Jan Lindhe. Clinical Periodontology

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584 • CHAPTER

Fig. 27-14. A prominently positioned 13 showing soft tissue recession (a). The same tooth following the completion

of the orthodontic tooth movement (b). Note the reduction of the recession that has taken place as a consequence of

the changed position of the tooth.

Fig. 27-15. Occlusal view of the maxilla in a monkey

showing the position of the central incisors before (a)

and after (b) bodily movement in labial direction. The

canines and lateral incisors were joined in an individ

ual fabricated silver splint and used as anchorage teeth.

studies have shown that labial bone will reform in the

area of a dehiscence when the tooth is retracted to-

wards a proper positioning of the root within the

alveolar process (Engelking & Zachrisson 1982, Kar-

ring et al. 1982) (Fig. 27-13). It is therefore likely that

the reduction in recession seen at a previously promi

nently positioned tooth which has been moved into a

more proper position within the alveolar process, is

also accompanied by bone formation (Fig. 27-14).

Alterations occurring in gingival dimensions and

marginal tissue position in conjunction with ortho-

dontic therapy are related to the direction of tooth

movement. Facial movement results in reduced facial

gingival dimensions, while an increase is observed

following lingual movement (Coatoam et al. 1981,

Andlin-Sobocki & Brodin 1993). Batenhorst et al.

(

1974) and Steiner et al. (1981) used the monkey as an

experimental animal and studied soft tissue altera-

tions following either tipping and extrusion move-

ments or bodily movements of incisors. It was re-

ported that such tooth movements resulted in reces-

sion of the labial gingival margin and loss of attach-

ment. However, similarly designed studies carried out

in dogs (Karring et al. 1982, Nyman et al. 1982) and

humans (Rateitschak et al. 1968) failed to demonstrate

that labial tooth movement is accompanied by mar-

ginal tissue recession and attachment loss. This dis-

crepancy in the response of the marginal soft tissue to

orthodontic therapy in the studies referred to is diffi-

cult to understand but may be related to differences

with respect to (1) the amount of labial tooth displace

ment, (2) the magnitude of force applied, (3) the pres-

ence/absence of plaque and gingival inflammation in

the regions subjected to tooth movement and/or (4)

differences in gingival dimensions. Steiner et al. (1981)

speculated on mechanisms by which gingival tissue

could be lost as a result of labial tooth movement and

suggested that tension in the marginal tissue created

by the forces applied to the teeth could be an impor-

tant factor. If this hypothesis is valid, obviously the

volume (thickness) of the gingival tissue at the pres-

sure side rather than its apicocoronal height would

determine whether or not marginal tissue recession

develops during orthodontic therapy.

Support for this hypothesis is obtained from an

experimental study in monkeys (Wennstr6m et al.

1987) in which teeth were orthodontically moved into

areas with varying thickness and quality of the mar-

MUCOGINGIVAL THERAPY — PERIODONTAL PLASTIC SURGERY • 585

Fig. 27-16. The buccal aspect of the central incisors in the same monkey as in Fig. 27-15, before (a) and after (b) the

labial tooth movement. No obvious change in the location of the gingival margin has occurred despite the pro-

nounced labial displacement of the incisors.

ginal soft tissue. Following extensive bodily move

ment

of incisors in labial direction through the alveolar bone

(Fig. 27-15), most teeth showed a small apical

displacement of the soft tissue margin but no loss of

connective tissue attachment (Fig. 27-16). In other

words, the apical displacement of the gingival margin

was the result of a reduced height of the free gingiva

(

Fig. 27-17), which in turn may be related to tension —

stretching" — in the soft tissues during the facial tooth

movement and reduced buccolingual tissue thickness.

Similar to results presented by Foushee et al. (1985)

from a study in humans, no relationship was found

between the initial apicocoronal width (height) of the

gingiva and the degree of apical displacement of the

soft tissue margin during orthodontic therapy. Hence,

the findings do not lend support to the hypothesis that

certain zone of gingiva is essential for the prevention

recession during orthodontic therapy, but rather

corroborate clinical observations reported by Coa

toam

et al. (1981) suggesting that the integrity of the

periodontium can be maintained during orthodontic

therapy also in areas which have only a minimal zone

of gingiva.

