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.

Surgery-first in interdisciplinary class II cases

OBJECTIVES

To present an interdisciplinary case treated with a surgery-first orthognathic approach, followed by orthodontic and prosthodontic treatment.

CLINICAL CONSIDERATIONS

After an accurate pre-operative virtual planning, a young patient with skeletal class II, retrognathia, and an anterior open bite was treated with bimaxillary orthognathic surgery without pre-surgical orthodontic decompensation. Orthodontic treatment was carried out post-operatively. The treatment was completed with a prosthodontic phase to improve the final esthetic outcome of the smile.

CONCLUSIONS

A surgery-first approach allowed to achieve esthetic and functional results in a reduced treatment duration that remained stable over the course of 1 year. The outcomes were consistent with prior research in terms of advantages brought by following an accurately planned surgery-first protocol. Nevertheless, longer-term follow-up was required to evaluate the treatment stability.

CLINICAL SIGNIFICANCE

An accurately planned surgery-first approach significantly helped in shortening the duration of the treatment, while providing a stable, functional, and esthetic solution to the patient's problems.

Dental Implant Positioning Accuracy Using a Key or Keyless Static Fully Guided Surgical System: A Prospective Systematic Review and Meta-analysis

PURPOSE

To realize a systematic review with prospective meta-analysis aiming to compare the accuracy of static fully guided implant placement depending on the drill key modality (conventional drill key surgery systems vs newer keyless systems) and evaluate the impact of deviation factors.

MATERIALS AND METHODS

An electronic systematic search was conducted to identify prospective clinical trials matching inclusion criteria. The variables of interest were coronal global, apical, vertical, and angular deviations. The types of edentulism and surgical guide support were investigated as deviation factors. Meta-regression (mixed-effect model) was performed. Heterogeneity was assessed using Cochrane's I. test and interpretation thresholds.

RESULTS

A total of 1,233 implants in 475 patients were analyzed (18 studies included). Coronal global deviation was significantly lower in the keyless group than in the key group (-0.36 mm; 95% CI -0.62, -0.09; P = .008). Angulation control of the keyless system was superior to that of the key system (-0.36 degrees; 95% CI -0.75, 0.02; P = .063). Nonsignificant differences were found between both groups in apical (P = .684) and vertical deviations (P = .958). Significant influence of the type of edentulism (single, partial, total) and surgical guide support (tooth, mucosa, bone) on the overall amount of coronal global, apical, and angular deviations was found (P < .001). The lowest deviations were found in partial edentulism and tooth-supported surgical guide groups. (P < .001).

CONCLUSIONS

Keyless static fully guided surgical systems allowed significantly better control of coronal and angular deviations than conventional systems. The types of edentulism and surgical guide support seemed to influence the positioning accuracy.

Ultrasound-Guided Suprazygomatic Maxillary Nerve Block Is Effective in Reducing Postoperative Opioid Use Following Bimaxillary Osteotomy

BACKGROUND

Ultrasound-guided maxillary nerve block has recently been described, though its impact upon bimaxillary osteotomy has not been formally investigated.

PURPOSE

The present study was carried out to determine whether the addition of ultrasound-guided maxillary nerve block in subjects undergoing bimaxillary osteotomy reduces opioid use.

STUDY DESIGN, SETTING, SAMPLE

A randomized clinical trial was carried out in adults undergoing bimaxillary osteotomy between April 2019 and January 2020 at Teknon Medical Center (Barcelona, Spain).

PREDICTOR VARIABLE

The predictor variable was the treatment technique used (maxillary nerve block or no block). The subjects were randomized to either receive (test group) or not receive (control group) bilateral ultrasound-guided suprazygomatic maxillary nerve block (5 ml of 0.37% ropivacaine) before surgery.

MAIN OUTCOME VARIABLE(S)

The primary outcome variable was the intravenous methadone requirements in the first two postoperative hours. The secondary outcome variables were postoperative pain, rescue subcutaneous methadone, intravenous remifentanil used intraoperatively, the incidence of postoperative nausea-vomiting, and complications derived from maxillary nerve block.

COVARIATES

Subject age, sex, weight, height, and anesthetic risk, and the duration of surgery were recorded.

ANALYSES

Descriptive and inferential analyses were performed using the χ2 test and Mann-Whitney U test. Statistical significance was considered for P < .05.

RESULTS

The baseline sample consisted of 68 subjects scheduled for bimaxillary osteotomy. The follow-up sample comprised 60 subjects: 30 in the control group (10 females and 20 males, aged 34.0 ± 10.2 years) and 30 in the test group (13 females and 17 males, aged 29.8 ± 10.8 years). The subjects who received maxillary nerve block showed less intravenous methadone use in the first 2 hours postsurgery (median 2.0 mg control group vs 0 mg test group; P < .001), lower pain levels at any time during the first 18 hours postsurgery (median visual analog score 4 control group vs 2 test group; P < .001), and a lesser percentage required methadone (33.3% control group vs 0% test group; P < .01) at 4-18 hours postsurgery.

CONCLUSION AND RELEVANCE

The results obtained suggest that ultrasound-guided maxillary nerve block is a promising anesthetic technique capable of reducing intraoperative and postoperative opioid use, with greater patient comfort in bimaxillary osteotomy.

On the feasibility of minimally invasive Le Fort I with patient-specific implants: Proof of concept

A novel approach to Le Fort I osteotomy is presented, integrating patient-specific implants (PSIs), osteosynthesis and cutting guides within a minimally invasive surgical framework, and the accuracy of the procedure is assessed through 3D voxel-based superimposition. The technique was applied in 5 cases. Differences between the surgical plan and final outcome were evaluated as follows: a 2-mm color scale was established to assess the anterior surfaces of the maxilla, mandible and chin, as well as the condylar surfaces. Measurements were made at 8 specific landmarks, and all of them showed a mean difference of less than 1 mm. In conclusion, the described protocol allows for minimally invasive Le Fort I osteotomy using PSIs. Besides, although the accuracy of the results may be limited by the small sample size, the findings are consistent with those reported in the literature. A prospective comparative study is needed to obtain statistically significant results and draw meaningful conclusions.

