Meta-analysis of immediate changes with rapid maxillary expansion treatment

Meta-analysis of immediate changes with rapid maxillary expansion treatment

C L I N I C A L P R A C T I C E Meta-analysis of immediate changes with rapid maxillary expansion treatment Manuel O. Lagravère, DDS, MSc; Giseon He...

109KB Sizes 0 Downloads 99 Views

C L I N I C A L

P R A C T I C E

Meta-analysis of immediate changes with rapid maxillary expansion treatment Manuel O. Lagravère, DDS, MSc; Giseon Heo, PhD; Paul W. Major, DDS, MS, FRCD(C); Carlos Flores-Mir, DDS, MSc, Cert Orth, PhD

axillary expansion treatments have been used for more than 140 years1 and have been used widely since the mid-1960s.2,3 Various expansion protocols have been applied (slow maxillary expansion, semirapid maxillary expansion, rapid maxillary expansion [RME] and surgically assisted maxillary expansion). All of these treatment modalities have advantages and disadvantages, and their selection depends on the clinician’s choice. RME gained preference from clinicians and researchers; therefore, a large range of studies on this topic has been found.4 These studies vary concerning their sample size, the appliance used and the results obtained.4-6 Schiffman and Tuncay7 published a meta-analysis that summarized all of the maxillary expansion literature available from 1978 to 1999 included in the MEDLINE electronic database. They tried to determine the appropriateness and stability of maxillary expansion. They concluded that, owing to a lack of uniformity between studies and the use of improper study design and

M

44

JADA, Vol. 137

http://jada.ada.org

ABSTRACT Background. The authors conducted a literature review to evaluate immediate transverse, anteroposterior, and vertical dental and skeletal changes produced by rapid maxillary expansion (RME). Types of Studies Reviewed. The authors reviewed clinical trials that assessed immediate dental and/or skeletal changes after RME using cephalometric analysis, model casts or both. No surgical or other simultaneous treatment was accepted during the evaluation period. Results. The authors searched electronic databases and found 31 articles that met the initial inclusion criteria. The authors later rejected 12 of these articles because they did not report immediate changes, three because they lacked detailed descriptions of their results and two because of their nonconventional appliance designs. Fourteen articles satisfied the final inclusion criteria; however, they had methodological deficiencies. Clinical Implications. The greatest changes resulting from RME in the studies analyzed were dental and skeletal transverse changes. Few vertical and anteroposterior immediate changes were statistically significant, though they probably are not clinically important. Key Words. Rapid maxillary expansion; rapid palatal expansion; systematic review; meta-analysis; skeletal changes; dental changes. JADA 2006;137:44-53. Dr. Lagravère is a doctoral resident, Orthodontic Graduate Program, Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada. Dr. Heo is an assistant professor of statistics, Orthodontic Graduate Program, Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada. Dr. Major is a professor and the director, Orthodontic Graduate Program, Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada. Dr. Flores-Mir is a clinical associate professor, Orthodontic Graduate Program, Department of Dentistry, Faculty of Medicine and Dentistry, Room 4051A, Dentistry/Pharmacy Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2N8, e-mail “[email protected]”. Address reprint requests to Dr. Flores-Mir.

January 2006

Copyright ©2006 American Dental Association. All rights reserved.

C L I N I C A L

P R A C T I C E

results reporting, they could not draw clear conclusions regarding the effects of maxillary expansion procedures on dental and skeletal structures.7 Possible limitations of this metaanalysis were the exclusion of non-English reported studies and a lack of differentiation of the results between maxillary expansion techniques and appliances. Two systematic reviews5,6 showed that a significant amount of literature could be missed if researchers use only MEDLINE to evaluate RME. Several other studies3,8-10 evaluating RME have been published since 1999. We conducted a systematic review and a metaanalysis of the results to evaluate the immediate transverse, anteroposterior, and vertical dental and skeletal changes produced by RME.

