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Gingival response to removable orthodontic appliances
Gingival response to removable orthodontic appliances Josef Jerusalem,
Goultschin,
D.D.S.,*
and Yerucham
Zilberman,
D.M.D.**
Israel
The gingival state of twenty-four young patients (Imean age 9.4 years) wearing simple removable orthodontic appliances was assessed and followed at monthly intervals for 4 months. In nine of the patients intentional relief of the appliance was made in the upper right area. The plaque index levels were similar in both “relief” and “no-relief” groups and reached a similar score at 4 months. The gingival index was significantly higher in the “relief” group, and all five cases that showed gingival hyperplasia of the experimental area belonged to this group.
Key words: Removable appliances, gingival response,relief-hyperplasia
R
emovable orthodontic appliances, whether passive or active, present a dilemma to the clinician, since gingival reactions are at times a cause of concern. The type of relationship between the appliance and the marginal gingiva is still a controversial issue. Considerable information may be extrapolated from the abundant literature on the subject of removable partial denture design. I, * However, the special needs of the orthodontic removable appliance with respect to retention and provision of anchorage make many of the recommendations about relief and noncoverage of margins difficult to apply. In a 1977 article, Bissada and associates” concluded that when gingival margins are covered by partial dentures severe pathologic changes occur within a period of 12 months in areas covered without relief. It is the purpose of this article to present the results of a follow-up study of the gingival response in children undergoing orthodontic therapy with removable appliantes, with and without relief of the gingival margins. METHODS
AND MATERIALS
The gingival conditions of twenty-four children aged 7 to 17 years (mean age, 9.4) attending the orthodontic clinic of the Hebrew University-Hadassah Faculty of Dental Medicine in Jerusalem, Israel, were assessed by a trained periodontist (J.G.). The children were selected for the study on the basis of their being treated by means of simple removable appliances. For this study, the appliances were of the Hawley
From Hebrew University-Hadassah School of Dental Medicine the Alpha Omega Fraternity). *Depaltment of Periodontics and Endodontics. **Department of Orthodontics. 00X!-9416/82/020147+03$00.30/0
0
1982 The C.V.
(founded
Mosby Co.
by
I. Number and distribution of cases in the two groups during the study
Table
Experimental period
No. of patients
Relief
No relief
Before One month Two
months
Four months
13
7 girls 6 boys
type, in which an acrylic base, covering the palatal area of the maxillary arch, was retained by means of Adams clasps on the first molars and a labial bow on the anterior segment.4 The active elements of these appliances were as follows: (1) A palatal spring5 to correct the linguoversion of an incisor tooth. (2) An active labial bow to retract an increased overjet in an anteriorly spaced Angle Class I malocclusion. In this situation, the acrylic was cut away behind these teeth to allow the movement. (3) An expansion screw in a split plate, for slow expansion of the dental arch657 in cases in which there was a unilateral dental cross-bite of a functional nature. These appliances were worn 24 hours per day, and the forces were of light magnitude, conforming to the retention and anchorage limitations of such appliances. No randomization was made, but all patients attending the Monday and Thursday afternoon clinics were examined and followed for a period of up to 4 months. Of the twenty-four patients, nine were selected at random and 2 to 3 mm. of acrylic was removed from the 147
148
Goultschin
Am. J. Orrhod Fehrutq 1982
md Zilberman
II. Mean gingival index (G.I.) scores and (p) levels of significance
Table
Experimental
period
Relief x
Before
SE x SE (p x
Hyperplasia
= 0.333 = = = = =
0.093 0.75 0.170 0.274) 0.80
One
month
Two
months
SE = 0.199 (p = 0.028) jT = 1.142
Four
months
SE = 0.092 (p = 0.002)
Ill. Mean plaque index (Pl.1.) values before and along the study
Before One
month
Two
months
Four
months
period
Relief
No relief
x = 1.055 SE = 0.149 x = 1.208
x = 1.163 SE = 0.130 x = 1.385
SE = 0.332 x = 1.400 SE = 0.269
SE = 0.213 ?t = 1.167
k = 1.428 SE = 0.186
Hyperplasicr
None
x = 0.35 SE = 0.053
None
None
None
2
i? SE (p 2
5
SE = 0.076 (p = 0.032) x = 0.916
= = = =
0.673 0.091 0.025) 0.792
None
None
SE = 0.083 (p = 0.028)
