Functional needs of subjects with dentofacial deformities: A study using the index of orthognathic functional treatment need (IOFTN)
Introduction
Orthognathic surgery often involves surgical procedures on the mandible, maxillae, or both, as well as their dentoalveolar segments to reposition the jaws into their normalised or functional relationship in subjects with dentofacial deformities.
Reports indicates that approximately 5% of the UK or USA population present with dentofacial deformities that are not amenable to orthodontic treatment only, requiring orthognathic surgery as a part of their definitive treatment.1 Although preparation of orthognathic patients has been recently modified with introduction of the surgery-first approach,2 conventional approach often includes a course of orthodontic treatment before and after orthognathic surgery.
Approximately, 2600–2900 patients undergo orthognathic surgery annually in England and Wales and the average costs of these treatments in 2012 ranged from £4000 to £8000 per case.3 In the UK, orthognathic surgeries are funded by NHS England for patients with malocclusions and severe dentofacial deformities. The funding should be allocated to patients with the Index of Orthodontic Treatment Need (IOTN)4 score of 4 or 5 and functional symptoms that have an important impact on patients' quality of life. With the current drive to reduce costs within the NHS, and in particular, to redirect resources from low priority treatments, to those considered to be high priority and their use is supported by evidence, having an index to objectively identify those treatment/patients seems necessary.
The index of orthognathic functional treatment needs (IOFTN) has been recently developed by Ireland et al. in the UK, aiming at prioritizing severe malocclusions not amenable to orthodontic treatment alone and need orthognathic surgery.5 IOFTN has 5 categories, from a Very Great Need (grade 5) through to No Need for treatment (grade 1) (Table 1). Ideally, the funding should be used for patients with grades 4 and 5 of the IOFTN. The index has similarities with the IOTN, however, it has modifications to reflect the functional aspects of treatment need for orthognathic patients, which are missing in the IOTN, such as patients with sleep apnoea not amenable to Mandibular Advancement Device (MAD) or Continuous Positive Airway Pressure (CPAP), complete buccal scissors bite with functional implications (both categorised as graded 5 IOFTN) as well as maxillary labial gingival exposure greater than 3 mm (grade 4 IOFTN). The index does not support the provision of orthognathic treatment for speech or TMJ disorders.
IOFTN has been used in the UK,5, 6, 7 but its external validity has not been tested outside the UK. It would be interesting to see if IOFTN identifies subjects who had orthognathic treatment outside the UK as having great or very great functional need for surgery. Therefore, the primary objective of the present study was to assess, retrospectively, the functional needs of orthognathic cases treated in a university setting in Isfahan, Iran, using the IOFTN; and to compare the finding to reports from the UK. The secondary aim was to compare the functional needs (using the IOFTN) of patients with different malocclusions and sagittal skeletal patterns.
Section snippets
Materials and methods
The present research was approved by Isfahan University of Medical Sciences institutional review board (ethical approval committee) and complies with the World Medical Association Declaration of Helsinki on medical research protocols and ethics. A retrospective study was conducted on 103 subjects were assessed [58 female, 45 males, 16–45 years, mean (SD) age = 23.47 (6.44) years] who had orthognathic surgery between September 2011 to June 2015.
Statistical analysis
Descriptive analyses such as Mean and standard deviation were calculated. The frequency of different components of the IOFTN and IOTN (DHC) were compared between genders using the Chi-Square test as well as among subjects with different malocclusions and sagittal skeletal patterns. The percentages of cases with IOFTN scores of 4/5 for various malocclusions and sagittal skeletal patterns were also calculated. The P < 0.05 was considered statistically significant.
Result
Gender differences detected for malocclusions/skeletal patterns (P < 0.05). Class III malocclusion was the most prevalent type (45.6%), which appeared most often in males (Table 2). Class II skeletal pattern was the most prevalent type (51.5%) and mainly seen in females. There were 9, 42, 5, and 47 subjects with Class I, Class II Division I, Class II Division II, and Class III malocclusions, as well as 4.8%, 51.5%, and 43.7% presenting with subjects with Class I, Class II, and Class III
Discussion
According to Posnick, “dentofacial deformity” refers to significant deviations from normal proportions of the maxilla–mandibular complex that also negatively affect the relationship of the teeth within each arch and the relationship of the arches with one another (occlusion).1 The objective of orthognathic surgery is beyond achieving short-term improved occlusion.9 Dentofacial deformities may be associated with traumatic bite (damage to dento-alveolar tissues in deep bite subjects), difficulty
Conclusion
IOFTN identified 92.2% of subjects who had orthognathic surgery as having great and very great functional needs and appears to be a valid tool for identifying patients in need of orthognathic surgery. Higher percentages of Class III subjects scored grade 5 of IOFTN, indicating higher functional need for orthognathic surgery.
Conflict of interest
Authors have no conflict of Interest to report.
Funding
The study was self-funded.
Author contribution
Drs Eslamipour and Shahmoradi contributed to data collection for the manuscript. Dr Borzabadi-Farahani extracted the IOTN and IOFTN scores as well as contributed to study design, auditing the data, statistical analysis, preparation of the manuscript draft and revisions of the manuscript.
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