Does Aesthetic Osseous Genioplasty Impact Upper Airway Volume?

BACKGROUND

Although maxillomandibular advancement is the treatment of choice for obstructive sleep apnea syndrome (OSAS) in the presence of underlying maxillomandibular complex hypoplasia, there is still a gap in the literature regarding the impact of genioplasty upon upper airway volume (UAV).

OBJECTIVES

The aim of this study was to evaluate the impact of isolated osseous genioplasty upon UAV.

METHODS

A retrospective analysis of all patients subjected to isolated osseous genioplasty between July 2015 and July 2022 was conducted. Cone-beam computed tomography was performed preoperatively and postoperatively to assess the chin and hyoid 3-dimensional (3D) spatial position and UAV changes after surgery.

RESULTS

A total of 44 patients were included in the study. Regarding surgical movements of the chin, almost all patients received a sagittal movement (n = 42; 39 forward and 3 backward), while in 8 patients a vertical movement (5 upward and 3 downward) was applied, and in 6 patients the chin was centered. Statistically significant increases in total UAV (P = .014) and at the level of the oropharynx (P = .004) were observed. Specifically, chin centering, upward and forward movements enlarged the oropharynx volume (P = .006, .043 and .065, respectively). Chin advancement enlarged the hypopharynx volume (P = .032), as did upward movement of the hyoid bone (P < .001).

CONCLUSIONS

Results of the study suggest that aesthetic osseous genioplasty impacts the UAV: each 3D spatial chin movement differently impacts the upper airway by enlarging or narrowing it. However, further studies addressing the apnea-hypopnea index are required to assess its effectiveness in treating OSAS.

LEVEL OF EVIDENCE: 4

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.

Bilateral sagittal split osteotomy with or without concomitant removal of third molars: a retrospective cohort study of related complications and bone healing

PURPOSE

To carry out a comparative evaluation of the intra- and postoperative complications, and bone healing, following bilateral sagittal split osteotomy (BSSO) with or without concomitant removal of third molars.

MATERIAL AND METHODS

A retrospective analysis was performed of two cohorts subjected to BSSO with the intraoperative removal of third molars (test group) versus the removal of third molars at least 6 months prior to BSSO (control group), comprising at least 1 year of clinical and radiographic follow-up. Partially or completely erupted third molars were extracted immediately before completing the osteotomy, whereas impacted third molars were removed after the osteotomy had been performed. Hardware reinforcement was performed in bimaxillary cases where concomitant molar extraction impeded placement of the retromolar bicortical screw of the hybrid technique.

RESULTS

A total of 80 surgical sites were included (40 in each group). Concomitant extraction of the molar represented a mean increase in surgery time of 3.7 min (p < 0.001). No additional complications occurred in the test group (p = 0.476). The gain in bone density was preserved in both groups (p = 0.002), and the increase was of the same magnitude in both (p = 0.342), despite the fact that the immediate and final postoperative bone densities were significantly higher in the control group (p = 0.020).

CONCLUSION

The results obtained support concomitant molar extraction with BSSO as a feasible option.

Effectiveness of virtual reality in relieving anxiety and controlling hemodynamics during oral surgery under local anesthesia: A prospective randomized comparative study

It was the aim of the study to evaluate the contribution of a relaxing immersive experience with virtual reality (VR) goggles in reducing patient anxiety related to wisdom tooth extraction under local anesthesia. A prospective randomized comparative study in consecutive patients scheduled for bilateral wisdom tooth extraction under local anesthesia was carried out between March and December 2022. Both sides were operated upon in the same surgery, but on one side VR goggles were applied (VR), while on the other they were not (noVR). Anxiety was evaluated both subjectively (State-Trait Anxiety Inventory [STAI] and visual analogue scale [VAS]) and objectively (measuring heart rate, blood pressure [BP] and blood oxygen saturation) before (T1) and after each surgical step (T2VR and T2noVR). The study sample consisted of 27 patients: 9 men and 18 women, with an average age of 25.8 ± 6.5 years (range: 18-43). Anxiety as assessed by the STAI and VAS decreased from T1 to T2 (p < 0.001 and p < 0.001, respectively), although to a similar degree regardless of whether VR was used or not. Heart rate showed significant differences influenced by RV exposure (p = 0.013): it increased +2.5 ± 8.8 bpm in the control group and decreased -2.22 ± 7.55 bpm with VR (p = 0.013). Both minimum and maximum BP after surgery were significantly higher in the noVR group (p = 0.002 and p = 0.040, respectively). Regarding minimum BP, VR proved more effective among male patients (p = 0.057) and on starting the procedure using VR (p = 0.055). The results provided evidence of meaningful control of the hemodynamic variables, but less predictable performance in the subjective evaluation of anxiety.

Vascular Delay Soft Tissue Technique in Oral/Maxillary Bone Reconstructive Surgery: A Technical Note

PURPOSE

The present study describes a new presurgical soft tissue technique in oral/maxillary bone reconstructive surgery for reducing the risk of soft tissue dehiscence and its related complications.

MATERIALS AND METHODS

Ten consecutive patients with Cawood and Howell type V atrophy were scheduled for CAD/CAM titanium mesh bone reconstructive surgery after applying the vascular delay technique 21 days before regenerative surgery. The surgical and healing complications were clinically assessed at nine time points, ranging from the time of bone regenerative surgery to 9 months after surgery. Surgical complications included flap damage and neurologic and vascular complications. Healing complications were subdivided into four classes. These classes comprised Class I: small membrane exposure (≤ 3 mm) without purulent exudate; Class II: large membrane exposure (> 3 mm) without purulent exudate; Class III: membrane exposure with purulent exudate; and Class IV: abscess formation without membrane.