We determined if studies should be included in our meta-analysis by reading the abstracts of the articles identified by the electronic databases. We made the selections independently using the inclusion criteria and then comparing the results (interexaminer κ = 0.900). In cases of discrepancies, we made a consensus decision. We gathered articles from the abstracts from each database that apparently fulfilled the inclusion criteria based on the abstract information. Before making a final inclusion decision, we obtained articles for which the abstract did not provide sufficient information to make a decision regarding the selection. We also searched the reference lists of the selected articles for additional relevant publications that may have been missed in the database searches. MATERIALS AND METHODS We gathered and evaluated all of We selected the terms or “key the selected complete articles to The authors words” we used in the literature determine if we wanted to include determined if studies search with the assistance of a them in the final selection. We used senior librarian who specialized in the selection criteria again to make should be included in health sciences databases. The their meta-analysis by this final decision. In cases of disterms are provided in Table 1. We crepancies, we made a consensus reading the abstracts conducted computerized searches decision (interexaminer κ = 0.995). of the articles using the following databases: In cases in which relevant data identified by the MEDLINE (from 1966 to week four were missing from the article, we electronic databases. of December 2004), MEDLINE Inmade an effort to contact the Process & Other Non-Indexed Citaauthors to obtain the required extra tions (Jan. 14, 2005), LILACS—a information. We evaluated the artiliterature database of Latin and Caribbean health cles that satisfied the inclusion criteria following research—(from 1982 to January 2005), PubMed the methodological criteria listed in the Box. We (from 1966 to week four of December 2004), have used these criteria previously.6 EMBASE Excerpta Medica (from 1988 to week We conducted the meta-analysis on the three of 2005), Thomsen’s ISI Web of Science selected studies following a two-step procedure. (from 1975 to week four of December 2004) and The first step consisted of testing the hypothesis all databases in All Evidence Based Medicine that the true treatment effects were the same in Reviews (Cochrane Database of Systematic all the studies selected. There were two possible Reviews, American College of Physicians Journal sources of variation in estimating the effect size Club, Database of Abstracts of Reviews of Effects from different studies: between-study and and Cochrane Central Register of Controlled within-study variance. If the difference between Trials) (to the fourth quarter of 2004). studies was only due to random variation, the We determined the following inclusion criteria effect estimates were considered to be homogein advance and applied them to all of the abstracts neous. The variation also could arise owing to that resulted from the database searches: systematic differences between studies. If this dhuman clinical trials; was so, we considered the effect estimates to be ddental and skeletal measurements made from heterogeneous.11 cephalometric radiographs, dental casts or both; In the second step, we made calculations using dno history of surgical or other treatment that two ways of combining several study estimates. would affect the RME effects during the expanFor homogeneous studies, we applied the fixedsion period; effect model to obtain statistical inferences. Each study estimate was weighed as inversely propordimmediate changes after RME active expantional to its variance. For heterogeneous studies, sion phase reported. JADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

January 2006

45

C L I N I C A L

P R A C T I C E

TABLE 1

Search results from databases. DATABASE

KEY WORDS

NO. OF ABSTRACTS FOUND

NO. OF ABSTRACTS SELECTED

% OF TOTAL SELECTED ABSTRACTS (31)

NO. OF ABSTRACTS NOT INCLUDED IN PUBMED

MEDLINE

Rapid maxil$* expan$.mp†, rapid palat$ expan$.mp, 1 OR 2, limit to human

269

21

67.7

2

PubMed

Rapid maxillary expansion, rapid palatal expansion, #1 OR #2, limit to human

311

23

74.2

NA‡

MEDLINE In-Process & Other Non-Indexed Citations

Rapid maxil$ expan$.mp, rapid palat$ expan$.mp, 1 OR 2

9

0

0

0

EMBASE Excerpta Medica

Rapid maxil$ expan$.mp, rapid palat$ expan$.mp, 1 OR 2, limit to human

37

0

0

0

All Evidence Based Medicine Reviews (Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, Database of Abstracts of Reviews of Effects and Cochrane Central Register of Controlled Trials

Rapid maxil$ expan$.mp, rapid palat$ expan$.mp, 1 OR 2

24

7

22.6

0

Thomsen’s ISI Web of Science

TS‡ = rapid palatal expansion OR TS = rapid maxillary expansion

223

15

48.4

2

LILACS

Rapid maxillary expansion, rapid palatal expansion, #1 OR #2

35

6

19.4

6

Reference Lists

NA§

NA

0

0

0

* † ‡ §

$: The word was truncated during the search. .mp: The word search included title, original title, abstract, name of substance word and subject heading word. TS: Terms that were searched. NA: Not applicable.

we applied the random-effects model to obtain the statistical inferences. The random-effects model takes care of the two sources of variations, between and within study variance, to weigh each study estimate.12 RESULTS

We initially selected 31 abstracts from the electronic databases. PubMed had the greatest diversity of the abstracts we selected (23, 74.2 percent) among the database search engines we used. A majority (21, 67.7 percent) of these abstracts also appeared in other database results. Only eight (25.8 percent) of the selected abstracts were not included in PubMed. We identified two additional 46

JADA, Vol. 137

http://jada.ada.org

abstracts (6.5 percent) using MEDLINE, two (6.5 percent) using Thomsen’s ISI Web of Science and six (19.4 percent) using LILACS. The search results and the final number of abstracts selected according to the inclusion criteria from the various databases are provided in Table 1. Of the 31 abstracts, we rejected 12 because they failed to report immediate changes after the activation phase of RME and instead reported changes only after the retention phase.3,8,9,13-21 Another one reported changes in an overall manner with no specific details,22 and two others gave neither time specification nor had a clear treatment protocol.23,24 We attempted to contact the authors of these studies by elec-

January 2006

Copyright ©2006 American Dental Association. All rights reserved.

