Multilevel surgery has been established as the mainstay of treatment for the surgical management of obstructive sleep apnea (OSA). Combined with uvulopalatopharyngoplasty, tongue-base surgeries, including the genioglossus advancement (GA), sliding genioplasty, and hyoid myotomy and suspension, have been developed to target hypopharyngeal obstruction. Total airway surgery consisting of maxillomandibular advancement (MMA) with/without GA has shown significant success. Skeletal procedures for OSA with or without a palatal procedure is a proven technique for relieving airway obstruction during sleep. A case study demonstrating the utility of virtual surgical planning for MMA surgery is presented.
Key points
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Combined with a uvulopalatopharyngoplasty, tongue-base surgeries, including the genioglossus advancement (GA), sliding genioplasty, and hyoid myotomy and suspension, have been developed to target hypopharyngeal obstruction.
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Total airway surgery consisting of maxillomandibular advancement with or without GA has shown significant success in patients with obstructive sleep apnea (OSA).
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Skeletal procedures for OSA with or without a palatal procedure is a proven technique for relieving airway obstruction during sleep.
Introduction
Obstructive sleep apnea (OSA) continues to be a pervasive condition that is linked to an increased incidence of cardiovascular diseases, endocrine disorders, and overall increased health care utilization. Multilevel surgery has been established as the mainstay of treatment for the surgical management of OSA. Skeletal surgery for OSA has traditionally consisted of a phased protocol to address airway obstruction secondary to nasopharyngeal, oropharyngeal, and hypopharyngeal obstruction. Combined with a uvulopalatopharyngoplasty (UPPP), tongue-base surgeries, including the genioglossus advancement (GA), sliding genioplasty (SG), and hyoid myotomy and suspension, have been developed to target hypopharyngeal obstruction. Total airway surgery, consisting of maxillomandibular advancement (MMA) with or without GA, has shown significant success in patients with OSA. Skeletal procedures for OSA with or without a palatal procedure are a proven technique for relieving airway obstruction during sleep.
It has been well established that skeletal advancement procedures typically accomplish a goal of 8 to 14 mm of advancement, thus increasing tension on the pharyngeal, genioglossus, and geniohyoid muscles with the goal of reducing the severity of sleep apnea. Patients are traditionally selected for surgery based on the level of obstruction, which often occurs at the level of the base of tongue, although most patients demonstrate retropalatal obstruction as well. Since the introduction of a skeletal surgery to advance the genioglossus muscle along with UPPP, as described by Riley and colleagues, multilevel reconstruction surgery has demonstrated improved outcomes in relieving OSA in those who demonstrate multilevel obstruction.
Although physical examination, drug-induced sleep endoscopy (DISE), and polysomnography (PSG) help to guide the clinician’s decision-making process in selecting patients who are candidates for GA, SG, or MMA combined with UPPP, intraoperative factors, such as length and width of the velum, degree of palatal and tongue-base obstruction, and concomitant lateral pharyngeal wall obstruction, are currently being studied. DISE and sleep MRI have emerged as modalities to diagnose the site of airway obstruction before surgery.
Preoperative Considerations
All patients considered for skeletal surgery are first diagnosed by PSG, Epworth evaluation, and fiberoptic laryngoscopy. Candidates for surgery present with an apnea-hypopnea index (AHI) of more than 5 events per hour, and/or a respiratory disturbance index (RDI) greater than 5 with an Epworth Sleepiness Scale (ESS) greater than 8, who either did not tolerate, or refused a trial of continuous positive airway pressure (PAP). Presurgical patients present with evidence of obstruction as demonstrated by awake physical examination documenting Friedman II or III classification. Exclusion criteria for skeletal surgery include age younger than 12 years, chronic pulmonary disease on oxygen, and those affected with an untreated sleep disorder other than OSA that represents their primary sleep disorder. Preoperative assessment included history taking; ESS evaluation; complete physical examination; and PSG. Outcomes are defined by success, cure, and responder criteria. Success is defined as an AHI less than 20 and/or a 50% decrease in AHI of the preoperative value. Cure is defined as an AHI less than 5 events per hour. Responder is defined as significant improvement in the AHI and/or RDI after surgical intervention.
