Increasing a band of keratinized gingiva during surgical exposure of an impacted maxillary lateral incisor: a case report

Gregg Caserta &;Michael Young

A 13 year old patient presented with an impacted maxillary lateral incisor labially positioned in alveolar mucosa. Periodontal surgery was undertaken to expose the tooth and to establish a zone of keratinized gingiva. The importance of such a procedure should be considered in regard to maintaining gingival health in cases of inadequately keratinized gingiva.

INTRODUCTION
In the mixed dentition, the position of a tooth erupting through the alveolar process and its ultimate position in relation to the buccolingual dimension of the alveolar process can have a profound outcome on the amount of attached gingiva around the tooth.1 The keratinized gingiva of the facial area of the human dentition extends from the gingival margin to the mucogingival junction.2 It includes the free and attached gingiva. The width of the keratinized gingiva varies not only from one individual to another but also between different areas of the dentition. Bowers (1963) suggested that it ranges from one to nine millimeters.3 Usually, the facial keratinized gingiva is widest in the area of upper and lower incisors and narrowest in the area of mandibular canines and first premolars.4 The lingual gingiva of the lower jaw exhibits its greatest width in the area of the premolars and molars. The incisor shows the narrowest lingual gingiva.4 In the maxilla the facial gingiva is generally 0.5 - 1 millimeter wider than in the mandible.4 Keratinized tissue possesses the unique characteristic of being more suitable to withstand the trauma of mastication and toothbrushing than the non-keratinized alveolar mucosa. Lang &;Loe (1972) showed that areas with minimal amounts of attached gingiva may, by their increased mobility, facilitate subgingival plague deposition.4 Consequently, a variety of surgical procedures have been developed to maintain or to establish a zone of keratinized gingiva or to increase its width as part of the overall treatment of periodontitis. In this paper, a case report is presented to discuss the validity of utilizing periodontal surgery to increase a band of keratinized tissue in a case of an impacted incisor erupting from the alveolar mucosa.

CASE REPORT

The patient was a healthy 13 year old Hispanic female. Upon intra-oral examination, a delayed eruption of the maxillary left lateral incisor was noted (Fig. 1).

The tooth showed an erupting position that was facial to the crest of the alveolar process and entirely within the area of the non-keratinized alveolar mucosa (Fig. 2).

Following local anesthesia, a horizontal, approximately 3 millimeters wide, incision was made through the keratinized gingiva along the incisal edge of the unerupted incisor. Two vertical releasing incisions were subsequently made. A partial thickness flap was then elevated while carefully retaining the keratinized tissue. Next, the alveolar mucosa was retracted to expose the crown of the tooth (Fig. 3).

An orthodontic bracket was cemented in place on the labial surface. The elevated flap was sutured apical to the incisor and the carefully preserved zone of keratinized gingiva was sutured apical to the exposed crown. The flap was secured in place with the use of two interrupted 5-O silk sutures. The patient was given oral hygiene instruction that included normal rinsing of the mouth for seven days but no toothbrushing. One week later, sutures were removed and the area evaluated. The clinical examination revealed favorable response that bleeding an inflammation were not noticed. Mechanical tooth brushing was reinstated one week after the surgery. After three weeks, the surgical site had revealed with a zone of keratinized gingiva (Fig. 4).

The patient was followed-up by her orthodontist to bring the maxillary lateral incisor into proper occlusion.

DISCUSSION

Mucogingival surgery was performed to create a healthy band of keratinized gingiva through careful manipulation of the gingival epithelium. In areas with no keratinized tissue gingival inflammation may result in gingival recession. Treating or not treating mucogingival problems before or after recession has occurred remains controversial. The rationale for performing mucogingival therapy in the child or adolescent varies from an adult. For instance, the majority of young patients are not known to practice good oral hygiene which is essential for plaque control. Moreover, pediatric patients present with a greater concern over their root sensitivity and cosmetic appearance. Medico-legal issue should also be addressed in this case since the patient is entitled to be informed about the outcome of not receiving mucogingival therapy that may result in potential gingival complication. All these factors play an important role in determining the decision to perform mucogingival therapy.

