Prospective, multi-centric, international, single-arm, cohort study to assess a synthetic polyamide suture material in oral surgery to close the mucosa - MUCODA study.

OBJECTIVES: The aim was to collect different clinical parameters systematically and proactively regarding safety, effectiveness, and performance of a nylon monofilament suture under routine clinical practice for oral surgery. METHODS: The study design was prospective, bicentric, international, single-armed, and observational. A non-absorbable suture was applied to close the mucosa after different dental surgical interventions. Main objective was the incidence of combined postoperative complications until suture removal. The 95 % Confidence Interval (Agresti-Coull method) was used to prove the non-inferiority with a pre-specified upper margin of 21.9 %. Secondary variables were intraoperative suture handling, patient pain and satisfaction, wound healing, aesthetic appearance, and bacterial contamination. RESULTS: 105 patients were enrolled. Complication rate was low (1.9 %), 2 swellings occurred. Pain was present for 1.61 days ± 1.42 after various dental interventions with an average pain level of 20.98 ± 22.60 (VAS). Patients with impacted third molar extraction showed the longest pain duration (6 days) combined with the highest mean pain level of 35.33 ± 30.45 (VAS). Intraoperative suture handling was very good to excellent. Suture removal was done after an average duration of 7.56 ± 2.09 days. Patient's satisfaction was high, and an excellent wound healing was reported by the dentists. Aesthetic appearance only performed in implant patients was rated by oral surgeons with an average of 96.19 ± 3.79 points [min. 80 - max. 100] at 5 months postoperatively. Thread bacterial analysis showed that F. nucleatum was the most present species. CONCLUSIONS: Our findings indicate that the non-absorbable, nylon-based monofilament suture used is safe and quite suitable for oral mucosal closure after various dental surgical interventions such as tooth extraction, implant placement and impacted third molar extraction. CLINICAL SIGNIFICANCE: This study showed the safe use of a non-absorbable, nylon-based monofilament suture for different oral surgical interventions under daily routine clinical practice.

Mouth opening limitation and influence of age and surgical location for static fully guided dental implant placement: an observational, cross-sectional clinical study.

The influence of age and region of the mouth was assessed in regard to mouth opening in fully guided implant placement. Ninety patients were included in this study, 30 in each of three age groups (20-34, 35-55, and >55 years). Maximum passive mouth opening was recorded in three locations: incisal, canine, and molar. The minimum distance required to allow the bone drilling sequence through a static fully guided approach was analysed for four implant systems: Straumann, MIS Dentsply, Astra Tech Dentsply, and Dentium. The mean ± standard deviation maximum mouth opening (all 90 patients) was 46.34 ± 7.70 mm, 36.82 ± 5.92 mm, and 30.99 ± 5.40 mm in the incisal, premolar, and molar region, respectively. No significant difference in mouth opening at any of the three locations was found between the age groups (all P > 0.05). However, a correlation was found between increasing age and decreasing average mouth opening in all three mouth regions; each additional 1 year resulted in a mean reduction of 0.13 mm, 0.09 mm, and 0.08 mm in the incisal, premolar, and molar region, respectively. The minimum required mouth opening was most likely to be met for implant placement in the incisal region (98.9% of all patients) and least likely to be met for placement in the molar region, particularly for older patients (as low as 30% of patients). Mouth opening remains a major limitation in fully guided implant surgery, especially in posterior areas and in older patients. The use of some implant systems in the posterior area may be limited to only one in three patients.

Le fort I osteotomy with or without concomitant removal of upper third molars: A prospective cohort study of intraoperative findings, related complications, and level of pterygomaxillary separation after down-fracture.