Obstruction can occur at a number of points in the airway. Physical examination of these patients may reveal hypertrophy of the adenoids and tonsils, retrognathia, micrognathia, macroglossia, deviation of the nasal septum, turbinate hypertrophy, a thick short neck, or tumors in the nasopharynx or hypopharynx. Both primary and secondary medical conditions are associated with OSA, owing to their effects on the upper airway anatomy. These may include temporomandibular joint disorders, myxedema, goiter, acromegaly, and lymphoma.
Fiberoptic nasopharyngoscopy is used to identify obstruction at the nasopharynx, oropharynx, and hypopharynx, and to rule out laryngeal anomalies. It can help estimate the degree of lateral wall collapse, palatal narrowing, and tongue-base obstruction. The site of obstruction can be classified by Fujita classification, with type I being palatal obstruction only, type II presenting as a combined palatal and tongue-base obstruction, and type III a tongue-base obstruction pattern only. Without performing fiberoptic evaluation, the site of obstruction may not be discernable.
Cephalometric evaluation is a simple way to evaluate individual patient upper airway site of obstruction. Cephalometric evaluation has long been used in evaluation of the airway in OSA. The metrics used for evaluation are SNA, SNB, PNS, Mandibular angle, posterior airway space (PAS), and MP-H ( Fig. 1 ). These metrics are used to evaluate preoperative obstruction and follow postoperative results. It is recommended that this 2-dimensional radiograph be supplemented with a 3-dimensional fiberoptic to evaluate the airway. At our institution, the most consistent finding is a narrowed PAS and low hyoid position (MP-H).
The definitive objective test is a study during sleep. The gold standard at present is an attended PSG evaluation. This level I study assesses the cardiorespiratory system, revealing oxygenation information, and records electroencephalogram, electrooculogram, and electromyogram. It reveals sleep stage information and estimates the percentage of apnea, hypopneas, and respiratory-related events during sleep. Ambulatory studies are estimated as level III and do not determine sleep stage data.
Surgical Technique
Retropalatal obstruction is addressed with UPPP. Fujita and colleagues introduced UPPP with tonsillectomy in 1979. Many modifications have been published; the basic procedure involves palate shortening with closure mucosal incisions, tonsillectomy, and lateral pharyngoplasty. For multilevel surgery candidates, patients undergo a UPPP with GA or SG.
Genioglossal Advancement
The GA must be distinguished from tongue suspension. The advancement of the geniotubercle in the GA procedure is distinct from suture fixation and suspension of the tongue base. The tongue suspension technique does not advance the mandible and is not considered a skeletal procedure. GA is performed as described by Riley and colleagues. To review, after local anesthetic with a concentration of 1:100,000, epinephrine is injected at the lower gingivolabial sulcus, an incision is created along the anterior mandible. Subperiosteal dissection is then achieved exposing the anterior face of the mandible along its inferior border and then laterally identifying the mental neurovascular bundles. A horizontal window osteotomy is then created using a sagittal saw approximately 5 mm below the roots of the canine and approximately 10 mm above the inferior border of the mandible. The bone cut is then connected with 2 vertical osteotomies completing the rectangular window. Making a bicortical anterior osteotomy performs the GA. The width of the mandible, which had been pulled forward via the window osteotomy, is measured. The facial cortex and medullary bone is then removed and the lingual cortex holding the origin of the genioglossus muscle is rotated perpendicular to the window osteotomy. The osteotomized segment is then secured inferiorly with a single bicortical titanium screw ( Fig. 2 ). Closure is performed with a 3 to 0 chromic with closure of the mentalis muscle and gingiva-buccal sulcus.
Sliding Genioplasty Technique
The SG is an advancement genioplasty that is occasionally recommended for patients with microgenia due to both a retrognathic and foreshortened mandible. Patients in whom the GA cannot be performed due to increased risk for tooth injury or in patients with significant retrognathia greater than 2 cm from the subnasale vertical tangent may be considered for SG. The SG procedure seldom includes the entire genial tubercle, thereby not affecting pull on the genioglossal muscle. It will likely pull the geniohyoid muscle that may lead to an unfavorable vector on the tongue base. The procedure may be amenable for patients with retro-epiglottic obstruction. The SG is performed through subperiosteal dissection with exposure of the inferior border of the anterior mandible. A reciprocating saw is used to cut both lateral edges of the parasymphysis along its inferior border and then laterally tapering the cut below the mental neurovascular bundles. The SG operation is often performed for both functional and aesthetic concerns. When the anterior osteotomy incorporates the geniotubercle through adjacent vertical window osteotomies, the operation is described as a mortised genioplasty. A patient with mild OSA with microgenia and nasal obstruction is depicted with postoperative cure in OSA after functional rhinoplasty and SG in Fig. 3 .
