Orthodontic Management of Cleft Lip and Palate: A Comprehensive Guide for Students
Cleft lip and palate are complex craniofacial conditions that require a multidisciplinary approach, with orthodontic management playing a crucial role throughout a patient's life. This guide provides a detailed overview of the orthodontic interventions used in treating patients with oro-facial clefts, from infancy through adulthood, highlighting the critical collaboration between orthodontists and surgeons.
The goal of orthodontic involvement is to achieve satisfactory dental and occlusal relationships, support reconstructive surgeries, and monitor craniofacial growth and dental development. Modern advancements, including presurgical nasoalveolar molding (NAM) and maxillary distraction osteogenesis, have significantly improved treatment outcomes.
The Multidisciplinary Team Approach to Cleft Care
Effective management of oro-facial clefts relies heavily on a team approach involving various specialists. The orthodontist is an essential member of this team, assisting the surgeon at all stages of reconstructive care.
Their responsibilities span from early interventions to final prosthetic rehabilitation and orthognathic surgery. This collaborative effort has dramatically improved outcomes in speech, occlusion, lip aesthetics, and skeletal balance for cleft patients.
Orthodontic Interventions in Infancy: Nasoalveolar Molding (NAM)
For infants with severe clefts and marked distortions of the maxillary segments and nasal cartilages, presurgical nasoalveolar molding (NAM) is a crucial early intervention. This technique aims to align maxillary and premaxillary segments and reposition nasal cartilages prior to lip repair.
Unilateral Cleft Lip Management with NAM
In unilateral clefts, NAM addresses the distorted nasal cartilage, nasal tip deviation, and columella angulation towards the noncleft side. The process involves a modified intraoral plate made of light-cured acrylic, fitted with a nasal stent covered in soft acrylic.
The plate is held in place with denture adhesive cream, and parents are instructed on daily cleaning and adhesive replacement. Weekly adjustments reshape the nasal stent and selectively grind/add acrylic to narrow the distance between maxillary segments, sometimes complemented by facial taping.
Expected results include repositioning the nasal tip, straightening the columella, and equalizing nasal dome height. The nasal stent also exerts lateral pressure on the lateral nasal wall, leading to a straighter nose with convex nasal cartilages and flattened hyperplastic tissues.
This combined orthopedic and surgical effort provides better primary nasal reconstruction, potentially reducing the need for extensive secondary revisions. In cases with severe initial nasal distortion, postsurgical nasal stents may be used for 2–3 months.
Bilateral Cleft Lip and Palate: Addressing Protrusive Premaxilla
Bilateral clefts present a more challenging condition due to a protrusive premaxilla, deficient columella, wide palatal clefts, and often collapsed maxillary palatal shelves. Repositioning the premaxilla into a more favorable relation with the maxillary segments is imperative for successful lip closure.
An intraoral appliance with an elastic strap for premaxillary retraction is used for this purpose. Grayson and coworkers' nasoalveolar molding appliance for bilateral clefts was designed to retract the premaxilla and mold nasal cartilage, incorporating extraoral taping.
Our modified design uses a self-retained intraoral plate with orthodontic buttons or custom wires for retraction with an elastomeric band. After premaxillary retraction, the plate is further modified with nasal stents and an elastomeric chain across the prolabium. The nasal stents gradually elevate the nasal tip, reposition nasal domes, and elongate the columella. This approach improves lip and nasal repair, often eliminating the need for secondary columella elongation in early childhood.
Orthodontic Care in Primary Dentition: Early Corrections
Orthodontic treatment during the primary dentition stage is generally limited. It focuses on correcting mild to moderate posterior and anterior crossbites.
Managing Posterior Crossbites
Posterior crossbites in cleft patients can be skeletal or dental. Skeletal crossbites result from maxillary segment collapse after cleft palate surgery, often causing the cleft-side primary canine to erupt medially to the lower one. Dental crossbites can also occur.
While expansion can be achieved, it must be retained until alveolar reconstruction with a bone graft. Therefore, transverse expansion is often delayed until the transitional dentition stage, just before secondary alveolar bone grafting.
Addressing Anterior Crossbites
Mild to moderate anterior crossbites can be managed using elastic protraction forces delivered via a facial mask. However, if severe skeletal maxillary hypoplasia is present, a surgical approach or distraction osteogenesis might be necessary.
An intraoral technique using a spring system with highly flexible wires and a screw-type expander has shown impressive outcomes for maxillary protraction, activating the circummaxillary suture complex.