Both Steiner et al. (1981) and Wennstr6m et al.

(

1987) reported that teeth which experienced loss of

connective tissue attachment when orthodontically

moved facially showed obvious clinical signs of in-

flammation throughout the experimental period.

Since

it has been demonstrated that, in the presence of

plaque-induced suprabony lesions, orthodontic forc

generating bodily tooth movement are incapable of

causing accelerated destruction of the connective tis-

sue attachment (Ericsson et al. 1978), it can be assumed

that "stretching" of the facial gingiva may favor the

destructive effect of the plaque-associated inflamma-

tory lesion due to the decreased buccolingual dimen-

sion of the border tissue. This assumption is validated

by the observations that, in the presence of plaque-in-

duced gingivitis, a thin marginal soft tissue is more

susceptible to complete breakdown than a thick one

(

Baker & Seymour 1976). Furthermore, since attach-

ment loss was found to be similar for plaque-infected

teeth which had been bodily moved

within the alveolar

bone

irrespective of the type of soft tissue (gingiva or

lining mucosa) (Wennstr6m et al. 1987), the thickness

rather than the quality of the marginal soft tissue on

the pressure side of the tooth seems to be the deter-

mining factor for the development of recession defects

during orthodontic therapy in plaque-infected denti-

tions. Hence, the observations made in the studies

Fig. 27-17. Histologic specimens showing (a) reduced

alveolar bone height at an incisor bodily moved in la-

bial direction and (b) normal alveolar bone height at a

non-moved control tooth. Note the maintained level of

connective tissue attachment and the reduced height of

the free gingiva at the labially displaced incisor (a).

Large arrows indicate the position of the cemento-

enamel junction and small arrows the position of the al-

veolar bone crest.

586 • CHAPTER

discussed strongly emphasize the importance of ade-

quate plaque control during orthodontic treatment.

Conclusion

The clinical implication of the results from the studies

discussed is that labial tooth movement should be

preceded by careful examination of the dimensions of

the tissues covering the facial aspect of the teeth to be

moved. As long as the tooth can be moved within the

envelope of the alveolar process, the risk of harmful

side-effects in the marginal tissue is minimal, irrespec

tive of the dimensions and quality of the soft tissue. If,

however, the tooth movement is expected to result in

the establishment of an alveolar bone dehiscence, the

volume (thickness) of the covering soft tissue should

be considered as a factor that may influence the devel

opment of soft tissue recession during and/ or after the

phase of active orthodontic therapy. A thin gingiva

may serve as a locus

m-inorlts

resistentine

to developing

soft tissue defects in the presence of plaque-induced

inflammation or toothbrushing trauma.

Gingival dimensions and restorative therapy

The claim has been made that in segments of the

dentition involved in restorative therapy there is a

particular demand for gingiva (Maynard & Wilson

1979, Nevins 1986). The placement of restoration mar

gins subgingivally may not only create a direct opera-

tive trauma to the tissues (Donaldson 1974), but may

also facilitate subgingival plaque accumulation, with

resultant inflammatory alterations in the adjacent

gingiva and recession of the soft tissue margin (Val-

derhaug 1980, Parma-Benfenati et al. 1985). Valder-

haug (1980) evaluated longitudinally over a 10-year

period the soft tissue alterations taking place at facial

sites of 286 teeth with subgingivally or supragingi-

vally placed crown margins in 82 patients. The re-ex-

amination performed 1 year after insertion of the res-

torations revealed that the gingivae at teeth with sub-

gingival restoration margins were more inflamed than

at those with supragingivally placed borders. Of the

150 teeth which at the time of cementation had the

facial crown margin located subgingivally, 40%

showed supragingival exposure of the crown margin

already after 1 year and at the 10-year examination as

many as 71% had become supragingivally positioned

due to recession of the soft tissue margin. Compared

to teeth with supragingivally placed crown margins,

the amount of recession and clinical attachment loss

was greater at sites with subgingivally placed restora-

tion margins.

