The association of OSAS and uvula: the role of MRI in this egg-chicken problem in OSAS.

PURPOSE: Obstructive sleep apnea syndrome (OSAS) is a condition resulting from repetitive partial or complete upper airway obstruction, and its etiology remains uncertain. Polysomnography is the gold standard diagnostic test for OSAS. However, there are long wait times for this evaluation, so questionnaires or ancillary diagnostic methods are used to select appropriate patients. One of these is magnetic resonance imaging (MRI). The present study aimed to investigate the association between clinical features of OSAS and uvular changes on MRI. MATERIALS AND METHODS: A total of 102 participants, 80 with OSAS and 22 controls, were included in the study. All participants underwent full-night polysomnography, MRI, and anthropometric measurements. RESULTS: In comparisons of MRI measurements of the uvula, statistically significant differences in uvular length, thickness, and angle were observed between the OSAS and control groups. MRI measurement significantly associated with apnea-hypopnea index was uvular thickness. Evaluation of anthropometric and MRI measurements revealed statistically significant associations between waist circumference and uvular thickness, uvular width, and oropharyngeal space among the OSAS patients. CONCLUSION: Thickened uvula on MRI is associated with the presence of OSAS, and its thickness is well correlated with the severity of the diseases. Thus, it may be a reliable indicator of OSAS and could be used as a supportive finding to identify patients suitable for referral for diagnostic polysomnography.

The relationship of the uvula with snoring and obstructive sleep apnea: a systematic review.

Currently, the relationship between uvula size and sleep-disordered breathing (snoring and obstructive sleep apnea) lacks data for objective interpretation. This study conducted a systematic review of the international literature for research describing the measurable characteristics of the uvula (i.e., size, length, width) and any association with snoring and obstructive sleep apnea (OSA). PubMED, Scopus, Google Scholar, Embase, and the Cochrane Library were each systematically searched from inception through November 15, 2016. We screened 1037 titles and abstracts. We conducted a full review of 54 downloaded articles. Sixteen articles met inclusion and exclusion criteria. The 16 studies included a total of 2604 patients. The selected articles included data and information for (1) normative data for uvular size in the control groups, (2) snoring and uvula size, (3) OSA and uvula size, and (4) overall uvula function. Our review noted variability in findings; however, in general, a uvular length > 15 mm was considered elongated and a uvular width > 10 mm was considered to be wide. The studies included in this systematic review reveal a relationship between uvula size, snoring, and OSA. Further, larger uvulas appear associated with more severe snoring and OSA. The direct correlation between uvula size and its relationship specifically to snoring and OSA remain as topics for future prospective research.

Complete concentric collapse at the soft palate in sleep endoscopy: what change is possible after UPPP in patients with CPAP failure?

PURPOSE: The aim of this work was to assess whether uvulopalatopharyngoplasty in patients with failure for positive airway pressure not only reduces the degree of obstructive sleep apnea but also to determine as well if it changes the collapse pattern of the soft palate and thereby fulfills the qualifications for implementing upper airway stimulation (UAS) as an adjunctive solution. METHOD: Fifteen patients with intolerance for positive airway pressure were included in this retrospective cohort study. Polygraphy and drug-induced sleep endoscopy were used in order to evaluate the reduction of the apnea-hypopnea index (AHI), as well as the change of collapse pattern at the soft palate level before and about 3 months after uvulopalatopharyngoplasty and tonsillectomy (TE-UPPP). RESULTS: In 93% of the patients, a postoperative change of the initially complete concentric palatal collapse pattern could be found during drug-induced sleep endoscopy. In one patient, no obstruction at all was seen at the soft palatal level. Only one patient still presented with a complete concentric collapse at velum level. AHI decreased from mean 34.7 events per hour to 20.2/h and oxygen desaturation index from 25.3 events per hour to 16.1/h. CONCLUSION: Patients seeking for positive airway pressure alternatives could not only benefit from reduction of AHI by TE-UPPP postoperatively; additionally, by changing the collapse pattern at the soft palate, they might also fulfill criteria for upper airway stimulation (UAS) in case of persistent OSA of at least moderate degree.

Neuromuscular function of the soft palate and uvula in snoring and obstructive sleep apnea: A systematic review.