C L I N I C A L

tronic mail, but we received no response throughout the preparation of this article, so we rejected them. We rejected two additional studies25,26 because they included all anterior teeth in the acrylic coverage of the expansion appliance. The figure shows an overview of the process for selecting the final articles. Of the 14 studies that reported immediate changes, eight measured dental and skeletal changes through radiographs,27-34 three measured dental and skeletal changes through radiographs and dental casts,35-37 and three measured only dental changes through dental casts.10,38,39 A description of the selected studies is summarized in Table 2. We pooled measurement landmarks that were reported in two or more studies into a metaanalysis. The pooled estimates and their respective confidence intervals are shown in Table 3 (page 49). Transverse dental changes. When we measured maxillary intermolar width via posterior anterior (PA) cephalometric radiographs and models, we found an increase of 6.04 and 6.74 millimeters, respectively. The maxillary intermolar mesioapex root width increased 4.44 mm. The maxillary intermolar angulation increased approximately 3.10 degrees, though this increase was not statistically significant in the model casts. Maxillary intercanine width increased 5.35 mm when measured from the crown apex. When viewing transverse changes on the incisors, PA cephalometric radiographs showed a 3.9 mm increase in the maxillary interincisal apex width and a 2.98 mm increase in the midline diastema. The average mandibular intermolar width increase measured on models and PA cephalometric radiographs was small (0.49 mm each) and was not statistically significant. Vertical and anteroposterior dental changes. When analyzing dental changes in the lateral plane, we found that the maxillary molar cusp was extruded 0.53 mm using the palatal plane as a reference (P < .05). An increase of 1.29 mm in overjet was observed. Change in angulation of the maxillary incisor to sella nasion (SN) plane (0.86 degrees) was significant (P < .05), while change in the mandibular incisor (2.31 degrees) was not significant (P > .05). Transverse skeletal changes. With respect to transverse skeletal changes, the only statistically significant changes were nasal cavity width (intercondyle width) and left jugale-right jugale

P R A C T I C E

BOX

Methodological criteria. STUDY DESIGN (8 √*) A. Objective: objective clearly formulated (√) B. Population: described (√) C. Inclusion criteria: clearly described (√); adequate (√) D. Sample size: considered adequate (√); estimated before collection of data (√) E. Baseline characteristics: similar baseline characteristics (√) F. Timing: prospective (√) STUDY MEASUREMENTS (5 √) G. Measurement method: appropriate to the objective (√) H. Blind measurement: blinding (examiner √, statistician √) I. Reliability: described (√), adequate level of agreement (√) STATISTICAL ANALYSIS (6 √) J. Dropouts: dropouts included in data analysis (√) K. Statistical analysis: appropriate for data (√); combined subgroup analysis (√) L. Confounders: confounders included in analysis (√) M.Statistical significance level: P value stated (√); confidence intervals (√) MAXIMUM NUMBER OF √ = 19 * √: The criterion received a check mark if it was met.

Electronic search 337 articles

Selection criteria applied to 337 articles

Excluded 306 articles

Selection criteria applied to 31 articles Manual search 0 articles

Excluded 12 articles

Potentially appropriate to be included 19 articles

Potentially appropriate to be included 0 articles

19 articles

Excluded 3 articles (method report flaws)

16 articles

Excluded 2 articles (different appliance design)

14 articles finally selected

Figure. Flow diagram of the literature search and selection process.

JADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

January 2006

47

C L I N I C A L

P R A C T I C E

TABLE 2

Description of studies included in the final selection process. AUTHORS (YEAR)

AGE (YEARS)

SIZE

MALES

FEMALES

APPLIANCE

Akkaya and Colleagues 27 (1999)

10.413.5 (12)

12

7

5

Hyrax (with acrylic bite plates)

0.5 mm daily; overcorrection

Lateral cephalometric radiographs

Asanza and Colleagues 28 (1997)

8.5-16

14

7

7

Hyrax

0.5 mm daily; overcorrection

Posterior anterior (PA) and lateral cephalometric radiographs

5-10.1 (8)

30





Haas

0.25 mm daily, 1-2 weeks, overcorrection 2-3 mm

Lateral cephalometric radiographs

da Silva Filho and Colleagues 30 (1995)

5-11 (8)