Stetler & Bissada (1987) evaluated the periodontal

conditions at teeth with subgingivally placed restora-

tion margins on teeth with varying apicocoronal

height of gingiva and found that teeth having a nar-

row (< 2 mm) band of gingiva showed more pro-

nounced clinical signs of inflammation than restored

teeth with a wide gingival zone, but that there was no

difference in loss of probing attachment. However, if

subgingivally placed restorations facilitate plaque ac-

cumulation and the adjacent gingiva is thin, there may

be a potential risk for the development of soft tissue

recession. An experimental study in the beagle dog

(

Ericsson & Lindhe 1984), in which metallic strips

were inserted subgingivally in areas with varying

width of gingiva, showed that in sites with a thin

gingival margin, recession was a more likely conse-

quence of the combined tissue trauma caused by the

insertion of the strip and subsequent plaque accumu

lation during a 6-month period than in sites with a

broad gingival zone. The authors suggested that the

placement of restorations in a subgingival position at

sites with a thin gingiva may in the presence of sub-

gingival plaque favor an inflammatory tissue reaction

which results in loss of tissue height, i.e. in apical

displacement of the soft tissue margin. Accordingly, if

such an apical displacement as a consequence of

plaque-induced inflammation is to be prevented,

either the plaque control standard has to be improved

or the

thickness

of the gingival margin has to be in-

creased. However, an increased gingival dimension

will not reduce the apical propagation of the plaque-

associated lesion and the associated loss of periodon

tal attachment.

Conclusion

Subgingival placement of the margin of a restoration

is likely to result in soft tissue recession over time.

Experimental and clinical data suggest that the thick

ness of the marginal gingiva, but not the apicocoronal

width of the gingiva, is influencing the magnitude of

recession taking place as a result of direct mechanical

trauma during tooth preparation and bacterial plaque

retention.

Indications for gingival augmentation

Scientific data obtained from well-controlled clinical

and experimental studies have unequivocally demon

strated that the apicocoronal width of gingiva and the

presence of an attached portion of gingiva are not of

decisive importance for the maintenance of gingival

health and the height of the periodontal tissues. Con

sequently, the presence of a narrow zone of gingiva

per

cannot justify surgical intervention (Proceedings of

the 1st European Workshop on Periodontology 1994,

Proceedings of the World Workshop on Periodontics

1996). However, gingival augmentation should be

considered in situations where the patient experiences

discomfort during toothbrushing and/or chewing

due to an interfering lining mucosa. Furthermore,

when orthodontic tooth movement is planned and the

final positioning of the tooth can be expected to result

in an alveolar bone dehiscence, an increase of the

thickness

of the covering soft tissue may reduce the risk

for development of soft tissue recession. An increase

of the

thickness

of the gingival margin may in certain

MUCOGINGIVAL THERAPY - PERIODONTAL PLASTIC SURGERY • 5

Fig. 27-18. The use of vestibular extension operations for increasing the width of the gingiva involves the produc-

tion of a wound extending from the gingival margin to a level some mm apical to the mucogingival junction. With the

"denudation" technique all soft tissue is removed, leaving the alveolar bone exposed. With the "split flap" pro-

cedure

only the superficial portion of the oral mucosa is removed, leaving the bone covered with connective tissue.

Fig. 27-19.

Pedicle graft procedure for gingival augmentation. A

lower central incisor with facial soft tissue recession as-

sociated with high attachment of a frenulum (a). The frenulum is released and a split flap of keratinized tissue is

dissected from the area of the neighboring tooth (b). The mobilized soft tissue flap is laterally moved and secured

position at the recipient site (c). The healing result 1-year post-treatment shows the establishment of a broad

zone

of keratinized tissue without interfering frenulum (d).

situations also be considered when subgingival resto-

rations are placed in areas with a thin marginal tissue.

Gingival augmentation procedures

The gingival augmentation operations comprise a

number of surgical techniques, the majority of which

have been developed mainly on an empirical basis

and

without sufficient knowledge of the biology of the

involved tissues. The earliest of these techniques are

the

"vestibular extension operations", which were de-

signed

mainly with the objective of extending the

depth of the

vestibular sulcus (Bohannan 1962a,b). In

recent years,

however, pedicle or free soft tissue grafts

have become

the most commonly used techniques in

588 •

CHAPTER

the management of "insufficient" gingival dimen

sions,

because of higher predictability of the healing

result.