OBJECTIVE: A collapsible upper airway is a common cause of obstructive sleep apnea. The exact pathophysiology leading to a more collapsible airway is not well understood. A progressive neuropathy of the soft palate and pharyngeal dilators may be associated with the progression of snoring to OSA. The purpose of this study is to systematically review the international literature investigating the neurophysiologic changes in the soft palate and uvula that contribute to progression from snoring to OSA. METHODS: PubMed/MEDLINE and 4 other databases were systematically searched through July 4, 2017. Eligibility: (1) Patients: controls, snoring or OSA patients (2) Intervention: neuromuscular evaluation of the palate and/or uvula (3) Comparison: differences between controls, snoring and OSA patients (4) Outcomes: neuromuscular outcomes (5) Study design: Peer reviewed publications of any design. RESULTS: 845 studies were screened, 76 were downloaded in full text form and thirty-one studies met criteria. Histological studies of the soft palate demonstrated diffuse inflammatory changes, muscular changes consistent with neuropathy, and neural aberrancies. Sensory testing studies provided heterogeneous outcomes though the majority favored neuronal dysfunction. Studies have consistently demonstrated that increasing severity of snoring and sleep apnea is associated with worsening sensory nerve function of the palate in association with atrophic histological changes to the nerves and muscle fibers of the soft palate and uvula. CONCLUSIONS: Recent evidence highlighted in this systematic review implicates the role of neurogenic pathology underlying the loss of soft palate and/or uvular tone in the progression of snoring to sleep apnea.

Depth-dependent changes of obstruction patterns under increasing sedation during drug-induced sedation endoscopy: results of a German monocentric clinical trial.

PURPOSE: Drug-induced sedation endoscopy (DISE) and simulated snoring (SimS) can locate the site of obstruction in patients with sleep-disordered breathing (SDB). There is clinical evidence for a change in collapsibility of the upper airway depending on the depth of sedation. So far, a dose-response relationship between sedation and collapsibility has not been demonstrated. METHODS: DISE and SimS were performed in 60 consecutive patients with SDB under monitoring of depth of sedation by BiSpectral Index® (BIS). Initially, SimS was conducted followed by DISE using bolus application of propofol. Sedation was performed up to a sedation level representing slow wave sleep (BIS = 40). The collapsibility of the upper airway was documented at decreasing sedation levels by an identical pictogram classification. RESULTS: For all levels and patterns of obstruction, a dose-dependent increase in the collapsibility of the upper airway was detected. A maximum collapsibility was achieved at sedation levels representing slow wave sleep. The collapsibility during SimS corresponded to light sleep stages and did not cover slow wave sleep. CONCLUSION: A dose-dependent change of patterns of obstructions can be observed during DISE under BIS monitoring indicating sedation depth. The obtained patterns of obstruction during DISE and SimS should thus be interpreted with regard to the sedation depth.

Drug-induced sleep endoscopy and simulated snoring in patients with sleep-disordered breathing: agreement of anatomic changes in the upper airway.

Drug-induced sleep endoscopy (DISE) and simulated snoring (SimS) are performed as part of the diagnostic procedure in patients with suspected sleep-disordered breathing (SDB). Despite both techniques frequently performed, they have rarely been evaluated yet in terms of agreement of the obtained results. Both diagnostic procedures were performed consecutively in 40 patients with SDB and documented identically. The obtained data were analysed with respect to the agreement of both procedure at different levels of the oropharynx as well as different patterns of obstruction and vibration. The anterior-posterior collapsibility of the soft palate/uvula revealed a moderate agreement between SimS and DISE (κ = 0.42; 95 % CI 0.22-0.63). The dorsal shift of the tongue base agreed moderate for patients with an AHI below 10 (κ = 0.47) and above 25 (κ = 0.44) between SimS ad DISE. The lateral and circular pharyngeal collapsibility at velum and tongue base level did not agree between SimS and DISE, was higher for DISE and could be partially reversed by mandibular protrusion. Collapse patterns of the soft palate and uvula can be induced by SimS and resemble the patterns induced by DISE. The dorsalization of the tongue base can be simulated to a lower extent by SimS. Lateral and circular patterns of collapse at the upper and lower oropharynx induced by DISE do not seem to be simulated by SimS. SimS seems to be an additional method to screen the collapsibility of the soft palate and uvula prior to DISE.

Analysis of the dynamic changes in the soft palate and uvula in obstructive sleep apnea-hypopnea using ultrafast magnetic resonance imaging.

