Managing the consequences of periodontal diseases/treatment: gingival recession

Plaque-induced factors

When subgingival plaque is present, an associated lateral and apical extension of the inflammatory cell infiltrate is usually present to a maximum depth of 1−2 mm. In thick gingival tissues this infiltrate will therefore only occupy a small portion of the connective tissue, whereas in thin gingiva potentially the entire connective tissue will be occupied. Histologically, this then leads to proliferation of the basal layers of the epithelium into this area.⁸ In addition, the proliferation of the epithelial cells from the oral and dento-gingival epithelium into the thin and degraded connective tissue may cause subsidence of the epithelial surface which will manifest itself as recession.

Recessions associated with periodontitis

As a consequence of the resolution of periodontal lesions following non-surgical and surgical treatment, loss of surrounding tissue height can occur. This may result in compensatory remodelling at the buccal or lingual aspects and thereby an apical shift of the gingival margin.

Mechanical and physical trauma

In the past, ‘improper toothbrushing’ technique was considered to be the most significant traumatic, mechanical factor contributing to the presence of GR lesions (Figure 1). This suggests that recession may be equally distributed throughout the mouth. However, the buccal surfaces of upper canines and premolars have often been described as being common sites of toothbrushing-associated GR.⁹ This is often also related to ‘handedness’ whereby the intra-oral site, which is opposite to the user's dominant hand, is often brushed first and for the longest period of time.¹⁰ This may explain the increased presence of GR at certain sites in the mouth.

The choice of toothbrush used could also have an effect. Dorfer et al¹¹ conducted a study in which sites with pre-existing recession sites were brushed with either a manual or a powered toothbrush for six months. Of the sites, 51% remained unchanged with use of the powered brush and this was greater than the number of unchanged manually brushed sites. This suggests that perhaps, if individuals use a powered brush with force control, the incidence of GR may be lower. Overall, it appears that the association between toothbrushing and GR is not straightforward. The conclusions of the systematic review by Rajapakse et al, where it stated that ‘there was insufficient evidence to support or refute the association between tooth brushing and GR’ at this point, seem well founded.¹² It should be noted that the combination of a traumatic factor, be it toothbrushing or otherwise, when exerted in the presence of a predisposing factor such as a thin periodontal phenotype, will more likely lead to GR.

Physical trauma can arise from self-induced factors such as lip and tongue piercings. In this regard, tongue piercing is affiliated with lingual recession of anterior teeth and damage of posterior teeth,¹³ whereas buccal/labial recession is more common with lip piercing, depending on the position of the stud.¹⁴ Long-term use of these piercings increases the prevalence of the above recession defects.^13,14

Poorly designed/ill-fitting partial dentures act as other physical factors which can cause GR, particularly on abutment teeth, and place pressure on the supporting tissues. The association between removable partial dentures and recession has been affirmed in case reports and studies.^15,16 Habitual behaviours, such as pen/pencil and fingernail biting, can also lead to self-induced injuries, with the latter being highlighted as a frequent cause of GR.¹⁷

Chemical trauma

Gingival recession can also result from contact of chemicals with the attached gingiva. Drugs such as aspirin, when held on the tissues, can lead to a chemical burn, as can hydrogen peroxide and endodontic irritants such as sodium hypochlorite. The habitual topical application of cocaine has also been seen to cause localized injury.¹⁸

Smoking tobacco has long been a well-established risk factor for periodontitis and, in comparison to non-smokers, an increased prevalence of GR has been shown in those who either smoke or use smokeless tobacco.^19,20 The exact mechanisms for this finding are not yet fully understood, but it has been suggested that reduced gingival blood flow that has been reported in smokers, or their reduced immune response, such as the altered neutrophil chemotaxis and phagocytosis, may also act as contributory factors.

Tooth position/malposition

The bucco-lingual position and orientation of the tooth in the alveolar housing can influence the thickness of the overlying gingival tissues and thus also the degree of recession present. It has been reported that the mandibular incisors are the teeth most susceptible to post-orthodontic recession²¹ and, where labial GRs is present, it was shown that an underlying alveolar bone dehiscence always existed. In addition, in the same study, the authors concluded that a direct correlation existed between the labial bone dehiscence and the corresponding degree of recession.²¹ Furthermore, malocclusions such as a deep overbite can contribute to both hard and soft tissue injury, with sites of GR frequently being found palatal to the upper incisors and labial in the mandibular anterior segment.²²

Other factors

Other incidental causes of GR include overheated ultrasonic scaler tips causing thermal injury, and incorrect flossing technique by individuals particular about their oral hygiene.¹⁶

Measuring the recession defect

The clinical and radiographic assessment of GR and the associated hard tissues is imperative for effective diagnosis and treatment planning. For a basic periodontal examination, the use of the periodontal probe measuring from the cemento-enamel junction to the level of the gingival margin is adequate for the initial recession measurements and this can be taken at three labial and three lingual points in order to gain a greater understanding of the local variations and underlying alveolar architecture.

