608 Heier et aL American Journal of Orthodontics and Dentofacial Orthopedics
All measurements were taken in the maxilla and
mandible from canine to canine just before debonding
(baseline) and 1, 3, and 6 months later. The same clinician
scored the lingual, interdental, and buccal tooth sites.
Modified Gingival Index (MGI)
The MG114'I5 permits a noninvasive evaluation of
early and subtle visual changes in the severity and extent
of gingival inflammation. It is scored as follows: absence
of inflammation (0), part of gingival unit mild inflamma-
tion (1), complete gingival unit mild inflammation (2),
moderate inflammation (3), and severe inflammation (4).
Bleeding On Probing (BOP)
Fig. 1. Fixed lingual retainer bonded in Dentaflex 0 The BOP 16 is widely used in diagnosis of gingival
0.0175 arch from canine to canine.
inflammation. To obtain a standardized pressure of 25
gm, 17'18a Florida probe 19with a Michigan O probe tip was
inserted into the gingival crevice. This way the probing
to evaluate the differences in gingival conditions in force was standardized and could not be influenced by the
patients w h o wear b o n d e d or removable retainers. clinician. Bleeding was registered after 15 seconds2°: no
Moreover, differences in plaque and calculus accu- bleeding (0), point-bleeding (1), and profuse bleeding (2).
mulation were analyzed.
Gingival Crevicular Fluid Flow (GCFF)
MATERIAL AND METHODS
The examined teeth were isolated with cotton rolls
Thirty-six orthodontic patients, between the ages of and cheek retractors and gently dried with the air syringe.
12.8 and 21.1 years, (mean 16.3 years) were treated with The tip of a Periopaper strip (Pro Flow Inc.) was placed at
fixed Begg appliances in the upper and lower arches. the entrance of the gingival sulcus for 30 seconds. The
Some of them were recruited in a private orthodontic amount of gingival crevicular fluid absorbed into the
practice, others in the dental clinic at the Free University Periopaper is proportional to the digital reading on the
of Brussels. A majority of patients wore retainers in both Periotron 600021-23 (Pro Flow Inc.). Values higher than 30
arches. The decision whether a removable or bonded are considered as pointing to gingival inflammation. The
lingual retainer would be used after active treatment was Periotron registrations were limited to the following sites:
made at treatment planning. Patients with pretreatment the mesial and buccal surfaces of the upper right central
spacing or extensive incisor rotations were given perma- incisor, the distal and lingual surfaces of the upper left
nent bonded retainers. The others received removable canine, the distal and lingual surfaces of the lower left
retainers. The level of oral hygiene was not taken into central incisor, and the mesial and buccal surfaces of the
account in the choice of retention device. Thus two lower right canine.
experimental groups were created: the fixed retainer
group (FRG) with 22 patients and the removable retainer Plaque Index (PI)
group (RRG) containing 14 patients.
At the end of active orthodontic treatment, standard Plaque was disclosed with Diaplac (OY Mdlnlycke
procedures for adhesive removal, polishing, and prophy- Ab). The modified plaque index, according to Quigley and
laxis were performed. The fixed retainers were bent in Hein (modification according to Turesky), 24 was regis-
flexible spiral wire (Dentaflex 0.0175, Dentaurum) and tered for the buccal and lingual tooth surfaces according
bonded to each lingual tooth surface from canine to to the following scale: no plaque (0), spots of plaque at the
canine (Fig. 1). Care was taken not to leave any bonding cervical margin (1), thin continuous band of plaque at the
substance (Super C Ortho, Amco) in contact with gingival cervical margin (2), gingival third of tooth surface covered
tissues. All removable retainers had a labial arch and with plaque (3), two thirds of tooth surface covered with
several retention clasps embedded in an acrylic plate. At plaque (4), and more than two thirds of tooth surface
the time of retainer insertion, oral hygiene instructions covered with plaque (5).
were given. The patients were instructed to brush three
times a day. In order not to influence measurements, Dental Calculus Index (DCI)
disinfecting or fluoride containing mouthrinsing solutions To measure the amount of dental calculus, the assess-
could not be applied. The daily use of wooden toothpicks ment according to Volpe et alY was used. A calibrated
for interdental hygiene was expected from patients with periodontal probe was applied at three locations of the
fixed retainers, whereas patients wearing removable re- buccal and lingual sides of each lower incisor and canine:
tainers used dental floss. a mesial location, at the tooth center, and a distal location.