Vestibular/gingival

extension procedures

The "denudation techniques" included the removal of

all soft tissue within an area extending from the gin-

gival margin to a level apical to the mucogingival

junction, leaving the alveolar bone completely ex-

posed (Ochsenbein 1960, Corn 1962, Wilderman 1964)

(Fig. 27-18). Healing following this type of treatment

resulted often in an increased height of the gingival

zone, although in some cases only a very limited effect

was observed. However, the exposure of alveolar bone

produced severe bone resorption with permanent loss

of bone height (Wilderman et al. 1961, Costich & Ram

fjord 1968). In addition, the recession of marginal

gingiva in the surgical area often exceeded the gain of

gingiva obtained in the apical portion of the wound

(

Carranza & Carraro 1963, Carraro et al. 1964). Due to

these complications and severe postoperative pain for

the patient, the use of the "denudation technique" can

hardly be justified.

With the "periosteal retention" procedure or "split

flap" procedure (Fig. 27-18) only the superficial por-

tion of the oral mucosa within the wound area is

removed, leaving the bone covered by periosteum (

Staffileno et al. 1962, Wilderman 1963, Pfeifer 1965,

Staffileno et al. 1966). Although the preservation of the

periosteum implies that less severe bone resorption

will occur than following the "denudation technique",

loss of crestal bone height was observed also

following this type of operation unless a relatively

thick layer of connective tissue was retained on the

bone surface (Costich & Ramfjord 1968). If a thick

layer was not secured, the periosteal connective tissue

tended to undergo necrosis and the subsequent heal-

ing closely resembled that following the "denudation

technique" described above.

Other described gingival extension procedures

maybe regarded as modifications of the "denudation"

and "split flap" techniques or combinations of these

procedures. The apically repositioned flap procedure

(

Friedman 1962), for instance, involved the elevation

soft tissue flaps and their displacement during

suturing in an apical position, often leaving 3-5 mm

of alveolar bone denuded in the coronal part of the

surgical area. This resulted in the same risk for exten

sive bone resorption as other "denudation tech-

niques". It was proposed by Friedman (1962) that a

postsurgical increase of the width of the gingiva can

be predicted with the "apically repositioned flap", but

several studies indicated that the presurgical width

most often was retained or became only slightly in-

creased (Donnenfeld et al. 1964, Carranza & Carraro

1970).

The described vestibular/ gingival extension proce-

dures were based on the assumption that it is the

frictional forces encountered during mastication

which determine the presence of keratinized tissue

adjacent to the teeth (Orban 1957, Pfeifer 1963). There

fore, it was believed that by the displacement of mus-

cle attachments and the extension of vestibular depth,

the regenerating tissue in the surgical area would be

subjected to physical impacts and adapt to the same

functional requirements as those met by "normal"

gingiva (Ivancie 1957, Bradley et al. 1959, Pfeifer 1963).

Later studies, however, showed that the characteristic

features of the gingiva are determined by some inher-

ent factors in the tissue rather than being the result of

functional adaptation, and that the differentiation

(

keratinization) of the gingival epithelium is control-

led

by morphogenetic stimuli from the underlying

connective tissue (see Chapter 1).

Grafting procedures

The gingival and palatal soft tissues will maintain

their original characteristics after transplantation to

areas of the alveolar mucosa (see Chapter 1). Hence,

the use of transplants offers the potential to predict the

postsurgical result. The type of transplants used can

be divided into (1) pedicle grafts, which after place-

ment at the recipient site maintain their connection

with the donor site (Fig 27-19), and (2) free grafts,

which have no connection with the donor area (Fig.

27-20). Free grafts have most commonly been used for

gingival augmentation (Haggerty 1966, Nabers 1966,

Sullivan & Atkins 1968a, Hawley & Staffileno 1970,

Edel 1974).