Apnea and the respiratory cycle are dynamic processes in obstructive sleep apnea-hypopnea (OSAH), which occur only during sleep. Our study aimed to observe the dynamic changes in the soft palate and the uvula during wakefulness and sleep using ultrafast magnetic resonance imaging (UMRI) to provide reference data for the pathogenesis and treatment of OSAH. The dynamic changes in the soft palate and uvular tip of 15 male patients (average age: 50.43 ± 9.82 years) with OSAH were evaluated using UMRI of the upper airway while asleep and awake after 1 night of sleep deprivation. A series of midline sagittal images of the upper airway were obtained. The distance from the center of the soft palate to the x-axis (an extended line from the anterior nasal spine to the posterior nasal spine), from the uvular tip to the x-axis, from the center of the soft palate to the y-axis (a perpendicular line from the center of the pituitary to the x-axis), and from the uvular tip to the y-axis (designated as PX, UX, PY, and UY, respectively) were measured during sleep and wakefulness. The minimum PX, PY, UX, and UY were shorter during sleep than during wakefulness, whereas the maxima were longer during sleep (P < 0.01), the differences between the maximum and minimum PX, PY, UX, and UY were larger during sleep (P < 0.01). The upward, downward, forward, and backward ranges of movement of the soft palate and the uvular tip were larger during sleep in OSAH patients. This increased compliance may trigger each airway obstructive event.

Assessment of the uvulo-glossopharyngeal dimensions in patients with ß-thalassemia major.

OBJECTIVES: Thalassemia patients present varying degrees of craniofacial characteristics, while the morphology of the upper airway is less studied. The purpose of this study was to compare the uvula-glossopharyngeal dimensions (UGDs) of patients with ß-thalassemia major (BTM) with non-thalassemic subjects who had similarities in the maxillo-mandibular skeletal pattern. SUBJECTS AND METHODS: The material for this cross-sectional retrospective study consisted of lateral cephalograms of 40 BTM patients (23 males, 17 females, aged 9.5 ± 0.97 years). These were compared with lateral cephalograms of a control group of 40 non-thalassemic subjects (23 males, 17 females, aged 11.0 ± 0.87 years). The control group was chosen so that they had similarities with the BTM patients in the following cephalometric variables: SNA (in degree), SNB (in degree), ANB (in degree), and anterior facial height (N-Me). RESULTS: The following UGDs in thalassemic subjects were significantly shorter in patients with BTM: tongue length (P < 0.05), the distance between the hyoid bone and the mandibular plane (P < 0.01), and the vertical distance between hyoid bone and the C3-RGN line (line connecting third vertebra and retrognathion) (P < 0.05). The middle airway space in BTM patients was significantly wider (P < 0.05), and a trend was observed for the wider inferior airway space (P = 0.07). CONCLUSIONS: Based on this study, some UGDs in BTM patients were significantly different, compared to non-thalassemic subjects who had a similar maxillo-mandibular skeletal pattern. These findings may have implications for the long-term treatment of BTM patients; however, since groups were not exactly age-matched, the observed differences between groups could be attributed to either BTM, age, or both. Additional studies with age-matched subjects are needed to investigate the relationship between BTM and UGDs.

The impact of pretreatment assessment of oropharynx on interstitial soft palate radiofrequency surgery outcome--a multi-center study in patients with habitual snoring.

PURPOSE: Interstitial radiofrequency (RF) surgery of the soft palate (SP) is an established option in the treatment of habitual snoring. The decision-making process in the management of habitual snoring would benefit from diagnostic guidelines for oropharyngeal findings. Our aim was to investigate the correlation of systematic clinical pretreatment oropharyngeal examination scores with the efficacy of interstitial RF surgery of SP in a multi-center study. METHODS: Seventy-four patients (58 (78%) males and 16 (22%) females) with the median age of 42 years (range, 23-64), pre-treatment BMI of 25.6 kg/m(2) (range, 20.0-28.0), and preoperative AHI of three events/h (range, 0-10), received a single session of RF surgery. Thirty-two, five, 16, and 21 patients, respectively, were treated at the participating centers with a follow-up time of 13 weeks (range 12-16). The primary outcome measure was the efficacy of the treatment on snoring assessed by the patient and the bed partner with visual analog scale (VAS). RESULTS: The snoring showed a significant change demonstrating decreased snoring (VASpatpre 7 (range, 5-10) ≥VASpatpost 4.25 (range, 1-8), P < 0.001, VASbedppre 8 (range, 4-10) ≥VASbedppost 5 (range, 1-10), P < 0.001). Twenty-one patients (28.4%) experienced a successful treatment outcome. The increased grade of the uvula had a negative impact on the snoring results. CONCLUSION: Systematic clinical pretreatment oropharyngeal examination scores showed that the increasing grade of the uvula correlated significantly with the short-term post-treatment change in snoring. We suggest that patients with habitual snoring and uvula grade III should be initially treated with SP interstitial RF surgery and concomitant uvular surgery. A grading tool is proposed for oropharyngeal examination to help in the most appropriate treatment decision for each individual snoring patient.