The main objective of our study was to assess the clinical implications of concomitant intraoperative removal of maxillary third molars (M3M) with the Le Fort I osteotomy 'twist' technique (LF1twist). A prospective comparative study was carried out regarding the necessity of bone trimming around the pedicle, intra- and postoperative complications, surgery time, and the level of pterygomaxillary junction (PMJ) separation following LF1twist with concomitant intraoperative removal of M3M (test group) versus LF1twist alone (control group). Outcome parameters were assessed from clinical and radiographic measurements. In total, 100 surgery sites were included (50 in each group). The mean surgery time was 53.4 ± 7.8 min, with nonsignificant differences between groups. The frequency of intraoperative complications was negligible, with no significant differences between groups - though all bleeding events (n = 4) occurred when M3M was not removed concomitantly. No postoperative complications were recorded. Percentages of disarticulations occurring at the PMJ were similar in both groups. In conclusion, the results demonstrate that removal of M3M in conjunction with LF1twist does not imply additional surgery time, or differences regarding the level of PMJ separation or perioperative complications. Furthermore, the concomitant procedure reduces the amount of maxillary and palatal bone in the disjunction area, which facilitates down-fracture and field clearing for maxillary repositioning.

Additional pre-extubation local anaesthetic application to improve the postoperative course in orthognathic surgery: a randomised controlled trial.

A clinical trial was performed to assess the analgesic efficacy of adding ropivacaine pre-extubation for pain management after bimaxillary osteotomy. Forty-eight patients were assigned to receive general anaesthesia followed by either a single pre-incisional infiltration with lidocaine (control group, n = 24) or the same pre-incisional infiltration with lidocaine and an additional second infiltration with ropivacaine before awakening (test group, n = 24). Postoperative pain was assessed subjectively using a visual analogue scale and objectively based on the frequency of postoperative rescue opioid consumption. The dose of opioids (methadone) consumed and frequency of postoperative-nausea-vomiting were also recorded. Patients who received the two infiltrations of local anaesthetic had better results in terms of lesser pain during the first 8 hours postoperative (P<0.001 at 2 and 4 hours; P = 0.028 at 8 h), a lesser need for rescue opioids (P = 0.020) and lower doses of rescue opioids (P = 0.011), and consequently a lesser incidence of postoperative-nausea-vomiting (0-4 hours postoperative, P<0.03). The results obtained suggest that the infiltration of an additional dose of local anaesthetic is a simple strategy for reducing pain perception and opioid use, and for ensuring greater patient comfort after bimaxillary osteotomy.

Does orthognathic surgery have an incidentally beneficial effect on mild or asymptomatic sleep apnoea?

A prospective study was performed to assess the effect of orthognathic surgery on mild obstructive sleep apnoea (OSA) in patients with an underlying dentofacial deformity treated for occlusal and/or aesthetic reasons. As the main outcome variables, changes in upper airway volume and apnoea-hypopnoea index (AHI) were evaluated at 1 and 12 months of follow-up, in patients undergoing orthognathic surgery with widening movements of the maxillomandibular complex. Descriptive, bivariate, and correlation analyses were performed; significance was set at P < 0.05. Eighteen patients diagnosed with mild OSA were enroled (mean age 39.8 ± 10.0 years). An overall upper airway volume widening of 46.7% after orthognathic surgery was observed at 12 months of follow-up. The AHI decreased significantly from a median 7.7 events/hour preoperatively to 5.0 events/h at 12 months postoperative (P = 0.045), and the Epworth Sleepiness Scale score decreased from a median 9.5 preoperatively to 7 at 12 months postoperative (P = 0.009). A cure rate of 50% was obtained at 12 months of follow-up (P = 0.009). Despite the limited sample size, this study provides evidence that in patients with an underlying retrusive dentofacial deformity and mild OSA, a slight decrease in AHI is obtained after orthognathic surgery due to upper airway enlargement, which could be added as a beneficial effect of orthognathic surgery.

Impact of 3-dimensional anatomical changes secondary to orthognathic surgery on voice resonance and articulatory function: a prospective study.

