Secondary bone grafting of the cleft maxilla following reverse quad-helix expansion in 103 patients.

INTRODUCTION: The main points to consider in secondary alveolar bone grafting (ABG) of cleft patients are age at the time of surgery, the type of bone graft, and pre/postorthodontic expansion of the upper jaw.
PURPOSE: The aim of this study is to evaluate the reverse quad-helix (RQH) expander device. Does RQH improve the surgical procedure before ABG? We will evaluate the outcome of the procedure, duration of the operation, hospitalization time, satisfaction of the surgeon with this procedure and the success of the bone graft in the long-term. PATIENTS AND METHODS: We reviewed the medical records of 103 cleft patients who underwent secondary bone grafting at our institution between 2001 and 2012. All patients were treated presurgically with a RQH appliance to expand the cleft area. The following data were recorded for each of the patients: Unilateral/bilateral cleft, surgery time, hospital stay, success/failure, and follow-up.
CONCLUSION: Presurgical orthodontic application of the RQH expander in the cleft area enabled improved anterior expansion rather than posterior expansion. This technique improves access for surgery and bone grafting, the use of RQH facilitates the improved manipulation of the nasal mucosa via direct view due to the wide separation of the alveolar segments in the cleft area. Furthermore, this gap enables improved access for the bone grafting procedure, shortens the surgery time and provides stable maxillary transverse correction.

INTRODUCTION

The management of patients with cleft lip and palate includes orthodontic treatment prior to autogenous bone grafting of the alveolar cleft because these patients present with a collapsed maxillary arch associated with dental crossbite.[12] There has been debate regarding primary and secondary alveolar bone grafting (ABG), although most centers today advocate secondary ABG.[34]

The rehabilitation of the v-shaped (triangular) collapsed cleft maxilla requires transverse maxillary expansion for access during surgical bone grafting manipulation. Moreover, in unilateral cleft lip and palate (UCLP) affected patients, the medical inward position of the lesser alveolar segment is aggravated as a result of the restored musculature achieved by primary lip and palate closure. The greater alveolar segment, however, is relatively more resistant to orthodontic force.[2] Hence, many conventional orthodontic expansion devices have been suggested.[5678910] All originally constructed to achieve a posterior maxillary expansion in healthy subjects. Some of these devices have been modified to achieve a differential anterior maxillary expansion for cleft-affected patients. One of the most widely used appliances for maxillary expansion in cleft patients is the quad-helix (QH) appliance, a variation of the Porter wire appliance and a modification of the Coffin W-spring.[11] This fixed expansion appliance was initially used by Ricketts to treat cleft palate patients with a collapsed dental arch.[12]

Lately a reverse QH (RQH) appliance was introduced, as a modification of the traditional QH, which was specifically designed for the expansion of the cleft maxilla in order to improve surgical access during bone graft manipulation.[1314]

The aim of this study was to estimate surgeons’ satisfaction when implementing RQH novel expansion technique for preorthodontic expansion of the cleft maxilla.

PATIENTS AND METHODS

Quad-helix appliance originally included four helical loops that are incorporated into an inverse W arch design, thus maintaining an increased range of force and flexibility. In the RQH modification, [Figure 1], which was first reported by Aizenbud et al., the spring carrying the four helical loops is posteriorly positioned relatively to the banded teeth. Thus, the expansion effect is focused toward the anterior maxillary region, as opposed to the traditional QH device, whereby expansion is focused on the opposite region with the spring positioned anteriorly to the banded teeth.[15] In the case of missing or loose deciduous canines, first primary molars or first premolars, are used as abutments [Figure 2a and b]. Anterior expansion is observed on the orthopantogram at the beginning of the process and at the end of the expansion [Figures 3 and 4]. If further expansion is indicated, the appliance can be reactivated by the orthodontist using three-jaw pliers directly in the mouth. After adequate expansion of 6–8 mm for appropriate surgical access, the bone graft procedure is scheduled. The RQH appliance is kept until the day of surgery to maintain the alveolar expansion gap. It is then removed to facilitate surgical access. During the surgery, we infiltrate the vestibular and palatal area with local anesthetic (2% lidocain with 1–1,000,000 epinephrine). An incision along the adjacent teeth from the first molar of the greater segment to the first molar of the lesser segment is executed. A vertical cut is applied bilaterally in a back-cut manner. Hence, two separate full thickness, keratinized advancement mucoperiosteal flaps are formed. The palatal flaps are created via a sulcular incision along the teeth adjacent to the molar/premolar area. The buccal and palatal flaps are divided in a pyramidal fashion from the nasal mucosa in the cleft area.