Table
Experimental
No reliej
SE = 0.238 % = 1.416 SE = 0.247
gingival margin for relief. The area included the mesiolingual line angle of the upper right canine distal to the mesiolingual line angle of the last molar in the right upper quadrant. The width of the relief area was about 5 mm. Gingival index (G.I.)X and plaque index (Pl.1.)” scores of the lingual and mesiolingual surfaces of the teeth from the upper right canine to the last molar present in the upper right quadrant were recorded, as well as the presence or absence of hyperplasia of the gingival tissues of the area. This was performed prior to appliance insertion and subsequently at monthly intervals. At the initiation of the experiment all children were instructed in the use of a soft multitufted toothbrush following the modified Bass technique.“) No attempt was made to reinforce the instructions during the experiment. Because of changes in schedules at school or because of personal requirements, several of the patients changed their days of attendance at the clinic; thus, of the twenty-four original patients, only nineteen were examined at the l-month interval, eleven at 2 months, and thirteen at the 4-month re-examination (Table I). Two groups were selected and categorized as “relief” and “no-relief” subjects, rather than using a split-mouth approach, because of the difference in effectiveness of tooth brushing on each side of the mouth. All the computed mean score values for the gingival index (G.I.) figures were subjected to the Mann-
Whitney U test for assessment of their levels of significance. RESULTS
Table II shows the G.I. scores during the experimental period. From an almost identical beginning (0.33 for the “relief” group versus 0.35 of the “norelief” group), the values diversely increased, reaching a significantly different level at the 4-month period when the ‘ ‘relief’ ’ group was 25 percent higher than the “no-relief” group (p = 0.002). The Plaque Index (Pl.1.) values are given in Table III. It may be noted that both groups started at a higher than 1 level, a condition common in this age group. The plaque scores increased slightly, reaching nearly identical scores for the “relief” group ( 1.43) and the “no-relief” group ( 1.42), at the 4-month period. The gingival tissues in both groups appeared inflamed upon examination, and many hemorrhaged easily on probing. The group in which intentional relief was performed had the highest scores of clinical gingival pathosis at the end of the study. At the 4-month examination, gingival hyperplasia was noted in five cases with relief (Table II) out of a total of thirteen cases checked at this time (Table I). It is worth noting that these five patients were all females whereas the two male subjects in the group did not show hyperplasia. DISCUSSION
Tissue-borne appliances can have deleterious effects on the gingiva. Furthermore, there seems to be agreement among foremost periodontists” and experts in oral rehabilitation12 on the matter of the appliance-gingiva relationship. In 1968 Waerhaug” stated: “. denture material, clasps, bars and teeth should be kept as far away from the gingival margin as possible. ” The reasons for these deleterious effects have been summarized by McCracken” as (1) pressure, (2) uncleanliness, and (3) amount of time the appliance is worn.
Volume 81 Number 2
Since the Plaque Index at the 4-month period was identical in both groups and very similar from the start and throughout the duration of the study, it is suggested that areas covered with intentionally relieved acrylic resulted in a greater gingival response (G.I. values of 1.142, p = 0.002, contrasting the 0.916 of the norelief group). Conspicuously, the only cases in which hyperplasia was present belonged to this relief group. An explanation of this phenomenon was offered in a previously cited article3 in which histologic examination of areas under relieved acrylic revealed a thinner surface keratin, which may be due to lack of physiologic stimulation. Why the void under relieved acrylic generates a hyperplastic response is not known. The need for stability and retention of these types of removable appliances and the manner of their activation preclude positioning of the periphery of the acrylic as far away from the gingival margin as 5 to 6 mm. 12,i3 This dictates full coverage of the gingival margins, with or without relief, as the only alternatives. From our study, coverage without relief would appear to be the least harmful, in view of such factors as plaque and possible hormonal overtones of this age group.