Technique

• The surgical procedure is initiated with the prepa-

ration of the recipient site (Fig. 27-20a,b). By sharp

dissection a periosteal bed free from muscle attach-

ment and of sufficient size is prepared. The partial

thickness flap is displaced apically and sutured.

• In order to ensure that a graft of sufficient size and

proper contour is removed from the donor area,

usually the palatal mucosa in the region of the

premolars, it is recommended to produce a foil

template over the recipient site. The template is

transferred to the donor site where it is outlined by

shallow incision (Fig. 27-20c). A graft with a thick

ness of approximately 1.5-2 mm is then dissected

from the donor area (Fig. 27-20d). It is advocated to

place the sutures in the graft before it is cut com-

pletely free from the donor area, since this may

facilitate its transfer to the recipient site.

• The graft is immediately transferred to the prepared

recipient bed and sutured (Fig. 27-20e). In order to

immobilize the graft at the recipient site the sutures

must be placed in the periosteum or the adjacent

attached gingiva. After suturing, pressure is exerted

against the graft for 5 min in order to eliminate

blood and exudate between the graft and the recipi-

ent bed. The graft as well as the palatal wound is

protected with a periodontal dressing. To retain the

dressing in the palatal site, a stent usually has to be

used.

MUCOGINGIVAL THERAPY — PERIODONTAL PLASTIC SURGERY • 5

Fig. 27-20.

Grafting procedure for gingival augmentation. A

mandibular molar at which the patient experiences discom

fort during toothbrushing due to interfering lining mucosa and high attachment of a frenulum (a). The decision

was made to apically displace the attachment of the frenulum and augment the gingival zone through the place-

ment of a free graft.

partial thickness flap is dissected to prepare a recipient bed. The flap is apically displaced

and sutured (b).

graft with a thickness of 1.5-2 mm and of sufficient size and contour (a foil template of the recipi

ent site may be used) is dissected from the palatal mucosa in the region of the premolars (c-d). The graft is immedi

ately transferred to the prepared recipient bed and anchored by sutures to secure a close adaptation of the graft to

the recipient bed (e).

periodontal dressing is applied to protect the graft. Following healing, a broad zone of kerat

inized tissue has been established (f).

• The sutures and periodontal dressing are removed

after 1-2 weeks.

For a description of the pedicle graft procedure, see

Root coverage procedures" later in the chapter.

Healing following gingival augmentation

procedures

Vestibular/gingival extension procedures

Since the specificity of the gingiva is determined by

some inherent factor in the tissues, the postoperative

results of vestibular extension procedures depend on

the degree to which the various tissues contribute to

the

formation of granulation tissue in the wound area

590 • CHAPTER 27

Fig. 27-22. Clinical photographs of the buccal aspect of

a canine and a premolar following the removal of the

entire zone of gingiva by a gingivectomy procedure (a).

The healing result 9 months after surgery (b) shows the

regain of keratinized tissue.

(Karring et al. 1975). Following the "denudation" or

split flap technique", the wound area is filled with

granulation tissue derived from the periodontal liga-

ment, the tissue of the bone marrow spaces, the re-

tained periosteal connective tissue, and the surround-

ing gingiva and lining mucosa (Fig. 27-21). The degree

of bone resorption induced by the surgical trauma

Fig. 27-23. Clinical photographs of a tooth region sub-

jected to excision of the entire zone of gingiva by a flap

procedure. The alveolar mucosa has been coronally dis

placed to achieve complete coverage of the surgically

exposed alveolar bone (a). Healing has resulted in the

reformation of a narrow zone of gingiva on the buccal

aspect of the teeth, 9 months post-surgery (b).

influences the relative amount of granulation tissue

which grows into the wound from these various tissue

sources. The resorption of crestal bone exposes vary

ing

amounts of the periodontal ligament tissue in the

marginal area allowing granulation tissue from the

periodontal ligament to fill out the coronal portion of

the

wound. The greater the bone loss, the greater the

Fig. 27-21. Schematic drawing illustrating different stages of healing following the "split flap" (a) and "denuda

tion" (

b) techniques. Cells from the oral mucosa, bone and periodontal ligament (arrows) participate in granulation tissue

formation. Due to the difference in the degree of bone resorption (a-2, b-2), a larger area of the coronal por

tion of

the wound is filled with granulation tissue from the periodontal ligament following "denudation" than fol

lowing the

"split flap" technique. Since granulation tissue from the periodontal ligament possesses the ability to in

duce a

keratinized epithelium,

denudation" usually results in a wider zone of keratinized tissue than is the case

following

the "split flap" technique (a-3, b-3).