Figure 1

Reverse quad-helix

Figure 2

(a) Reverse quad-helix-expansion effect is focused toward the anterior maxillary region, the spring carrying the four helical loops is posteriorly positioned relative to the banded teeth (b) Postexpansion result with the reverse quad-helix device. The expansion was mostly focused on the anterior part of the maxilla

Figure 3

Preexpansion with the reverse quad-helix

Figure 4

Postexpansion with the reverse quad-helix

The correction of the cleft area focuses on the creation of a bi-layered separation of the nasal from the oral cavity. Thus, the nasal mucosa is separated from the oral mucosa and off the lateral wall of the nose. It is then sutured with a 4.0 vicryl suture, creating a water tight seal between the oral and nasal cavities.

The buccal flaps are elevated above the piriform rim exposing the nasal floor of the affected side. It is important to expose the bone of the medial and lateral parts of the cleft in the alveolar area. Particulate cancellous bone marrow (PCMB) is then packed in a routine fashion, elevating the nasal floor to the same level as the unaffected side. Bone is packed to the level of cement-enamel junction of adjacent teeth. The buccal and palatal flaps are sutured to each other in the cleft area via horizontal mattress with 4.0 vicryl sutures. The area of the exposed alveolar bone is left for secondary healing [Figure 5a and b].

Figure 5

(a) Preparing the alveolar cleft area, raising two buccal advancement flaps, two palatal flaps and elevating the nasal floor to the same level as the unaffected side (b) Particulate cancellous bone marrow is packed in a routine fashion, elevating the nasal floor to the same level as the unaffected side. Bone is packed to the level of cement-enamel junction of adjacent teeth

A second team works simultaneously to harvest PCMB from the anterior iliac crest. A skin incision is applied 1 cm postero-laterally to the anterior superior iliac spine of the iliac crest. The incision though skin and fat exposes the cartilaginous part of the iliac crest. We suggest conservative stripping of the muscles from the cartilaginous iliac crest to avoid gait disturbances in the healing phase. A blunt H incision is made along the crest to expose the cancellous bone underneath. The PCMB is harvested using curettes and kept in normal saline.

The surgical site is copiously irrigated. Closure of the harvesting site includes: suturing the iliac cartilaginous cap using 2–0 vicryl sutures, subcutaneous tissue is sutured with 3–0 vicryl, and skin suturing using 4–0 monofilament covidien.

Retention of the expanded maxillary arch after bone grafting is crucial for success. This may be accomplished by re-cementation of the RQH appliance over the surgical palatal field or by incorporating an expanded, previously prepared, square profile orthodontic wire into the brackets’ slot of the fixed orthodontic appliance over the buccal aspect of the maxillary arch.

We reviewed all the medical records of the cleft-affected patients who underwent a secondary bone graft surgical procedure at our institution between the years 2001 and 2012. Totally 103 patients were treated according to Rambam's cleft protocol – the use of naso-alveolar molding technique and later at 3 months lip closure, 12 months palatal closure, at 6 years orthodontic treatment, which included a presurgical orthodontic preparation stage of anterior maxillary expansion using a RQH. All the patients were treated by the same orthodontists and surgeons. The following data were recorded for each of these patients: Gender, cleft type (unilateral – UCLP or bilateral – bilateral cleft lip and palate (BCLP)) age at the time of surgery, type of bone graft used, duration of the surgical procedure, postoperative hospitalization stay, postoperative complications/failure during the 1st year follow-up [Table 1].

Table 1

Patients data

In addition, we compared our data of surgical duration and success rate to other reports found in the scientific literature, which dealt with bone graft procedure in cleft patients matched by age and cleft type.

RESULTS

The duration of surgical procedure, length of hospitalization and success rate of our cohort is presented in [Table 2].

Table 2

Operation & Hospitalization time

Of the 103 patients, 62 (60.1%) were male and 41 (39.8%) were female, with a mean age at surgery of 12.01 ± 4.35 years UCLP and 13.25 ± 6.83 BCLP. 63 (61.1%) patients were diagnosed as UCLP: 20 (19.4%) had right side UCLP and 43 (41.7%) patients had left UCLP; 40 (38.8%) patients had a BCLP. The mean hospitalization duration was 5.45 ± 1.11 days. The surgical duration for UCLP was 82.49 ± 21.77 min (range: 40-135 min) and for BCLP 106.89 ± 29.13 minutes (range: 50-190 min), respectively [Table 2]. The treatments of five patients (two patients with UCLP and three patients with BCLP) were considered failures, and these patients had to undergo reoperation due to extensive or total bone resorption of the augmented bone. The mean follow-up time was 49.46 months.

