firmly pressed on the teeth and held in place for 5 minutes. Finally, the appliance was inspected and cleared of excessive bonding material (Fig. 7). Routine instructions were given regarding use of the expansion key to activate the appliance. Particular emphasis was placed on the following instructions: (1) The appliance was to be kept clean at all times; this would require brushing
Palatal expansion treatment was uneventful. The desired goal of midpalatal suture widening was achieved (Fig. 8) and, as expected, a transient dental midline diastema developed during treatment (Figs. 9 and 10). The patient was cooperative and tolerated the appliance well. No decalcification of the teeth was present upon removal of the bonded appliance. DISCUSSION I designed
this acrylic-lined
bondable
palatal
ex-
pander in an effort to provide routinely effective palatal expansion treatment for patients at any stage of dental development without the use of orthodontic bands and without covering the palate with acrylic. While other expansion appliances are effective, each has specific design elements which can affect clinical acceptability. For example, the tissue-borne fixed split acrylic appliance requires considerable care in construction, since it comprises several units. First, orthodontic bands are adapted to the patient’s teeth and an impression is taken. The bands are transferred to a working model and soldered to a wire framework. This framework is
Fig.
Fig. view
4. Pretreatment
5. Pretreatment intraoral photograph. just prior to appliance placement.
Maxillary
photographs
occlusal
of the patient,
a 12-year-old
Fig. 6. Injection of the appliance.
girl.
of the bonding
adhesive
into the acrylic
collars
Palatal expansion with bonded appliance
Vohme 82 Number 6
Fig.
7. Expander
Fig. 8. Occlusal during activation
bonded
in place
prior
x-ray view of the midpalatal of the appliance.
to activation.
suture
separation
embedded in blocks of palatal acrylic which connect, in turn, to the midpalatal jackscrew. Occasional failures in delivery may result from inaccurate band placement prior to the model-pouring and soldering steps. Potential difficulty in speech accommodation and the possibility of food entrapment between the acrylic and palatal mucosa are present. Also, painful ulceration of the palatal mucosa, which can occur during activation, requires removal of the appliance and interruption of the expansion treatment. An advantage of this appliance could be the possibility that it minimizes dent2 tipping during activation. The hygienic type, acrylic-free expansion appliance requires less construction effort than the tissue-borne fixed split acrylic appliance, since the palatal acrylic is omitted. Once again, however, accurate band placement in the impression, prior to the pouring and soldering steps, is critical in obtaining an acceptable clinical fit. The principal limitation of this design is that the appliance must be connected to orthodontic bands. Many patients have adequate numbers of erupted permanent teeth which are sufficiently parallel to allow
Fig.
9. Occlusal
photograph
Fig. 10. Transient midline palatal suture separation.
during
diastema
activation
which
resuits
467
stage.
from
mid-
insertion of this rigid appliance. Howev;7r, a significant number of patients have malposed teeth, making parallel insertion of the appliance difficult. Furthermore, fitting bands and keeping banded appliances cemented in the mouth can be a problem for patients whose dentitions are in either the deciduous or mixed-dentition stages. An advantage of the hygienic design is that the acrylic is omitted from the palate. Therefore, the likelihood of ulceration is minimized and hygiene is improved. The all-acrylic bonded expander is easily fabricated. Unlike the tissue-borne fixed split expander or the acrylic-free hygienic type of expander, it requires no orthodontic bands and is applied by conventional bonding techniques. Some difficulty can be experienced in removing the appliance after treatment and, like the tissue-borne fixed split acrylic expander, the all-acrylic appliance has the potential for palatal mucosa ulceration. Use of a bonded appliance which has an acrylic-free palate may overcome some of the limitations of the previously mentioned appliances. Unlike the tissue- ’
borne fixed split acrylic expander and the hygienic expander, this appliance does not rely on orthodontic bands. Therefore, it can be used in patients with deciduous dentitions and in patients with severely malposed teeth. Yet, unlike the tissue-borne fixed split acrylic appliance and the all-acrylic bonded appliance, both of which cover the palate, the current design eliminates the palatal acrylic. This may reduce the likelihood of food entrapment as well as mucosal ulceration. As with any fixed appliance, it is prudent to minimize the possbility of decalcification by careful hygiene and dietary instruction. I have not collected sufficient data to compare stability of the treatment result achieved with this type of expansion appliance with that achieved with other appliances. This may be a fruitful area of investigation.
The author would like to thank Dr. James A. McNamam. Jr.. for William
his review L. Rrudon.
of
this
manuscript.
Illustrations
are
bj
REFERENCES I. Bell, R. A.: A review of maxillary expansion in relation to rate of expansion and patient’s age, AM. J. ORTHOD. 81: 32, 1982. 2. Genecov, E. R.: Personal communication. 1982. 3. Greenbaum, K. R., and Zachrisson, B. U.: The effect of palatal expansion therapy on the periodontal supporting tissues, AM. J. ORTHOD.
81:
13, 1982.
4. Haas, A. J.: Rapid expansion of the maxillary dental arch and nasal cavity by opening of the midpalatal suture. Angle Orthod. 31: 73, 1961. 5. Haas, A. J.: Palatal expansion: Just the beginning of dentofacial orthopedics, AM. J. ORTHOD. 57: 219, 1970. 6. Haas. A. J.: Long-term posttreatment evaluation of rapid palatal expansion, Angle Orthod. 50: 189, 1980.