32





Haas

0.25 mm daily, 1-2 weeks; overcorrection 2-3 mm

PA cephalometric radiographs

Almeida and Colleagues 31 (1999)

11.4-17.1 (14.1)

15

6

9

Haas

1 mm daily; 5-12 days; 2-3 mm overexpansion

Lateral cephalometric radiographs

Kawakami and Colleagues 32 (1999)

10.1-17.8 (13.5)

20

8

12

Haas

Lateral cephalometric radiographs

10.8-14.1 (12.1)

21

7

14

Hyrax

0.5 mm initial; 1 mm daily; 8-9 days; overcorrection

Faltin and Colleagues 33 (1999)

7.6-15.1

8





Haas

1 mm initial; 0.5 mm daily; overcorrection

Lateral cephalometric radiographs

Mazzieiro and Colleagues 34 (1996)

10-16.2

20





Hyrax acrylic splint expander

1 mm daily; overcorrection

PA cephalometric radiographs

10-16.2

21





Hyrax

9.2 ± 1.3

34

15

19

Hyrax acrylic splint expander

0.5 mm daily first week 0.25 mm thereafter; overcorrection

PA and lateral cephalometric radiographs, dental casts

12.7 ± 1.2

17

10

7

Hyrax acrylic splint expander

Sandikcioglu and Hazar 36 (1997)

8.9

10





Hyrax

0.5 mm daily; around 19.2 days; overcorrection

PA and lateral cephalometric radiographs, dental casts

Bhatt and Jacob 37 (1978)

11-24

7





Hyrax

1 mm initial; 0.5 mm daily; 11-13.5 mm total

Lateral cephalometric radiographs, dental casts

7.8-13.9 (11.3)

15

9

6

Hyrax

0.5 mm initial; 0.5 mm daily; overcorrection

Dental casts

6.6-14.6 (10.8)

15

6

9

Hyrax

Akkaya and Colleagues 38 (1998)

10.4-13.5 (12)

12

7

5

Hyrax (with acrylic bite plates)

0.5 mm daily; overcorrection

Dental casts

Cozzani and Colleagues 39 (2003)

8.1

19

6

13

Haas

Dental casts

8.3

13

3

10

Haas

0.2-0.4 mm daily; around 15 days; 4-8 mm total

da Silva Filho and Colleagues 29 (1991)

Sari and Colleagues 35 (2003)

Lamparski and Colleagues 10 (2003)

48

JADA, Vol. 137

http://jada.ada.org

ACTIVATION

January 2006

Copyright ©2006 American Dental Association. All rights reserved.

EVALUATION

C L I N I C A L

P R A C T I C E

TABLE 3

Pooled estimate of immediate changes and 95 percent confidence intervals. MEASUREMENT

POOLED ESTIMATE OF IMMEDIATE CHANGES DURING ACTIVATION OF THE APPLIANCE

95 PERCENT CONFIDENCE INTERVAL

Maxillary Intermolar Width (Midpoint-Midpoint)

6.74 millimeters*

4.59 to 8.89

Maxillary Intercanine Width (Canine-Canine)

5.35 mm*

4.31 to 6.39

Maxillary Intermolar Angle

3.10 degrees

−2.08 to 8.27

Mandibular Intermolar Width (Midpoint-Midpoint)

0.49 mm*

0.16 to 0.82

Maxillary Interincisal Apex Width

3.90 mm*

3.3 to 4.49

Maxillary Molar (Intermolar Width Buccal-Buccal)

6.04 mm*

5.63 to 6.45

Maxillary Intermolar Mesioapex Width

4.44 mm*

3.83 to 5.06

0.53 mm

−0.07 to 1.14

2.98 mm*

2.77 to 3.2

0.53 mm

0.24 to 0.82

−0.86 degrees*

−1.02 to –0.7

1.29 mm*

1.02 to 1.56

2.31 degrees

−0.62 to 5.25

1.88 mm*

0.32 to 3.44

1.06 mm

−0.11 to 2.23

Nasal Cavity Point (Nasal Width)

2.14 mm*

1.56 to 2.72

Left Jugale-Right Jugale (Interalveolar Width)

2.73 mm*

1.84 to 3.62

MP §-SN Plane (MP-Cranial Base)

1.97 degrees*

1.75 to 2.19

MP-PP (MP-PP)

1.65 degrees*

1.4 to 1.9

0.30 degrees

−0.19 to 0.79

0.87 degrees*

0.48 to 1.25

−0.62 degrees*

−0.76 to −0.49

1.17 degrees*

0.63 to 1.7

0.79 degrees

−0.16 to 1.74

Mandibular Intermolar Width (Buccal-Buccal) Midline Diastema Maxillary Molar Cusp to

