CHAPTER 7 Soft Tissue Management and Grafting
Pedicles must be created with care. The mucosa must not be thinned too much, or devascularization may result. If excessive connective tissue is allowed to remain, the graft may be bulky, unsuitable, and esthetically displeasing.
Regional block anesthesia is preferable to infiltration, because the tissues requiring plastic surgery respond best if they are not bloated with anesthetic solution (which causes distortion) and ischemia from the vasoconstrictor.
Soft tissues are required to cover bone, transport vascular channels, enclose implant host sites, and bring functional and esthetic contour to critical anatomic areas. Defatted and split-thickness skin and mucosa from the patient make the best free grafts. These grafts may be taken by dermatome from the lateral thigh, the skin behind the ear and the overlying the mastoid process, and the palate. Mucosa for pedicle grafts is taken primarily from the superior and inferior vestibular areas. To a lesser extent, mucosa for closing oroantral fistulae is taken from the palate. Gingival defects may be repaired reliably with palatal split-thickness, connective tissue, or free grafts covered by gingivomucosal pedicles.
Incisions made properly result in rapid, consistent primary wound healing because they cause fewer postoperative sequelae (e.g., edema, pain, and bleeding), and they create a surgical environment that preserves and protects the implants that have been placed.
Surgical assistants should be taught that suctioning, particularly when powerful, can do harm. It can tear tissues, injure small blood vessels, encourage bleeding to continue and, as the tip sweeps back and forth, disturb the alignment of flaps. Suctioning also aspirates the organisms floating in the aerosol above the wound directly into it, inviting infection. Suction should be used only to enable the surgeon to see the operative field and to evacuate the pharynx. If neither of these needs exists, the suction tip should be kept away from the operative site, and the surgical assistant should be instructed to use sponges first. The following rules are crucial to an optimal outcome.
FIGURE 7-1. The linea alba, a fine, white crestal line found on edentulous ridges, is avascular and does not allow cross-ridge capillary anastomoses. If novel incisions are made (e.g., S-shaped or visor type), the site may break down or heal slowly, resulting in bone loss around implant cervices.
Careful, thorough, and complete flap design, and elevation without tearing or injuring the periosteum, is necessary for a smooth operative and postoperative course. For this purpose, the surgeon must have new or freshly sharpened periosteal elevators available (Fig. 7-3). The fibers must not be ripped or torn. Instead, they should be sharply incised at the level of the cortical bone; this requires a keen-edged elevator. Before each operation, the auxiliary staff should make sure that the elevators are as flawless and as sharp as new ones.
Flaps with releasing incisions should have bases that are wider than their alveolar margins, essentially trapezoidal (Fig. 7-4). If tooth areas are to be included in the surgical exposure, the gingival papillae should never be split, but rather should be included totally in the flap. Such gingival tissues must be elevated gently with a fine-pointed elevator only after thorough incision.
In areas where previous surgery or trauma has occurred or where evident scarring is present, or in other cases in which the investing tissues are resistant to easy, complete reflection, the procedure can be expedited using a technique that accomplishes this challenging task easily and consistently. The technique requires a small-toothed pickup forceps (Adson or Gerald) and a scalpel armed with a new BP No. 12 blade (Fig. 7-5). The practitioner lifts an edge of the flap with forceps so that the tip of the blade can gently stroke the scarred, adherent fibers in the fashion of a periosteal elevator. The practitioner proceeds a bit at a time, carefully elevating the flap until a zone is reached that allows conventional periosteal separation. This technique should not be attempted for the first time on a patient. Implantologists should practice on a cow mandible (which can be obtained from a butcher) until they achieve a high level of confidence in their ability to perform full-thickness reflection without perforating the mucoperiosteum (a serious but not always irrevocable occurrence). If the blade tip is kept against the bone and the strokes are made in a short, gentle fashion, the technique can be mastered readily. If the overlying mucosa is perforated, the laceration must be kept to a minimal length, the reflection is continued, and the subsequent surgery is completed. After suturing and closure, the iatrogenic laceration is closed with 6-0 Vicryl or Polysorb continuous horizontal mattress sutures using a fine, tapered, small half-circle (SH) needle (see the sutures and suturing section in Chapter 6).
FIGURE 7-5. Adherent or scarred tissue often resists elevation. To resolve this, the practitioner can grasp an end of the mucoperiosteum with an Adson or Gerald forceps and stroke beneath the flap gently with a No. 12 scalpel blade. This allows the flap to be lifted effortlessly and atraumatically.
In two areas, the palatal and the mandibular facial, special care must be taken in the reflection of mucosal flaps so that the greater palatine and mental neurovascular bundles are protected. Such efforts are abetted if a 2 × 2 gauze sponge is inserted beneath the flap. By pushing the sponge with a periosteal elevator, the surgeon can enlarge the separation safely and accurately (Fig. 7-6). In this fashion, as a foramen is approached, it comes into view in a trauma-free fashion, sparing injury to its neurovascular bundle.
FIGURE 7-6. Flaps can be elevated in mucosal areas with minimal trauma by teasing them away from the bone; this is done by pushing a 2 × 2 sponge ahead of the periosteal elevator. The neurovascular bundle, when reached, is clearly visible, and the gentle progress of the sponge protects it from damage (see Figs. 7-8 and 7-9).
Once the flaps have been reflected, they must be managed gently. They should be kept well hydrated with saline-moistened sponges. The manner in which they are kept retracted also plays a role in subsequent healing. Retractors should be smooth surfaced; these include the Henahan, Seldin, beaver tail, and blunt-toothed rake (Mathieu) (Fig. 7-7). The staff should make sure that these instruments are not nicked or scratched. All rakes in the armamentarium should have blunt, not sharp, tips.
FIGURE 7-7. Polished edges on retractors prevent tissue injury. Blunt rakes, smooth Henahans, beaver tails, and Seldins should be used. Retractors cause the least damage when they are allowed to rest against bone.
A suitable, convenient alternative to manual reflection is autoretraction using sutures. Buccal flaps may be sutured to the buccal mucosa. Palatal flaps may be sutured into a midline bundle, which keeps these tissues out of the operative field. Unilateral palatal flaps may be sutured to the teeth on the contralateral side, which keeps the surgical site well exposed without the need for retractors. Bilateral mandibular lingual flaps may be sutured to each other across the dorsum of the tongue; this configuration serves not only as an excellent means of retraction, but also as a competent tongue depressor (Fig. 7-8). Unilateral mandibular flaps may be kept retracted by suturing them across the dorsum of the tongue to teeth on the unoperated side.
FIGURE 7-8. Sutures can serve as excellent retractors. In surgery of the mandible that involves both sides, the two lingual flaps can be tied together across the dorsum of the tongue in a shoelace configuration. This not only keeps the lingual flaps out of the field, it also stabilizes the sublingual adnexa and immobilizes the tongue. In unilateral procedures, the contralateral teeth may be used as anchorage for the retracting sutures.
In planning and designing flaps, the dental surgeon must not split papillae, frenula, or muscle attachments; rather, they should be included totally within the flap design. When palatal flaps are planned, all incisions should be made in the gingival crevices or at the ridge crest and never across the palatal mucoperiosteum. In this way, only full-thickness, total palatal mucosa is reflected (Fig. 7-9). If, as a worst case scenario, palatal tissues are segmented, the risk arises that the palatine artery will be cut; at best, such incisions retard healing and cause cons/>