American Journal of Orthodontics and Dentofacial Orthopedics H e i e r e t al. 609
Volume 11.2, No. 6
Table I. M e a n s of five o u t c o m e m e a s u r e s o n d i f f e r e n t l o c a t i o n s b y t r e a t m e n t g r o u p a n d t i m e o f f o l l o w - u p
Baseline measure 1-month follow-up 3-month follow-up 6-month follow-up
Index Site FR RR FR RR FR RR FR RR
MGI B 0.71 0.74 0.44 0.68 0.21 0.68 0.24 0,89
IB 1.71 1.40 1.01 1.02 0.56 1.23 0.66 1,40
IL 1.42 1.26 1.03 0.87 0.86 0.99 0.94 1,23
L 0.79 0.80 1.12 0.49 0.30 0.63 0.40 0,74
BOP B 0.25 0.40 0.18 0.30 0.19 0.34 0.22 0,41
IB 0.36 0.57 0,23 0.46 0.23 0.35 0.30 0.47
IL 0.50 0.70 0.37 0.43 0.32 0.45 0.30 0.40
L 0.32 0.34 0.56 0.23 0.18 0.18 0.23 0.22
GCFF B 24.57 25.56 11.I1 12.04 11.04 12.32 22.29 16.88
ID 46.91 55.27 28.31 21.71 20.07 28.98 25.46 35.18
L 15.29 15.70 16.25 4.56 8.86 10.83 8.04 11.00
PI B 2.86 2.56 1,12 1.18 1,38 1.59 1.02 1.24
L 2.78 2.78 3.34 2.50 2.82 2.43 3.03 2.52
DCI B 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00
L 0.20 0,05 0.13 0.01 0.19 0.01 0.20 0.06
MGI: Modified Gingival Index; BOP." Bleeding On Probing; GCFF: Gingival Crevicular Fluid Flow; Ph Plaque Index; DCI: Dental Calculus Index.
B: Buccal; IB: Interdental Buccal; IL: Interdental Lingual; L: Lingual; ID: Interdental.
FR: Fixed Retainer; RR: Removable Retainer.
Statistical Analysis retainer types. The changes were not significant at
A univariate repeated measurement analysis of vari- the lingual sites for both retainer types and at the
ance (ANOVA) model was used, containing one repeated buccal sites for the removable retainers (Table II).
factor (time) and one between factor (code:distinguishing After the first month, however, the mean MGI
the removable versus the fixed retainer group). Each tended to increase in the group with removable
analysis resulted in three P values, one for each factor and
retainers, but generally these increases were not
one as interaction term. Subsequently, a Scheff6 post hoc
analysis calculated the significance levels of the differ- significant (Table II). At the 6-month follow-up, the
ences between pairs. Throughout the entire statistical mean values remained below score 1 at the buccal
analysis, a significance level ofp <- 0.05 was maintained. and lingual sites. At 6 months, the lingual sites
showed a mean MGI of 1.23 and the buccal sites
RESULTS showed a mean MGI of 1.40 (Table I). In the group
For each of the two study groups (fixed or with fixed retainers, a reduction in MGI values was
removable retainer), mean values at baseline, at found between months 1 and 3, followed by a small
1-month, 3-month, and 6-month follow-up examina- increase between the months 3 and 6 (Table II). At
tions are presented in Table I. The changes through the 6-month evaluation, the mean MGI values at all
time are visualized in Figs. 2 through 6. Table II sites were lower in the group with fixed retainers
shows the changes from baseline to 1-month follow- than in the removable retainer group (Table I). The
up, from 1- to 3-month follow-up, and from 1- to mean MGI after wearing retainers for 6 months
6-month follow-up. The differences for the five remained below score 1 for both retainer types at
outcome measures between the group wearing fixed the buccal and lingual sites. The highest mean MGI
retainers (FR) and the group with removable retain- after 6 months (1.40) was seen for removable retain-
ers (RR) can be seen in Table III. ers at the interdental buccal sites. In contrast, for the
At baseline, the mean MGI (Fig. 2) of both fixed retainer group, the lowest mean MGI (0.66)
retainer groups was below score 1 for the buccal and was registered at these interdental buccal sites (Ta-
lingual sites. The mean interdental values (Table I) ble I).
were slightly higher in the F R than in the R R group The mean BOP index (Fig. 3) of both retainer
(at the lingual aspect FRIL:l.42; RRIL:1.26 and at groups stayed below score i at all sites from baseline
the buccal aspect FRIB:I.71; RRIB:I.40). These to 6-month follow-up (Table I). In all instances, the
differences were only significant for the interdental mean BOP index at baseline was lower in the fixed
buccal region (p = 0.0163). The mean MGI after retainer group than in the group that would receive
wearing retainers for 1 month showed a tendency to a removable retainer (Table I). Statistical analysis
be lower than at baseline for all sites and for both showed that these differences were only significant
610 Heier et al. American Journal of Ot¢hodontics and Dentofacial Orthopedics
i . . . . . . . .
e - -
- - c o ~ :
1.4 • 1.4
1.2 . . . . . . . . . . .
