Timing of orthognathic surgery on the changes of oral health-related quality of life in Chinese orthognathic surgery patients


Although the association between orthognathic surgery and oral health-related quality of life (OHRQoL) has been explored, few studies have been carried out to describe the influence of surgery type on perceived OHRQoL. The aim of this study was to evaluate the difference of OHRQoL between a surgery-first approach and an orthodontics-first approach, using the 14-item Oral Health Impact Profile questionnaire (Chinese version).


Fifty adult Chinese orthodontic patients who received either surgery-first or orthodontics-first treatment completed 5 distinct sections of the questionnaire. Chi-square tests were used to compare categorical variables. All analyses were carried out with Stata software (version 11.2; StataCorp, College Station, Tex).


The quality of life significantly improved after treatment in both groups. However, overall scores were highest before treatment in the surgery-first group but increased significantly from before treatment to 6 months after surgery and then significantly decreased after surgery in the orthodontics-first group. There were relatively lower scores in the surgery-first group than in the orthodontics-first group before surgery, at 12 months after beginning orthodontics, and at the end of treatment, although these differences did not reach significant levels.


Both treatment methods can obtain the same results. The timing of the orthognathic approach did not affect the final OHRQoL in Chinese orthognathic surgery patients.


  • The orthognathic approach did not affect final OHRQoL in Chinese surgery patients.

  • Both treatment methods can obtain the same results.

Patients with dentofacial deformities face many psychological problems such as self-abasement and lack of confidence. Such deformities interfere not only with oral functions, but also with mental health, thus affecting the entire spectrum that constitutes the quality of life.

Orthognathic surgery is recognized as the mainstay of treatment for dentofacial deformities. However, the conventional surgical-orthodontic treatment for patients with dentofacial deformities includes preoperative orthodontic treatment, orthognathic surgery, and postoperative orthodontic treatment. Although these procedures generally produce satisfactory results, such as appropriate dental decompensation, proper arch coordination, and accurate prediction of surgical results before orthognathic surgery, several disadvantages have been reported, including worsening of the facial profile and dental functions during preoperative orthodontic treatment, discomfort, and longer treatment.

Recently, the surgery-first approach has been proposed to overcome the disadvantages of conventional surgical-orthodontic treatment procedures. This approach has some advantages, such as short total treatment duration, early improvement of the facial profile, and establishment of a proper maxillomandibular relationship before orthodontic treatment.

Many studies have shown that patients enjoy great benefits of the surgery-first approach, such as psychological aspect, improved facial and dental esthetics, and improved function. A recent systematic review also showed that orthognathic surgery has a positive impact on the patient’s facial appearance and oral function, as well as social advantages, such as improved self-confidence. Although most previous studies have emphasized the effects of conventional surgical-orthodontic treatment on the quality of life, it is necessary to attribute importance to the effects of different surgical interventions on the patients’ mental health.

Several oral health-related quality of life (OHRQoL) measures have been developed to assess the impact of orthognathic surgery on quality of life. Because generic measurement tools such as the Short-Form 36-item Health Survey and the Euro Qol have been reported to be invalid for sensitive changes in oral health and furthermore to exhibit limited construct validity, disease-specific measures with disease-related attributes have been developed with greater sensitivity to clinical conditions. One of the most widely used questionnaires is the Oral Health Impact Profile (OHIP), which measures a patient’s perceptions of the social impact of oral disorders on well-being. The 14-item OHIP (OHIP-14) questionnaire was developed from the OHIP-49. It focuses especially on specific aspects of oral health, including functional limitations, physical disabilities, and psychological and social aspects of disability.

Taking all of these aspects into consideration, we aimed to evaluate the difference of OHRQoL between the surgery-first approach and the orthodontics-first approach by using the OHIP-14 in this study.

Material and methods

Ethical approval was obtained from the ethics committee of the Hospital of Stomatology, Wenzhou Medical University, Wenzhow, China. The participants were informed about the examination procedures and assured of the confidentiality of the collected information. Only those who provided written informed consent were included in the research.

The size of each group was calculated based on a significance level of 0.05 and a beta of 0.1 to achieve 90% power to detect a clinically meaningful difference between the 2 groups. The power analysis showed that 20 patients in each group were needed.

The study was a longitudinal prospective cohort design with 50 patients, who would receive orthognathic surgery at the Department of Orthodontics at the Hospital of Stomatology of Wenzhou Medical University. Eligible patients were randomized into 2 groups via a computer-generated sequence (SAS, Cary, NC): the surgery-first group and the orthodontics-first group. The randomization sequences were stored in opaque envelopes by 2 clinicians (W.C., Y.Z.) who were not involved in the enrollment, intervention implementation, or outcome assessments of this study. The outcome assessors and statisticians were blinded to the allocations.

We recruited patients with skeletal malformations displaying mandibular prognathism, who had either surgery-first or orthodontics-first orthognathic treatment. Patients were excluded for conditions including cognitive disorders, cleft lip and palate, craniofacial syndromes, posttraumatic deformities, previous orthodontic treatment, or additional procedures such as genioplasty or distraction. Therefore, orthognathic surgery purely consisted of bilateral sagittal split ramus osteotomy to resolve mandibular prognathism. Condylar positioning devices were not used. Patients remained in the hospital for 5 days after surgery. Rigid fixation and an interocclusal splint were applied for 2 weeks. Afterward, the patients wore light training elastics for a 2-week period and then returned to their orthodontists. All patients were treated by the same surgeon and orthodontists.