PP †

Maxillary Incisor-SN‡ Plane (Maxillary Incisor-Cranial Base) Overjet Interincisal Angle

Maxillary Point (Intermaxillary Width) Antegonion Point (Antegonial Width)

PP-SN Plane (PP-Cranial Base) Maxillary Prominence Mandibular Prominence Maxillary/Mandibular Prominence SN–Anterior Nasal Spine Point (Cranial BaseAnterior Nasal Spine) * † ‡ §

AUXILIARY EVALUATION

CHANGES

Models

Dental transverse

Posterior anterior (PA) cephalometric radiographs

Lateral cephalometric radiographs

Dental vertical

Lateral cephalometric radiographs

Dental anteroposterior

PA cephalometric radiographs

Skeletal transverse

Lateral cephalometric radiographs

Skeletal vertical

Lateral cephalometric radiographs

Skeletal anteroposterior

P < .05. PP: Palatal plane. SN: Sella naison. MP: Mandibular plane.

JADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

January 2006

49

C L I N I C A L

P R A C T I C E

TABLE 4

Methodological assessment of final selected studies.* AUTHORS

A

B

C

D

E

F

G

H

I

J

K

L

M

NO. OF CHECK MARKS

% OF TOTAL (N = 19)

Almeida and Colleagues 31

à



√√





−‡













≠§

8.5

44.7

Faltin and Colleagues 33



























6.5

34.2

Cozzani and Colleagues 39



























7

36.8

Sari and Colleagues 35

















≠≠









8

42.1

Kawakami and Colleagues 32



























7.5

39.5

Lamparski and Colleagues 10

















≠√



√√





9.5

50.0

Akkaya and Colleagues 27





















√√





8

42.1

Mazzieiro and Colleagues 34



























7

36.8

Da Silva and Colleagues 29





















√√





7.5

39.5

Da Silva and Colleagues 30





















√√





7.5

39.5

Akkaya and Colleagues 38





















√√





8

42.1

Sandikcioglu and Hazar 36





















√√





7.5

39.5

Bhatt and Jacob 37



























7

36.8

Asanza and Colleagues 28



























7.5

39.5

* † ‡ §

A-M: Methodological criteria are defined in the Box. √: Satisfactorily fulfilled the methodological criteria (1.0 check marks assigned). −: Did not fulfill the methodological criteria (0.0 check marks assigned). ≠: Partially fulfilled the methodological criteria (0.5 check marks assigned).

(interalveolar width) landmarks of 2.14 mm and 2.73 mm, respectively. Vertical and anteroposterior skeletal changes. Concerning skeletal lateral changes, the only statistically significant changes observed were changes in the mandibular plane (with respect to the palatal plane and SN plane) being 1.65 and 1.97 degrees, respectively. The angulation of the palatal plane with respect to the SN plane was not significant (0.30 degrees; P > .05). Methodological quality of the final selected studies. When applying the methodological criteria evaluation on the selected studies, none of the studies had a number of check marks that were more than 50 percent of the total. All of the studies had methodological 50

JADA, Vol. 137

http://jada.ada.org

problems regarding sample selection, description and statistical approach (Table 4). DISCUSSION

A previous meta-analysis7 that evaluated the stability of maxillary expansion found some limitations (languages of publications considered and combination of different expansion appliance results). Our meta-analysis focused on the evaluation of immediate transverse, anteroposterior, and vertical dental and skeletal changes produced by RME. The inclusion criteria we used in our metaanalysis focused mainly on the report of immediate changes after the active phase in RME (before screw fixation for the retention period).

January 2006

Copyright ©2006 American Dental Association. All rights reserved.