. . . . . . /2 ',, . . . . . .
.L -1 3
Fig. 2. Modified gingival index. A, Buccal sites. B, Interdental buccal sites. C, Interdental
lingual sites. D, Lingual sites.
for the interdental sites (Table III). At the lingual sites were nearly identical for both retainer types
sites, the mean BOP increased to 0.56 after 1 month (Table I).
with fixed retainers (Table I). This change was not The lowest mean values for the gingival crevic-
significant (Table III). ular fluid (Fig. 4) at baseline were found on the
At the other sites, a nonsignificant downward lingual surfaces for both groups (15 periotron units).
evolution of the mean BOP was noticed at i-month For the buccal sites, level 25 was reached; the
follow-up for both retainer groups. With both kinds interdental sites reached up to 47 in the fixed
of retainers, the changes in the mean BOP toward 6 retainer group and to 55 in the group that would get
months were very small (Table II). A slight reduc- removable retainers (Table I). None of the differ-
tion was observed toward the 6-month follow-up for ences between RR and FR proved to be statistically
the lingual and lingual interdental sites. A tendency significant (Table III). One month later, the peri-
toward an increased BOP was found for the buccal otron score had dropped for all, but one measure
and interdental buccal sites (Table II). The maxi- that remained practically unchanged, i.e., the lingual
mum mean BOP at 6 months was found at the sites in the fixed retainer group. Toward the 6-
interdental buccal sites. However, it remained lim- month follow-up, this downward trend was stopped
ited to 0.47 (Table I). At that time, the mean BOP or reversed (Table II). The values for the fixed
values were slightly, but not significantly, lower in retainer group were not significantly different from
the group with fixed retainers compared with the those in the removable retainer group (Table III).
removable retainer group. The values at the lingual The highest GCFF values after 6 months were found
American Journal of Orthodontics and Dentofacial Orthopedics Heier et al. 611
Volume 112, No. 6
I ....... i !
B L E ~ N ~ ON ~ROBZNG=X~OENT~L ~ I N ~ U ~ ~ZTE~
-~ 2 3
°°i! . . . . . . .
Fig. 3. Bleeding on probing. A, Buccal sites. B, Interdental buccal sites. C, Interdental
lingual sites. D, Lingual sites.
for the interdental sites: 35 in the removable re- remained near zero throughout the evaluation pe-
tainer group and 25 with fixed retainers. The lowest riod. The mean DCI on the lingual surface at
GCFF values were situated at the lingual sites: 11 in baseline was slightly above zero (0.2 ram) in the
the RR group, and 8 in the FR group. group receiving a fixed retainer, whereas calculus
Before debonding, comparable mean plaque in- was almost absent (0.05 ram) in the other group.
dexes near 2.8 were found in the two groups on the One month 'later, the mean calculus level was
buccal and lingual surfaces (Fig. 5). The buccal brought down further to 0.1 mm for the FR group
value had dropped significantly to about 1.2 on the and to 0.01 mm for the RR group. At 6 months, the
buccal surfaces at 1-month follow-up (Table I). It mean lingual measurements had gone up to the
remained at approximately the same level at 6 original values (Table I).
months, after a small but nonsignificant increase at
the 3-month follow-up (Table II). The mean lingual DISCUSSION
PI in the removable retainer group was reduced to At the end of the presence of fixed orthodontic
2.5 after 1 month, 2.4 at month 3, and 2.5 at the appliances on the buccal tooth surfaces, the record-
6-month follow-up. In the fixed retainer group, the ings of MGI, BOP, and GCFF for the buccal and
mean PI at the lingual sites climbed to 3.3 at lingual gingival units indicate that generally only
1-month, to end at 3.0 at 6 months (Table I). This limited parts of these gingival units showed mild
score was significantly higher than the score in the inflammation, very few bleeding points were
removable retainer group (Table III). present, and a normal gingival crevicular fluid flow
On the buccal surfaces, the mean DCI (Fig. 6) existed. For the interdental areas, the MGI pointed
6"12 Heier et al. American Journal of Orthodontics and Dentofaciat Orthopedics
G I ~ ~RE~ICU~R ~LU~ ~ L O W : ~ C C ~ L SZ~E~
L 2 3
-i 2 ~ 4
- - oa.:
B C t Jm~(~anths)
Fig. 4. Gingival crevicular fluid flow. A, Buccal sites. B, Interdental sites. C, Lingual sites.