RESULTS

The study sample included seven men and three women (mean age: 48.2 ± 3.5 years) with seven mandibular cases and three maxillary cases. The defect length ranged from three to six teeth, with a mean mesiodistal distance of 29.9 ± 8.5 mm and a mean volume augmentation of 2.03 ± 0.9 cm3. There were no surgical complications. One patient presented a Class I healing complication that did not affect the regeneration outcome.

CONCLUSIONS

The vascular delay technique appears to reduce the risk of soft tissue dehiscence and exposure in bone regenerative surgery, though randomized studies involving larger samples and longer follow-up periods are needed in order to draw firm conclusions.

Guided Customization and Fixation of Allogenic Cortical Lamina in Alveolar Bone Regeneration. A Case Report

Bone reconstruction surgeries such as the autogenous and allogenic shell techniques where cortical laminates are used to regenerate bone defects, requires time and expertise to adapt and fix the laminated cortical blocks onto the defect area. This case report illustrates the process of customizing and fixing an allogenic cortical laminate (ACL) to reconstruct a horizontal bone defect with guided surgical stents. Two types of surgical stents were designed: one to aid in cutting a prefabricated ACL into the desired shape for the defect to be regenerated, and the other type of stent, was used to assist in the positioning and fixation of the resulting laminates. These stents enabled the clinician to regenerate a horizontal defect with reduced surgical time, increased precision and safety during laminate fixation. After 5 months of healing a dental implant could be placed in the regenerated site. The use of surgical stents in this type of bone regeneration surgeries can be helpful specially in more complex bone defects where precision is key. Further clinical studies are needed to validate this technique.

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.

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.

Three-Dimensional Evaluation of the Accuracy of Zygomatic Implant Placement Through an In-House Fully Guided Approach

Purpose: To validate guided surgery for zygomatic implants (ZIs) by analyzing the final position of the implants relative to the preoperatively planned position. Material and Methods: Five patients with fully edentulous atrophic maxillae treated with four ZIs through a fully guided implant surgical approach were evaluated. The preoperative phase included digital planning, through which the surgical guide was designed and created. Analysis of the guided surgery accuracy was carried out by superimposing the digital planning over the final position of the implants using preoperative and postoperative CBCT. The radiologic evaluation included implant angular deviation, entrance deviation, exit deviation, platform deviation, and apex apicocoronal and mesiodistal deviation. Results: All five patients (two men and three women; mean age: 61.8 ± 3 years) were each treated with four ZIs using a fully guided approach with an extrasinusal path, obtaining ideal emergence of the implants. Superimposition comparison found a mean axial angular implant deviation of 0.79 ± 0.41 degrees and a mean implant entrance deviation of 0.95 ± 0.26 degrees. The platform deviation was 0.62 ± 0.19 mm buccopalatally and 0.76 ± 0.14 mm mesiodistally, while the apical deviation was 0.42 ± 0.13 mm buccopalatally and 1.06 ± 0.37 mm mesiodistally. Conclusions: Guided surgery in zygomatic implants appears to be sufficiently accurate to make it a safe and predictable technique.

Dynamic Implant Surgery-An Accurate Alternative to Stereolithographic Guides-Systematic Review and Meta-Analysis

(1) Background: Dynamic guided surgery is a computer-guided freehand technology that allows highly accurate procedures to be carried out in real time through motion-tracking instruments. The aim of this research was to compare the accuracy between dynamic guided surgery (DGS) and alternative implant guidance methods, namely, static guided surgery (SGS) and freehand (FH). (2) Methods: Searches were conducted in the Cochrane and Medline databases to identify randomized controlled clinical trials (RCTs) and prospective and retrospective case series and to answer the following focused question: "What implant guidance tool is more accurate and secure with regard to implant placement surgery?" The implant deviation coefficient was calculated for four different parameters: coronal and apical horizontal, angular, and vertical deviations. Statistical significance was set at a p-value of 0.05 following application of the eligibility criteria. (3) Results: Twenty-five publications were included in this systematic review. The results show a non-significant weighted mean difference (WMD) between the DGS and the SGS in all of the assessed parameters: coronal (n = 4 WMD = 0.02 mm; p = 0.903), angular (n = 4 WMD = -0.62°; p = 0.085), and apical (n = 3 WMD = 0.08 mm; p = 0.401). In terms of vertical deviation, not enough data were available for a meta-analysis. However, no significant differences were found among the techniques (p = 0.820). The WMD between DGS and FH demonstrated significant differences favoring DGS in three parameters as follows: coronal (n = 3 WMD = -0.66 mm; p =< 0.001), angular (n = 3 WMD = -3.52°; p < 0.001), and apical (n = 2 WMD = -0.73 mm; p =< 0.001). No WMD was observed regarding the vertical deviation analysis, but significant differences were seen among the different techniques (p = 0.038). (4) Conclusions: DGS is a valid alternative treatment achieving similar accuracy to SGS. DGS is also more accurate, secure, and precise than the FH method when transferring the presurgical virtual implant plan to the patient.

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.

Definition of New Three-Dimensional Cephalometric Analysis of Maxillomandibular Sagittal Relationship for Orthodontics and Orthognathic Surgery: Normative Data Based on 700 CBCT Scans

The objective of the study was to define the norm of new 3-dimensional cephalometric analysis of maxillomandibular sagittal relationship with the patient in Natural Head Position. A cross-sectional study was performed using 700 consecutives cone beam computed tomography datasets of pre-orthodontic patients received for three-dimensional craniofacial analysis. To stablish the clinical norm of the new sagittal reference (linear distance A-B), the correlation with the gold standard (ANB angle) was estimated with the Pearson's correlation coefficient. Subsequently, the prognostic values of the linear distance A-B was calculated to define the clinical norm. The sample was composed by 463 women (66.1%) and 237 men (33.9%). The mean age was 30 ± 14,5 years old (range 6-71 y old). According to the skeletal class classification (ANB), 46.1% (323) were class I, 42% (294) class II, and 11.9% (83) class III. The regression model found that each additional grade of the ANB angle imply a mean increase of 1.24 mm of the distance A-B ( P <0.001). The normative value of the linear distance A-B was obtained through the prognostic values of the distance for the limits of the ANB norm 0 to 4. These values were on the range of 0.52 to 5.48 mm. Therefore, the clinical norm for cephalometric maxillomandibular sagittal relationship using linear distance from point A-B is: 3±2.48 mm. With this new approach, we can define the skeletal sagittal relationship of the patient in natural head position overcoming the limitations of using intracranial or occlusal plane references improving the diagnosis and orthognathic surgical planning process.