Gingival
response to removable uppliances
149
REFERENCES D., and Steffel, 1. Henderson,
V. L.: McCracken’s removable partial prosthodontics, ed. 4, St. Louis, 1973, The C. V. Mosby Company, pp. 99-100. 2. McCracken, W. L.: Survey of partial denture design by commercial dental laboratories, J. Prosthet. Dent. 12: 1089, 1962. 3. Bissada, N. F., Ibrahim, S. I., and Barsoum, W. M.: Gingival response to various types of removable partial dentures, J. Periodontol. 45: 65 l-659, 1974. 4. Adams, C. P.: Removable appliances yesterday and today, AM. J. ORTHOD.
55: 748-764,
1969.
5. Van der Linden, F. P. G. M.: The removable orthodontic appliance, AM. J. ORTHOD. 59: 376-385, 1971. 6. Tulley, W. J., and Campbell, A. C.: A manual of practical orthodontics, Bristol, 1960, John Wright & Sons, Ltd., p. 134. 7. Walther, D. P.: Orthodontic notes, ed. 2, Bristol, 1967, John Wright & Sons, Ltd., p. 110. 8. Liie, H., and Silness, J.: Periodontal disease in pregnancy, Acta Odontol. Stand. 21: 533, 1963. 9. Liie, H.: The gingival index, the plaque index and the retention index systems, J. Periodontal. 38: 610, 1967. 10. Bass, C. C.: An effective method of personal hygiene. II, J. La. M. Sot. 106: 100, 1954. 11. Grant, D. A., Stem, I. B., and Everett, F. G.: Periodontics, ed. 5, St. Louis, 1979, The C. V. Mosby Company, p. 892. 12. Waerhaug, J.: Periodontology and partial prosthesis, Int. Dent. J. 18: 101, 1968. K. L.: Removable partial denture prosthesis for the 13. Willarson, periodontal patient, Dent. Clin. North Am. 13: 263, 1969.
Goultschin,
D.D.S.,*
and Yerucham
Zilberman,
D.M.D.**
Israel
The gingival state of twenty-four young patients (Imean age 9.4 years) wearing simple removable orthodontic appliances was assessed and followed at monthly intervals for 4 months. In nine of the patients intentional relief of the appliance was made in the upper right area. The plaque index levels were similar in both “relief” and “no-relief” groups and reached a similar score at 4 months. The gingival index was significantly higher in the “relief” group, and all five cases that showed gingival hyperplasia of the experimental area belonged to this group.
Key words: Removable appliances, gingival response,relief-hyperplasia
R
emovable orthodontic appliances, whether passive or active, present a dilemma to the clinician, since gingival reactions are at times a cause of concern. The type of relationship between the appliance and the marginal gingiva is still a controversial issue. Considerable information may be extrapolated from the abundant literature on the subject of removable partial denture design. I, * However, the special needs of the orthodontic removable appliance with respect to retention and provision of anchorage make many of the recommendations about relief and noncoverage of margins difficult to apply. In a 1977 article, Bissada and associates” concluded that when gingival margins are covered by partial dentures severe pathologic changes occur within a period of 12 months in areas covered without relief. It is the purpose of this article to present the results of a follow-up study of the gingival response in children undergoing orthodontic therapy with removable appliantes, with and without relief of the gingival margins. METHODS
AND MATERIALS
The gingival conditions of twenty-four children aged 7 to 17 years (mean age, 9.4) attending the orthodontic clinic of the Hebrew University-Hadassah Faculty of Dental Medicine in Jerusalem, Israel, were assessed by a trained periodontist (J.G.). The children were selected for the study on the basis of their being treated by means of simple removable appliances. For this study, the appliances were of the Hawley
From Hebrew University-Hadassah School of Dental Medicine the Alpha Omega Fraternity). *Depaltment of Periodontics and Endodontics. **Department of Orthodontics. 00X!-9416/82/020147+03$00.30/0
0
1982 The C.V.
(founded
Mosby Co.