C L I N I C A L

P R A C T I C E

Since this activation phase varied from two to RME treatments.5 In our study, though changes four weeks on average, the need for a control was in the anteroposterior angulation of the maxillary not considered necessary since growth is not an and mandibular incisors were not significantly influential factor during this short time changed, we found an increase of 1.29 mm in the lapse.20,23,24,26-40 We could not analyze the direction overjet. This could have been caused by the minor and magnitude trends of the excluded studies anteroposterior change with respect to the angle because of the reasons for their rejection: failing between points A and B in which point A moved to report immediate changes,3,8,9,13-21 overall forward 0.87 degrees, while point B retruded changes,22-24 and inclusion of anterior teeth in the 0.62 degrees. expansion appliance.25,26 Skeletal transverse changes with RME have The greatest dental and skeletal changes remained controversial. One study39 reported that occurred at the dentition, especially in the there were no significant changes while another9 transverse dental dimension. This confirms reported the existence of significant changes. Our results from various studies,3,9,26,41-43 including analysis supports both findings, depending on the some3,9,26 we did not include in our final selection, landmarks considered. We identified significant which used tooth-anchored appliskeletal increases for intercondyle ances for maxillary expansion. (valid only for the mandible) width The greatest dental Exerting the expansion force on the and maxillary interalveolar width and skeletal changes teeth produced some undesirable measured from the buccal plates. effects such as dental tipping28,44 and However, these increases were occurred at the root resorption.38,45 An average of around 2 to 3 mm, clearly showing dentition, especially 6.7 mm of expansion was obtained, that a great portion of the true in the transverse measured from the molar crowns, expansion was dental rather than dental dimension. while a 4.5 mm expansion increase skeletal. was observed on the molar root We found nonsignificant anteroapex. This corroborates the concept posterior skeletal changes that conthat using an RME tooth–anchored appliance will firmed results reported by other studies.8,49,50 Con28 produce tipping of the tooth (an average of cerning vertical skeletal changes after RME 3 degrees) instead of true skeletal expansion, treatments, one study reported that there were no though this tipping is not considered clinically statistically significant changes,49 while others significant. affirmed that there were significant vertical We rejected two studies25,26 because their applichanges.8,50 In our study, we identified some staance designs were based on posterior and anterior tistically significant skeletal vertical changes. tooth anchorage, which significantly differed from Although there was an increase in angulation the other appliance designs that used posterior between the mandibular, SN and palatal planes, teeth anchorage only. This exclusion decision was this increase ranged between 1 to 2 degrees, supported by our findings. When comparing the which is not clinically significant. expansion increase on molars, canines and midSome studies have reported an indirect expanline diastema, we found that the greatest expansion occurring on the mandible after an RME sion was at the molars with progressively reduced treatment.9,51 The results of our meta-analysis did expansion in the anterior part of the arch. This not identify any statistically significant can be explained by the fact that the appliances mandibular expansion with the exception of the used for RME exert their force directly on the posintercondyle width. Future studies are needed terior teeth46 used for anchorage. This also supconcerning this parameter since this could be a ports the theory that a significant portion of temporary change that could relapse after a expansion is dental instead of solely skeletal. period. Some authors have suggested that application Previous systematic reviews5,6 regarding longof RME will cause an opening of the bite due to term changes after RME reported no clinically the molar extrusion.47,48 According to the results significant vertical and anteroposterior changes. obtained in our study, the molar has only 0.5 mm Transverse changes were significant when they extrusion, which is not clinically significant. were compared with the control groups, though A previous study reported that no significant these changes were more dental than skeletal in long-term anteroposterior changes occurred after nature. This relates to our meta-analysis in which JADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

January 2006

51

C L I N I C A L

P R A C T I C E

the most significant changes we found were on the transversal plane and they were more dental than skeletal in nature. All of the studies had methodological deficiencies. Lack of intra- and interexaminer agreement reporting was common; only one study35 clearly reported these values. The report of confounders and dropouts in the sample analysis, as well as descriptions of the inclusion criteria, was absent in the majority of studies (Table 4). Therefore, the scientific evidence we found in this meta-analysis should be interpreted carefully. Clinicians will have to consider their experience, the opinion of experts and the limited evidence on RME to decide whether to use this treatment on patients. To have a comprehensive picture of RME changes, the information provided in this systematic review with a meta-analysis should be considered simultaneously with two published systematic reviews5,6 about long-term dental and skeletal changes after RME. CONCLUSIONS

The greatest changes were in the maxillary transverse plane in which the width gained was caused more by dental expansion than true skeletal expansion. Few vertical and anteroposterior changes were statistically significant, and none was clinically significant. ■ The authors offer special thanks to Linda Seale for her assistance in the database search. 1. Angell EH. Treatment of irregularity of the permanent or adult teeth. Dent Cosmos 1860;1:99-600. 2. Haas AJ. The treatment of maxillary deficiency by opening the midpalatal suture. Angle Orthod 1965;35:200-17. 3. Cross DL, McDonald JP. Effect of rapid maxillary expansion on skeletal, dental, and nasal structures: a postero-anterior cephalometric study. Eur J Orthod 2000;22:519-28. 4. Petren S, Bondemark L, Soderfeldt B. A systematic review concerning early orthodontic treatment of unilateral posterior crossbite. Angle Orthod 2003;73:588-96. 5. Lagravère MO, Major PW, Flores-Mir C. Long-term dental arch changes after rapid maxillary expansion treatment: a systematic review. Angle Orthod 2005;75:155-61. 6. Lagravère MO, Major PW, Flores-Mir C. Skeletal changes with rapid maxillary expansion treatments: a systematic review. Angle Orthod 2005;75:1046-52. 7. Schiffman PH, Tuncay OC. Maxillary expansion: a meta analysis. Clin Orthod Res 2001;4:86-96. 8. Cozza P, Giancotti A, Petrosino A. Rapid palatal expansion in mixed dentition using a modified expander: a cephalometric investigation. J Orthod 2001;28:129-34. 9. Baccetti T, Franchi L, Cameron CG, McNamara JA Jr. Treatment timing for rapid maxillary expansion. Angle Orthod 2001;71:343-50. 10. Lamparski DG Jr, Rinchuse DJ, Close JM, Sciote JJ. Comparison of skeletal and dental changes between 2-point and 4-point rapid palatal expanders. Am J Orthod Dentofacial Orthop 2003;123:321-8. 11. Sutton AJ, Abrams KR, Jones DR, Sheldon TA, Song F. Methods for meta-analysis in medical research. Chichester, Sussex, England: Wiley; 2000. 12. Sutton AJ, Duval SJ, Tweedie RL, Abrams KR, Jones DR. Empirical assessment of effect of publication bias on meta-analyses. BMJ 2000;320:1574-7.

