Material and Methods
skeletal malocclusion, malocclusion, bleeding, Pain, overbite, crowding, tooth, Bleeding, NRS, orthodontic
TEMPOROMANDIBULAR JOINT DISORDER, BLEEDING, RECRUITMENT, DENTAL PLAQUE, SECONDARY, PERIODONTAL DISEASE, PLAQUE, BLEEDING
- Trial designWe report a 2-arm parallel, randomized, clinical trial with an allocation ratio of 1:1. The study was approved by the Institutional Review Board at our hospital (IRB number 095/17). This study followed the Declaration of Helsinki on medical protocols and ethics. No changes to the methods after trial commencement occurred. The presentation of this report is according to the CONSORT guidelines for reporting trials.- ParticipantsThe participants were recruited from the outpatient clinic at the craniofacial department of Ramón y Cajal University Hospital, University of Alcalá de Henares, Madrid, Spain. The surgeons in the craniofacial team were responsible for recruitment. Eligibility criteria were: 1) skeletal malocclusion requiring combined surgical and orthodontic treatment without extractions; and 2) informed consent for this novel protocol. The exclusion criteria were: 1) temporomandibular joint disorders or severe symptoms; 2) uncontrolled periodontal disease; 3) severe crowding requiring extractions; 4) class II division 2 malocclusion with overbite or severely altered curves of Spee; or 5) severe asymmetry.- InterventionsBaseline characteristics including periodontal status were recorded. After recorded, all patients in the study received professional oral hygiene treatment by an experienced dental hygienist. They were also instructed on the same standardized oral hygiene protocol before and during orthodontic treatment. This included the proper use of toothbrush and interdental brushes three times daily. Baseline data recording and hygiene treatment took place before random allocation.Participants were randomly assigned to postsurgical orthodontic treatment with either clear aligners (Invisalign group) or fixed appliances (brackets group). All patients were eligible for a surgery-first OS approach. The Invisalign system was used in all clear aligner cases. All surgical procedures were performed by the same surgical team and all patients were treated by an Invisalign certified orthodontist with experience in OS. All patients signed an informed consent document after questions and concerns were clarified by the surgical team.All patients had an appointment with the dental hygienist for professional tooth cleaning after recruitment. The initial diagnostic work-up, preoperative planning, orthodontic preparation and surgical execution proceeded according to our standardized protocol for surgery-first orthognathic procedures. Patients allocated to the brackets group underwent a preoperative orthodontic appointment one week prior to surgery for bracket bonding. Patients in the Invisalign group undergoing non-segmented maxillary surgery had an orthodontic appointment one week before surgery for intraoral scanning in order to fabricate the aligners.The patients were operated upon under general anesthesia. Single jaw or bimaxillary surgery was performed, depending on the individualized treatment plan. For patients in the Invisalign group, 4 to 8 transmucosal 2.0 mm screws were placed before incision. If the maxilla needed segmentation, 8 screws were placed; in one-piece maxillas, 4 screws were used. Surgical protocol was the same for both groups. The duration of surgery was recorded.All patients had the first appointment with the orthodontist one week after surgery. The brackets group began orthodontic treatment following that appointment. Patients in the Invisalign group and with segmented maxillary surgery were scanned within the first week and started using the aligners in the second week after surgery. Patients in the Invisalign group with non-segmented maxillary surgery began to use the first aligner within the first 10 days after surgery. The finishing criteria were the same for each group. They were established following our standard practice, in accordance with the American Board of Orthodontics Objective Grading System.- OutcomesPatient periodontal health status was evaluated based on the plaque index, probing depth and bleeding on probing. The plaque index was assessed from 0 to 3 by grading plaque accumulation in the gingival area according to the Ramfjord scale. The highest score was assigned to each sextant and the median value was selected for each patient. Probing depth was recorded with the periodontal probe. The probing sites were the mesiovestibular surface of the upper left central incisor and the lower right first molar. Bleeding on probing was registered 20 seconds after probing, and recorded as either absent or present. These parameters were recorded at three time points: at initial assessment after professional dental cleaning (baseline), 1 month after surgery (T1) and at follow-up evaluation at the end of orthodontic treatment, following removal of the brackets or last aligner (T2). This periodontal assessment protocol was designed following those reported in previous studies (Two QoL questionnaires were used to assess patient satisfaction: the 14‑item short version of the Oral Health Impact Profile (OHIP‑14) and the 22‑item Orthognathic Quality of Life Questionnaire (OQLQ‑22). Pain intensity was assessed based on a 10‑point numerical rating scale (NRS). These parameters were recorded after bracket bonding for the brackets group patients and immediately before surgery (T0) and at T1 and T2.The primary outcome measures were dental plaque as assessed with the plaque index and QoL related to OS as assessed with the Orthognathic Quality of Life Questionnaire at the 3 time points. The secondary outcomes were probing depth, bleeding on probing and QoL related to general oral health as assessed with the Oral Health Impact Profile questionnaire.- Sample sizeSample size calculation was set to detect differences of 30% between groups for the main outcome by Mann-Whitney test. Standard deviation of 0.5 and 0.8 were assumed based on a pilot study of 10 patients. A minimum of 28 patients (14 per group) was needed in order to achieve 80% power at the 5% significance level.- Randomization (sequence generation, allocation concealment and implementation)Randomization was accomplished by the principal investigator (P.L.) by using an online software program (http://www.graphpad.com/quickcalcs/index.cfm), independent of the clinical investigator involved in recruitment (JM.E.) The program was set to provide a 1:1 allocation ratio, and automatically generated a randomization plan for treatment assignment.Allocation concealment was achieved with sequentially numbered, opaque, sealed envelopes, containing the treatment allocation cards. Envelopes were prepared before commencement of the trial, and they were kept locked and safe. The orthodontist was responsible for implementing the randomization process. This sequence is shown in Fig. - Statistical analysisThe analyses comprised observed data; there was no missing data. Continuous and categorical variables were reported as means and quartiles, and as numbers and frequencies, respectively. Cross-sectional between-group comparisons were made using the Student t-test or Mann-Whitney U-test (for continuous data with or without a normal distribution), or the Pearson chi‑squared test or Fisher exact test (for categorical data). A significance level of 5% (alpha = 0.05) was used. The SPSS version 19 statistical package was used for the study.