An evaluation was made of the impact of orthognathic surgery (OS) on speech, addressing in particular the effects of skeletal and airway changes on voice resonance characteristics and articulatory function. A prospective study was carried out involving 29 consecutive patientssubjected to OS. Preoperative, and short and long-term postoperative evaluations were made of anatomical changes (skeletal and airway measurements), speech evolution (assessed objectively by acoustic analysis: fundamental frequency, local jitter, local shimmer of each vowel, and formants F1 and F2 of vowel /a/), and articulatory function (use of compensatory musculature, point of articulation, and speech intelligibility). These were also assessed subjectively by means of a visual analogue scale. Articulatory function after OS showed immediate improvement and had further progressed at one year of follow up. This improvement significantly correlated with the anatomical changes, and was also notably perceived by the patient. On the other hand, although a slight modification in vocal resonance was reported and seen to correlate with anatomical changes of the tongue, hyoid bone, and airway, it was not subjectively perceived by the patients. In conclusion, the results demonstrated that OS had beneficial effects on articulatory function and imperceptible subjective changes in a patient's voice. Patients subjected to OS, apart from benefitting from improved articulatory function, should not be afraid that they will not recognise their voice after treatment.

Orthognathic surgery and aligners. A comparative assessment of periodontal health and quality of life in postsurgical orthodontic treatment with aligners versus traditional fixed appliances: a randomized controlled trial.

BACKGROUND: Removable clear aligners have become very popular in the last few decades, but they are still little used in the field of orthognathic surgery (OS). The objective of this study was to compare periodontal health and quality of life (QoL) associated to postsurgical orthodontic treatment. MATERIAL AND METHODS: Patients with dentofacial deformities undergoing OS were randomly allocated to receive postsurgical orthodontic treatment with either fixed orthodontic appliances or Invisalign. The main outcomes were periodontal health and QoL. Plaque index, probing depth and bleeding on probing were assessed as periodontal health indicators. QoL was assessed through the Orthognathic Quality of Life Questionnaire (OQLQ-22) and the Oral Health Impact Profile (OHIP-14). Data were analyzed before surgery and end of treatment. Total duration of treatment was also recorded. RESULTS: Twenty-eight patients were randomized, (16 women, 12 men). Periodontal assessment showed better outcomes for the Invisalign group: bleeding on probing (p=0.013), plaque index (p=0.001) and probing depth (p<0.001). The QoL questionnaires showed significant differences in favor of the Invisalign group: OHIP-14 (p=0.004) and OQLQ-22 (p=0.002). Total duration of treatment was similar in both groups (p=0.575). CONCLUSIONS: Compared to traditional orthodontics with fixed appliances, patients managed with clear aligners after OS (surgery-first approach) had better periodontal health and QoL outcomes.

'Pillow technique' to improve lip support in the context of zygoma implant rehabilitation.

This study proposes a simple, off-the-shelf ancillary method for application in the dental rehabilitation of severe maxillary atrophy with zygoma implants, allowing simultaneous improvement of lip support in cases with a moderate lack of premaxillary projection. Three consecutive patients with an atrophic maxilla were evaluated retrospectively. All were treated with a fixed rehabilitation over four zygomatic implants and the pillow technique. The study variables included radiological assessment of the premaxilla volume, upper lip and perinasal soft tissue changes, clinical complications, and subjective evaluation of functional and aesthetic patient satisfaction based on a visual analogue scale. All of the zygomatic implants showed osseointegration. The survival rate was 100%. The immediate postoperative course was uneventful, and no surgical complications were noted at the follow-up visits. Radiological assessment of the premaxilla volume enhancement showed a final mean skeletal projection improvement of +9.4 mm, while the nasolabial angle decreased an average of + 0.6 mm. On the other hand, only small changes in nasal width were detected. Patient satisfaction with the functional and aesthetic outcomes at the 1-year follow-up was excellent. The pillow graft is an easy-to-handle technique that can be included in the armamentarium for moderately incrementing the maxillary sagittal dimension and enhancing lip support in the context of zygoma implant rehabilitation.

Three-dimensional dentoskeletal changes following minimally invasive surgically assisted rapid palatal expansion: a prospective study.