to more complete gingival units with mild gingival The other group had the opportunity to perform
inflammation, the BOP test showed the existence of completely normal oral hygiene procedures as the
more point bleedings, and the GCFF was found to removable retainers were used only at nighttime.
correspond with the presence of mild gingival in- Considering the change from fixed orthodontic ap-
flammation. The differences between the fixed and pliances present on the buccal tooth surfaces at
removable retainer groups being very small, this baseline, to naked buccal tooth surfaces 1 month
suggests that the oral hygiene at the end of the later, we were not surprised to find that the three
active orthodontic treatment had been acceptable indices concerning gingival inflammation tended to
for the buccal and lingual tooth surfaces in both be lower at 1-month follow-up. The buccal tooth
groups, but some inflammation was present in the surfaces, being easier to clean, could be considered
approximal area. Somewhat more calculus was as healthy. This also applied for the lingual surfaces
present at the lingual sites of the FR group. in the removable retainer group, but not for the
The 1-month, 3-month, and 6-month follow-up lingual aspect with fixed retainers. There, the indices
recordings have been gathered in two different scored somewhat higher, suggesting a little less
situations, as far as access for oral hygiene was favorable gingival health. In the interdental regions,
concerned. In one group, wires bonded to the all indices showed lower mean values at 1-month
lingual surfaces of incisors and canines were cross- than at baseline, especially the GCFF dropped
ing the interdental spaces. The use of wooden below 30 periotron units, taking it below the inflam-
toothpicks for plaque removal in the interproximal mation limit. At all tooth surfaces, the gingival
areas had been explained and required in this group. condition could be considered as healthy for both
American Journal of Orthodontics and Dentofacial Orthopedics H e i e r et al. 61:3
Volume 112, No. 6
. . . . CODE*
-~ e t e 3 4 ~
-'k . .....
""-.. ....... -
Fig, 5. Plaque index. A, Buccal sites. B, Lingual sites.
kinds of retainers. Some of the mean indices were a ever, these increases were not statistically signifi-
little lower in the fixed retainer group, some a little cant. In general, the m e a n MGI, BOP, and G C F F
higher than in the removable retainer group, but in the fixed retainer group remained below the
these small differences were not statistically signifi- indices for the removable retainer group. A strik-
cant. On this basis, it can be concluded that, in the ing difference between the two groups concerning
scored patient groups who wore fixed lingual retain- gingival health could not be observed. The trend
ers during a 1-month period, this did not lead to a toward increased values at 6 months for both
gingival condition, which was more unfavorable than groups could be interpreted as an indication for
that in the group wearing removable appliances. the need for r e p e a t e d motivation and oral hygiene
Our assessments of MGI, BOP, and G C F F at instructions at least on a 6-month interval basis.
3-month recall appeared to bring all mean values of Further investigation could test the validity of this
the group with fixed retainers at a lower level than interval on a long-term basis.
those with the removable retainers worn only during In both groups, the mean buccal PI before
the night. As the differences were seldom statisti- debonding was found to be very close to the lingual
cally significant, we cannot state that oral hygiene values. The mean value near 2.8 shows that, at the
conditions were more favorable in the group with end of the orthodontic treatment, the patients did
fixed retainers. Moreover, there is even less reason not succeed in reaching a high standard of oral
to accept that they had worse gingival conditions. hygiene. The mean MGI, BOP, and GCFF values
Going to 6-month recall, a tendency toward discussed previously suggest that, in those regions
higher indices was noticed in both groups. How- with a buccal and lingual presence of at least a
614 Heier et aL American Journal of Orthodontics and Dentofacial Orthopedics
, , ; , ; %- 7
D N A C L U U Z D XL N U L S T S
E T L AC L S N E : Z G R Z E
e . 24
. , 1 7.
B. ia . . . . . . . . . . . . . . . . . . .
B.ll . . . . . . . . . . . . . . .
