INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) has an incidence ranging from 5% to 25% in adults, and it is more commonly observed in men (2–4%) than in women (1–2%).^1–7 OSAS is defined according to the number of abnormal respiratory events that occur per hour of sleep. Apneas are pauses in breathing of at least 10 seconds, and hypopneas are characterized by a reduction in air volume, accompanied by a decline of up to more than 4% in blood oxygen saturation, lasting more than 10 seconds. A patient is diagnosed with apnea when at least five such episodes occur per hour.^4,5,8,9 At night, the most frequent and obvious symptom is snoring. Breathing difficulties can lead to several awakenings during the night.^{2,4,8,10–12} During the day, OSAS patients often complain of headaches, tiredness, difficulty in concentrating, memory loss, stress, and moodiness. These complaints tend to worsen throughout the day.^{2,4,6,7,9,11,13,14}

There are two main risk factors for the development of OSAS: low upper airway volume or the presence of constriction that leads to increased airflow resistance. Thus, OSAS is related to predisposing anatomical factors such as craniofacial anomalies, macroglossia, hypotonia of the soft tissues of the oropharynx, tongue base retro position, mandibular hypoplasia, and maxillary retro position/retrusion.¹ The reduction in jaw length may have repercussions on the oropharyngeal dimensions between the soft palate and the tongue and between the soft palate and the pharyngeal wall.^2,4,8 This phenomenon is explained by the fact that the soft palate is enlarged by about 20%, further reducing the efficiency of the airway. Despite tongue size being normal, its functional space is reduced due to the decreased length of the mandible, which forces it to recede into the pharynx.^2,4

OSAS can predispose to several cardiovascular and metabolic implications, which are believed to be due to a lower saturation of hemoglobin levels during sleep, resulting in neurocognitive impairment and, subsequently, a lower quality of life (QOL).^1,5 Nocturnal hypoxemia occurs whenever there are episodes of apnea, and if these episodes are prolonged, they may result in hypertension and heart problems. Cardiac arrhythmia, nocturnal angina, and myocardial ischemia can also occur, the latter potentially resulting in an acute myocardial infarction.^2,7–11

The gold-standard nonsurgical treatment technique for individuals with OSAS is continuous positive airway pressure (CPAP). This treatment is shown to be effective in reducing symptoms and consequently improving the patient’s overall QOL. However, despite being an effective technique, it heavily relies on patient cooperation.^6,7 For this reason, orthognathic surgery for maxillomandibular advancement of approximately 10 mm provides an alternative to the use of CPAP in cases of moderate to severe OSAS.^{5,10,11,15–17} This surgery promotes an increase in airway dimensions, reducing potential airway collapse during sleep.^{9,10,14,16–18} Authors of previous studies assessing the satisfaction of OSAS patients after undergoing orthognathic advancement surgery reported that most were satisfied with the outcomes.⁹ However, unsatisfactory results regarding facial esthetics have also been reported, even if they achieved airway improvement.^6,11,15 Understanding the patient’s perspective when choosing the treatment is key to providing more personalized and effective health care, ensuring that his or her needs, preferences, and concerns are considered throughout the therapeutic process. This study aimed at investigating and evaluating the available evidence regarding QOL after surgical treatment in OSAS management.

MATERIALS AND METHODS

Database Search Protocol

For this systematic review, a search was made in several databases including Medline (PubMed), Web of Science all databases, Embase, and Cochrane. Table 1 describes the search keys used, when conducted on July 3, 2023.

Table 1. Search Keys of Several Databases

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Beyond these databases, search of the gray literature was also done on the Websites: OpenGrey Europe (https://opengrey.eu, accessed on March 10, 2023) and ProQuest (https://www.proquest.com, accessed on July 3, 2023).

RESULTS

Study Selection

From the eligibility processes, 1407 articles were initially found, none of which had cross-references. After removing duplicates, 973 articles were analyzed by title and abstract, resulting in 17 articles to be read in full (Figure 1). Of the 17 articles included in this systematic review, 17 were evaluated qualitatively, and 6 were subjected to quantitative evaluation.

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Characteristics of the Included Studies

The studies included were published between 2004 and 2023, with 10 of the 17 included being published in 2020 or more recently. Study samples ranged from 10 to 210 individuals, obtaining a total sample of n = 690 with an average age of 45.8 years. In all studies, more men than women were included, except for one study in which authors did not mention patient sex.⁵