by
I. Number and distribution of cases in the two groups during the study
Table
Experimental period
No. of patients
Relief
No relief
Before One month Two
months
Four months
13
7 girls 6 boys
type, in which an acrylic base, covering the palatal area of the maxillary arch, was retained by means of Adams clasps on the first molars and a labial bow on the anterior segment.4 The active elements of these appliances were as follows: (1) A palatal spring5 to correct the linguoversion of an incisor tooth. (2) An active labial bow to retract an increased overjet in an anteriorly spaced Angle Class I malocclusion. In this situation, the acrylic was cut away behind these teeth to allow the movement. (3) An expansion screw in a split plate, for slow expansion of the dental arch657 in cases in which there was a unilateral dental cross-bite of a functional nature. These appliances were worn 24 hours per day, and the forces were of light magnitude, conforming to the retention and anchorage limitations of such appliances. No randomization was made, but all patients attending the Monday and Thursday afternoon clinics were examined and followed for a period of up to 4 months. Of the twenty-four patients, nine were selected at random and 2 to 3 mm. of acrylic was removed from the 147
148
Goultschin
Am. J. Orrhod Fehrutq 1982
md Zilberman
II. Mean gingival index (G.I.) scores and (p) levels of significance
Table
Experimental
period
Relief x
Before
SE x SE (p x
Hyperplasia
= 0.333 = = = = =
0.093 0.75 0.170 0.274) 0.80
One
month
Two
months
SE = 0.199 (p = 0.028) jT = 1.142
Four
months
SE = 0.092 (p = 0.002)
Ill. Mean plaque index (Pl.1.) values before and along the study
Before One
month
Two
months
Four
months
period
Relief
No relief
x = 1.055 SE = 0.149 x = 1.208
x = 1.163 SE = 0.130 x = 1.385
SE = 0.332 x = 1.400 SE = 0.269
SE = 0.213 ?t = 1.167
k = 1.428 SE = 0.186
Hyperplasicr
None
x = 0.35 SE = 0.053
None
None
None
2
i? SE (p 2
5
SE = 0.076 (p = 0.032) x = 0.916
= = = =
0.673 0.091 0.025) 0.792
None
None
SE = 0.083 (p = 0.028)
Table
Experimental
No reliej
SE = 0.238 % = 1.416 SE = 0.247
gingival margin for relief. The area included the mesiolingual line angle of the upper right canine distal to the mesiolingual line angle of the last molar in the right upper quadrant. The width of the relief area was about 5 mm. Gingival index (G.I.)X and plaque index (Pl.1.)” scores of the lingual and mesiolingual surfaces of the teeth from the upper right canine to the last molar present in the upper right quadrant were recorded, as well as the presence or absence of hyperplasia of the gingival tissues of the area. This was performed prior to appliance insertion and subsequently at monthly intervals. At the initiation of the experiment all children were instructed in the use of a soft multitufted toothbrush following the modified Bass technique.“) No attempt was made to reinforce the instructions during the experiment. Because of changes in schedules at school or because of personal requirements, several of the patients changed their days of attendance at the clinic; thus, of the twenty-four original patients, only nineteen were examined at the l-month interval, eleven at 2 months, and thirteen at the 4-month re-examination (Table I). Two groups were selected and categorized as “relief” and “no-relief” subjects, rather than using a split-mouth approach, because of the difference in effectiveness of tooth brushing on each side of the mouth. All the computed mean score values for the gingival index (G.I.) figures were subjected to the Mann-
Whitney U test for assessment of their levels of significance. RESULTS
Table II shows the G.I. scores during the experimental period. From an almost identical beginning (0.33 for the “relief” group versus 0.35 of the “norelief” group), the values diversely increased, reaching a significantly different level at the 4-month period when the ‘ ‘relief’ ’ group was 25 percent higher than the “no-relief” group (p = 0.002). The Plaque Index (Pl.1.) values are given in Table III. It may be noted that both groups started at a higher than 1 level, a condition common in this age group. The plaque scores increased slightly, reaching nearly identical scores for the “relief” group ( 1.43) and the “no-relief” group ( 1.42), at the 4-month period. The gingival tissues in both groups appeared inflamed upon examination, and many hemorrhaged easily on probing. The group in which intentional relief was performed had the highest scores of clinical gingival pathosis at the end of the study. At the 4-month examination, gingival hyperplasia was noted in five cases with relief (Table II) out of a total of thirteen cases checked at this time (Table I). It is worth noting that these five patients were all females whereas the two male subjects in the group did not show hyperplasia. DISCUSSION
Tissue-borne appliances can have deleterious effects on the gingiva. Furthermore, there seems to be agreement among foremost periodontists” and experts in oral rehabilitation12 on the matter of the appliance-gingiva relationship. In 1968 Waerhaug” stated: “. denture material, clasps, bars and teeth should be kept as far away from the gingival margin as possible. ” The reasons for these deleterious effects have been summarized by McCracken” as (1) pressure, (2) uncleanliness, and (3) amount of time the appliance is worn.