. . . . . i
. . . . ............ . .
z.m ~ . . . . . . . . . . i RRG
-B.eI - - i
Fig. 6. Dental calculus index. A, Buccal sites. B, Lingual sites.
continuous band of plaque at the cervical margins, a rather small, but nonsignificant increase in plaque
rather mild gingival inflammation existed. accumulation on the lingual surfaces. Until the
After removal of the buccal fixed appliances, an 6-month follow-up, the measured plaque levels
improvement in plaque condition was seen on the had not caused any significant gingival inflamma-
buccal surfaces in both retainer groups. Continuous tion. This confirms and extends the results of
bands of plaque were rarely recorded. Rather com- Artun et al. 13 of finding no significant differences
monly, spots of plaque have been noticed at the in gingival inflammation nor accumulation of
cervical margin. This nonideal situation of oral plaque and calculus after 4 months with fixed or
hygiene remained until the 6-month follow-up. It removable retainers.
could be considered acceptable because the local The deposit of calculus was nearly nonexistent
gingival condition showed no real inflammation. on the buccal tooth surfaces. For the lingual sites,
The lingual plaque condition in both groups this applied for both kinds of retainers.
did not improve after debonding. This could be
explained by the remaining lack of direct view on CONCLUSION
those surfaces, which makes oral hygiene more A comparable limited gingival inflammation was
difficult and seemingly less necessary. The pres- found in the presence of both types of retainers. The
ence of the fixed wires was accompanied by a clinical observation of an increased tendency of calculus
American Journal of Orthodontics and Dentofacial Orthopedics Heier et al. 615
Volume 112, No. 6
T a b l e II. Mean differences a n d p levels from baseline to 1 month follow-up, from 1 to 3 month follow-up, and from 1 to 6 month
follow-up, for five outcome measures on different locations by treatment groups
Baseline to 1-month follow-up 1- to 3-month follow-up 1- to 6-month follow-up
FR RR FR RR FR RR
Index Site X P X J P X P X J P X P X P
MGI B -0.27 0.0540* -0.06 0.9519 -0.23 0.1474 0.00 0.9999 -0.20 0,2717 +0.21 0.2420
IB -0.70 0.0000" -0.38 0.0013" -0.45 0.0000" +0.21 0.1832 -0.35 0.0027* +0.38 0.0016"
IL -0.39 0.0004* -0.39 0.0005* -0.17 0.3137 +0.12 0.6343 -0.09 0.8064 +0.36 0.0015"
L +0.33 0.9436 -0.31 0.9567 -0.82 0.4913 +0.14 0.9954 -0.72 0.6077 +0.25 0.9748
BOP B -0.07 0.8420 -0.10 0.6177 +0.01 0.9999 +0.04 0.9594 +0.04 0.9763 +0.11 0.5257
IB -0.13 0.2364 -0.11 0.3140 0.00 1.0000 -0.11 0.3621 +0.07 0.7124 +0.01 0.9963
IL -0.13 0.1980 -0.27 0.0006* -0.05 0,8996 +0.02 0.9944 -0.07 0.7370 -0,03 0.9815"
L +0.24 0.8963 -0.11 0.9896 -0.38 0.6653 -0.05 0.9990 -0.33 0.7662 -0.01 0.9999
GCFF B -13.46 0.1933 -13.52 0.2350 -0.07 1.0000 +0.28 0.9999 +11.18 0.3518 +4.84 0.9073
ID -18.60 0.1398 -33.56 0.0021" -8.24 0.7808 +7.27 0.8724 -2.85 0.9880 +13.47 0.4921
L +0.96 0.9994 -11.14 0.5851 -7.39 0.7904 +6.27 0.8927 -8.21 0.7318 +6.44 0.8846
PI B - 1,74 0.0000" - 1.38 0.0000" +0.26 0.3915 +0.41 0.0814 0.10 0.9209 +0.06 0.9858*
L +0.56 0.0009* -0.28 0.2553 -0.52 0.0023* -0.07 0.9684 -0.31 0.1590 +0.02 0.9995
DCI B -0.01 0.2472 -0.01 0.9854 0.00 0.1102 0.00 0.9999 0.00 0.1253 0.00 0.9999
L -0.07 0.1272 -0.04 0.7354 +0.06 0.1903 0.00 1.0000 +0.07 0.1976 +0.05 0.5194
MGI: Modified Gingival Index; BOP: Bleeding On Probing; GCFF: Gingival Crevicular Fluid Flow; PI: Plaque Index; DCI: Dental Calculus Index.
B: Buccal; IB: Interdental Buccal; IL: Interdental Lingual; L: Lingual; ID: Interdental.
