Article
The laterally closed tunnel is a novel technique to achieve root coverage over narrow recession defects. This article presents three clinical cases completed in private practice settings demonstrating positive outcomes using the technique for both single and multiple recession defects in the anterior mandible. The techniques are described in detail, including appropriate case selection.
The use of tunnelling techniques for root coverage has gained popularity within the field of periodontal mucogingival surgery. Historically, the tunnelling approach was first proposed by Raetzke in 1985 where the preparation of a supra-periosteal envelope that allowed for insertion of a connective tissue graft, which was left partially exposed was described.1 The technique evolved to treat multiple gingival recessions, as described by Allen in 1994, and was finally coined the ‘tunnel’ approach by Zabalegui et al in 1999.2,3
Zuhr et al and Aroca et al described a modified microsurgical tunnel technique whereby the entire gingiva-papillary unit was coronally advanced with the use of either anchoring sutures into the palatal mucosa, or suspensory sutures with composite stops to allow coverage of the connective tissue graft.4,5,6 More recently, Sculean and Allen described a laterally closed tunnel (LCT), whereby tension-free lateral closure of the tunnel over isolated mandibular recession defects is obtained following the principles of tunnel preparation described in previous techniques.7 A similar technique (if not identical) has also been termed the laterally stretched flap (LAST) by Carranza.8
Here we present a series of cases, performed by two different clinicians in private practice settings, to highlight the use of the novel laterally closed tunnel with connective tissue graft as a viable and effective alternative root coverage technique over isolated mandibular incisor recession defects.
Case 1
A 22-year-old female patient was referred in private practice by her general dental practitioner (GDP) regarding a localized recession defect affecting the lower right central incisor. The patient's main complaint was of tenderness on cleaning around the LR1, and concern over the extent of the recession defect. She was medically fit and well, taking no medication and was a non-smoker.
On examination there was evidence of an RT1 defect (2017 World Workshop Classification)/Miller Class 2 defect (1999 classification) affecting the LR1. The dimensions of the defect were approximately 11 x 3 mm. There were two frenal attachments into the mesial and distal aspect of the LR1, impeding the ability of the patient to adequately clean the full extent of the recession defect, with no keratinized tissue apical to the defect. There was also an approximately 4–5-mm width of apico-coronal attached gingivae on both mesial and distal aspects of the recession defect (Figure 1).
The options presented to the patient were as follows:
Procedure
Local anaesthetic was given as buccal infiltrations in the anterior mandible and palate using lidocaine 2% with 1:80,000 adrenaline.
The procedure was split into three stages:
Preparation of tunnel
Using a microsurgical blade (SN69, Swann Morton), an inverse bevel incision was made around the recession defect of LR1. Intra-crevicular incisions were also made around the buccal aspects of the LR2 and LL1 to allow preparation of a supra-periosteal tunnel with sufficient ability to obtain primary closure with lateral movement.
Tunnel preparation involved the use of specific tunnelling knives (TKN1X/TKN2X, Hu-Friedy) and a modified Orban knife (Hu-Friedy) to ensure release of muscle attachment from the overlying soft tissue, including the frenula evident in Figure 1. This involved adequate mesio-distal and apico-coronal tunnel preparation to allow for tension-free closure.
Harvest of connective tissue graft
The connective tissue graft was harvested via a free gingival graft that was subsequently de-epithelialized outside the mouth. The graft dimensions were approximately 10 mm in length to allow the graft to sit on a vascularized bed at least 3 mm either side of the recession defect and 6 mm in height.
Suturing of graft and tunnel
The graft was introduced into the tunnel at the LR1 and sutured to secure it against the inner aspect of the mucosa (Figure 2). A separate sling suture (6-0 Vicryl Rapide, Ethicon) was placed to adapt the connective tissue graft to root surface. Finally, single interrupted sutures (6-0 Prolene, Ethicon) were placed to close the tunnel by approximating the lateral borders of the recession.
The 4-week review
The patient reported significant improvements in root coverage around the LR1 and was very satisfied at this point. It was noted that there was a residual 1-mm recession associated with the LR1. Figure 3 shows the surgical site after 4 weeks compared with the pre-operative situation. Further follow up was anticipated.
Case 2
A 32-year-old male patient was referred by his GDP regarding a localized recession defect affecting the lower left central incisor. The patient's main complaint was of sensitivity and concern over the rapid deterioration of the defect over the previous 2 years. He was medically fit and well, taking no medication and had recently stopped smoking.
