Dentofacial deformities and their treatment have physical and psychological repercussions on quality of life (QOL). Seventy-four patients were evaluated preoperatively (T0) and at 4–6 months postoperatively (T1). Oral health-related QOL was assessed using the short form of the Oral Health Impact Profile (OHIP-14). There was a statistically significant reduction in the average overall OHIP-14 score between T0 (13.23 ± 6.45) and T1 (3.26 ± 4.19). In addition, there were significant decreases in all seven OHIP-14 domains. Class III patients benefited in all domains evaluated, while a significant improvement was seen only in the psychological disability domain for class I patients. Class II patients showed a significant benefit in all domains except the domain of functional limitation. With regard to the total sample ( n = 74) and class III patients ( n = 58), correlations between domains were identified for all domains. The same correlation was not identified for class I ( n = 5) and II ( n = 11) patients. The entire sample and class III patients showed significant improvements in OHIP-14 scores for all degrees of postoperative sensory disturbance in the upper and lower lips, except for patients with degree 5 (extreme) disturbance of the upper lip. Orthognathic surgical treatment had a positive impact on oral health-related QOL in the patients evaluated.
Orthognathic surgery combined with orthodontic treatment is a well-established treatment modality for the correction of moderate to severe dentofacial deformities, and has been performed routinely for over 100 years.
The possible psychological repercussions and effects of dentofacial deformities and their treatment on body image have been approached in several studies, which have reported improved self-confidence and quality of life (QOL). The World Health Organization (WHO) defines QOL as ‘an individual’s perception of their position in life in the context of culture and value systems in which they live and about their goals, expectations, standards and concerns’. It is a vast and comprehensive concept, affected in a complex way by the person’s physical health, psychological state, social relationships, and environment. It can also be defined as the ‘sense of well-being of a person who derives satisfaction or dissatisfaction with areas of life that are important to them’.
Health-related QOL is typically measured using disease-specific or generic measures. However, generic measure instruments are not sensitive to changes in oral health and exhibit limited construct validity.
An impressive range of questionnaires has been developed to assess the impact of oral conditions and interventions on the well-being of patients, and these are proven tools for the evaluation of a person’s perceptions. One of the most used questionnaires is the Oral Health Impact Profile (OHIP), which measures the individual’s perception of the social impact of current oral diseases and/or oral conditions on their well-being and QOL.
The OHIP was originally developed by Slade and Spencer to evaluate dysfunction, discomfort, and disability attributed to oral conditions in adults or elderly populations, and presents 49 items grouped into seven domains. A shorter version that includes 14 items (OHIP-14) was also developed (1997), and has well-documented psychometric properties, covering specific aspects of oral health (domains): functional limitation, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicap.
There is growing interest in how orthognathic surgery affects patients’ lives, and some studies have shown significant improvements in QOL. Therefore, the goal of this study was to use the OHIP-14 to evaluate the impact of oral health-related problems on QOL in adults with dentofacial deformities of classes I, II, and III assessed preoperatively (T0) and at 4–6 months postoperatively (T1) following orthognathic surgery. Furthermore, the study aimed to identify correlations between the OHIP-14 domains for the different dentofacial patterns and possible improvements in the OHIP-14 score according to the degree of postoperative hypoesthesia/sensory disturbance to the lips.
Materials and methods
The study protocol was reviewed and approved by the regional research ethics committee. Informed consent was obtained from each patient, and they were assured of the confidentiality of the questionnaire. Patients with dentofacial deformities who presented for treatment between 2010 and 2013 were recruited for this study. The sample consisted of consecutive patients, thus it can be considered a convenience sample.
To be included in the sample, patients had to have undergone previous orthodontic treatment and be considered healthy. Patients were excluded from the study if they had cleft lip and palate, syndromes, facial deformities due to trauma or congenital malformation, pre-existing systemic disease, or if they were pregnant women or children younger than 15 years of age. Patients with Angle classes I, II, and III dentofacial deformities were included in the study.
Patients were asked to complete a questionnaire before surgery (T0) and another at the follow-up, 4–6 months after surgery (T1). OHIP-14 presents 14 questions, divided into seven evaluation domains (two questions per domain): functional limitation (questions 1 and 2), physical pain (questions 3 and 4), psychological distress (questions 5 and 6), physical disability (questions 7 and 8), psychological disability (questions 9 and 10), social disability (questions 11 and 12), and handicap (questions 13 and 14). Each question evaluates a frequency, with five possible answers, ranging from ‘never’ (score zero) to ‘often’ (score 4). These scores are multiplied by the weight of each question (weights 0.51, 0.49, 0.34, 0.66, 0.45, 0.55, 0.52, 0.48, 0.60, 0.40, 0.38, 0.62, 0.59, and 0.41 for questions 1–14, respectively); total scores range from 0 to 28, with higher scores indicating a worse impact on oral health. In addition to the questions of the OHIP-14, patients were also questioned on the degree of hypoesthesia of the upper and lower lip postoperatively. The response ranged from ‘none’ (score 1) to ‘extreme’ (score 5).
The non-parametric Kolmogorov–Smirnov test was used to assess the normality of data. Fisher’s exact test was used to examine the significance of the association (contingency) between gender, age, type of surgery, and type of deformity.
The Wilcoxon matched-pairs test was used to evaluate significant changes in OHIP-14 scores between T0 and T1 for all domains and questions, for all patients and according to the type of deformity. The power of the test and effect sizes of the samples were also recorded. Power is the probability that the test will reject the null hypothesis when it is false. Power can also indicate the sample size required such that an effect of a given size is reasonably likely to be detected. An effect size is a measure that describes the magnitude of the difference between two groups. It is the degree to which randomly selected data can likely be identified with regard to the group that it belongs to based on its value. An effect size is calculated to indicate the impact of a treatment; a larger effect size means the treatment had a greater impact.
The same analysis was used to evaluate significant changes in OHIP-14 score between T0 and T1 for all patients and according to the types of deformity in relation to the postoperative degree of hypoesthesia/sensory disturbances in the upper and lower lip. Spearman’s correlation coefficient was used to assess the existing significant correlation in changes between T0 and T1 between the domains of the OHIP-14. The level of significance was set at 5%; P -values of ≤0.05 reject the null hypothesis that there is no difference or significant correlation for each measurement analyzed between the preoperative and postoperative periods. IBM SPSS version 22.0 software (IBM Corp., Armonk, NY, USA) was used for the processing and analysis of data.