Bone Grafting of Alveolar Clefts

The goals of alveolar cleft repair include (1) stabilization of the maxilla, (2) permitting tooth eruption, (3) eliminating the oronasal fistula, (4) improving aesthetics, and (5) improving speech. Alveolar cleft repair should be considered one of the steps of a larger comprehensive orthodontic management plan. In conjunction with closure of the oronasal fistula, a variety of grafting materials can be used in the alveolar cleft. Autogenous grafts have been found to have greater efficacy compared with allogenic or xenogeneic bone, substitute bone, and alloplasts but with more donor site morbidity.

Key points

  • Alveolar cleft repair should be considered one of the steps as part of a larger, comprehensive orthodontic management plan.

  • Repair of the oronasal fistula is a crucial component of the surgical repair.

  • Autogenous grafts likely has greater efficacy compared with allogenic or xenogeneic bone and bone substitutes but with more donor site morbidity.

  • Minimally invasive harvest techniques being developed provide promising balance of efficacy with decreased morbidity.

Introduction

An alveolar cleft is a bony defect that involves the maxillary arch, which classically forms owing to abnormal primary palate formation. Given that alveolar cleft forms owing to abnormalities with the primary palate, alveolar clefts are frequently associated with cleft lip, but not isolated cleft palate. The treatment of these deformities have evolved over the years, with the primary justifications for treatment being the following as outlined by Wolfe and colleagues : (1) Providing stabilization of the maxilla, (2) permitting tooth eruption, (3) eliminating the oronasal fistula, (4) improving esthetics, and (5) improving speech. The treatment of alveolar clefts has been based off of a technique described by von Eiselsberg in 1901 in which autologous tissue was used to repair the defect. The use of nonvascularized bone graft was first described in 1908 by Lexer. These concepts continued to change the way surgeons approach alveolar clefts, with the use of tibial and iliac bone for grafting. ,

However, the primary method for grafting until the 1970s was primary bone grafting with the use of rib bone, as described by Rosenstein and Dado. Primary bone grafting is a method that aims to close the defect at an earlier age (4–5 months) using presurgical palatal appliances. The criteria for primary bone grafting include having a complete cleft palate and proper alignment of the alveolar segments. Secondary bone grafting occurs just before the eruption of the permanent canine teeth with orthodontic treatment (approximately 9–12 years of age). , Importantly, this approach is completed when midface growth is nearly complete. Ultimately, addressing an alveolar cleft is a crucial component in the care and managing children with cleft deformities. This article reviews the preoperative assessment of an alveolar cleft, surgical management (including various grafting materials and approaches), and postoperative care.

Preoperative assessment

There are several key components to consider during the preoperative evaluation of patients undergoing bone grafting of alveolar clefts. First, patients should be followed by a comprehensive cleft care team that has both an experienced orthodontist and surgeon who specialize in craniofacial care. Some of the most important factors for a surgeon to consider are maxillary growth and the dental age of the patient. The number and position of teeth also impacts surgical timing. In patients who have a lateral incisor on the side of the cleft deformity that is functional, there is a push to perform grafting at an earlier age. The integration of presurgical orthodontic treatment is also a crucial step in the preoperative assessment of patients requiring repair of alveolar clefts. Through a randomized, single-blinded trial comparing bone grafting with and without integration of presurgical orthodontic treatment, it was found that those who underwent orthodontic treatment had improved bone volume compared with those who have bone grafting alone. There was also improved inclination and rotation of the central incisors among the presurgical orthodontic treatment group. Fig. 1 shows a collapsed arch in need of expansion before alveolar bone grafting. Surgery should be viewed as a component of comprehensive orthodontic management. The decision to move forward should be done in close coordination with the patient’s orthodontist. Eruption of the canine is an important consideration and does not always occur at precise ages in children with cleft lip and palate. Arch alignment with expansion is important and presurgical expansion may improve bone graft success. The width of the alveolar cleft may also be associated with success and should be discussed with families, although it is not a modifiable risk factor. The degree of expansion will typically be guided by the patient’s orthodontist with the orthodontic plan in mind and should balance the orthodontic benefits and the impact on bone graft success ( Fig. 2 ).

