Maxillomandibular Deformities

Definitive Correction of Associated Maxillomandibular Deformities in TCS

Surgical interventions:
Maxillo-mandibular Orthognathic Surgery

Postponed until skeletal maturity occurs, but children with severe cases of obstructive sleep apnea can get the surgery if the nonsurgical approach did not help, and since growth will be unpredictable, further surgeries might be required in the future.
Many patients with severe open bites with reverse curve of Spee undergo surgical
orthodontics and bimaxillary orthognathic surgery.

TCS severity and surgical treatment options
Severity Treatment
Mild bimaxillary surgery: bilateral sagittal split, LeFort, and +/− genioplasty
Moderate: Kaban type I TMJ & type IIa
- Determined by the ramus height and stability of TMJ 		Bilateral inverted L, LeFort, genioplasty
Sever:
Sever hypoplasia, & deformity of the temporomandibular joint complex.
Ex: Kaban type IIb and III joints. 		TMJ total joint replacement + LeFort and genioplasty
Eliminate obstructive sleep apnea
Provide functional occlusion
Create a facial profile that is within normal limits
Goal of definitive Maxillo-mandibular surgery

Management of the Mandibular Deformity in the children with Craniofacial Microsomia

Treatment of the growing child

Correction of end stage deformities is usually done on older children and adults, but for certain malformations earlier intervention is encouraged. ex: obstructive sleep apnea
Reason:
it would normalize the functional matrix, therefore improving the growth potential by placing strucures in a better anatomic locations. additionally, it will improve function, aesthetic and symmetry.
Treatment approach:
it's determined by the mandibular skeletal type (Kaban types I, IIA, IIB and III), presence of midface deformity, age based on chronical, dental and skeletal, and psychosocial development.
Treatment goal:
- Create an open bite surgically by elonagtion and rotation of the mandible to the midline

General assessment principles
by dentition and skeletal type:

Steps of the treatment

  1. Functional appliance treatment

    • It enhances the neuromuscular environment, promotes mandibular and maxillary growth, and expands the soft tissue envelope on the affected side.
    • It holds the affected side of the mandible in a lowered and protrusive position.
    • It stimulates bone apposition in the ramus-condyle unit and coronoid process by acting as the normal translatory and protrusive motion produced by the lateral pterygoid muscle.
    • Indicated for patients with type I CFM.
    • Good response to appliance therapy eliminates the need for surgical lengthening of the ramus.
    • Reduces the tendency for postoperative skeletal relapse.

  2. orthodontic treatment

    • Focus is on control of tooth eruption.
    • It prevents or corrects dentoalveolar adaptations to the asymmetrical position of the maxilla and mandible.

  3. Mandibular Operation and Immediate Postsurgical Dental Appliance

    • Indicated for type I, IIA, and some IIB patients.
    • The mandible is elongated and rotated to the correct midline.
    • Methods: conventional orthognathic surgical methods or by distraction osteogenesis (DO).
    • Prevents the need for a Le Fort I osteotomy after completion of skeletal growth.

TMJ prosthesis

Treatment

General anesthesia is employed with a breathing tube that is typically placed through the nose.

The results of jaw surgery are usually apparent immediately but will reveal themselves fully as swelling and bruising subside over a period of a month or two.

All incisions are made in the mouth and sometimes additional very small incisions are made on the cheeks. The bones will be mobilized into the planned positions and fixed with plates and screws. Your surgeon may keep a splint (a mouth guard that is fixed to your teeth) in place after surgery.

From Posnick JC, Treacher Collins syndrome: Perspectives in evaluation and treatment, J Oral Maxillofac Surg 55:1120, 1997. F (bottom left, bottom right), G, From Posnick JC, Goldstein JA, Waitzman A: Surgical correction of Treacher Collins malar deficiency: quantitative CT scan analysis of long-term results, Plast Reconstr Surg 92:12, 1993.