Bidirectionally positioned flap technique for molar class II furcation defect- 1 year follow up.

In the treatment of Class II furcation defects, guided tissue regeneration (GTR) in combination with bone grafts has provided better treatment outcomes in comparison to GTR alone. A 48-year-old male patient reported with a chief complaint of pain and bleeding in the right lower back teeth area from 3 months. On clinical and radiographic evaluation, a Class II buccal furcation defect was detected in tooth #46. A bidirectionally positioned flap (BPF) technique in combination with bone graft was done to treat the defect following nonsurgical therapy. The healing was satisfactory postoperatively. The patient was recalled for supportive periodontal therapy at 3, 6, and 12 months. Clinical and radiographic outcomes after 12 months revealed possible new attachment and stable periodontal status. It is concluded that inner periosteal flap in BPF technique may serve as an alternative technique to GTR barrier membranes in case of Class II furcation defects.

INTRODUCTION

Treatment of Class II molar furcation defects continually remains a treatment dilemma. Present-day evidence advocates guided tissue regeneration (GTR) alone and in combination with bone grafts over open flap debridement (OFD) for the same.[1] However, the quest for newer treatment strategies continues, and newer materials are being explored for regeneration in furcation defects. The regenerative potential of the alveolar periosteum has also been evaluated in Class II furcation defects. It has been used in the form of connective tissue grafts (CTGs) incorporating its periosteum from the palate[2] as well as pedicle periosteal repositioned flaps.[34] Nonetheless, there is little evidence to support the role of periosteal barriers for GTR therapy in the treatment of Class II furcation defects.

A bidirectionally positioned flap (BPF) technique was proposed by Iwano et al.[5] in case of recession defect as an alternative to CTG. It delivered an advantage of using a periosteal flap having an inherent blood supply complimented with large regenerative potential of the periosteum. The present case report is unique as it describes the BPF technique in the treatment of mandibular molar Class II furcation defect. The inner pedicle periosteal flap in BPF was used as a barrier for GTR therapy in combination with a bioactive glass particulate bone graft substitute (PerioGlas®).

CASE REPORT

A 48-year-old male patient reported with a chief complaint of dull, continuous pain which aggravates on chewing food and bleeding while brushing in the right lower back teeth area from 3–4 months. The patient was systemically healthy and reported no abnormal habits. He used the scrub technique of toothbrushing and brushed once daily in the morning. The patient reported of a restoration done on the same tooth 6 months ago. On clinical examination, the tooth number 46 (FDI System) showed diffuse inflammation, bleeding on probing, presence of subgingival deposits, vertical probing pocket depth of 6 mm, relative vertical clinical attachment level of 9 mm, and buccal horizontal probing depth of 6 mm (Hamp's Class II furcation defect) [Figure 1a]. With respect to the same tooth, the cervical abrasion was restored with glass ionomer cement. It was nontender on percussion. An intraoral periapical radiograph (IOPAR) was taken using long cone paralleling technique with a millimeter grid scale. It showed radiolucency in the furcation area [Figure 1b], suggestive of furcation involvement. The endodontic evaluation using an electric pulp test and a cold test revealed that the tooth was vital.

Figure 1

(a) Preoperative horizontal probing depth; (b) preoperative intraoral periapical radiograph

In the Phase 1 therapy, the patient underwent a thorough supragingival and subgingival scaling under optimum magnification, using × 2.5 loupes. Minor occlusal adjustments were performed. Detailed oral-hygiene instructions were given, which involved (a) the modification of brushing technique from scrub to modified Stillman's technique, (b) use of an interdental brush, (c) use of warm saline rinses after every meal, and (d) to avoid using any object which may traumatize the area to eliminate the trapped food particles. A gum astringent was prescribed to be applied twice daily. The patient was evaluated after 4 weeks, and the oral hygiene instructions were reinforced. Subsequently, the patient was evaluated at the end of 8 weeks, it was observed that the vertical probing pocket depth reduced was reduced from 6 to 4 mm, there was a gain in relative vertical clinical attachment level from 9 to 7 mm and the horizontal probing depth remained 6 mm [Figure 1a]. The gingival biotype was thick (>2 mm). It was measured by transgingival probing using an endodontic reamer with a rubber stopper after anesthetizing the buccal gingival tissue using local infiltration anesthesia. The reamer was kept parallel to a Williams probe to approximately measure the gingival biotype. However, the patient still complained of dull pain due to which he avoided chewing food on the right side of the mouth.

Therefore, in Phase II therapy, BPF surgery in combination with bone graft substitute was performed for #46. Under local anesthesia and all aseptic conditions with #15c blade an initial sulcular incision was made, following which a mesial and distal full thickness vertical releasing incision were made [Figure 2a], and a trapezoidal partial thickness flap was reflected. Then, the underlying periosteal pedicle flap was reflected up to the mucogingival junction connected with mesial and distal vertical releasing incisions [Figure 2b and c]. At its base, a horizontal releasing incision was made to join the periosteal flap into the outer trapezoidal partial thickness flap. The exposed furcation defect and the adjacent bone was thoroughly debrided, irrigated using betadine mouthwash and exposed roots were thoroughly planned. Bioactive glass particulate graft (PerioGlas®) was then thoroughly condensed into the furcation defect. Care was taken that the defects were adequately filled and not under or overfilled [Figure 2d]. Then, the periosteal pedicle flap was coronally advanced, overlying the bone graft contained furcation defect and sutured with 4-0 resorbable suture using one sling suture [Figure 2e]. The coronally positioned outer partial thickness flap was sutured with 5-0 non-resorbable silk suture using simple interrupted sutures for vertical releasing incisions and the first horizontal incisions [Figure 2f]. Periodontal dressing was then placed to cover the surgical site completely.