Fifty-two patients were recruited, but 2 refused to participate in this study. The full study sample comprised 50 adults (25 men, 25 women; ages, 25.2 ± 6.8 years), who were divided into 2 groups according to surgical-orthodontic treatment concept: surgery-first group (n = 25; mean age, 25.4 ± 6.4 years) and orthodontics-first group (n = 25; mean age, 25.1 ± 6.8 years). The mean treatment times were 16.6 ± 2.4 months in surgery-first group and 25.3 ± 2.4 months in orthodontics-first group. A P value greater than 0.05, which indicated the treatment times, was significantly greater in the orthodontics-first group compared with the surgery-first group.

Before treatment, the 2 groups were comparable with respect to age, sex, and socioeconomic status. Descriptive statistics indicated no significant differences between the surgery-first and orthodontics-first groups for age, sex, and socioeconomic status ( Table I ).

Table I
Demographic and clinical characteristics of surgery-first and orthodontics-first groups
Surgery-first group n (mean ± SD or %) Orthodontics-first group n (mean ± SD or %) P value
Female (n) 12 (48) 13 (52)
Male (n) 13 (52) 12 (48) 0.867
Age (y) 25 (25.4 ± 6.4) 25 (25.1 ± 6.8) 0.968
Maxilla (mm) 25 (−0.16 ± 1.23) 25 (0.12 ± 1.34) 0.456
Mandible (mm) 25 (−1.24 ± 1.65) 25 (−1.48 ± 1.32) 0.534
ANB (°) 25 (−7.81 ± 3.44) 25 (−7.28 ± 3.40) 0.725
PAR 25 (31.68 ± 4.56) 25 (31.49 ± 5.62) 0.824
Socioeconomic class
High (n) 20 (51) 19 (49)
Low (n) 5 (45) 6 (55) 0.905

PAR , Peer Assessment Rating.

During the interviews, the patients provided information concerning demographic factors such as sex, age, and socioeconomic status before appliance placement. For the OHRQoL assessment, the Chinese version of the OHIP-14 was used, which had shown great psychometric properties. The subjects completed 5 sets of interviews and clinical evaluations in the surgery-first group: before treatment (T1), 1 month after surgery (T2), 6 months after surgery (T3), 12 months after surgery (T4), and end of treatment (T5). The subjects in orthodontics-first group also completed 5 sets of interviews and clinical evaluations: before treatment (T1), 1 month after beginning orthodontics (T2), 6 months after beginning orthodontics (T3), 12 months after beginning orthodontics (T4), and end of treatment (T5).

Fourteen items were included in the Chinese version of the OHIP-14, covering 7 conceptualized domains: functional limitations, physical pain, psychological discomfort, physical disability, psychological disability, social disability, and handicaps. Each item was scored on a 5-point scale to rate the impact of overall oral health status as it relates to OHRQoL. The responses were scored as follows: never (score 0), hardly ever (1), occasionally (2), fairly often (3), and very often (4). OHIP-14 scores were calculated by summing the response codes for the 14 items. Consequently, the total scores could range from 0 to 56, with higher scores indicating poorer OHRQoL.

The surgery-first group did not have their orthodontic appliances placed before surgery. Routine reference models were taken before and after treatment for recording crowding and Peer Assessment Rating index, and all models were scored independently by an orthodontic technician (Y.Z.). Crowding was calculated by the difference between the sum of tooth widths and arch circumferences, taken from the line of best fit through the contact points mesial to the first molars on a photocopy of the patient’s occlusal arch form. The lateral cephalometric measurements were taken before and after treatment.

Statistical analysis

Chi-square tests were used to compare categorical variables. Changes over time were evaluated by using nonpaired t tests.

All analyses were carried out with Stata software (version 11.2; StataCorp, College Station, Tex). Significance levels were set at 0.05.


Surgery type showed no statistical differences with the clinical outcome of the malocclusion. There were no significant differences in the percentages of PAR scores, Wits appraisal, crowding, and ANB angle between the 2 groups after treatment ( Table II ).

Table II
Posttreatment occlusal dimensions and skeletal varies of subjects
Before treatment After treatment Changes
Surgery-first group Orthodontics-first group P Surgery-first group Orthodontics-first group P Surgery-first group Orthodontics-first group P
Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD
Maxillary arch crowding (mm) −0.16 1.23 0.12 1.34 0.052 0.02 0.88 0.04 0.76 0.587 0.18 0.82 0.16 0.76 0.657
Mandibular arch crowding (mm) −1.24 1.65 −1.48 1.32 0.365 0.16 1.20 0.12 1.34 0.358 1.40 1.02 1.60 1.10 0.524
Overjet (mm) −6.65 2.68 −6.21 2.36 0.587 0.56 0.46 0.48 0.39 0.124 7.21 2.34 6.69 2.45 0.304
Overbite (mm) −0.02 1.23 −0.15 1.46 0.014 0.16 0.64 0.14 0.48 0.689 0.18 0.68 0.21 0.54 0.621
Wits appraisal (mm) −9.65 3.61 −9.82 4.02 0.485 0.65 1.20 0.84 0.94 0.701 10.30 4.20 10.66 4.52 0.633
ANB (°) −7.81 3.44 −7.28 3.40 0.687 0.82 1.26 0.86 1.22 0.368 8.63 3.62 8.04 3.80 0.234
PAR 31.68 4.56 31.49 5.62 0.634 6.35 2.45 6.02 2.36 0.795 −25.67 5.38 −24.53 4.86 0.635
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Apr 4, 2017 | Posted by in Orthodontics | Comments Off on Timing of orthognathic surgery on the changes of oral health-related quality of life in Chinese orthognathic surgery patients
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