Fig. 1
Collapse of the maxillary arch before expansion.

Fig. 2
( A ) Before and ( B ) after maxillary expansion.

Surgical management

The repair of alveolar clefts has both function and aesthetic outcomes for the patient. The ultimate functional goal is to close the nasolabial fistula, because a persistent fistula will lead to chronic nasal regurgitation and chronic inflammation. After securing the airway, the expansion device is removed and retained for replacement, working closely with orthodontist or dentist for replacement at the completion of the surgery.

Injection is completed using a local anesthetic with epinephrine. Next, many surgeons use chlorhexidine mouthwash to rinse out the oral cavity. After an appropriate amount of time for the injection to take effect, an incision is made along the alveolar cleft extending to the posterior aspect of the remaining nasolabial fistula on the hard palate. Sometimes the posterior extent of the fistula is only fully identified during the dissection. The incision on the labial side of the alveolar cleft extends toward the piriform aperture on each side of the cleft. This tissue is dissected and reflected into the nasal passage as the dissection continues up to the piriform aperture. Next, attention is turned to closure. The nasal mucosa along the floor of the nose is closed starting at the posterior aspect of the fistula and working forward. A running locking suture may improve the ability to obtain a watertight closure in this region. Next, any fistula present on the hard palate is closed, as is the lingual surface of the alveolar ridge. Relaxing incisions may help to rotate the gingiva into a larger cleft in the alveolar ridge, but care needs to be taken not to devascularize the gingival flaps. A random blood supply rotational advancement flap from the gingivobuccal sulcus may help to provide additional mucosal tissue for closure of large defects, although gingiva is preferred ( Fig. 3 ). When a small defect remains to be closed, the grafting material is placed in the alveolar cleft as well as the hard palate cleft and deficient piriform aperture.

Fig. 3
Closure of the nasolabial fistula with a local rotational flap.

There are a variety of grafting materials and approaches that can be uses, all with their own benefits and risks ( Table 1 ). There has been great interest in the literature to determine what is the optimal donor site and materials to use. Overall, autogenous grafts have been found to have greater efficacy compared with allogenic or xenogeneic bone, substitute bone, and alloplasts. The tradeoff is donor site morbidity.

Table 1
Risks and benefits for selected bone grafting materials choices
Material Type Risks Benefits Other Details
Iliac crest bone graft Increased pain
Vascular or neurologic injury
Increased operative time
Scarring
Delayed ambulation
Histocompatibility
Nonimmunogenic
Ability to obtain large amount of material for grafting
Current gold standard, particularly with minimally invasive technique
Rib bone graft Increased pain
Vascular or neurologic injury (Intercostal neuralgia)
Increased operative time
Intraoperative pneumothorax
Scarring
Poor orthodontic tooth movement
Histocompatibility
Nonimmunogenic
Mandible bone graft Decreased volume of bone graft
Vascular or neurologic injury (mental nerve)
Histocompatibility
Nonimmunogenic
Same operative field
No operative scar
Decreased postoperative pain
Calvarial bone graft Potential for more serious complications, including cerebrospinal fluid leak, dural tear, vascular injury including sinus, epidural hematoma Histocompatibility
Nonimmunogenic
Hidden scar
Decreased postoperative pain
Easy accessibility
rhBMP-2 Local tissue reactions
Graft failure, infection
Need for revision surgery
Role of BMP in the development of osteosarcoma
Decreased operative time and morbidity
Decreased blood loss
Reduced pain
Potential for lower cost.
DBM Immune reaction
Potential for disease transition
Prohibitive cost
Decreased operative time and morbidity
Encourages osteoinduction
Need another graft product for success of the graft (rhBMP-2)
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Jun 12, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Bone Grafting of Alveolar Clefts
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