An overview of patient-reported outcome measures to analyze the quality of life after orthognathic surgery

Society imparts great importance to physical appearance in this modern age. The physical and psycho-social impact of a dentofacial deformity on an individual is often impossible to assess with certainty. A facial deformity can profoundly affect the quality of life and thereby entailing lifelong adjustments. Facial aesthetics affect an individual’s con idence and their overall acceptance in society, which in turn has an apparent effect on their quality of life. Corrective jaw surgeries are indicated in cases not amenable to produce acceptable post-treatment results with orthodontics alone. Orthognathic surgery aims to produce a more aesthetic facial appearance and strives to improve stomatognathic functions in the process. WHO de ines Quality of Life asAn individual’s perception of their position in life in the context of the culture and value systems in which they live and concerning their goals, expectations, standards and concerns. It is a broad-ranging concept affected in a complicated way by the person’s physical health, psychological state, level of independence, social relationships, personal beliefs and their relationship to salient features of their environment. The impact of dentofacial deformities on an individual’s holistic emotional, physical and social development has been a focus of research for a long time. Several patients reported outcome scales are employed to assess the quality of life and this review aims to discuss the use of these scales as an indicator of successful surgical treatment. At the same time, these scales may serve as a patient education tool because a holistic health indicator is required which considers the psychological well being of the patient along with regards to functional and aesthetic demands before formulating a surgical treatment plan.

Dentofacial deformities, Orthognathic Surgery, Quality of Life (QoL), the patient-reported outcomes, Orthognathic Quality of Life Questionnaire (OQLQ), FACE-Q A Society imparts great importance to physical appearance in this modern age. The physical and psycho-social impact of a dentofacial deformity on an individual is often impossible to assess with certainty. A facial deformity can profoundly affect the quality of life and thereby entailing lifelong adjustments. Facial aesthetics affect an individual's con idence and their overall acceptance in society, which in turn has an apparent effect on their quality of life. Corrective jaw surgeries are indicated in cases not amenable to produce acceptable post-treatment results with orthodontics alone. Orthognathic surgery aims to produce a more aesthetic facial appearance and strives to improve stomatognathic functions in the process. WHO de ines Quality of Life as-An individual's perception of their position in life in the context of the culture and value systems in which they live and concerning their goals, expectations, standards and concerns. It is a broad-ranging concept affected in a complicated way by the person's physical health, psychological state, level of independence, social relationships, personal beliefs and their relationship to salient features of their environment. The impact of dentofacial deformities on an individual's holistic emotional, physical and social development has been a focus of research for a long time. Several patients reported outcome scales are employed to assess the quality of life and this review aims to discuss the use of these scales as an indicator of successful surgical treatment. At the same time, these scales may serve as a patient education tool because a holistic health indicator is required which considers the psychological well being of the patient along with regards to functional and aesthetic demands before formulating a surgical treatment plan.

INTRODUCTION
The decision of an individual to partake in any corrective jaw surgery depends upon the aesthetic, functional, psychological and social impact of the dentofacial deformity on their quality of life. Facial aesthetics play a pivotal role in the emotional and psychological well being of the individual. Patients with severe dentofacial deformities usually opt for an ortho-surgical treatment to achieve a functionally robust and aesthetically acceptable treatment outcome.
Evidence-based dentistry suggests that any treatment should be designed based on a systematic assessment of clinically relevant scienti ic data such as an individual's chief complaint, dental history, medical history, treatment needs, preferences and expectations. Patients usually report for orthosurgical treatment as a result of their chief complaint aiming to achieve a speci ic treatment outcome which in turn helps in improving their overall quality of life as (Miguel et al., 2014).
The concept of quality of life is subjective and thus can not be judged by others. Patient expectations are usually different from those of the clinicians. Therefore pre-treatment investigations should include questionnaire-based subjective scales as they provide an insight into the impact and perception of the patient towards their problem (Alanko et al., 2010;Choi et al., 2010). These results can help in guiding the treatment course by prioritizing patient expectations in general and oral healthcare delivery system.
Currently, a signi icant chunk of research is focused on the effect of orthognathic surgery on the quality of life of the patient (Lee et al., 2007). Patient acceptability of facial aesthetics post-treatment is of paramount importance when dealing with any cosmetic procedure, as the "perfect result" from a surgeon's point of view might not be congruent with that of the patient's wishes, making it imperative to include patient inputs in their expectations ).
There is no shortage of published literature on the importance of quality of life prior and post orthognathic surgery. This article aims to enlist the various types of patient-reported outcome instruments reported in the literature for the evaluation of improvement in the quality of life of patients postsurgery (Table 1).