Classification of gingival recession

Miller's Classification

Miller's Classification of GR was first proposed in 1985 and is widely used today. There are four types of recession defects in the classification, and each one considers the evaluation of both the soft and hard periodontal tissues, and is used to predict potential root coverage from surgical techniques.²³

The original Miller's classification, along with the expected root coverage following surgical treatment, is presented in Table 1 and Figure 2.

Table 1. Miller's classification of gingival recession.

Class	Description	Expected Root Coverage
Class I	Marginal tissue recession, which does not extend to the mucogingival junction (MGJ). There is no loss of the interdental bone or soft tissue	Full root coverage
Class II	Marginal tissue recession, which extends to or beyond the MGJ. There is no loss of interdental bone or soft tissue	Full root coverage
Class III	Marginal tissue recession, which extends to or beyond the MGJ. There is loss of interdental bone or soft tissue, and/or malpositioning of the tooth	Partial root coverage
Class IV	Marginal tissue recession extending to or beyond the MGJ There is severe loss of interdental bone or soft tissue, and/or severe malpositioning of the tooth	No root coverage

The surgical management techniques for GR defects have significantly developed since the introduction of the above classification, but there are no reported successful techniques for the management of Miller Class IV recession defects.

Various limitations of the classification have become apparent through practice. Some of these include difficulty in identifying the mucogingival junction, and therefore differentiating between Class I and Class II,⁵ and also lack of detail regarding assessment of bone loss interdentally.²³ The importance of interdental clinical attachment level (CAL) for predicting root coverage has been widely reported.

Conservative management of gingival recession

Managing the aetiological components and recognizing the contributing factors are essential in developing interventions for GR. Some local factors, such as periodontal phenotype, are difficult to modify, however, tooth position may be corrected using orthodontics. Patient education regarding atraumatic toothbrushing and optimal oral hygiene practices are primary concerns, as is the management of gingival inflammation through preventive therapies. The response can be monitored using objective sequential measurements, clinical photographs or dated study models.

Gingival veneers

In advanced conditions of GR, principally in the upper anterior region, where the loss of interdental papillae may cause notable aesthetic distress in patients, surgical intervention may not be possible. This is especially true where there is generalized Miller IV recession, for instance following treatment of generalized periodontitis. A gingival veneer prosthesis, made of acrylic or silicone materials, can be used to conceal the deficit of soft tissue (Figure 3).

The gingival veneer may be used as a provisional measure for patients who want to assess their treatment options before complex treatment. Some may choose to wear it long term when the risk of complex treatment, as recognized by patients, outweighs the advantages.²⁴ The veneer is easy to fabricate and tends to be comfortable to wear. However, the design must incorporate open embrasures. There may also be difficulty in achieving retention, staining, possibility of fracture during cleansing and plaque accumulation,²⁵ although many of these risks are eliminated by the use of silicone materials.

Pedicle flap procedures

This method classically involves displacing a soft tissue flap laterally or vertically to a donor site whilst maintaining its intact vascular supply.

Coronally Advanced Flap (CAF)

This is based on the coronal shift of a pedicle flap onto the exposed root surface. The flap must have adequate keratinized tissue apical to the defect. It is one of the most predictable techniques for the treatment of localized or multiple recession type defects if sufficient donor tissue is available. It can be used in combination with grafts to achieve expected root coverage and gain in keratinized gingival tissue width²³ (Figure 4).

Epithelialized free gingival graft

Free gingival grafts (FGG) are generally considered as a means of management of narrow, isolated recession defects, usually in areas of low aesthetic demand due to an unpredictable colour match between the grafted tissue and adjacent tissue. However, they may also be used to replace keratinized tissue in order to facilitate local oral hygiene, with any other (root) coverage as a secondary aim, either around teeth or implants.