The most commonly referred instruments were Epworth Sleepiness Scale (ESS; n = 9), 36-Item Short Form Survey (SF-36; n = 4), Functional Outcomes of Sleep (n = 3), Ottawa Sleep Apnea (n = 2), and Rustemever’s (n = 2). The most evaluated outcomes were sleep quality, daytime function, facial esthetics, dental function, and emotional health. Follow-up of the included studies ranged from 2 months to 20 years, with authors of only one study not reporting this information.¹⁵ Authors of most studies evaluated patient QOL by examining improvements in function, with the most commonly reported outcomes including sleep quality, daytime performance, dental function, and emotional health. Of these variables, the ones that reported the most improvement were sleep quality (average 4.02) and daytime performance (average 3.7). Patients with OSAS did not show significant differences in masticatory function before and after surgery. Authors of studies that evaluated the Apnea-Hypopnea Index (AHI) observed a significant reduction, with at least 1° of severity being reduced. Authors of six of the included articles also considered esthetic evaluation of orthognathic surgery to treat OSAS. Most patients reported that the facial changes brought about by orthognathic surgery improved their overall facial appearance, namely, facial rejuvenation, smile appearance, and nasal cosmetics. These changes promote alterations in lay perceptions of emotions. Authors of all studies reported that maxillomandibular advancement surgery for OSAS provided significant improvement in overall patient QOL as well as personal satisfaction, sleep quality, and functional outcomes at very long-term follow-up. It should be noted that improving perioral neurosensation contributes to the recovery of oral functional behavior. Table 2 shows a summary of the characteristics of the included studies.

Table 2. Characteristics of Included Studies in the Qualitative Analysis^a

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Synthesis of the Best Evidence

Considering the results of the quantitative assessment, the selected papers showed a high heterogeneity between studies (I² = 74.36%), so a random effects model was applied, observing a mean effect of 6.36 ± 1.33 with statistical significance (P < .001; Figure 2). One study had a smaller effect than what was expected, creating heterogeneity.²⁵ Despite this fact, according to Egger’s test, no publication bias was found (the effect size reported by the authors of the studies did not depend on their precision: b = 1.33; P = .139). Therefore, the results were clinically significant, demonstrating that maxillomandibular advancement surgery significantly improves overall subjective QOL for patients.

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Risk of Bias

The quality assessment of the included studies is summarized in Table 3. Most studies were classified as good quality (≥7 points) except for two studies that were classified as fair.^15,17 It was observed that all studies had three or four stars in the selection domain, one or two stars in comparability, and two or three stars in the outcome/exposure domain. Of the studies considered to be of good quality, six had the minimum score in this category,^15,17 and three studies had a maximum score of nine.^10,29,30

Table 3. Risk of Bias

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DISCUSSION

OSAS is a respiratory disease that interferes with the QOL of patients. The aim of this review was to assess the impact of surgical treatment for OSAS on QOL. The results obtained showed that this treatment provided a significant improvement in overall QOL as well as in personal satisfaction, sleep quality, and functional results in very long-term follow-up.

The prevalence of obstructive sleep apnea varies according to sex and age, being more common in men and increasing with age. At 63.4% vs 36.6%, males exhibit a higher prevalence than females, as described in the literature. Physiological differences between the sexes, such as anatomy and physiology of the upper airway, may be indicative of these differences. Obesity and hormonal differences may also explain the sex difference; however, the exact mechanisms remain unknown.^19,31–34 Additionally, the severity of OSAS increases with age and is more prevalent after the age of 50.^33,35 According to results of the present study, the age of patients with OSAS ranged from 34.75 ± 11.33 to 59.8 years. As described by Gabbay and Lavie,³⁴ the average age of OSAS patients is 51.12 ± 13.01. Also, it should be noted that, in females, there is a linear increase in the AHI with increasing age, while in males, there is a sharp increase from the age of 20 to 40, and after this age, a linear increase is maintained.³⁴

From the patient’s perspective, QOL can be assessed through several outcomes related to function, mental health, sleep quality, esthetics, and postoperative condition. Functional outcomes evaluate daily productivity, activity levels, mobility, chewing, phonation, swallowing, and sexual life quality. Sleep quality is assessed through issues like insomnia, daytime sleepiness, nocturnal diuresis, and snoring. Esthetic outcomes focus on facial changes from orthognathic surgery, while mental health outcomes address well-being, emotional status, mood, anxiety, and depression. Finally, postoperative condition is evaluated based on recovery experiences such as pain or discomfort. Currently, several questionnaires for assessing QOL in OSAS patients exist, such as the ESS, QOL/Functional Outcomes of Sleep Questionnaire (FOSQ), Patient-Reported Outcome Measures (PROMS), Rustemeyer’s, Ottawa Sleep Apnea Questionnaire (OSA-Q), European Quality of Life-5D (EQ-5D). These are recognized as an important means of assessing the impact of OSAS symptoms and, in addition, comparing the presurgical and postsurgical status of maxillomandibular advancement.^{9,10,13,17,19,21,22,29,30} Of the various questionnaires analyzed, the most widely used was the ESS. This consists of a subjective assessment that evaluates the degree of daytime sleepiness.^36,37 Walker et al.³⁸ analyzed the clinical usefulness of this questionnaire, demonstrating the results obtained were reliable compared with other means of clinical assessment such as polysomnography. However, some authors identified some disadvantages in this questionnaire, namely, inconsistencies in the results after repeating the test, measurements of different variables between populations, as well as the sensitivity of negative results.^39–41