Narrow diameter titanium-zirconium tissue-level implants supporting multi-unit FDPs in the anterior area: A 5-year prospective study

BACKGROUND

Narrow diameter implants (NDIs) are used in cases of limited mesio-distal space, or if the alveolar ridge does not allow placement of a standard diameter implant.

PURPOSE

The aim of this prospective case series study is to present the 5-year clinical-, radiological-, and patient-reported outcome measures (PROMs) of patients with partial edentulism in the anterior area of the jaws requiring the placement of two narrow diameter implants to support a 3- or 4-unit fixed partial denture (FPD).

MATERIALS AND METHODS

Thirty partially edentulous patients missing 3 or 4 adjacent teeth in the anterior area of the jaws were included in the study. Two titanium-zirconium tissue-level NDIs were placed in each patient in healed anterior sites (60 implants). A conventional loading protocol was performed to provide a FPD. Implant survival, success, marginal bone-level changes (MBL), clinical parameters, buccal bone stability with CBCT, adverse events and PROMs were recorded.

RESULTS

The survival and success rates for the implants were 100%. The mean MBL (±SD) after prosthesis delivery, and 5-year follow-up (mean 58.8 months; range: 36-60) was 0.12 ± 0.22 and 0.52 ± 0.46 mm, respectively. Decementation and screw loosening were the most frequent prosthetic complications, yielding a prosthetic survival and success rates of 100% and 80%, respectively. Patient satisfaction was high with a mean (±SD) score of 89.6 ± 15.1.

CONCLUSIONS

The use of tissue-level titanium-zirconium NDIs supporting splinted multi-unit FPDs in the anterior area seems to be a safe and predictable treatment option after a 5-year follow-up period.

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.

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.

Fat grafting in patients with cleft lip and palate: A systematic review

This systematic review aims to compare different fat-grafting techniques for cleft lip and palate repair. A search was conducted in PubMed, Embase, Cochrane Library, gray literature and reference lists of selected articles. A total of 25 articles were included, 12 on closure of palatal fistula and 13 on cleft lip repair. The rate of complete resolution of palatal fistula ranged from 88.6% to 100% in studies with no control group, whereas in comparative studies patients receiving a fat graft showed better outcomes than those not receiving a graft. Evidence suggests that fat grafting can be indicated for the primary and secondary repair of cleft palate, with good results. The use of dermis-fat grafts in lip repair was associated with gains in surface area (11.5%), vertical height (18.5%-27.11%), and lip projection (20%). Fat infiltration was associated with increased lip volume (6.5%), vermilion show (31.68% ± 24.03%), and lip projection (46.71% ± 31.3%). The available literature suggests that fat grafting is a promising autogenous option for palate and fistula repair and for improvement of lip projection and scar aesthetics in patients with cleft. However, to develop a guideline, further studies are needed to confirm whether one technique is superior to the other.

Accuracy of Orthognathic Surgical Planning using Three-dimensional Virtual Techniques compared with Conventional Two-dimensional Techniques: a Systematic Review

Objectives

The objective was to assess the accuracy of orthognathic surgical planning using three-dimensional virtual planning compared with conventional two-dimensional planning.

Material and Methods

MEDLINE (PubMed), Embase and Cochrane Library search combined with hand-search of relevant journals was conducted to identify randomized controlled trials (RCTs) published in English through August 2^nd, 2022. Primary outcomes included postsurgical accuracy of hard and soft tissue. Secondary outcomes included treatment planning time, intraoperative time, intraoperative blood loss, complications, financial expenses, and patient-reported outcome measures (PROMs). Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool and GRADE system.

Results

Seven RCTs characterised by low, high, and unclear risk of bias fulfilled inclusion criteria. Included studies disclosed conflicting results regarding accuracy of hard and soft tissue as well as treatment planning time. The intraoperative time was shortened, and financial expenses were increased with three-dimensional virtual surgical planning (TVSP), while no planning-related complications were revealed. Comparable improvement in PROMs were reported with TVSP and two-dimensional planning.

Conclusions

Future orthognathic surgical planning will indisputable be performed by three-dimensional virtual planning. The financial expenses, treatment planning time, and intraoperative time will therefore probably decrease due to further development of three-dimensional virtual planning techniques. The hard and soft tissue accuracy between planned position and achieved surgical outcome seems to be improved by three-dimensional virtual planning compared with two-dimensional planning, although results are inconsistent. Further development of three-dimensional virtual planning involving cutting guides and patient-specific osteosynthesis plates are therefore needed to improve the accuracy of orthognathic surgical planning.