Transitional Dentition: Preparing for Bone Grafting
This developmental stage is critical for cleft patients involving the alveolus, as it precedes secondary alveolar bone grafting. The dentition around the cleft often presents severe malposition, hindering surgical access.
Orthodontic treatment aims to reposition adjacent teeth and prepare the cleft site for the bone graft. This reconstruction is typically deferred to this stage to minimize growth restriction from surgical trauma.
Orthodontics should be initiated based on dental development (near-complete root development of incisors) rather than chronological age to minimize root resorption. Cleft patients often experience delayed dental development and eruption.
Maxillary Arch Expansion and Alignment
To prepare the maxillary arch for a bone graft, orthodontists address incisor malposition and anterior arch collapse. A bonded edgewise appliance, often with self-ligating brackets and highly flexible wires, is used for slow, efficient tooth movement. This process allows surrounding thin alveolar bone to remodel, maintaining periodontal support.
Arch expansion can also be done with this appliance, sometimes supported by a quad helix expander. Screw expanders are typically reserved for cases with severe palatal scarring, which is less common with modern delicate surgical techniques.
Optimal expansion should provide well-aligned maxillary segments with a minimal increase in the alveolar gap, as wider gaps are challenging to close. If significant expansion would create a wide gap, bone grafting may be deferred until adolescence, when segments can be surgically mobilized.
Presurgical orthodontics for bone grafting usually takes 6–12 months. Prior to the graft, palatal appliances are removed, labial wires segmented, and supernumerary or primary teeth in the surgical site are extracted 8–12 weeks before surgery to ensure intact gingival tissues.
Preservation of Cleft-Side Teeth
The presence of alveolar bone is dependent on teeth. If a viable cleft maxillary lateral incisor is present with good anatomy, attempts are made to preserve it. If it erupts through the bone graft, it provides suitable alveolar bone for itself and the erupting canine.
If the permanent lateral incisor is missing or needs extraction, the actively erupting canine can take its place, preserving the reconstructed alveolus. Orthodontic treatment continues 8–12 weeks after bone graft surgery. Appliances are removed once arch and dental relations are achieved, and retention follows until permanent dentition is complete.
Permanent Dentition: Definitive Orthodontic Treatment and Orthognathic Surgery
In the permanent dentition stage, definitive orthodontic treatment addresses complex goals similar to non-cleft patients, but with specific considerations:
- Arch length and extractions: Managing crowding and potential need for dental extractions.
- Dental integrity: Ensuring the health of teeth and supporting structures, especially near the cleft.
- Unusual tooth positions: Dealing with impactions, transpositions, congenitally missing teeth, or severely abnormal teeth that may require extraction and prosthetic replacement or orthodontic space closure.
- Midline and relationships: Correcting maxillary/mandibular midlines, and anterior/posterior, transverse, and vertical relationships.
New flexible wires and self-ligating appliances facilitate physiologic forces and favorable tissue remodeling. The aim is often to achieve Class I cuspid and molar relationships with ideal overjet and overbite.
Managing Missing Lateral Incisors
If the cleft lateral incisor is missing, decisions include prosthetic replacement, orthodontic space closure, or a combined surgical-orthodontic approach. Prosthetic replacement (bonded prosthesis or osseointegrated fixture) is considered when ideal Class I cuspid relationships exist.
If the maxillary canine has migrated forward into the grafted ridge, it might replace the lateral incisor, with posterior teeth moved forward. In non-extraction cases, this leads to Class II relations on the cleft side; with lower bicuspid extractions, Class I relations are possible.
If the alveolar bone graft outcome is not ideal, moving the canine forward can improve bone morphology. Factors like canine shape, size, color, and gingival contour influence the decision.
Incorporating Impacted Canines
After bone grafting, cleft-side maxillary canines can have unusual eruption paths and may be impacted. These require surgical exposure and orthodontic incorporation into the dental arch.
Bone Anchorage Screws (BAS)
Bone Anchorage Screws (BAS), or temporary anchorage devices, significantly enhance orthodontic tooth movements. They provide anteroposterior and vertical control for single teeth or groups of teeth, a simple office procedure with no negative sequelae upon removal.
Orthognathic Surgery and Distraction Osteogenesis
Moderate to severe skeletal and dental discrepancies are best managed with a combined surgical/orthodontic approach. While mandibles in cleft patients are usually normal or slightly smaller, maxillary hypoplasia is common.
Planning for Orthognathic Surgery
Before surgery, the orthodontist positions teeth within their basal bones, aligns incisors, and coordinates arches for ideal occlusal interdigitation. Interdental spaces may be created for instrumentation.
The orthodontic appliance is used during intermaxillary fixation and postsurgical elastic therapy. Close cooperation between orthodontist and surgeon ensures favorable outcomes.