Dentoskeletal changes in minimally invasive surgically assisted rapid palatal expansion (SARPE) were evaluated using cone beam computed tomography (CBCT). This was a prospective study of 30 patients who underwent minimally invasive SARPE performed under local anaesthesia plus sedation by the same surgeon, in an ambulatory setting. Pre- and postoperative CBCT images were obtained for each patient. A statistically significant increase in the linear transverse dimensions of the maxilla occurred systematically. In the canine region, a mean increase of 5.84 mm occurred at the apex level and 7.82 mm at the crown level. These dimensions were 4.83 mm and 7.68 mm, respectively, in the molar region. The cross-sectional area of the maxilla increased by a mean 12.9 mm2 at the palate level and 23.3 mm2 at the crown level. Dental inclination to the buccal aspect was detected (mean 6.1° at the canines and 8.4° at the first molars). The alveolar process tipped buccally 10° at the molar level. Nasal width increased a mean of 3.0 mm at the canine level. Through a three-dimensional analysis, this study found that minimally invasive SARPE was effective in the correction of transverse maxillary discrepancies> 5 mm in non-growing patients. Although dental inclination to the buccal aspect occurred, significant expansion of the maxilla at the skeletal and dentoalveolar levels was confirmed.

Three-dimensional evaluation of postoperative stability: a comparative study between surgery-first and surgery-late protocols.

The main objective of this study was to compare the stability of the surgery-first and surgery-late approaches according to the standardized centre protocols, by three-dimensional evaluation after 1 year of follow-up. A retrospective study was designed that included a test group (surgery-first protocol) and a control group (surgery-late protocol), with a follow-up period of at least 1 year (average 14 months; range 12-24 months). Stability was evaluated using linear and angular measurements by superimposing cone beam computed tomography images obtained at specific points in time: preoperatively, 1 month after surgery, and at the end of the orthodontic treatment. A total of 56 patients with a mean age of 32.2 ± 11.1 years were included in the study. After surgery there were significant changes in all of the measurements in at least one dimension in both groups (except for the transverse maxillary dimension), which remained stable at the end of the treatment, with no statistically significant differences between the two groups. At the 1-year follow-up, both groups presented a SNA angle relapse; this relapse was more significant in the surgery-late group (P = 0.031) and was present only in Class III patients (P = 0.013). In conclusion, an equivalent three-dimensional stability between surgery-first and surgery-late protocols was demonstrated after 1 year of follow-up when eligibility criteria were strictly adhered to.

Transmucosal pterygomaxillary disjunction using a piezoelectric device, in the context of the minimally invasive Le Fort I osteotomy protocol.

The aim of this study was to assess the accuracy and clinical implications of pterygomaxillary junction (PMJ) disjunction with a transmucosal PMJ osteotomy using a piezoelectric hand-piece device, in the context of Le Fort I osteotomy, by evaluating the level of PMJ disarticulation and the need for bone trimming around the pedicle. An ambidirectional 1-month follow-up cohort study was designed involving consecutive patients undergoing minimally invasive maxillary Le Fort I osteotomy through the twist technique. Two cohorts were defined according to whether or not the transmucosal PMJ osteotomy was performed. The site of PMJ disjunction was analysed radiographically. A total of 114 patients were included in the study, 57 in each group. The overall accuracy of the PMJ disjunction path was higher in the test group (43.9%) than in the control group (15.8%). Multiple logistic regression analysis identified the need for bone trimming (odds ratio 0.02; P < 0.001) and removal of the upper third molar (odds ratio 0.17; P < 0.001) as relevant factors. In conclusion, compared with the originally described twist technique, combination of the latter with the PMJ osteotomy increased its accuracy at the level of the PMJ. As a result, there is a decrease in resistance during down-fracture and decrease in the need for bone trimming around the pedicle, with preservation of the minimally invasive concept.

Buccal fat pad as a sealant in palatal mucosa tearing: technical note.

For patients with a dentofacial deformity undergoing a planned segmentation of the maxilla for the management of a transverse maxillary arch discrepancy, palatal mucosa tearing may occur during sawing or palatal expansion traction, giving rise to an oronasal communication. This technical note describes the covering of a tear in the palatal mucosa using a buccal fat pad (BFP) flap, in the context of maxillary segmentation during Le Fort I osteotomy. Through the limited buccal incision used for the Le Fort I osteotomy, a small incision is made in the right periosteum posteriorly, and a supraperiosteal dissection is performed to access the BFP. After a sufficient amount of flap is made available, it is gently introduced through the osteotomy gap until it reaches the palatal mucosa defect and is then sutured. In the patient case presented, the palatal mucosa healed fully within 18 days, and the patient reported no nasal regurgitation of food, defective speech, fetid odour, bad taste, or upper respiratory tract or ear infection during the postoperative period. This technique using a BFP flap should therefore be considered in the context of unexpected tearing of the palatal mucosa in patients undergoing a segmented Le Fort I osteotomy.