Barcelona line. A multicentre validation study of a facial projection reference in orthognathic surgery

The purpose of this study was to validate an already published facial anteroposterior reference: upper incisor (UI) to soft tissue plane or so-called Barcelona line (BL) to trace the most aesthetic sagittal position of the maxilla. A cross-sectional multicentre evaluation of Caucasian patients from Spain and Brazil with different anteroposterior maxillary positions was designed. Sagittal images in natural head orientation of grouped patients according to the horizontal distance from the UI to BL were ranked by healthcare professionals and non-professional Caucasian raters according to the aesthetic perception of each profile, using a digital survey. Seventy-four raters (50 laypeople, 12 orthodontists, and 12 maxillofacial surgeons) rated 40 profiles. The best-rated profile corresponded to group 3 (0-4 mm UI-BL) with 61.8% of positive evaluations, followed by group 4 (≥ 4 mm UI-BL): with 61.1%. On the other hand, group 1 (≤-4 mm UI-BL) was the worst-ranked profile with 71.8% of negative evaluations, followed by group 2 (-4-0 mm UI-BL): with 59.6% of negative evaluations. The correlation between the mean assessment score and UI-BL showed a moderately-strong association (r = 0.68, p < 0.001). The inter-rater reliability of assessment (74 evaluators) was moderate (k = 0.49, 95% CI: 0.39 to 0.59). The results suggest that protrusive middle-third facial profiles are preferable. The BL is proposed as a simple, individualised, and reproducible tool to trace an aesthetic sagittal position of the maxilla in orthognathic surgery.

Accuracy of dynamic implant navigation surgery performed by a novice operator

AIM

The main objective was to evaluate the accuracy of dynamic navigation-guided surgery (DNGS) for implant positioning performed by a novice operator. The secondary objectives were to analyze the operator's learning curve and identify possible complications deriving from the technique.

MATERIALS AND METHODS

Twenty-five implants were placed in eight partially edentulous human heads. Preoperative CBCT scans were imported to planning software to determine the implant positions. Implants were placed using a dynamic navigation system. Postoperative CBCTs were superimposed onto the implant planning images. Discrepancies between the virtually planned implant positions and the postoperative positions were evaluated by measuring horizontal platform deviation, apex deviation, apicocoronal (vertical) deviation, and angular deviation.

RESULTS

Mean platform, apex, vertical, and angle deviations were 1.55 ± 0.81 mm, 2.45 ± 0.84 mm, 1.59 ± 0.70 mm, and 5.56 ± 4.03 degrees, respectively. No significant differences were found between the maxilla and mandible or between anterior and posterior sites. A flat learning curve was observed, with the exception of the implant platform, where a tendency toward improvement in accuracy was observed between the 8th and the 17th implant placed. No complications were reported.

CONCLUSIONS

Based on the results of a study performed by a novice operator on a cadaveric model, DNGS allows accurate implant placement within a 2-mm safety margin in terms of implant platform and vertical positions, and a 3-mm margin in apical vicinities. The technique requires practice to learn the required eye-hand coordination. (Int J Comput Dent 2022;25(4):377-0; doi: 10.3290/j.ijcd.b2588207).

‘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.

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.

Clinical Evidence on a Novel Macrohybrid Design Dental Implant with 12° Angled Platform: A Systematic Review

Background: Immediate implant placement with immediate esthetics has become a more common procedure over time, though ensuring good emergence of the axis of the implant has been a challenge. A novel macroimplant design with an angled platform (Co-Axis^®) has been developed to ensure exit of the head of the implant in the correct prosthetic position. A systematic literature review was carried to determine the survival rate and marginal bone loss associated with these implants. Material and Methods: An electronic and manual literature search was made in accordance with the PRISMA statement. The search strategy was limited to human studies, retrospective and prospective clinical trials, cross-sectional studies, and cohort studies reporting outcomes of a novel macrohybrid implant with a 12° angled implant connection. Results: Three articles met the inclusion criteria and were reviewed in the analysis. The estimated success rate was 95.9%. The global marginal bone loss was estimated to be −0.17 ± 0.58 mm in an environment characterized by great heterogeneity (I² = 99%). The estimated mean implant stability was 69.6 ± 0.92 (ISQ). As only two studies provided the required information, it was not possible to determine publication bias. Lastly, mean recession was estimated to be practically zero (0.06 ± 0.23 mm), with great heterogeneity. Conclusions: Within the limitations of this systematic review, it can be affirmed that immediate implant treatment with Co-Axis^® implants shows a survival rate of 95.9% at one year of follow-up, with low marginal bone loss values, near-zero soft tissue recession, and favorable papilla index values. Nevertheless, the great heterogeneity of the data requires the findings to be interpreted with caution.

Computed tomography imaging superimposition protocols to assess outcomes in orthognathic surgery: a systematic review with comprehensive recommendations

OBJECTIVES

A systematic review was performed to analyze the current evidence on three-dimensional (3D) computed tomography (CT) superimposition protocols used to assess dentomaxillofacial changes after orthognathic and orthofacial surgery. Accuracy, reproducibility, and efficiency were evaluated.

METHODS

The search was divided into Main Search (PubMed, EMBASE, Cochrane Library, LILACS, and SciELO), Grey Literature search (Google Scholar and Open Grey), and Manual search. Thirteen studies were included. Of these, 10 reported data on accuracy, 10 on reproducibility and five on efficiency. Seven proposed or evaluated methods of voxel-based superimposition, three focused on the surface-based technique, one compared surface- and voxel-based superimposition protocols, one used the maximum mutual information algorithm, and one described a landmark-based superimposition method. Cone-beam computed tomography (CBCT) was the most common imaging technique, being used in 10 studies.

RESULTS

The accuracy of most methods was high, showing mean differences smaller than voxels' dimensions, ranging between 0.05 and 1.76 mm for translational accuracy, and 0.10-1.09° for rotational accuracy. The overall reproducibility was considered good as demonstrated by the small mean error (range: 0.01-0.26 mm) and high correlation coefficients (range: 0.53-1.00). Timing to complete virtual superimposition techniques ranged between a few seconds up to 40 min.

CONCLUSIONS

Voxel-based superimposition protocols presented the highest accuracy and reproducibility. Moreover, superimposition protocols that used automated processes and involved only one software were the most efficient.

Extramaxillary Zygomatic Implant Coverage with a Pedicled Buccal Fat Pad Flap Through a Tunnel Approach: A Prospective Case Series

PURPOSE

To describe the benefits of covering the extrasinusal length of extramaxillary zygomatic implants with a pedicled buccal fat pad flap through a tunnel approach.

