**9. Distraction osteogenesis and OSA**

Recently, many surgeons suggest distraction osteogenesis for treating OSA. Distraction osteogenesis has many advantages over the traditional MMA surgical technique; better soft tissue adaptation, elimination of the need of a bone graft, less soft tissue dissection and better stability. On the other hand, lengthy treatment and the need of postoperative orthodontic treatment are the disadvantages of this kind of treatment [70] [71].

## **10. Summary**

normal mandibular anteroposterior dimension [52]; it requires careful assessment of the genial tubercle, based on a study done by Mintz et al [55] on 14 human skulls, the superior border of the genial tubercle is 6.45 mm inferior to the apices of central incisors with 35.4% of the genial tubercle were located less than 5mm inferiorly. After estimating genial tubercle location a rectangular window osteotomy is performed leaving the inferior border of the mandible intact then advancing the segment to stabilize the hypopharyngeal airway. It will require a 90 degree rotation of the osteotomized segment and placing the lingual cortical plate anterior to the buccal/labial cortical plate [52]. Trephine osteotomy approach is another technique using the same concept but with trephine burr in an attempt to decrease postoperative complications (anterior teeth roots amputation) [54]. Foltán and René [56] published a follow-up of 31 patients who had genioglossus advancement by the modified genioplasty with hyoid myotomy. They reported 74% success rate showed by significant dropping in RDI and oxygen desaturation index. Genioglossus advancement with or without hyoid suspension is a valid technique to treat OSA; it could be performed alone or as an adjunct to UPPP [57]. Another technique to address retrolingual obstruction is tongue base surgeries. Tongue suspension is a revisable minimally invasive surgery performed via submental incision. By introducing a large suture into the base of the tongue and suspending the tongue to the mandibular lingual surface. Omur et al reported high success (81.81%)of tongue base surgery with UPPP. They conclude that tongue base suspension combined with UPPP has been shown to reduce RDI better than UPPP alone [58].

It is well recognized that patients with maxillomandibular deficiencies will ultimately develop OSA; from this observation MMA is advocated for OSA treatment even in patients with normal skeletal proportion [59]. MMA will increase the posterior airway dimension by physically expanding the skeletal structure. The forward movement of the maxilloman‐ dibular complex improves the tension and collapsibility of the velopharyngeal and suprahyoid muscles [60] [61]. Since the majority of OSA patients are middle age with a saggy and droopy soft tissue; forwarded movement of the mandibulomaxillary complex will not only bypass the obstruction; it will also provide facial rejuvenation by augment‐ ing soft tissue support [62]. MMA has many advantages such as decrease number of surgeries needed by utilizing one surgery to bypass several sites of obstructions (by performing Le Fort I advancement; it will open the nasal valve and consequently im‐ prove air flow, tighten the soft palate and pharyngeal muscles at the same time while mandibular advancement will tighten genioglossus and suprahyoid muscles), avoid the need for tracheostomy in the postoperative period and ultimately decrease medical costs by decreasing hospital stay. If the patient will undergo simultaneous MMA and soft tissue procedure such as UPPP or tongue reduction surgeries; temporary tracheostomy may be indicated to ensure patent airway. Other indications for temporary tracheostomy are difficult airway, RDI >60 and Sao2 <60, morbid obesity and significant craniofacial abnormality [1] [59]. MMA is considered one of the most successful treatment modalities for OSA after tracheostomy and CPAP [63] [64]. MMA success rate is very high compar‐

**8.6. Maxillomandibular advancement**

400 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

OSA surgical treatment success is primarily dependent on careful diagnosis and recognition of levels of obstruction. Many surgical protocols are there in the literature. MMA along with tracheostomy are the most successful surgical procedures to treat OSA.


**Table 1.** Differences between Orthognathic and Telegnathic surgery


**Table 2.** OSA classification


**Table 3.** OSA Treatment

### **Author details**

Dina Ameen\*

Address all correspondence to: dr.dinaameen@gmail.com

Clinical Fellow at the University of Alabama at Birmingham, USA