Hyoid Myotomy and Suspension
There are 2 generally accepted techniques in performing hyoid myotomy and suspension; the hyoid-mandibular and the hyoid-thyroid technique. The author describes the hyoid-thyroid technique in this publication. The hyoid bone is a U-shaped bone suspended by the omohyoid, mylohyoid, and geniohyoid muscle; hyoepiglottic ligament; and accessory strap and laryngeal muscles. Its intimate connection with the tongue base and epiglottis makes it a viable technique for addressing hypopharyngeal obstruction. The hyoid-thyroid technique is performed through a cervical neck incision overlying the hyoid bone. Dissection is performed in a subplatysmal plane to expose the hyoid bone. Infrahyoid release of the strap muscles is performed using electrocautery medial to the greater cornu of the hyoid. Mobilization and suspension of the hyoid bone over the thyroid cartilage is performed using 2 to 0 Prolene sutures as depicted ( Fig. 4 ). The hyoid-thyroid technique may be performed under local anesthesia with fiberoptic evaluation of the hypopharynx or under general anesthesia with concomitant GA, SG, or UPPP.
Maxillomandibular Advancement
Patients who have had incomplete response or failed to respond to phase I intervention may be considered for a phase II operation or MMA. In addition, patients with significant skeletal-dental deformity with OSA may be candidates for MMA. The MMA advances the midface and provides more room for the tongue. Additionally, the sagittal split osteotomy of the mandible places additional tension on the tongue-hyoid complex. Several publications have described the use of MMA in treating large series of patients with OSA.
A bilateral sagittal ramus osteotomy is performed through a posterior gingivo-buccal incision. Care is taken to identify the lingula of the mesial ascending ramus and the inferior alveolar nerve. A Hunsuck osteotomy is made with Lindeman burr or reciprocating blade ( Fig. 5 ). The sagittal osteotomy then connects the ascending ramus cuts with the Dalpont osteotomy in the anterior mandible ( Fig. 6 ). The ramus is then split with osteotomes. The amount of advancement is determined preoperatively from the orthognathic model surgery and/or virtual plan. Adjunctive orthodontic treatment is frequently necessary to obtain the desired occlusion and to eliminate dental compensations that would otherwise limit the amount of advancement. Presurgical orthodontic evaluation with modeling may be considered before surgery but is not necessary. A thorough discussion is made with the patient to consider accompanying skeletal-dental abnormalities, and perioperative and postoperative management. Most patients retain their preoperative occlusion without need for orthodontic management. After advancement with the standard surgical technique, the fragments are rigidly fixed with screws or bone plates. For large advancements of 7 mm or more, long-term stability is enhanced with a 5-day to 7-day course of maxillomandibular fixation using orthodontic bands.
Combined advancement of the maxilla and mandible is the most recent and efficacious surgical procedure for the treatment of OSA. The surgical technique includes a standard Le Fort I osteotomy in combination with the aforementioned mandibular sagittal split osteotomy. A concomitant GA, as previously described, is an adjunct and recommended to improve tongue advancement ( Fig. 7 ). MMA surgery may result in some facial change, which is most often favorable. However, the patient must be made aware of the possibility of any unfavorable aesthetic outcomes that may occur from this surgical procedure.
Introduction
Obstructive sleep apnea (OSA) continues to be a pervasive condition that is linked to an increased incidence of cardiovascular diseases, endocrine disorders, and overall increased health care utilization. Multilevel surgery has been established as the mainstay of treatment for the surgical management of OSA. Skeletal surgery for OSA has traditionally consisted of a phased protocol to address airway obstruction secondary to nasopharyngeal, oropharyngeal, and hypopharyngeal obstruction. Combined with a uvulopalatopharyngoplasty (UPPP), tongue-base surgeries, including the genioglossus advancement (GA), sliding genioplasty (SG), and hyoid myotomy and suspension, have been developed to target hypopharyngeal obstruction. Total airway surgery, consisting of maxillomandibular advancement (MMA) with or without GA, has shown significant success in patients with OSA. Skeletal procedures for OSA with or without a palatal procedure are a proven technique for relieving airway obstruction during sleep.