MATERIALS AND METHODS

Four extramaxillary zygomatic implants were placed in 10 patients and loaded immediately with an acrylic provisional fixed prosthesis. The extrasinusal length of every implant was covered with a pedicled buccal fat pad flap. Study variables were implant survival rate, peri-implant soft tissue recession (PISTR), peri-implant soft tissue condition (PISTC), modified Bleeding Index (mBI), and suppuration. The statistical analysis comprised the Brunner-Langer model of longitudinal data for each variable and the analysis of variance to assess main effects and interactions.

RESULTS

All the zygomatic implants showed osseointegration, resulting in a survival rate of 100%. The PISTR was evaluated after surgery (T0) and after 12 months (T1), statistically significant differences being observed (P = .014). Recession also depended on specific implant positioning; zygomatic implants in the anterior were found to have a higher risk of recession vs implants in the posterior (P = .065). The PISTC was assessed at T0 and T1, and no statistically significant changes were observed (P = .718). Bleeding on probing was present in 10% of the implants at T0 and in 15% at T1, the difference being nonsignificant (P = .317).

CONCLUSION

The use of a pedicled buccal fat pad flap to cover the extrasinusal length of extramaxillary zygomatic implants appears to reduce the risk of soft tissue recession and exposure of the implant surface to the oral cavity.

Usefulness of the subepithelial connective tissue pedicled palatal flap in alveolar reconstruction: A report of case series

The purpose of this case series report was to describe the subepithelial connective tissue pedicled palatal flap technique, its indications, and its efficacy in closure of alveolar ridge reconstruction. The present case series consisted of all 11 consecutive subjects who underwent a ridge augmentation with biomaterials or with bone grafts. Furthermore, in other cases were placed immediate or delayed implants. All cases were closed with a subepithelial connective tissue pedicled palatal flap reconstruction in our private dental clinic between 2014 and 2020. The main advantages of this flap are that the donor site remains primarily covered, the soft tissue volume at the recipient site is increased, and there is good integration of the graft because the blood supply of the flap comes directly from the base of the pedicle. All cases exhibited an increase in soft tissue height and width after 6 months and primary closure was successful. This case series suggests that the subepithelial connective tissue pedicled palatal flap may be useful for moderate vertical and horizontal augmentation in the recipient site.

The Screen Technique for Safe Bone Regeneration of Noncontained Defects: A Novel Technique

Healing complications in guided bone regeneration (GBR) can be frequent when nonresorbable membranes are used. Exposure of dense polytetrafluoroethylene (d-PTFE) membranes to the oral cavity are usually located close to the incision line due to a lack of tension-free flap closure. This case report presents a safe, novel technique that uses d-PTFE membranes placed on the missing buccal and palatal bone walls without covering the coronal aspect of the regeneration. Therefore, these membranes can be kept away from the incision line to minimize the risk of exposure. The coronal part is then covered with a resorbable membrane. A clinical case is presented, using this novel technique to three-dimensionally reconstruct noncontained defects in the maxilla. This technique is safe and effective in regenerating these defects; after 8 months of healing, three implants could be placed with proper primary stability. Further, histologic and histomorphometric analyses revealed functional bone with areas of new bone formation. However, more long-term studies are required to validate this technique.

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.

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.

Key words:Guided surgery, dynamic navigation, dynamic guided surgery, computer assisted surgery.

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.

Mid-Term outcomes and periodontal prognostic factors Of autotransplanted third molars: A Retrospective Cohort Study

BACKGROUND

Tooth autotransplantation is a valid method for replacing non-restorable teeth. This study aimed to assess mid-term survival and success of autotransplanted third molars and the clinical periodontal parameters and factors predicting successful periodontal attachment apparatus regeneration.

METHODS

In total, 36 patients who had undergone extraction and subsequent autotransplantation of 36 third molars using virtual planning and computer-aided rapid prototyping models by an oral surgeon and endodontist were eligible. Probing pocket depth (PPD), gingival recession (REC), clinical attachment level (CAL), pulpal and periapical healing, root resorption, and radiographic bone loss (RBL) were evaluated. Additionally, a questionnaire evaluated patient-reported outcomes.

RESULTS

The mean age of the participants was 30.2 years with a mean follow-up duration of 29.42 ± 14.56 months. The overall survival and success rates were 97.2% and 91.7%, respectively. No statistically significant differences were found in success and survival rates between open and closed apex groups or between compromised and intact buccal bone groups. No signs of pulp necrosis were found in the open apex group. Progressive replacement resorption was detected in one closed apex case. The mean PPD was 2.7 ± 0.45 mm for all transplanted teeth. REC was 0.13 mm higher in transplanted teeth than in previous hopeless teeth. CAL changes were neither clinically relevant (-0.17 ± 0.66 mm) nor statistically significant. The reported patient satisfaction was high.

CONCLUSIONS

Autotransplantation of third molars is a predictable treatment method, with a 2.5-year cumulative tooth survival and success of 97.2% and 91.7%, respectively, which were not influenced by recipient site integrity or root development.

Intra-osseous heat generation during implant bed preparation with static navigation: Multi-factor in vitro study

OBJECTIVES

To compare the intra-osseous temperature reached during bone drilling for dental implant placement using open versus closed static surgical guides and evaluate the influence of bone density, osteotomy drilling depth, and irrigation fluid temperature.

MATERIAL AND METHODS

960 osteotomies were performed with 2 mm pilot drills in 16 solid rigid polyurethane foam blocks. Two main variables were considered: the guide type (open or closed guide) and bone density (hard (D1) or soft (D4). The blocks were divided into four groups according to the type of surgical template and bone density as follows: group one: closed guide and hard bone; group two: open guide and hard bone; group three: closed guide and soft bone; and group four: open guide and soft bone. A combination of different experimental conditions was used, including different bone osteotomy depths (6 or 13 mm) and irrigation fluid temperatures (5°C or 21°C).