Exploration of the relationship between sleep position and isolated tongue base or multilevel surgery in obstructive sleep apnea.

This study aimed to elucidate the role of sleep position as a confounding factor on apnea hypopnea index (AHI) and surgical success in isolated tongue base or multilevel surgery. This study was conducted using retrospective analysis of patients who underwent hyoid suspension because of obstructive sleep apnea (OSA), in the St. Lucas Andreas Hospital, Amsterdam, The Netherlands, from 2004 to 2011. Concurrent surgical treatment was documented. Sleep positions and corresponding AHIs before and after surgery were compared. A total of 130 patients were included. 94 patients underwent surgery of base of tongue and palate (either uvulopalatopharyngoplasty or Z-palatoplasty), of whom 72 underwent concurrent radiofrequent thermotherapy of the base of tongue. 36 patients underwent base of tongue surgery alone, of whom 22 underwent concurrent radiofrequent thermotherapy of the base of tongue. 65 patients either had a successful reduction in AHI or in AI. Isolated tongue base or multilevel surgery was as successful on the supine AHI as it was on the AHI in other sleeping positions. Surgery was not more successful in the group with position-dependent patients as compared with the non-position-dependent patients (P = 0.615). Successful and non-successful surgical results could not be explained by variations in percentages of supine sleep position. Sleep position is not a confounding factor on surgical outcomes in tongue base surgery. The results of isolated base of tongue or multilevel surgery in position-dependent OSA patients leave room for improvement, possibly through positional therapy.

Anatomy and physiology of the velopharyngeal mechanism.

Understanding the normal anatomy and physiology of the velopharyngeal mechanism is the first step in providing appropriate diagnosis and treatment for children born with cleft lip and palate. The velopharyngeal mechanism consists of a muscular valve that extends from the posterior surface of the hard palate (roof of mouth) to the posterior pharyngeal wall and includes the velum (soft palate), lateral pharyngeal walls (sides of the throat), and the posterior pharyngeal wall (back wall of the throat). The function of the velopharyngeal mechanism is to create a tight seal between the velum and pharyngeal walls to separate the oral and nasal cavities for various purposes, including speech. Velopharyngeal closure is accomplished through the contraction of several velopharyngeal muscles including the levator veli palatini, musculus uvulae, superior pharyngeal constrictor, palatopharyngeus, palatoglossus, and salpingopharyngeus. The tensor veli palatini is thought to be responsible for eustachian tube function.

The Role of Genioglossus Activity in Predicting Uvulopalatopharyngoplasty Outcomes.

OBJECTIVE: The aim of this study was to evaluate the association between genioglossus activity during sleep onset and the outcome of uvulopalatopharyngoplasty (UPPP) in patients with obstructive sleep apnea. STUDY DESIGN: Case series with planned data collection. SETTING: Sleep medical center. SUBJECTS AND METHODS: Forty-four patients with obstructive sleep apnea underwent overnight polysomnography with synchronous genioglossus electromyography (GGEMG) with intraoral electrodes. In addition, all patients underwent revised UPPP with uvula preservation and were followed up with polysomnography at least 3 months after surgery. RESULTS: Twenty-five patients (56.8%) were responders. Multiple regression analysis revealed that increasing tonsil size (odds ratio [OR], 0.086; P = .038) and higher sleep-onset GGEMG (OR, 0.664; P = .04) were significant predictors for surgical success. The area under the receiver operating characteristic curve was 0.942 (OR, 0.040; P < .001) for those predictors, 0.884 for GGEMG, and 0.848 for tonsil size. Moreover, all patients were divided into 4 groups according to tonsil size and sleep-onset GGEMG. The success rate of patients with tonsil size III or IV and sleep-onset GGEMG >11.20% (maximal GGEMG) was optimal (92.9%, 13 of 14), while the success rate of patients with tonsil size I or II and sleep-onset GGEMG ≤11.20% was 0% (0 of 10). CONCLUSIONS: Sleep-onset GGEMG and tonsil size are both important in deciding outcomes of UPPP. Patients with tonsil size III or IV and higher sleep onset may be more suitable candidates for UPPP because of the higher probability of surgical success.