Virtual surgical planning in orthognathic surgery with the use of patient-specific plates compared with conventional plates. A systematic review focusing on complications, financial expenses, professional and patient-reported outcome measures.

BACKGROUND: Orthognathic surgery is a well-known surgical procedure for correction of facial deformities. The surgical procedure is performed by the use of conventional plates and by patient-specific osteosynthesis plates (PSOPs). The aim of this study is to investigate any differences in complications, financial expenses, professional and patient-reported outcome measures (PROM) in orthognathic surgery performed by conventional plates and by PSOPs. MATERIAL AND METHODS: A MEDLINE (PubMed), Embase, and Cochrane Library search was conducted. Human studies published in English through August 27, 2020 were included. Grey literature, unpublished literature as well as other databases like Scopus, Google Scholar, or Research Gate were also included in the search strategy of the present systematic review. Randomized and controlled clinical trials were included. Risk of bias was assessed by Cochrane risk of bias tool and Newcastle-Ottawa Scale. RESULTS: Five studies with unclear risk of bias and moderate quality were included. Meta-analysis was not applicable due to considerable heterogeneity. There was no significant difference in intra- and postoperative complications or professional and PROM with the two treatment modalities, although higher tendencies to reoperations were observed with conventional plates. Financial expenses were significantly higher with PSOP, but treatment planning and intraoperative time were shortened by approximately one third compared with mock surgery and conventional plates. CONCLUSIONS: No significant differences were observed in complications, professional and PROM. Higher financial expenses were recorded in orthognathic surgery performed with PSOP. Treatment planning and intraoperative time were shortened with the use of conventional plates. Although further randomized trials are needed before definite conclusions can be provided about beneficial use of PSOPs in orthognathic surgery from a professional and patient perspective.

Redefining our protocol of the orthognathic surgery-first approach after 10 years of experience.

The objective of this study was to update and redefine some concepts of the surgery-first (SF) approach, regarding its indications and contraindications, virtual planning work-up, surgical tips, and postoperative orthodontic benefits, after 10 years of experience. A retrospective analysis was made of orthognathic surgical procedures following the SF protocol between January 2010 and December 2019 to review inclusion and exclusion criteria, diagnostic workflow, surgical tips, and postoperative outcomes. A total of 148 SF procedures were performed during this period, which corresponded to only 9.2% of the total orthognathic surgeries performed, which means that we have broadened the exclusion criteria instead of reducing them. Surgical tips include interdental corticotomies solely in cases of anterior crowding and leaving the intermaxillary fixation miniscrews in place postoperatively for orthodontic skeletal anchorage. The mean duration of postoperative orthodontic treatment was reduced in comparison to conventional surgery (36.8 vs 87.5 weeks). The overall degree of satisfaction was high not only for the patients, but also for the orthodontists and surgeon. SF is especially indicated for patients who desire an immediate aesthetic result, with short-term orthodontics, or for treatment of sleep-related breathing disorders, if they meet the established criteria.

Transmucosal posterior segmentation in the context of minimally invasive Le Fort I osteotomy: Technical note.

In patients in which posterior segmentation of the maxilla is planned in the context of a minimally invasive Le Fort I osteotomy, accessing the posterior segmentation may tear the soft tissues, causing the minimally invasive approach to become lost, and tissue vascularization may be jeopardized. A technical note is presented for maintaining the original incision length when posterior osteotomies are required in the context of a minimally invasive Le Fort I osteotomy. Two vertical incisions are performed at the level of the premolars, a subperiosteal tunnel is made to access the bone with the piezoelectric device, and then an osteotome is used to complete the osteotomy. It thus may be concluded that this simple and safe additional limited approach can be reproduced in all cases where reaching an anatomical structure in the posterior maxillary region is required in the context of a minimally invasive Le Fort I osteotomy. The described technique offers easy and direct access to the posterior region of the maxilla while maintaining the initial incision length and preserving vascularization through the buccal corridors.