RESULTS

The highest mean temperature was found in group one (28.29 ± 4.02°C). In the soft bone groups (three and four), the mean maximum temperature decreased compared to groups one and two (dense bone) and was always higher with closed guides (23.38 ± 1.92°C) compared to open guides (21.97 ± 1.22°C) (p < .001). The osteotomy depth and irrigation fluid temperature also significantly influenced the bone temperature (p < .001), especially in hard bone.

CONCLUSIONS

The greatest heat generation was observed in high-density bone. The final intra-bone temperature was about 1°C higher with a closed static surgical guide than with an open guide. The heat generation in osteotomy sites was substantially reduced by cooling the irrigation fluid to 5°C.

Improving accuracy of the intermediate splint in substantial intermaxillary sagittal discrepancies using an extra anterior anchorage point: technical note

Background

To describe a technical feature that increases the stability of the intermediate splint in patients where bimaxillary surgery with great maxillary/mandibular advancements are planned.

Material and Methods

Prospective evaluation of the intermediate splint dental vertical penetration in patients undergoing bimaxillary surgery where great sagittal discrepancy occur in the anterior sector between the upper and lower jaws when the intermediate splint is placed by adding an extra intermaxillary fixation (IMF) screw (2x9 mm) placed between the central incisors of the maxilla and fixed to the most anterior aspect of the intermediate splint following the direction of the sagittal maxillo-mandibular discrepancy from January to September 2018.

Results

The postoperative evaluation comparing the accuracy of conventional fixation versus fixation with an extra anterior anchorage point through photographic assessment and intraoral digital scanner demonstrated better dental penetration, and therefore improved intermediate splint precision with the latter in all cases

Conclusions

Our results suggest that this is a simple and safe technique that can be easily reproduced and optimizes the outcomes by increasing the accuracy of translation of the planned surgical movements to the operating room.

Key words:Orthognathic surgery, intermediate splint, accuracy, intermaxillary fixation, bone screw.

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.

Immediate implant placement in molar extraction sockets: a systematic review and meta-analysis

Background

Immediate implants are frequently employed in the anterior maxillary area. However, the installation of dental implants simultaneously with tooth extraction can also provide with benefits in the posterior areas with a reduction in time prior the recovery of the masticatory function. Results previously reported in the literature show high-survival and success rates for implants placed in extraction sockets in molar areas; however, this topic has received limited systematic analysis.

Material and methods

Electronic and manual literature searches were performed by two independent reviewers in several data-bases, including MEDLINE, EMBASE, and Cochrane Oral Health Group Trials Register, for articles up to January 2019 reporting outcomes of immediate implants placed in molar areas. Primary outcomes included survival and success rates, as well as marginal bone loss. Secondary outcomes included the influence of implant position, type of implant connection, grafting protocol, flap or flapless approach, implant diameter, surgical phase, presence of buccal plate, and loading protocol.

Results

Twenty studies provided information on the survival rate, with a total sample of 1.106 implants. The weighted mean survival rate of immediate implants after 1 year of follow-up was 96.6%, and the success rate was 93.3%. On the other hand, marginal bone loss was 1.29 ± 0.24 mm. Secondary outcomes demonstrated that grafting the gap and the loading protocol have an effect on survival and success rates. Similarly, the presence or absence of the buccal bone affect crestal bone levels. Meta-analysis of 4 investigations showed a weighted mean difference of 0.31 mm ± 0.8 IC 95% (0.15–0.46) more marginal bone loss at immediate implant placement versus implants in healed sites (p < 0.001) I² = 15.2%.

Conclusion

In selected scenarios, immediate implant placement in molar extraction socket might be considered a predictable technique as demonstrated by a high survival and success rates, with minimal marginal bone loss.

Interpositional collagenated cancellous bone blocks for nasal dorsum augmentation: A new technique for nasomaxillary hypoplasia treatment

Nasomaxillary hypoplasia is a rare congenital malformation involving the middle third of the face. The present paper describes a novel technique for restoring the nasal projection in a patient with nasomaxillary hypoplasia, analyses its advantages and limitations, and discusses its potential applicability in other similar contexts. After orthognathic surgery, lateral osteotomies of the nasal bones were performed integrally with a piezoelectric device using a long cutting saw tip through the intraoral approach. The nasal bones were then projected by interpositioning two triangular-shaped collagenated cancellous bone graft blocks on each side in the osteotomies between the nasal and the frontal processes of the maxillary bones. Cone-beam computed tomography (CBCT) data was used to perform a morphometric analysis at one and 12 months of follow-up through image superimposition, which revealed a stable increased projection of the nasal dorsum and an anterior nasal spine (ANS) of 5.18 mm and 5.52 mm, respectively. The results of this case suggest that the technique affords satisfactory nasal dorsum augmentation while avoiding the use of permanent foreign materials, with minimal morbidity, no unsightly and visible scars, great patient satisfaction, and adequate stability at 12 months of follow-up.

Evaluation of Peri-implant Tissue Stability and Patient Satisfaction After Immediate Implant Placement in the Esthetic Area: A 3-Year Follow-up of an Ongoing Prospective Study

Horizontal and vertical reduction of the ridge has to be expected after tooth extraction. Immediate implant placement and provisionalization is a viable treatment option that can help to minimize those changes. Additionally, it can better meet a patient's expectations about the treatment, reducing time and invasiveness. The aim of this prospective study is to evaluate the stability of the hard and soft tissues surrounding single immediate implants placed in the esthetic zone, as well as evaluating patient satisfaction. A total of 16 implants were placed, and 15 could be evaluated at the 3-year follow-up. Radiographic and clinical data was recorded after this period. Some marginal bone level reduction was detected after 3 years but was not statistically significant. The soft tissues, measured at 3 points, showed stability and even better positions with respect to the day of the final restoration placement. Patient satisfaction was analyzed using the modified Oral Health Impact Profile questionnaire (OHIP-14), and high satisfaction values were reported. The implementation of a precise surgical and prosthetic protocol when an immediate implant is placed into a fresh extraction socket is likely to result in high survival and success rates combined with excellent patient satisfaction. After the 3-year follow-up, favorable results were present.