DISCUSSION

The main goals of ABG in cleft patients are closure of the oro-nasal fistula, stabilization of the maxillary arch, provision of support for roots of teeth adjacent to the cleft, and support for the alar base (lower lateral cartilage) and future prosthesis.[315] Controversy exists regarding the use of orthopedic expansion of the cleft segments and the relationship between expansion and grafting. Most craniofacial centers prefer presurgical expansion, citing easier expansion because of less resistance, improved access to the cleft area for closure of the nasal floor, improved postoperative hygiene, and less chance of reopening the oro-nasal fistula.

Secondary ABG gained popularity in the 1970s and 1980s and is preferred in most craniofacial centers today.[3151617] Early secondary ABG phase is defined between the ages of 5 and 7 years within the mixed dentition stage after the eruption of the maxillary lateral incisors. An intermediate ABG phase is defined as between the ages of 8 and 12 years and involves the eruption of the permanent canines to gain more alveolar bone during the eruption. The late secondary ABG phase begins after the age of 12 when all permanent teeth have erupted. From our experience and based on the protocol of Boyne and Sands, the intermediate phase between the ages of 8 and 12 years is the preferred time to operate, due to the gain in alveolar bone mass as a result of the eruption of the canines. All of our patients were treated with an RQH to create space in the cleft area prior to the grafting.[1314]

Orthodontic expansion prior to bone grafting will facilitate additional surgical access to the nasal and oral layers. The traditional QH appliance is used on narrow, restricted maxillary arches to distally rotate and buccally tip the maxillary molars (abutments) and their alveolar sockets that result in warped alveolar ridges.

Because the extended QH arms have a fan-like sweeping action, they can also be adjusted to expand the maxillary premolars and canines into the final occlusion ovoid arch form. Consequently, cleft-affected patients with palatally tipped alveolar ridges are good candidates for dento-alveolar expansion using QH.[18]

With this method, expansion of the RQH is mediated by buccal and distal rotation of these anterior teeth and the entire cleft segment in a readily observed manner due to the presence of a cleft in the premaxillary region. The un-operated alveolar cleft site (low resistance area) is gradually widened minimally affecting the posterior maxillary segments. As in most cleft cases the posterior segments are not extremely constricted but rather an anterior maxillary segment, the maxillary expansion using traditional QH may result in over-expansion of the posterior maxillary segment.[13]

This may result in the difficulty of closing the oral masticatory mucosa over the expanded palate and suturing under stress that might re-open and cause failure of ABG.

Among the other advantages mentioned, the traditional QH does not depend on the patient's cooperation; this device has an increased range of force application, flexibility, molar rotational ability, and refined adjustment capability.[1318] The advantages of using the RQH prior to ABG can be evaluated during surgery due to the easier manipulation of the nasal and buccal layers. No differences were observed in the overall ABG surgical technique performed in our cases compared with other studies presented in the literature.[1617] Fewer forces work on the ABG after surgery due to the alignment of the greater and the lesser segment to create one unit. In contrast expansion prior to ABG can be problematic due to widening of the cleft area will create the need for more bone graft material. Orthodontic movement of teeth adjacent to the cleft before grafting increases the risk of moving these teeth into the cleft site, compromising osseous support. However, as seen in our study, only 4.8% (5/103) of the patients had to be re-grafted due to residual bone defects; no residual fistulae were detected. Success was considered when there was no oro-nasal fistula in the cleft area, continuous bone bridge between the lesser segment and the greater segment and spontaneous canine eruption.

The use of RQH facilitates the improved manipulation of the nasal mucosa via a direct view due to the wide separation of the alveolar segments in the cleft area. Furthermore, this gap ameliorates the access for the bone grafting procedure by raising the full thickness palatal flaps, enabling the proper stitching and sealing of the nasal mucosal layer, assisting in the adequate packing of the harvested autogenic cancellous bone graft and finalizing the suturing of the oral mucosa layer.

The retention after bone grafting was performed by orthodontic squared wire which was applied at the end of the surgery for 4 months.

CONCLUSIONS

The RQH is an efficient appliance for differential expansion of the anterior maxillary region, which precludes unnecessary posterior expansion. It is easily fabricated during the preparatory orthodontic stage for secondary bone graft procedures in BCLP-and UCLP-affected patients. The use of RQH ameliorates the manipulation of the nasal mucosa via a direct view due to the wide separation of the alveolar segments in the cleft area. Furthermore, this gap improves access for the bone grafting procedure by raising the full thickness palatal flaps, enabling the proper stitching and sealing of the nasal mucosal layer, facilitating the adequate packing of the harvested autogenic cancellous bone graft and finalizing the suturing of the oral mucosa layer. The use of RQH improves surgical access for bone grafting manipulations, offers enhanced access for nasal layer closure and provides a stable maxillary transversal correction, resulting in improved occlusion of the permanent dentition.