[Correlation analysis of standardized palatal sensory threshold with airway obstruction and hypoxia during sleep].

Objective: To study the correlation between the standardized palatal sensory threshold and airway obstruction and hypoxia during sleep, and to infer its role in the pathogenesis of OSAHS. Methods: From August 2016 to May 2017, 92 OSAHS patients as experimental group and 48 non-OSAHS volunteers as control group were recruited in Department of Otorhinolaryngology Head and Neck Surgery, Changhai Hospital Affiliated to the Naval Medical University. The tactile sense was measured by Smmes-Weinstein Monofilaments in the middle of uvula and both side of hard palate,then the threshold of the uvula minus, the average threshold of the hard palate as the standardized palatal sensory threshold(SPST). The control point of both groups was located in the central underlip. Mann-Whitney U test for comparing two independent samplesand partial correlation analysis. Results: There was no difference in tactile threshold of underlip between the experimental group and the control group(0.020[0.008,0.020] g/mm(2) vs. [0.020(0.008,0.020] g/mm(2), Z=293.0, P=0.221); the tactile sense of the experimental group was larger than that of the control group in thehardpalate(0.040[0.140,0.055] g/mm(2) vs. 0.138[0.064,0.400] g/mm(2), Z=4.5, P=0.000), soft palate(0.400[0.280,0.400] g/mm(2) vs. 1.400[1.000,4.000] g/mm(2), Z=0, P=0.000) and SPST(0.355[0.125,0.373] g/mm(2) vs. 1.285[0.896,3.025] g/mm(2), Z=0, P=0.000). The SPST was positive correlation with apnea hypopneaindex(AHI)(r=0.835, P=0.000) and negative correlation with the nadir oxyhemoglobin saturation (r=-0.636, P=0.000). Conclusion: The greater the standardized palatal sensory threshold, the worse the condition of OSAHS, the lower, the lowest blood oxygen at night, and the impaired upper airway sensory function plays an important role in the pathogenesis of OSAHS.

Upper-Airway Stimulation Before, After, or Without Uvulopalatopharyngoplasty: A Two-Year Perspective.

OBJECTIVE: Upper airway stimulation (UAS) is an effective second-line treatment for obstructive sleep apnea (OSA). In certain patients, there is a considerable need for advanced programming, notably with inadequate palatal response to therapy. The aim of the study was to investigate the impact of uvulopalatopharyngoplasty and tonsillectomy (UPPP-TE) on UAS therapy outcomes from a 2-year perspective after implantation. METHODS: This study included all consecutive patients implanted with UAS in which a full set of 1- and 2-year follow-up assessments (M12 and M24) were obtained. Cases were analyzed in three groups: patients with UPPP-TE after (group 1) and before (group 2) UAS, and those without UPPP-TE (group 3). RESULTS: Therapy success could be achieved in about 80% of the entire cohort. Groups 2 and 3 did not differ significantly with regard to obesity, Apnea-Hypopnea Index, or Oxygen Desaturation Index. With regard to initial sleep endoscopy, there were fewer patients without any obstruction at the palatal and oropharyngeal levels and higher prevalence of lateral obstruction patterns at oropharynx in group 1 in contrast to groups 2 and 3. Groups 2 and 3 showed similar results, although group 2 patients underwent UPPP-TE before UAS implantation. CONCLUSION: UPPP-TE should be considered in patients with persistent OSA after UAS implantation if the obstruction is identified at the level of velum and oropharynx. Although this approach has higher response rates and better outcomes can be achieved in patients with UAS, there is no indication for patients to routinely undergo UPPP-TE prior to UAS implantation. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:514-518, 2019.

Structural effectiveness of pharyngeal sleep apnea surgery.