FR: Fixed Retainer; RR: Removable Retainer.
*Significant atp -< 0.05.
Table Ill. Mean differences and p levels between wearing fixed and removable retainers for five outcome measures on different
locations by time of follow-up
Baseline 1-month 3-month 6-month
Index Site X P X I P X P X I P
MGI B -0.03 0.9950 -0.24 0.1261 -0.47 0.0000" -0.65 0.0000"
IB 0.31 0,0163" -0.01 0.9999 -0.67 0.0000" -0.74 0.0000"
IL 0.16 0.4032 0.16 0.3597 -0.13 0.5858 -0.29 0.0185"
L -0.01 1.0000 0.63 0.7108 -0.33 0.9436 -0.34 0.9403
BOP B -0.15 0.2615 -0.12 0.5010 -0.15 0.2525 -0.19 0.0789
IB -0.21 0.0051" -0.23 0.0035* -0.12 0.3196 -0.17 0.0517
IL -0.20 0.0242* -0.06 0.8250 -0.13 0.2679 -0.10 0.4466
L -0.02 0.9999 0.33 0.7708 0.00 0.9999 0.01 0.9999
GCFF B -0.99 0.9990 -0.93 0.9991 - 1,28 0.9978 5.41 0.8667
ID -8.36 0.7977 6.60 0.8887 -8.91 0.7648 -9.72 0,7126
L -0.41 0.9999 11.69 0.5042 - 1.97 0.9955 -2.96 0.9850
PI B 0.30 0.2762 -0.06 0.9830 -0.21 0.6134 -0.22 0,5321
L 0.00 0.9999 0.84 0.0000* 0.39 0.0533* 0.51 0.0040*
DCI B 0.00 0.8592 0.00 0.0214" 0.00 0.8582 0.00 0.9900
L 0.15 0.0012" 0.12 0.0242* 0.18 0.0000* 0.14 0.0101"
MGI: Modified Gingival Index; BOP." Bleeding On Probing; GCFF: Gingival Crevicular Fluid Flow; PI: Plaque Index; DCI: Dental Calculus Index.
B: Buccal; IB: Interdental Buccal; IL: Interdental Lingual; L: Lingual; [19: Interdental.
FR: Fixed Retainer; RR." Removable Retainer.
*Significant atp -< 0.05.
f o r m a t i o n a r o u n d fixed r e t a i n e r s w a s c o n f i r m e d . H o w - U n i v e r s i t y o f Brussels, f o r allowing u s to take m e a s u r e -
ever, this difference w a s a l r e a d y p r e s e n t b e f o r e t h e place- m e n t s f r o m s o m e o f h e r p a t i e n t s a n d to G i n o V e r l e y e ,
m e n t o f t h e fixed r e t a i n e r , I f a p r o f e s s i o n a l p l a q u e a n d A s s i s t a n t P r o f e s s o r in A p p l i e d Statistics, D e p a r t m e n t o f
calculus r e m o v a l a c c o m p a n i e d by a s e s s i o n o n m o t i v a t i o n Statistics, F r e e U n i v e r s i t y o f Brussels, f o r his a s s i s t a n c e
and oral hygiene i n s t r u c t i o n is r e p e a t e d every 6 m o n t h s , it w i t h t h e statistical analysis.
is likely t h a t t h e periodontal health should not be com-
p r o m i s e d by t h e p r e s e n c e o f b o n d e d lingual wires.
W e e x p r e s s o u r t h a n k s to K a t h y Goeffers, D D S , 1. GazitE, LiebermanMA.An estheticand effectiveretainerfor loweranteriorteeth.
A s s i s t a n t P r o f e s s o r , D e p a r t m e n t of O r t h o d o n t i c s , F r e e Am J Orthod 1976;70:91-3.
616 Heier et al. American Journal of Orthodontics and Dentofacial Orthopedics
2. Wolfson J, Servoss JH. Bandless but fixed retention. Am J Orthod 1974;66: 15. Lobene RR, Mankodi SM, Ciancio SG, Lamm RA, Charles CH, Ross NH. Correla-
431-4. tions among gingival indices: a methodology study. J Periodontul I989;60:159-62.
3. Z~.r J, Zacchrisson B. Improving the handling properties of a composite resin for
tun 16. Lang NP, Joss A, Orsanic T, Gusberti FA, Siegrist BE. Bleeding on probing. A
direct bonding. Am J Orthod 1982;81:269-76. predictor for the progression of periodontal disease? J Clin Periodontu11986;13:590-6.
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