52

JADA, Vol. 137

http://jada.ada.org

13. Erverdi N, Sabri A, Kucukkeles N. Cephalometric evaluation of Haas and Hyrax rapid maxillary appliances in the treatment of the skeletal maxillary transverse deficiency. J Marmara Univ Dent Fac 1993;1:361-6. 14. Ursi WJ, Dale RCXS, Claro CA, Chagas RV, Almeida G. Transversal changes produced by the bonded rapid maxillary expander, evaluated by postero-anterior cephalographs [in Portuguese]. Ortodontia 2001;34(3):43-55. 15. Gryson JA. Changes in mandibular interdental distance concurrent with rapid maxillary expansion. Angle Orthod 1977;47(3):186-92. 16. Linder-Aronson S, Lindgren J. The skeletal and dental effects of rapid maxillary expansion. Br J Orthod 1979;6(1):25-9. 17. Schneidman E, Wilson S, Erkis R. Two-point rapid palatal expansion: an alternate approach to traditional treatment. Pediatr Dent 1990;12(2):92-7. 18. Memikoglu TU, Iseri H. Effects of a bonded rapid maxillary expansion appliance during orthodontic treatment. Angle Orthod 1999;69:251-6. 19. Ciambotti C, Ngan P, Durkee M, Kohli K, Kim H. A comparison of dental and dentoalveolar changes between rapid palatal expansion and nickel-titanium palatal expansion appliances. Am J Orthod Dentofacial Orthop 2001;119(1):11-20. 20. Basciftci FA, Mutlu N, Karaman AI, Malkoc S, Kucukkolbasi H. Does the timing and method of rapid maxillary expansion have an effect on the changes in nasal dimensions? Angle Orthod 2002;72(2):118-23. 21. Sarver DM, Johnston MW. Skeletal changes in vertical and anterior displacement of the maxilla with bonded rapid palatal expansion appliances. Am J Orthod Dentofacial Orthop 1989;95:462-6. 22. Gray LP. Results of 310 cases of rapid maxillary expansion selected for medical reasons. J Laryngol Otol 1975;89:601-14. 23. Timms DJ. A study of basal movement with rapid maxillary expansion. Am J Orthod 1980;77:500-7. 24. Siqueira DF, Almeida RR, Henriques JFC. Frontal cephalometric comparative study of dentoskeletal effects induced by three rapid maxillary expansion appliances [in Portuguese]. Rev Dent Press Ortodon Ortopedi Facial 2002;7(6):27-47. 25. Basciftci FA, Karaman AI. Effects of a modified acrylic bonded rapid maxillary expansion appliance and vertical chin cap on dentofacial structures. Angle Orthod 2002;72(1):61-71. 26. Doruk C, Bicakci AA, Basciftci FA, Agar U, Babacan H. A comparison of the effects of rapid maxillary expansion and fan-type rapid maxillary expansion on dentofacial structures. Angle Orthod 2004;74(2):184-94. 27. Akkaya S, Lorenzon S, Ucem TT. A comparison of sagittal and vertical effects between bonded rapid and slow maxillary expansion procedures. Eur J Orthod 1999;21(2):175-80. 28. Asanza S, Cisneros GJ, Nieberg LG. Comparison of Hyrax and bonded expansion appliances. Angle Orthod 1997;67(1):15-22. 29. da Silva Filho OG, Boas MC, Capelozza Filho L. Rapid maxillary expansion in the primary and mixed dentitions: a cephalometric evaluation. Am J Orthod Dentofacial Orthop 1991;100(2):171-9. 30. da Silva Filho OG, Montes LA, Torelly LF. Rapid maxillary expansion in the deciduous and mixed dentition evaluated through posteroanterior cephalometric analysis. Am J Orthod Dentofacial Orthop 1995;107:268-75. 31. Almeida G, Capelozza Filho L, Trinidade ASJ. Rapid maxillary expansion: a prospective study [in Portuguese]. Ortodontia 1999;32(1):45-56. 32. Kawakami RY, Henriques JFC, Pinzan A, de Freitas MR, Janson G. Comparison of dentoskeletal effects produced by two types of rapid maxillary expansion appliances by means of lateral cephalometric evaluation [in Portuguese]. Ortodontia 1999;32(3):8-27. 33. Faltin KJ, Moscatiello VA, Barrios EC. Faltin Jr’s palatal expander: dentofacial changes resulting from rapid maxillary expansion [in Portuguese]. Rev Dent Press Ortodon Ortopedi Facial 1999;4(4):5-13. 34. Mazzieiro ET, Henriques JFC, Freitas MR. Study of frontal cephalometric the dentoskeletal changes after the rapid maxillary expansion [in Portuguese]. Ortodontia 1996;29(1):31-42. 35. Sari Z, Uysal T, Usumez S, Basciftci FA. Rapid maxillary expansion: is it better in the mixed or in the permanent dentition? Angle Orthod 2003;73:654-61. 36. Sandikcioglu M, Hazar S. Skeletal and dental changes after maxillary expansion in the mixed dentition. Am J Orthod Dentofacial Orthop 1997;111:321-7. 37. Bhatt AK, Jacob PP. Skeletal and dental changes in rapid maxillary expansion. J Indian Orthod Soc 1978;10(1-2):17-27. 38. Akkaya S, Lorenzon S, Ucem TT. Comparison of dental arch and