The study by Lang &;Loe (1972) demonstrated that although tooth surfaces may be kept free of clinically detectable plaque, areas with less than two millimeters of keratinized gingiva persisted to remain inflamed.4 The study proposed that a movable gingival margin would facilitate the introduction of microorganisms into the gingival crevice resulting in a thin subgingival bacterial plaque that would be difficult to detect and not easily removed byconventional toothbrushing.4 By creating a band of keratinized gingiva, the gingival integrity is augmented.

The study conducted by Powell and McEniery (1979) documented that 12% of the pediatric patients with localized recession continue to show further breakdown and recession even with professional cleaning and supervised brushing every two weeks for two years.5 Pediatric patients with difficulty maintaining a plaque free oral environment under such close attention are at greater risk for developing gingival recession. This strongly suggests that young patients with inadequate keratinized gingiva and inadequate oral hygiene can significantly benefit from prophylactic surgical therapy to augment the zone of keratinized tissue.

In the case of root sensitivity, a child possesses significantly larger pulp chambers and root canals than in an adult. Subsequently, more thermal and external irritation can be perceived by a pediatric patient than by an adult patient with similar root exposure. This can lead to a decrease in oral hygiene effectiveness since toothbrushing can create external irritation. As a result of the poor oral hygiene, plaque accumulation may lead to further gingival complications. Therefore, potential root exposure resulting from gingival recession may require a higher order of prophylactic mucogingival therapy to promote oral hygiene and avoid gingival destruction.

Regarding the consideration of the child's cosmetic appearance, a young child can be frequently challenged for his/hers physical appearance from his/hers peers. A child who shows receded gingiva may appear to have longer teeth which can be embarrassing. Thus, the esthetic impact of the mucogingival defect should not be ignored by the clinician.

As informed consent becomes an increasing sensitive issue, it is the duty of the dentist to provide the best treatment or any relevant information regarding the patient's overall health. Although recession may not arise without any prophylactic treatment, such treatment must be suggested and discussed with the patient or his/hers parent. Hall (1981) states that if recession that might have been prevented occurs and 'damage' in a legal sense occurs, it is malpractice and may result in a monetary award.6 In other words, failure of the dentist or the periodontist to inform the patient about the potential harm of not receiving mucogingival therapy in the case of inadequate keratinized gingiva can result in negligence.

CONCLUSION

Although no specific number of millimeters of keratinized gingiva has been proven to be 'adequate', clinical judgment factors which can be useful in assaying the adequacy of keratinized gingiva in individual cases have been commonly applied. Nevertheless, the patient in this case presented with the potential mucogingival destructive factors that could benefit from a prophylactic mucogingival treatment. The suggested therapy was undertaken to repair the defect before a loss of attachment and recession. This treatment demonstrates a more predictable outcome than attempting to cover up any root surface exposure that may develop later. Finally, the importance of allowing the patient to understand the potential defect and its outcome and the options to choose whether or not to receive prophylactic treatment is clearly the main issue of professional dedication to the patient.

SOURCES

1.Maynard, J. G., &;Ochsenbein, C.: Mucogingival problems, prevalence and therapy in children. J. Periodont. 46:543, 1975

2.Wennstr"m, J., Lindhe, J., &;Nyman, S.: Role of keratinized gingiva for gingival health. J. Clin. Periodontol. 8:311-328, 1981

3.Bowers, G.: A study of the width of attached gingiva. J. Periodont. 34:201-209, 1963

4.Lang, N. P. &;L"e, H.: The relationship between the width of keratinized gingiva and gingival health. J. Periodont. 43:623-627, 1972.

5.Maynard, J. G.: The rationale for mucogingival therapy in the child and adolescent. The international journal of periodontics and restorative dentistry. Jan.:37-51, 1987

6.Hall, W. B.: The current status of mucogingival problems and their therapy. J. Periodont. Sept.:569-575, 1981