Prevalence of maxillary sinus septa: systematic review and meta-analysis.

The aim of this systematic review and meta-analysis was to determine the prevalence and characteristics of maxillary sinus septa using cone beam computed tomography and computed tomography data. Publications were searched until October 5, 2020 in three electronic databases. Additionally, article bibliographies were searched, and authors were contacted if required. This review has been registered in PROSPERO (CRD42019124933). Two independent evaluators assessed methodological quality using the Joanna Briggs Institute levels of evidence; inter-rater reliability tests were performed (Cohen's κ). The prevalence of maxillary sinus septa was expressed as a proportion; differences according to sex were reported in terms of the odds ratio (OR) and 95% confidence interval (95% CI). Heterogeneity and sources of heterogeneity were evaluated by meta-regression. Publication bias was assessed by visual analysis of the funnel plot. Statistical significance was set at P < 0.05. The 62 studies identified and included in the review involved 13,701 patients (22,460 sinuses). The meta-analysis of 35 studies (14,664 sinuses) revealed an overall mean sinus septa prevalence per sinus of 33.2% (95% CI 27.8-38.5%; I2 = 98.32%). The meta-analysis of 42 studies (9631 patients) found an overall mean sinus septa prevalence per patient of 41.0% (95% CI 36.0-46.0%, I2 = 96.45%). The OR for the difference in septa prevalence between sexes was 0.785 (95% CI 0.590-1.046; P = 0.098, I2 = 73.24%). Septa were most frequent in the middle area of the sinus and with a transverse orientation (86.0%). Within the limitations, the results suggest a high proportion of septa in the sinus, commonly in the middle area, which can interfere with the success of sinus floor elevation required for implant rehabilitation.

Relapse-related factors of Le Fort I osteotomy in cleft lip and palate patients: A systematic review and meta-analysis.

A systematic review search was based on the PICOS approach, as follows: population: cleft lip and palate patients; intervention: Le Fort I osteotomy; comparator: different surgical protocols; outcome: stability, recurrence or surgical complications; study designs: only case reports were excluded from the review. No restrictions were placed on language or year of publication. Risk of bias was analyzed, heterogeneity was assessed, and subgroup analysis was performed using a level of significance of 1% (p = 0.01). The search identified 248 citations, from which 29 studies were selected and a total of 797 patients enrolled. The level of agreement between the authors was considered excellent (k = 0.810 for study selection and k = 0.941 for study eligibility). Our results reported a mean maxillary advancement of 5.69 mm, a mean vertical downward/upward of 2.85/-2.02 mm and a mean clockwise rotation of 4.15°. Greater surgical relapse rates were reported for vertical downward movement (-1.13 mm, 39.6%), followed by clockwise rotation (-1.41°, 33.9%), sagittal (-0.99 mm, 17.4%) and vertical upward (0.11 mm, 5.4%) movements. No relevance was found regarding the type of cleft, the type of Le Fort I osteotomy, concomitant bone grafting, surgical overcorrection, postoperative rigid or elastic intermaxillary fixation, or retention splint. Study limitations were heterogeneity and the low number of high-quality studies. In spite of reported high relapse rates, Le Fort I osteotomy for maxillary reposition is the first-choice procedure for selected cleft lip and palate patients in whom extensive maxillary movements are not required, because of its safety and its three-dimensional movement versatility in one-step surgery. Otherwise, distraction osteogenesis should be considered as the gold standard treatment.

Current state of dynamic surgery. A literature review.