The FGG is taken from the donor site, most commonly the premolar and first molar areas of the palate to avoid the palatine blood vessels, and placed on a de-epithelialized recipient bed at the defect area and sutured (Figure 5). A foil template of the GR defect can be used to establish the correct FGG dimensions from the harvested site. This technique increases the amount of keratinized tissue at the defect site.²⁸ This was supported by a retrospective long-term study.²⁹

Harvesting the graft from the palate requires a second surgical procedure which is often associated with increased patient morbidity, extended surgical time and potential post-operative complications, such as bleeding and infection and increased discomfort experienced by the patient, as the wound heals by secondary intention.³⁰

Subepithelial connective tissue graft

This method is widely employed to gain total root coverage in isolated and multiple defect sites. It requires harvesting of a connective tissue graft (CTG), commonly from the palate, which is sutured onto the defect and subsequently covered by a CAF. It carries advantages over the FGG as, firstly, the donor site may be a closed wound, healing by primary intention, which may produce less post-operative discomfort and, secondly, there is a closer colour blend of the graft with adjacent tissues.³¹

More recently, CTGs have been combined with partial and full thickness pouches, tunnels and pinhole surgical techniques to treat isolated and multiple defect sites. These approaches may improve the treatment outcome but are operator and technique sensitive. CTG under a CAF has not only the highest percentage of mean root coverage, but also the least variability³² and a high degree of long-term stability²⁶ (Figure 6).

Processed soft tissue graft

Xenogeneic collagen matrix (XCM)

Lately developed, XCM is a porcine-derived bioresorbable product which has been shown to encourage regeneration of keratinized gingiva around teeth with gingival defects in tissue augmentation procedures. Based on limited evidence, a study of the use of XCM under CAFs found this to be less invasive and time consuming with unlimited ‘off the shelf’ supply of grafting material and no additional harvest site with its associated pain and morbidity.³³ Also, this combination may improve mean root coverage and provide greater recession reduction compared to CAF alone (Figure 7). There is no significant difference in the above outcome when differentiating XCM from CTG for single or multiple recession sites.³⁴

Guided Tissue Regeneration (GTR)

This technique, originally used for the management of alveolar bone loss, has been proposed for the reconstruction of GR defects. The potential advantages of applying principles for GTR to gingival flap procedures is the possibility of achieving periodontal regeneration (regrowth of the entire attachment apparatus) to the exposed root surface.³⁶ In this situation, a bioresorbable membrane is placed beneath a CAF and adapted to the root surface, with the aim of excluding gingival epithelial growth that may inhibit periodontal regeneration. However, two systematic reviews concluded that connective tissue grafting techniques appear to generate better outcomes than GTR^37,38 when both are combined with a CAF.

Enamel Matrix Derivative (EMD)

Enamel Matrix Derivative, a porcine-derived product, can be used in combination with a CAF for periodontal regenerative therapy of recession defects. It can result in root coverage similar to CTG but without donor site surgery by enhancing soft tissue healing and root coverage.³⁵ However, a meta-analysis concluded that CTG, when combined with CAF, contributed more in the increase of keratinized tissue width³⁹ than with EMD. Furthermore, EMD is not suitable for all recession defects.⁴⁰

Leukocyte and Platelet Rich Fibrin (L-PRF)

Leukocyte and Platelet Rich Fibrin, a second generation platelet concentrate, is a novel approach used in the treatment of GR in conjunction with CAF. L-PRF is a source of autogenous growth factors that promote cell migration and proliferation, however, evidence regarding this is limited. A recent comparative study concluded that L-PRF may be utilized as an alternative treatment, when compared with CTG, as it had significant improvements in recession height and width, gain in keratinized tissue and clinical attachment.⁴¹

Anatomy

Anatomy of the area of the recession defect will influence treatment options. For example, CAFs may be a good choice for use in the maxilla, but often inappropriate for use in the mandible due to thin tissue apical to the recession and the presence of frenae and other critical anatomical structures. A CTG combined with a CAF can be used if there is a compromise in the quality of the tissue apical to the recession defect; this method may also be used around dental implants where the mucosa is thin.

Aesthetics

The major indicator for correction of recession defects is aesthetic demand, which is perhaps most appropriately assessed using patient-reported outcomes. However, there are insufficient data with respect to these, as well as other patient-centred outcomes such as root sensitivity, pain/discomfort and post-operative complications.⁴² When considering aesthetics as a primary treatment outcome, one must consider the amount of root coverage, tissue thickness, colour, texture and compare these to the adjacent teeth. Pedicle grafts are often good for achieving these aesthetic outcomes as the tissue will be similar to surrounding tissues.