Obstructive sleep apnea results from the combination of a structurally small upper airway combined with the loss of muscle tone during sleep. Most therapies aim to reduce apnea severity by increasing airway size and stability. Conceptually, upper airway surgery should be a highly effective method to treat obstructive sleep apnea and other forms of sleep disordered breathing. Although major reconstructive surgeries such as maxillomandibular advancement demonstrate high success rates, more limited forms of surgery often demonstrate significantly lower success rates. Reviews of such surgical procedures have uniformly ignored contributions of the structural effectiveness of surgery. The purpose of the review is to evaluate current knowledge of how surgery for OSA alters structure. The majority of data available on surgical outcomes involve uvulopalatopharyngoplasty. Data demonstrate that pre-morbid surgical anatomy and techniques have significant effects on ultimate outcomes. Further research on structural outcomes for palatopharyngoplasty, as well as other surgical procedures, is needed to improve clinical outcomes.

The effects of uvulopalatal flap operation on speech nasalance and the acoustic parameters of the final nasal consonants.

OBJECTIVE: The acoustic characteristics of voice are determined by the source of the sound and shape of the vocal tract. Various anatomical changes after uvulopalatal flap (UPF) operation can change nasalance and/or other voice characteristics. Our aim was to explore the possible effects of UPF creation on speech nasalance and the resonatory features of the final nasal consonants, and thus voice characteristics. METHODS: A total of 30 patients (26 males, 4 females) with obstructive sleep apnea who underwent UPF operation were recruited. A Nasometer II 3.4 instrument was used to assess nasalance pre- and post-operatively; the patients read standard Korean passages and the readings were recorded in Computer Speech Laboratory for later spectral analysis. Praat software was used to identify frequency bands affecting perioperative nasalance scores. Minima, maxima, and slopes were analyzed. RESULTS: We found no significant correlation between nasalance scores (any passage) and the respiratory distress index or body mass index. No significant perioperative change in any nasalance score. The moment variations in the final consonants /m/ and /n/ did not change significantly postoperatively. However, the postoperative moment variation of the final consonant /ng/ differed significantly in the third formant (F3) and second bandwidth (BW2). CONCLUSION: Few significant changes in nasal resonance speech quality were apparent after UPF operation. However, a postoperative acoustic change in the final sound /ng/ may be sustained. Patients may be preoperatively advised that the risk of voice change is very low, but not absent.

Uvulopalatopharyngoplasty reduces the incidence of cardiovascular complications caused by obstructive sleep apnea: results from the national insurance service survey 2007-2014.

OBJECTIVE: Untreated obstructive sleep apnea (OSA) is a risk factor for cardiovascular disease including myocardial infarction (MI), congestive heart failure (CHF), and atrial fibrillation (AF). Continuous positive airway pressure (CPAP) is an effective treatment for OSA; however, compliance with CPAP can be challenging for some patients. The objective of this study was to investigate whether uvulopalatopharyngoplasty (UPPP) reduced the risk of cardiovascular complications for patients with OSA. METHODS: Data from Korea National Health Insurance Corporation, a national health care database in South Korea, were analyzed. All patients with a new diagnosis of OSA from 2007 to 2014 were identified. Propensity score matching by age and sex was used to identify a control group five times larger than the OSA group for comparison. Patient demographics and comorbidities were collected. The OSA group was further divided into patients who had an UPPP and patients who did not undergo surgery. The primary endpoints were newly diagnosed MI, CHF, and AF. RESULTS: Of 192,316 patients with a new diagnosis of OSA, 22,213 had undergone UPPP. For the control group, 961,590 individuals were selected. Patients with OSA had an increased risk of CHF and AF, compared to control patients. UPPP reduced the incidence of CHF and AF significantly. Age, gender, and hypertension were also found to be risk factors for cardiac complications for patients with OSA. CONCLUSION: OSA increases the risk of CHF and AF. UPPP in this population can significantly reduce the risk of cardiac complications in patients with OSA.

Diagnostic studies in obstructive sleep apnea.

The standard for the diagnosis of obstructive sleep apnea (OSA) is polysomnography (PSG). Although PSG helps identify individuals who have OSA and guides medical management, it does not identify the obstruction site or predict surgical results. Radiologic and diagnostic studies have been used to direct surgical intervention and predict outcomes of sleep apnea surgery. These studies include lateral cephalometric radiographs, CT, MRI, asleep fluoroscopy, asleep and awake endoscopy, upper airway manometry, and acoustic reflection techniques. The ideal diagnostic study would identify individuals who have OSA, be cost-effective and readily accessible, and guide therapeutic, site-specific intervention with predictable results. In this article, the various modalities are reviewed in terms of their capability to effectively diagnose and guide treatment of OSA.