BACKGROUND: Recently, dental implant technology has been widely used for oral reconstruction. Dental implants are the treatment of choice for those patients with dental absences. An optimal implant placement is based on the prosthetic driven concept in order to achieve an aesthetic and functional restoration with a long-term prognosis. There are two types of guided implant surgery that are described in the literature: Static Guided Surgery (SGS) and Dynamic Guided Surgery (DGS). The aim of this study is to be aware of the current state of dynamic surgery and compare in the literature the discrepancies between planning and placement of dental implants. MATERIAL AND METHODS: The study consists of a bibliographic review on the topic. The research has been performed in the Medline/Pubmed of articles published by different professional associations and societies in the international context. RESULTS: Twenty two studies out of 100 articles from the initial search were finally included. Our results have been compared with other current available papers in the literature reviewed that obtained similar outcomes. CONCLUSIONS: Dynamic navigation shows a better accuracy and precision of implant placement. To corroborate the results of this review as well as to evaluate the different variables that could influence the accuracy of this technique, future randomized control trials will be needed.

Variation between natural head orientation and Frankfort horizontal planes in orthognathic surgery patients: 187 consecutive cases.

The purpose of this study was to assess the relationship between the Frankfort horizontal (FH) and natural head orientation (NHO), their correlation between patients' malocclusion, and the impact of counterclockwise rotation (CCW) on the FH-NHO angle variation after orthognathic surgery. An evaluation of 187 consecutive patients was performed at the Maxillofacial Institute (Teknon Medical Center, Barcelona). FH-NHO° was measured pre- and postoperatively at 1 and 12 months, after three-dimensional (3D) superimposition using a software (Dolphin®). Patients were classified as follows: 3.2%, 48.7% and 48.1%, class I, II and III, respectively. Baseline FH-NHO° was significantly positive for patients with dentofacial deformities (2.73°±4.19 (2.12-3.33°, P<0.001). The impact of orthognathic surgery in FH-NHO° was greater in class II when compared with class III patients, with a variation of 2.04°±4.79 (P<0.001) and -1.20°±3.03 (P<0.001), respectively. FH-NHO° increased when CCW rotational movements were performed (P=0.006). The results of this study suggest that pre- and postoperative NHO differs from FH in orthognathic patients. The angle between FH and NHO is significantly larger in class III than in class II patients at baseline, which converges after orthognathic surgery when CCW rotation is performed. Therefore, NHO should be used as the real horizontal plane when planning for orthognathic surgery.

Stability and surgical complications of tooth-borne and bone-borne appliances in surgical assisted rapid maxillary expansion: a systematic review.

The objective of this systematic review was to evaluate the stability and complications of tooth-borne (TB), bone-borne (BB) and hybrid (TB-BB) appliances in surgically assisted rapid maxillary expansion (SARME). Database searches were conducted (PubMed, Embase, Cochrane Library and SciELO), as well as a grey literature search (Google Scholar) and hand searches of reference lists. Forty-six articles were included after study selection (κ=0.854). After eligibility assessment, 16 articles and one article from the grey literature were processed (κ=0.866) and six articles were selected by hand searching, for a total of 23 articles included. Regarding stability, TB appliances showed width relapse rates ranging from 4 to 35% in canines, from 1 to 37% in premolars and from 0.2 to 49.5% in molars. In BB appliances, width relapse rates were 1.7-21% in canines, 1.5% in premolars and 4.6-11.5% in molars. In hybrid appliances, the width relapse rate was 14% in premolars, with a 1.8% overexpansion reported in the molar region. In TB and BB appliances, skeletal relapse rates were similar on the nasal floor (11-53% and 41.6%, respectively) and at the level of the maxilla (18% and 16%, respectively). The most common complications were bone resorption in TB appliances (18.14%) and appliance-related complications in BB appliances (17.9%). The risk of bias was high in 19 studies, medium in three studies and low in one study. The TB and BB appliances used in SARME were considered to have a high long-term stability. BB appliances appeared to have fewer relapses than TB appliances due to a more parallel distribution of forces exerted. However, relapse appears to be highly influenced by postorthodontic treatments, where arch-form coordination is achieved in the consolidation period with the purpose of overexpansion correction, alignment and final vertical adjustments. Further randomised controlled trials with long-term data and large sample sizes are needed to support evidence-based clinical decision-making and to allow meta-analytic studies of stability outcomes regarding the type of anchorage in SARME.