It has been well established that skeletal advancement procedures typically accomplish a goal of 8 to 14 mm of advancement, thus increasing tension on the pharyngeal, genioglossus, and geniohyoid muscles with the goal of reducing the severity of sleep apnea. Patients are traditionally selected for surgery based on the level of obstruction, which often occurs at the level of the base of tongue, although most patients demonstrate retropalatal obstruction as well. Since the introduction of a skeletal surgery to advance the genioglossus muscle along with UPPP, as described by Riley and colleagues, multilevel reconstruction surgery has demonstrated improved outcomes in relieving OSA in those who demonstrate multilevel obstruction.
Although physical examination, drug-induced sleep endoscopy (DISE), and polysomnography (PSG) help to guide the clinician’s decision-making process in selecting patients who are candidates for GA, SG, or MMA combined with UPPP, intraoperative factors, such as length and width of the velum, degree of palatal and tongue-base obstruction, and concomitant lateral pharyngeal wall obstruction, are currently being studied. DISE and sleep MRI have emerged as modalities to diagnose the site of airway obstruction before surgery.
Preoperative Considerations
All patients considered for skeletal surgery are first diagnosed by PSG, Epworth evaluation, and fiberoptic laryngoscopy. Candidates for surgery present with an apnea-hypopnea index (AHI) of more than 5 events per hour, and/or a respiratory disturbance index (RDI) greater than 5 with an Epworth Sleepiness Scale (ESS) greater than 8, who either did not tolerate, or refused a trial of continuous positive airway pressure (PAP). Presurgical patients present with evidence of obstruction as demonstrated by awake physical examination documenting Friedman II or III classification. Exclusion criteria for skeletal surgery include age younger than 12 years, chronic pulmonary disease on oxygen, and those affected with an untreated sleep disorder other than OSA that represents their primary sleep disorder. Preoperative assessment included history taking; ESS evaluation; complete physical examination; and PSG. Outcomes are defined by success, cure, and responder criteria. Success is defined as an AHI less than 20 and/or a 50% decrease in AHI of the preoperative value. Cure is defined as an AHI less than 5 events per hour. Responder is defined as significant improvement in the AHI and/or RDI after surgical intervention.
Obstruction can occur at a number of points in the airway. Physical examination of these patients may reveal hypertrophy of the adenoids and tonsils, retrognathia, micrognathia, macroglossia, deviation of the nasal septum, turbinate hypertrophy, a thick short neck, or tumors in the nasopharynx or hypopharynx. Both primary and secondary medical conditions are associated with OSA, owing to their effects on the upper airway anatomy. These may include temporomandibular joint disorders, myxedema, goiter, acromegaly, and lymphoma.
Fiberoptic nasopharyngoscopy is used to identify obstruction at the nasopharynx, oropharynx, and hypopharynx, and to rule out laryngeal anomalies. It can help estimate the degree of lateral wall collapse, palatal narrowing, and tongue-base obstruction. The site of obstruction can be classified by Fujita classification, with type I being palatal obstruction only, type II presenting as a combined palatal and tongue-base obstruction, and type III a tongue-base obstruction pattern only. Without performing fiberoptic evaluation, the site of obstruction may not be discernable.
Cephalometric evaluation is a simple way to evaluate individual patient upper airway site of obstruction. Cephalometric evaluation has long been used in evaluation of the airway in OSA. The metrics used for evaluation are SNA, SNB, PNS, Mandibular angle, posterior airway space (PAS), and MP-H ( Fig. 1 ). These metrics are used to evaluate preoperative obstruction and follow postoperative results. It is recommended that this 2-dimensional radiograph be supplemented with a 3-dimensional fiberoptic to evaluate the airway. At our institution, the most consistent finding is a narrowed PAS and low hyoid position (MP-H).