Figure 2

(a) Incisions; (b and c) periosteal pedicle flap reflected; (d) bone graft placed; (e) inner periosteal pedicle flap sutured; (f) Outer partial thickness flap sutured

Postoperatively, the patient was instructed to discontinue brushing around the periodontal dressing area for the following 2 weeks. A chlorhexidine mouthwash (0.2%) twice daily for 2 weeks, an anti-inflammatory analgesic – Paracetamol 500 mg (S-O-S) and an antibiotic-Amoxicillin 500 mg thrice daily for 3 days were prescribed. Thereafter, suture and pack removal were done 10 days postoperatively. The healing was satisfactory, and no adverse tissue reactions were noticed. The surgical site was irrigated with betadine mouthwash gently. The patient was instructed to avoid brushing for another 1 week, after which a roll brushing technique was advised. He was then recalled after 1, 3, 6, and 12 months for periodontal maintenance therapy. At 3, 6, and 12 months, the horizontal probing depth was 3, 3, and 2 mm [Figure 3a] respectively and the vertical probing pocket depth was 3, 2, and 2 mm respectively. At 12 months, an IOPAR using lone cone paralleling technique with the previously used millimeter grid scale was repeated, and it revealed an increase in the radiopacity in the furcation area in comparison to baseline [Figure 3b]. However, no improvement in the relative vertical clinical attachment level was observed over the period.

Figure 3

(a) Postoperative horizontal probing depth, (b) Postoperative Intraoral periapical radiograph

DISCUSSION

Periosteum is a specialized connective tissue that encapsulates the alveolar bone. A majority (approximately 90%) of the cell population in the periosteum are fibroblastic in origin. Additional cell subpopulation of progenitor cells (PGCs) and mesenchymal stem cells (MSCs) are existent that have the potential to differentiate into osteoblasts, fibroblasts, chondroblasts, adipocytes, and skeletal myocytes. This ability of differentiation into a variety of cell lineages enables periosteum to contribute significantly in the healing of bone wounds.[6] Therefore, researchers have studied the role of autogenous periosteal barriers for GTR therapy in the treatment of Class II furcation defects.[234]

In case of furcation defects, the periosteum displacement technique for GTR therapy has been previously used by Verma et al.[3] which consisted of lateral displacement of a periosteal flap from the adjacent tooth, primarily to cover the exposed furcation defect. Hazzaa et al.[4] used a semilunar incision design in the periosteum to coronally advance the periosteal barrier consequently overlying the exposed furcation defect. They tested this technique both alone as well as in combination with a bone graft substitute Demineralized freeze dried bone allograft (DFDBA) and found improved furcation bone levels along with bone graft use postsurgically. Although the flap design of BPF is different from the periosteal pedicle flap designs proposed by Verma et al.[3] and Hazzaa et al.,[4] the similarity in the placement of a periosteal pedicle flap to function as a barrier over the furcation defects, makes them comparable to BPF technique.

The biotype in the present case was thick. This was an essential requirement for performing the BPF technique, as the sequential reflection of the outer partial thickness and inner periosteal flap in a thin biotype may lead to tissue dehiscence, flap tear while suturing, jeopardize the circulatory capillary network, and decrease the chances of flap survival post.

Machtei et al.[7] had assessed the clinical parameters that governed the success of regenerative periodontal treatment in Class II furcation defects. They concluded that there was a definite association between the pretreatment pocket depth measurements and its extent of reduction posttreatment. The successful clinical results of horizontal probing depth and vertical probing pocket depth reduction obtained using the BPF technique in combination with bioactive glass particulate bone graft substitute (PerioGlas®), therefore, were in accordance with Machtei et al.;[7] The results were also similar to Verma et al.[3] and Hazzaa et al.,[4] who reported similar reduction in vertical and horizontal probing depths.

The increase in the furcation radiopacity as observed in the IOPAR suggested new bone formation [Figure 3b]. For most accurate determination of gain in the hard-tissue levels, a surgical reentry was required. It was not done because of the ethical issues, associated with a second reentry surgery which may jeopardize the healed furcation defect and additionally pose the financial cost to the patient. Therefore, appropriate comparisons with the previous studies were not possible owing to the diversity in literature obtained to compare the IOPA measurements.

Bioresorbable GTR membranes have been widely used as a barrier in the treatment of Class II furcation defects for GTR therapy. However, the numerous complications associated with the same like early postsurgery membrane exposure, infection, premature degradation, and additional patients cost has always created a mind block in several clinicians to utilize it as a barrier for GTR therapy.[8] BPF,[59] which incorporated the use of periosteal pedicle flap overlying the exposed furcation defect served analogous to a bioresorbable GTR membrane and without any complications associated with membrane exposure. In addition, in the era of using biologic agents for achieving new attachment, autogenous periosteum being a source of PGCs and MSCs, can be a superior alternative to conventional bioresorbable GTR membranes.

CONCLUSION

In the present case report, BPF in combination with bioactive bone graft was performed for treatment of mandibular molar buccal Class II furcation defect. It was observed that the clinical outcome after 3, 6, and 12 months were satisfactory, the patient followed the routine oral hygiene instructions and attended the follow-up appointments in the maintenance phase. The BPF is a technique sensitive procedure and requires careful case selection with adequate gingival biotype and width of the attached gingiva. Adequate patient oral hygiene maintenance is important to prevent the recurrence of infection as molar teeth are the most common areas that are ignored by the patients. BPF, therefore, may serve as a good candidate surgical technique in the treatment of molar Class II furcation defects. Future studies with larger sample size are required to validate the results observed in the present case report.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.