Clinical examination revealed an RT1 defect (2017 World Workshop Classification)/Miller Class 2 defect (1999 classification) affecting the LL1. The dimensions of the defect were approximately 7 x 3 mm. High frenal attachments into the mesial and distal aspect of the LL1 were noted, with a McCall's festoon at the most coronal aspect of the gingival margin. There was also an approximately 5-mm width of apico-coronal attached gingivae on both mesial and distal aspects of the recession defect (Figure 4). The tooth was positioned lingually to the adjacent teeth.
The same treatment options as in Case 1 were presented to the patient, and a laterally closed tunnel with an autogenous palatal connective tissue graft was deemed most appropriate. A similar surgical protocol was used as described in Case 1 (Figures 5–7). The graft was sutured with vertical mattress sutures lateral to the recession defect using a resorbable 6-0 suture (6-0 Resorba Glycolon). The defect edges were then approximated using single interrupted suturing with non-resorbable 6-0 sutures (Mopylen 6-0). The sutures remained in situ for 2 weeks.
The site was reviewed at 2 and 8 weeks post-operatively (Figure 8). There was significant improvement in the patient's presenting complaints. Clinically, substantial root coverage was achieved with a residual 1-mm defect. The gingival tissues around the LL1 now had a thicker phenotype, with greater than 2-mm of keratinized tissue apical to the gingival margin.
Case 3
A 34-year-old male patient was referred by his GDP regarding persistent gum inflammation and soreness around his lower anterior teeth. His medical and social history was unremarkable.
Clinical examination revealed RT1 defects (2017 World Workshop Classification)/Miller Class 2 defect (1999 classification) affecting the LR1 and LL2. The dimensions of the defects were approximately 6 x 3 mm (LR1) and 12 x 2 mm (LL2). There was moderate crowding of the lower anterior teeth with the LR1 and LL2 slightly rotated and buccally displaced. A high midline frenal attachment was noted mesial to the LR1. Both recession defects extended to the mucogingival junction. The oral hygiene around these sites was suboptimal, with supra- and subgingival plaque and calculus deposits. Localized gingival inflammation was also present (Figure 9).
The same treatment options as in Cases 1 and 2 were presented to the patient, and simultaneous laterally closed tunnels with an autogenous palatal connective tissue graft were selected (Figures 10–12). After an initial hygienic phase, the surgical and suturing protocol was as described in Case 2. An additional coronally advancing sling suture was placed around the LL1 to keep the tissues in an over-corrected coronal position by 1 mm to compensate for some relapse during the healing phase (Figure 13).
The site was reviewed at 2 and 8 weeks post-operatively (Figure 14), and there was substantial improvement in the clinical appearance and the patient's symptoms. The gingival tissues around both sites had a thicker phenotype, with a band of attached keratinized tissue re-instated. Residual recessions of 2–3 mm were noted at both sites. The patient was now able to perform oral hygiene more comfortably.
Discussion
The advantages of using a laterally closed tunnel include providing improved aesthetic outcome compared with a free gingival graft. Harvesting techniques for a connective tissue graft can also include single incision techniques, which result in all surgical sites having the possibility of primary closure, limiting secondary intention healing, and the increased morbidity that accompanies it. Furthermore, secondary intention healing associated with laterally positioned flaps is avoided, which can sometimes lead to cosmetically unsatisfactory scar formation.
The technique does not require the significant apico-coronal height of keratinized tissue required for a laterally positioned flap, although adjacent keratinized tissue is still required for adequate soft tissue handling and aesthetic outcomes. The lateral closed tunnel also seems to be an appropriate technique where there is a shallow vestibule and inserting frenula, which may contraindicate coronal advancement of tissues (either via a coronally advanced flap or coronally advanced tunnel).
The original technique described by Allen and Sculean included the addition of amelogenin (Emdogain, Straumann, Switzerland). Our cases demonstrate significant improvements in recession reduction without additional biological agents, which provides potential benefit for those individuals who do not wish to have xenogeneic biomaterials for ethical/religious reasons, as well as reducing the obvious financial implications of additional materials.
It must be noted that there is incomplete root coverage at 4–8 weeks, with a residual 1–3-mm recession. While this was acceptable to the patients, there are modifications that could be considered to improve this. First, we cannot rule out that the use of amelogenin may have provided improved root coverage. Furthermore, we could have coronally positioned the connective tissue graft and left a small exposure coronally, which is an accepted technique, providing most of the graft is covered. Finally, a supplemental sling suture coronally advancing the entire gingival unit and stabilizing the tissues at a more coronal level could have optimized outcomes further.
Conclusion
These cases demonstrate that, with appropriate case selection, the laterally closed tunnel provides an effective and aesthetic alternative to the free gingival graft or laterally positioned flap in the lower anterior mandible for single and alternate recession defects.