MUCOGINGIVAL THERAPY — PERIODONTAL PLASTIC SURGERY • 591

portion of the wound which becomes filled with

granulation tissue from the periodontal ligament. This

particular tissue possesses the capability to induce

keratinization of the covering epithelium. This means

that the widening of the keratinized tissue following "

denudation" and "split flap" operations is achieved

the expense of a reduced bone height. The "denu-

dation technique" results usually in more bone loss

than the "split flap technique". Therefore, a greater

amount of granulation tissue with the capability of

inducing a keratinized epithelium develops in the

marginal area following the "denudation technique"

than following the "split flap technique". This is in

accordance with the clinical observation that the

denudation technique" usually is superior to the

split flap technique" in increasing the width of kerat-

inized tissue (Bohannan 1962a,b).

In a clinical study by Wennstr6m (1983) periodontal

pockets were eliminated by the use of a "gingivec-

tomy" or a "flap" procedure, both of which involved

the

complete removal of the keratinized tissue. In the

gingivectomy" procedure the wounded area was left

heal by second intention, while in the "flap" proce-

dure the alveolar mucosa was repositioned to achieve

complete coverage of the surgically exposed alveolar

bone (Figs. 27-22a & 27-23a). Irrespective of the surgi

cal technique used, healing resulted in the reformation

of keratinized tissue, the width of which, however,

was greater following the "gingivectomy" procedure

than following the "flap" procedure (Figs. 27-22b &

27-23b). The gingiva was formed because granulation

tissue from the periodontal ligament with the capacity

of inducing a keratinized epithelium had proliferated

coronally along the root surface. This granulation tis-

sue formation was obviously favored by a more pro-

nounced bone resorption during the healing follow-

ing the "gingivectomy" procedure.

It can be concluded that the success or failure in

extending the width of keratinized tissue by the

denudation" or "split flap" techniques rests with the

origin of granulation tissue, which is related to the

extent of bone loss induced by the surgical trauma.

This in turn means that the result with respect to

increasing the gingival width by methods involving

periosteal exposure or denudation of the alveolar

bone is unpredictable. The use of such methods is

therefore not justified in periodontal therapy. The pro

cedures discussed merely represent examples of how

lack of knowledge about basic biologic principles may

Fig. 27-24. Schematic drawings illustrating healing of a free gingival graft placed entirely on a connective tissue re-

cipient bed (a). A cross-section through the area is shown in (b). The framed areas (c) illustrate the three phases into

which the healing process can be divided.

592 • CHAPTER 27

lead to the development of inappropriate therapeutic

methods.

Grafting procedures

Healing of free soft tissue grafts placed entirely on a

connective tissue recipient bed has been studied in

monkeys by Oliver et al. (1968) and Nobuto et al.

(

1988). According to these authors, healing can be

divided into the following three phases (Fig. 27-24).

The initial phase (from 0 to 3 dams)

In these first days of healing a thin layer of exudate is

present between the graft and the recipient bed. Dur-

ing this period the grafted tissue survives with an

avascular "plasmatic circulation" from the recipient

bed. Therefore, it is essential for the survival of the

graft that a close contact is established to the underly

ing recipient bed at the time of operation. A thick layer

of exudate or a blood clot may hamper the "plasmatic

circulation" and result in the rejection of the graft. The

epithelium of the free graft degenerates early in the

initial healing phase, and subsequently it becomes

desquamated. In placing a graft over a recession, part

of the recipient bed will be the avascular root surface.

Since the graft is dependent on the nature of its bed

for diffusion of plasma and subsequent revasculariza-

tion, the utilization of free grafts in the treatment of

gingival recessions involves a great risk of failure. The

area of the graft over the avascular root surface must

receive nutrients from the connective tissue bed that

surrounds the recession. Thus, the amount of tissue

that can be maintained over the root surface is limited

by the size of the avascular area.