Walia et al.^42–44 stated in their study that both the EQ-5D and the FOSQ are valid instruments for measuring QOL, with one being more global and the other being a more specific measure of sleep quality, respectively. Chasens et al.,⁴⁵ Rey de Castro et al.,⁴⁶ and Weaver et al.⁴⁷ described a self-reported measurement of functional status through which it is possible to understand how sleep-related problems interfere with everyday activities, and therefore, the FOSQ was developed and validated to capture patient experiences comprehensively. On the other hand, the EQ-5D questionnaire was developed to describe and assess health-related QOL, rather than just a specific disease, to complement other existing assessment measures.^48,49

Rustemeyer et al.⁵⁰ developed a questionnaire consisting of 14 questions asked during the first year after surgery to evaluate the negative effects of the postoperative period (edema and pain). This questionnaire aims at assessing both the factors that affect patient satisfaction and expectations after undergoing orthognathic surgery. Thus, it was concluded that the factors that contributed most to patient satisfaction were the improvement in masticatory function and facial esthetics. Rustemeyer et al.⁵⁰ also cited other questionnaires regarding the QOL of a patient with OSAS with the aim of assessing sleep quality, daytime sleepiness, energy levels, daily activities, mood, sexual activity, social outcome, and daily productivity, referring to satisfaction comparing situations before and after orthognathic surgery; significant improvements were reported in QOL in general and sleep quality in particular.^{19,20,22,23,27,30,31}

OSAS is a disease with a multifactorial etiology, which presents a potential risk for the development of other pathologies, such as alterations in the nervous system, inflammatory responses, oxidative stress, endothelial dysfunction, and a prothrombotic state, increasing the risk of cardiovascular diseases.⁵¹ Additionally, sleep deprivation is related to symptoms of anxiety and depression and, consequently, to a worse educational outlook and QOL.⁵² QOL and patient satisfaction are increasingly important in the field of clinical health, and it is important to guarantee patients a better QOL when choosing the most suitable therapeutic options.^53,54

The dual benefit of improved functionality and enhanced appearance often results in high satisfaction rates, as patients experience both health benefits and psychological gains. However, a small percentage of patients are dissatisfied. This dissatisfaction is not usually associated with surgical complications but with other factors, such as an undesired esthetic result, functional reasons, and unfulfilled psychosocial expectations.⁵⁵ In this sense, it is particularly important to assess the existence of psychological difficulties, namely, the presence of body dysmorphic disorder (BDD), to design a treatment plan adapted to each patient. This pathology involves a distorted perception of body image and is characterized by an exaggerated preoccupation with an imagined anomaly in physical appearance or with a minimal bodily defect present.⁵⁶ A study carried out by Vulink et al.⁵⁷ in 2008 revealed that 10% of patients undergoing orthognathic surgery met the criteria for BDD and, according to Phillips et al.,⁵⁸ the presence of BDD was related to lower satisfaction with the results.⁵⁹

Patient satisfaction after orthognathic surgery tends to increase over time as recovery progresses and the esthetic and functional benefits become more evident. Initially, patients may experience discomfort and swelling, which can temporarily affect their QOL and perception of the results. Authors of studies have indicated that overall satisfaction with the surgery is high, with many patients also experiencing improvements in self-esteem and psychological well-being. In the long term, these factors contribute to a positive perception of the surgical results, highlighting the importance of adequate follow-up and support during the recovery process.^60,61 Patients undergoing orthognathic surgery who experience psychological distress before the procedure generally report a greater recovery burden and face more challenges with symptoms, social and self-related concerns, and general health during the first 1 or 2 months postsurgery.⁶² Authors of the studies included in this analysis conducted postsurgical follow-ups after 2 months, which may help minimize the initial negative assessments. Most patients reported overall satisfaction with the treatment, noting significant improvements in oral function, facial esthetics, and respiratory issues.

This study had some limitations, one of which was that it only included retrospective and prospective studies, and no randomized controlled trial studies, which could contribute to a greater risk of bias, as those studies included did not all have a homogeneous sample. Additionally, according to the COMET Initiative, which seeks to facilitate the development and application of a set of outcomes in various medical fields, there is an agreed minimum set of outcomes that should be measured and reported in all clinical trials of a specific disease or test population. This set presents seven main outcomes, including the impact of esthetic self-perception, alignment and/or occlusion, skeletal relationship, stability, patient-related compliance, breakage, and adverse effects on teeth or tooth-supporting structures. When evaluating these questionnaires, not all of these parameters were considered. Nevertheless, the results showed that, in general, patients with OSAS, after undergoing orthognathic surgery for mandibular advancement and/or maxillomandibular advancement, show improvements in QOL.

CONCLUSIONS

• Maxillomandibular advancement surgery significantly improves patients’ subjective overall QOL, improving by 6.36 points in questionnaire ratings and demonstrating long-term stability.