January 2006

Copyright ©2006 American Dental Association. All rights reserved.

C L I N I C A L

arch perimeter changes between bonded rapid and slow maxillary expansion procedures. Eur J Orthod 1998;20(3):255-61. 39. Cozzani M, Rosa M, Cozzani P, Siciliani G. Deciduous dentitionanchored rapid maxillary expansion in crossbite and non-crossbite mixed dentition patients: reaction of the permanent first molar. Prog Orthod 2003;4:15-22. 40. Byrum AG Jr. Evaluation of anterior-posterior and vertical skeletal change vs. dental change in rapid palatal expansion cases as studied by lateral cephalograms. Am J Orthod 1971;60:419. 41. Harrison JE, Ashby D. Orthodontic treatment for posterior crossbites. Cochrane Database Syst Rev 2001(1):CD000979. 42. Handelman CS, Wang L, BeGole EA, Haas AJ. Nonsurgical rapid maxillary expansion in adults: report on 47 cases using the Haas expander. Angle Orthod 2000;70(2):129-44. 43. McNamara JA Jr, Baccetti T, Franchi L, Herberger TA. Rapid maxillary expansion followed by fixed appliances: a long-term evaluation of changes in arch dimensions. Angle Orthod 2003;73:344-53. 44. Capelozza Filho L, Cardoso Neto J, da Silva Filho OG, Ursi WJ. Non-surgically assisted rapid maxillary expansion in adults. Int J Adult Orthodon Orthognath Surg 1996;11(1):57-66.

P R A C T I C E

45. Darendeliler MA, Strahm C, Joho JP. Light maxillary expansion forces with the magnetic expansion device: a preliminary investigation. Eur J Orthod 1994;16:479-90. 46. Chaconas SJ, Caputo AA. Observation of orthopedic force distribution produced by maxillary orthodontic appliances. Am J Orthod 1982;82:492-501. 47. Memikoglu TU, Iseri H. Nonextraction treatment with a rigid acrylic, bonded rapid maxillary expander. J Clin Orthod 1997;31(2):113-8. 48. Iseri H, Ozsoy S. Semirapid maxillary expansion: a study of longterm transverse effects in older adolescents and adults. Angle Orthod 2004;74(1):71-8. 49. Chang JY, McNamara JA Jr, Herberger TA. A longitudinal study of skeletal side effects induced by rapid maxillary expansion. Am J Orthod Dentofacial Orthop 1997;112:330-7. 50. Garib DG, Henriques JFC, Janson GP. Longitudinal cephalometric appraisal of rapid maxillary expansion effects [in Portuguese]. Rev Dent Press Ortodon Ortopedi Facial 2001;6(5):17-30. 51. Sandstrom RA, Klapper L, Papaconstantinou S. Expansion of the lower arch concurrent with rapid maxillary expansion. Am J Orthod Dentofacial Orthop 1988;94:296-302.

JADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

January 2006

53