Revascularization phase (from 2 to 11 days)

After 4-5 days of healing, anastomoses are established

between the blood vessels of the recipient bed and

those in the grafted tissue. Thus, the circulation of

blood is re-established in the preexisting blood vessels

of the graft. The subsequent time period is charac-

terized by capillary proliferation, which gradually

results in a dense network of blood vessels in the graft.

At the same time a fibrous union is established be-

tween the graft and the underlying connective tissue

bed. The re-epithelialization of the graft occurs mainly

by proliferation of epithelium from the adjacent tis-

sues. If a free graft is placed over the denuded root

surface, apical migration of epithelium along the

tooth-facing surface of the graft may take place at this

stage of healing.

Tissue maturation phase (from 11 to 42 days)

During this period the number of blood vessels in the

transplant becomes gradually reduced, and after ap-

proximately 14 days the vascular system of the graft

appears normal. Also, the epithelium gradually ma-

tures with the formation of a keratin layer during this

stage of healing.

The establishment and maintenance of a "plasmatic

circulation" between the recipient bed and the graft

during the initial phase of healing is critical for the

result of this kind of therapy. Therefore, in order to

ensure ideal conditions for healing, blood between the

graft and the recipient site must be removed by exert-

ing pressure against the graft following suturing.

ROOT COVERAGE

The main indications for root coverage procedures are

esthetic /cosmetic demands (Fig. 27-25) and root hy-

persensitivity and management of shallow root caries

lesions and cervical abrasions. Changing the topogra-

phy of the marginal soft tissue in order to facilitate

plaque control is also a common indication for root

coverage procedures (Fig. 27-26).

It should be recalled that the two major causative

factors in the development of marginal tissue reces-

sions are plaque-induced periodontal inflammation

and trauma caused by toothbrushing. The control of

these factors will in most cases prevent further pro-

gression of the recession. This means that in tooth

regions with a thin covering soft tissue, with or with-

out an incipient recession, the patient should be en-

couraged to carry out effective but at the same time

non-traumatic plaque control measures. With respect

to toothbrushing, the Bass' method (Chapter 21)

should be avoided and the patient should be in-

structed to use a technique creating as little apically

directed pressure on the soft tissue margin as possible.

A soft toothbrush should, of course, be used.

Miller (1985a) described a useful classification of

recession defects, taking into consideration the antici

pated root coverage that it is possible to obtain (Fig.

27-27):

• Class I: Marginal tissue recession not extending to

the mucogingival junction. No loss of interdental

bone or soft tissue.

• Class II: Marginal tissue recession extends to or

beyond the mucogingival junction. No loss of inter-

dental bone or soft tissue.

• Class III: Marginal tissue recession extends to or

beyond the mucogingival junction. Loss of inter-

dental bone or soft tissue is apical to the cemento-

enamel junction, but coronal to the apical extent of

the marginal tissue recession.

• Class IV: Marginal tissue recession extends beyond

the mucogingival junction. Loss of interdental bone

extends to a level apical to the extent of the marginal

tissue recession.

While complete root coverage can be achieved in Class

I and II defects, only partial coverage may be expected

in Class III. Class IV recession defects are not amena-

ble to root coverage. Consequently, the critical clinical

variable to assess in order to determine the possible

outcome of a root coverage procedure is the level of

MUCOGINGIVAL THERAPY — PERIODONTAL PLASTIC SURGERY • 593

Fig. 27-25. A 25-year-old woman having esthetic concerns due to multiple soft tissue recessions in the maxilla and a

high lip line (a). The gingiva is healthy and several of the exposed root surfaces show abrasion defects, indicating

toothbrushing trauma as the causative factor for the development of the recessions. The brushing technique was al-

tered and root coverage was surgically achieved. The 2-year post-treatment view (b).

Fig. 27-26. A mandibular canine with a deep recession,

which offers problems with respect to self-performed

plaque control (a). To facilitate plaque control the posi-

tion of the soft tissue margin was altered surgically (b).

Fig. 27-27. The Miller classification of recession defects (see text).