HISTORY
A surge in the use of patient-reported psychometric outcome measures in medicine and surgery for assessment of the quality of life emerged during the early 1970s. The shift in focus of the entire health care community from the usage of traditional clinical outcome measures to those involving the functional and psychological well-being allowed for a holistic post-operative assessment (Stewart and Ware, 1992). This occurred as a result of the inclusion of a broader de inition of health as a "complete state of physical, mental, and social wellbeing" (World Health Organzation, 1947). And an ethical responsibility of surgeons to illustrate evidence of successful treatment outcomes incorporating this broader de inition of health.
Assessment of improvement in the quality of life objectively in the post orthognathic surgery phase is dif icult since the patient's life is neither extended nor the disease cured in the traditional understanding of health care needs (Murphy et al., 2011;Abdullah, 2015). Health-related quality of life (HRQoL) has multiple variables which must include physical, social and psychological aspects to help in quanti ication without bias. A lot of general health, general oral health as well as particular condition-speci ic outcome measures have been employed to assess the impact of orthognathic surgery in patients. A generic health questionnaire can compare the postsurgical outcomes with those of other ailments. However, without the use of speci ic and targeted outcome measures, it is not possible to address the needs and issues faced by individuals with dentofacial deformities. For example, 36 items Short Form Health Survey (SF-36) was unable to differentiate in quality of life amongst those with and without dentofacial deformities (Lee et al., 2008).
In the late 1980s, a need to study the social and psychological impact of oral diseases comprehensively was irst addressed. The irst to realize the importance of oral health-related quality of life were Reisine et al. In 1994, Slade developed Oral Health Impact Pro ile (OHIP-49) questionnaire as the irst generic oral health tool (Slade and Spencer, 1994). In 1997, Slade improved the OHIP-49 to the Short Form Oral Health Impact Pro ile Questionnaire (OHIP-14) (Slade, 1997).
OHIP was widely used but was designed for older people. Thus, Cunningham et al. (2000) developed a speci ic outcome measure for patients undergoing orthognathic surgery called Orthognathic Quality of Life Questionnaire (OQLQ) using sources such as literature reviews as well as unstructured interviews with clinicians and patients. OQLQ was developed as a quality of life questionnaire for patients with dentofacial deformities. It is a condition-speci ic instrument which focuses on a particular condition and population. This makes the scale responsive to even the smallest yet clinically signi icant and essential changes in post-operative health of the individual undergoing surgery.

Patient reported outcome measures
The various patient-reported outcome measures reported in the literature and used in orthognathic surgery for assessment of patient satisfaction are as follows (Soh and Narayanan, 2013;Finlay et al., 1995) (Table 1).

ORTHOGNATHIC QUALITY OF LIFE QUETIONNAIRE (OQLQ)
The OQLQ was developed and popularised by Cunningham in the year 2002. It measures and assesses the impact of various dentofacial deformities on the quality of life of an individual. The original questionnaire consists of a total of 22 items which have been used to assess the effects of dentofacial deformities on the QoL of patients by using the following four domains: 1. Facial esthetics ( ive items; total score range, 0-20 points); 2. Oral function ( ive items; total score range, 0-20 points); 3. Awareness of dentofacial esthetics (four items; total score range, 0-16 points); and 4. Social aspects of a dentofacial deformity (eight items; total score range, 0-32 points).
Within a domain each item was scored on a 5-point Likert scale with responses ranging from 1 point, indicating "bothers you a little," to 4 points, indicating "bothers you a lot," and 0 points indicating "the statement does not apply to you or the dentofacial deformity does not bother you." Total OQLQ scores range from 0-88 points where higher scores indicated a worsened quality of life. Studies conducted in different parts of the world have validated this patient-reported outcome measure for use in measuring and assessing the quality of life in patients undergoing orthognathic surgery.

FACE-Q
In 2015 a review of the literature was commissioned by the United Kingdom Department of Health to identify patient-reported outcome measures for cosmetic treatment which incorporated adequate psychometric analysis of patients (Liddle et al., 2015). From this review, nine such instruments of patient-reported outcome measures were identi ied out of which three met the latest recommendations for both the development as well as validation of patient-reported outcome measures. These scales are BREAST-Q , FACE-Q (Klassen et al., 2010) and Skindex (Chren, 2012).
FACE-Q is composed of more than 40 independently functioning scales and checklists to assess the experiences and results of any aesthetic facial surgical and non-surgical procedure from the patient's perspective (Pusic et al., 2013). Thereby it provides an unprecedented insight into their health-related quality of life and satisfaction post-treatment.
Patients are provided to ill the questionnaire preoperatively to provide a baseline measurement and postoperatively after their treatment is performed at a speci ic time depending upon the nature of the research being done. Conceptually FACE-Q framework developed as a result of very detailed and extensive research involving patients undergoing facial aesthetic surgery, evaluation of already existing research literature, and inputs from healthcare providers operating on individuals requiring facial rejuvenation and reconstruction.
As a part of patient evaluation both the researchers and clinicians may review the scores for individual scales with a score point from 0-100 and monitor changes in these scores from previous visits (e.g. Has satisfaction decreased or increased?). As with all quality of life outcome measure in general, the observed trends over some time are more valuable than absolute scores preoperatively or postoperatively when considering individual patient care.
FACE-Q provides the ability to have a tailored version of the questionnaire, which suits the needs of the research question and provisions available to the clinician and researcher. A tailor-made approach is possible because FACE-Q consists of about 40 scales which measure various concepts of importance to patients. FACE-Q consists of the following four domains of treatment procedure (Denadai et al.,  Based on independent FACE-Q scale scores, a higher score entails a better quality of life and greater treatment satisfaction for the patient. Overall there is no quanti iable FACE-Q score. However, total scores for each independent scale is quanti iable. Therefore FACE-Q can be used for evaluation and assessment of the quality of life in patients undergoing treatment for dentofacial deformities as the outcome of these cosmetic procedures depend mainly on patient perception of treatment outcome and their satisfaction.

CONCLUSION
Elective surgeries like orthognathic surgery are primarily cosmetic and should include the psychological analysis of the patient towards the already present dentofacial deformity and their expectations from the surgical treatment. Failing to do so may result in dissatisfaction of the patient even if the surgical outcome is ideal. The patient-reported outcome measures to take into account the various physical and psychometric criteria which can be used to assess the acceptance of surgical outcome by the patient even before the surgery. Also, these patients reported outcome measures could be used to determine the need for psychological counselling before and after the treatment. Based on the available literature and its review, the authors suggest the utilization of FACE-Q in the assessment of QOL for patients undergoing orthognathic surgery as it is one of the foremost and commonly performed cosmetic surgery by oral and maxillofacial surgeons.