Planning is similar to non-cleft dentofacial deformities, involving detailed clinical exams and records. Patients with palatal clefts undergoing maxillary advancement are at risk for velopharyngeal insufficiency, necessitating speech pathology evaluation.
Advancements in 3D Planning
Digital 3D software, based on CT/CBCT scans, now assists in planning craniomaxillofacial surgery. This technology creates virtual 3D models of the craniofacial skeleton, allowing digital surgical movements and stereolithographic construction of physical models or surgical splints. This replaces traditional model surgery, though clinician oversight remains crucial due to limited soft-tissue response knowledge.
Distraction Osteogenesis for Maxillary Hypoplasia
For severe maxillary hypoplasia, especially with substantial scarring or existing pharyngeal flaps, conventional orthognathic procedures may lack stability. Distraction osteogenesis, particularly with a Rigid External Distraction (RED) device or internal devices, offers a reliable solution.
The RED device technique involves an intraoral splint, a complete Le Fort I osteotomy, a cranial halo with an external adjustable distraction screw system, distraction, and rigid retention. Internal devices are used for less severe cases and offer the advantage of not requiring a second operation for removal.
Distraction osteogenesis has shown excellent functional and aesthetic results in children, adolescents, and adults, with remarkable stability and superior soft-tissue changes compared to conventional surgery. It also minimally affects the velopharyngeal mechanism.
Growth and Orthodontic Treatment: Long-Term Considerations
Orthodontists monitor cleft patients from infancy to adulthood, recognizing that abnormal facial growth presents added challenges. Cleft patients have significant growth potential that, if not negatively affected by reconstructive procedures, can lead to favorable outcomes. Minimizing growth disturbances simplifies and shortens orthodontic treatment.
Cleft teams should continuously assess protocols to minimize scarring, particularly in the anterior maxilla (e.g., delaying alveolar bone grafting and avoiding damage to the maxillary body). This approach reduces the need for extensive and complex orthodontic procedures.
Conclusion: The Critical Role of Orthodontics in Cleft Care
Orthodontics is indispensable in the comprehensive management of cleft patients. The orthodontist's role involves supporting the surgeon in all aspects of craniofacial growth, dental development, occlusion, and treatment planning to achieve ideal outcomes.
New technologies like nasoalveolar molding, maxillary distraction osteogenesis, flexible arch wires, self-ligating appliances, bone anchorage screws, and 3D imaging facilitate these complex interventions. This integrated approach provides new strategies for managing cleft patients, aiming for outstanding functional and aesthetic results. Close cooperation between the surgeon and orthodontist remains paramount for success.
FAQ: Frequently Asked Questions About Orthodontic Management of Cleft Lip and Palate
What is nasoalveolar molding (NAM) in cleft lip and palate treatment?
Nasoalveolar molding (NAM) is a presurgical orthopedic technique used in infants to reshape the gum pads, align maxillary segments, and mold the nasal cartilages. It helps to reduce the severity of the cleft deformity before surgical lip repair, improving nasal symmetry and columella length.
Why is a multidisciplinary team important for cleft care?
A multidisciplinary team is crucial because cleft lip and palate affect various structures (oral cavity, alveolus, dentition, nose, palate) that traditionally fall under different specialties. A coordinated approach involving orthodontists, surgeons, speech pathologists, and other specialists ensures comprehensive and integrated care, leading to better functional and aesthetic outcomes.
When does orthodontic treatment typically begin for cleft patients?
Orthodontic treatment for cleft patients typically begins in stages: early interventions like nasoalveolar molding in infancy, limited corrections in primary dentition, more significant preparation (e.g., for bone grafting) in transitional dentition, and definitive treatment in permanent dentition, often combined with orthognathic surgery in adolescence.
How are missing teeth, like the lateral incisor, managed in cleft patients?
Missing cleft-side lateral incisors can be managed in several ways: prosthetic replacement (e.g., bonded prosthesis, dental implant), orthodontic space closure (moving adjacent teeth like the canine into the lateral incisor position), or a combined surgical-orthodontic approach. The decision depends on factors such as existing occlusion, bone morphology, and the anatomy of adjacent teeth.
What is distraction osteogenesis and when is it used in cleft treatment?
Distraction osteogenesis is a surgical technique used to gradually lengthen bone. In cleft patients, it is primarily employed for severe maxillary hypoplasia (underdevelopment of the upper jaw) or significant scarring, often when conventional orthognathic surgery might lack stability or be too risky. It helps to advance the maxilla, improving facial balance and occlusion.