Volume 81 Number 2
Since the Plaque Index at the 4-month period was identical in both groups and very similar from the start and throughout the duration of the study, it is suggested that areas covered with intentionally relieved acrylic resulted in a greater gingival response (G.I. values of 1.142, p = 0.002, contrasting the 0.916 of the norelief group). Conspicuously, the only cases in which hyperplasia was present belonged to this relief group. An explanation of this phenomenon was offered in a previously cited article3 in which histologic examination of areas under relieved acrylic revealed a thinner surface keratin, which may be due to lack of physiologic stimulation. Why the void under relieved acrylic generates a hyperplastic response is not known. The need for stability and retention of these types of removable appliances and the manner of their activation preclude positioning of the periphery of the acrylic as far away from the gingival margin as 5 to 6 mm. 12,i3 This dictates full coverage of the gingival margins, with or without relief, as the only alternatives. From our study, coverage without relief would appear to be the least harmful, in view of such factors as plaque and possible hormonal overtones of this age group.
Gingival
response to removable uppliances
149
REFERENCES D., and Steffel, 1. Henderson,
V. L.: McCracken’s removable partial prosthodontics, ed. 4, St. Louis, 1973, The C. V. Mosby Company, pp. 99-100. 2. McCracken, W. L.: Survey of partial denture design by commercial dental laboratories, J. Prosthet. Dent. 12: 1089, 1962. 3. Bissada, N. F., Ibrahim, S. I., and Barsoum, W. M.: Gingival response to various types of removable partial dentures, J. Periodontol. 45: 65 l-659, 1974. 4. Adams, C. P.: Removable appliances yesterday and today, AM. J. ORTHOD.
55: 748-764,
1969.
5. Van der Linden, F. P. G. M.: The removable orthodontic appliance, AM. J. ORTHOD. 59: 376-385, 1971. 6. Tulley, W. J., and Campbell, A. C.: A manual of practical orthodontics, Bristol, 1960, John Wright & Sons, Ltd., p. 134. 7. Walther, D. P.: Orthodontic notes, ed. 2, Bristol, 1967, John Wright & Sons, Ltd., p. 110. 8. Liie, H., and Silness, J.: Periodontal disease in pregnancy, Acta Odontol. Stand. 21: 533, 1963. 9. Liie, H.: The gingival index, the plaque index and the retention index systems, J. Periodontal. 38: 610, 1967. 10. Bass, C. C.: An effective method of personal hygiene. II, J. La. M. Sot. 106: 100, 1954. 11. Grant, D. A., Stem, I. B., and Everett, F. G.: Periodontics, ed. 5, St. Louis, 1979, The C. V. Mosby Company, p. 892. 12. Waerhaug, J.: Periodontology and partial prosthesis, Int. Dent. J. 18: 101, 1968. K. L.: Removable partial denture prosthesis for the 13. Willarson, periodontal patient, Dent. Clin. North Am. 13: 263, 1969.