Volumetric changes in alveolar ridge preservation with a compromised buccal wall: a systematic review and meta-analysis

Background

Many studies have addressed socket preservation, though fewer publications considering buccal wall loss can be found, since the literature typically considers sockets with four walls. A systematic review was made on the influence of type II buccal bone defects, according to Elian’s Classification, in socket grafting materials upon volumetric changes in width and height.

Material and Methods

An electronic and manual literature search was conducted in accordance to PRISMA statement. The search strategy was restricted to randomized controlled trials (RCTs) and controlled clinical trials (CCTs) describing post-extraction sockets with loss of buccal wall in which alveolar ridge preservation (ARP) was carried out in the test group and spontaneous healing of the socket (SH) was considered in the control group.

Results

The search strategy yielded 7 studies. The meta-analysis showed an additional bone loss of 2.37 mm in width (p > 0.001) and of 1.10 mm in height (p > 0.001) in the absence of ARP. The reconstruction of the vestibular wall was not evaluated in any study. The results also showed moderate to great heterogeneity among the included studies in terms of the changes in width and height.

Conclusions

Despite the heterogeneity of the included studies, the results indicate a benefit of ARP versus SH. Further studies are needed to determine the volumetric changes that occur when performing ARP in the presence of a buccal bone wall defect.

Key words:Alveolar ridge preservation, buccal wall defect, volumetric changes, bone loss, meta-analysis.

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.

Minimally invasive intraoral proportional condylectomy with a three-dimensionally printed cutting guide

The aim of this study was to describe the steps of a minimally invasive surgical technique used to perform a proportional intraoral condylectomy with a three-dimensionally (3D) printed cutting guide. The technique consists of two steps: virtual surgical planning and intraoral condylectomy. During virtual surgical planning, the mandibular ramus was measured bilaterally, the height of the proportional condylectomy was planned virtually, and a cutting guide was 3D printed. In the intraoral condylectomy, the mandibular condyle was approached intraorally, the 3D printed cutting guide was positioned in the sigmoid notch, and the proportional condylectomy was performed. The protocol reported in this technical note is the sum of knowledge acquired from a series of studies published previously by the authors, who have jointly developed a surgical technique that is both minimally invasive and accurate for the treatment of condylar hyperplasia.

Influence of bone density, drill diameter, drilling speed, and irrigation on temperature changes during implant osteotomies: an in vitro study

OBJECTIVE

The aim of this in vitro study was to evaluate the influence of bone type, drill diameter, drilling speed, and irrigation on heat generation while performing osteotomy for dental implants.

MATERIALS AND METHODS

Six polyurethane foam blocks simulating type I (dense) and type IV (soft) bone were selected for the study. Each block was subjected to two different experimental conditions for each drill (2- and 3.5-mm diameter): three sub-groups were created: (a) revolutions per minute (50, 100, or 800 rpm) and (b) irrigation (with or without irrigation).

RESULTS

In 2-mm drill group, maximum temperature attained was practically identical: 23.73 ± 2.28 °C in the cortical bone and 23.74 ± 2.03 °C in the cancellous bone. For 3.5-mm, groups showed similar results (25.01 ± 1.88 °C for cortical and 24.05 ± 1.94 °C for trabecular bone). In any type of bone, the presence of irrigating fluid helped to control the maximum temperature (p = 0.001). When comparing the 2-mm and 3.5-mm drills, most differences were found at 100 rpm without irrigation (p < 0.001) and at 800 rpm with irrigation (p = 0.001).

CONCLUSIONS

Maximum temperature attained was always below the critical threshold that can cause osteonecrosis, showing that both external irrigation with higher drilling speeds and no irrigation with lower speeds were effective methods to avoid excessive heat generation.

CLINICAL RELEVANCE

Despite being always below the critical temperature, bone type, drill diameter, drilling speed, and irrigation must be considered temperature-influencing factors during implant osteotomies.

Short implants (<8mm) versus longer implants (≥8mm) with lateral sinus floor augmentation in posterior atrophic maxilla: A meta-analysis of RCT`s in humans

BACKGROUND

One of the greatest challenges that dentists face today is to rehabilitate severe atrophied alveolar ridges in partially and completely edentulous patients with implants. Despite the high survival rate of implants placed next to sinus elevation, this technique presents complications that can be avoided by placing short implants, an option that also presents high survival rates. For this reason, the aim of this study is to compare the survival rate, marginal bone loss and complications associated with short implants (<8 mm) versus longer implants (≥8mm) placed with lateral sinus floor elevation in posterior atrophic maxillae.

MATERIAL AND METHODS

A literature search was conducted by two independent reviewers in the PubMed/Medline (National Library of Medicine, Washington, DC) electronic database for articles published from January 2007 to July 2018. Seven qualified articles were selected for the meta-analysis.

RESULTS

The test for overall effect did not find statistical significance in the survival rates, overall complications, intra-operative complications, post-operative complications and prosthetic complications. However, the test showed statistically significant differences in biological complications in favor of standard implants, and marginal bone loss between control and test groups in favor of short implants (<8mm) was found.

CONCLUSIONS

Within the limitations of the present study, prosthetic rehabilitations with short implants (<8mm) in posterior maxilla is a reliable treatment option as an alternative to lateral wall sinus floor augmentation.

Relevance of 3D virtual planning in predicting bony interferences between distal and proximal fragments after sagittal split osteotomy

After sagittal split osteotomy, the mandibular distal and proximal fragments do not always align themselves passively to one another, resulting in bony interferences and subsequent anomalous settlement of the condyles. Predicting these interferences could be an important ancillary procedure for avoiding intra- and postoperative surgical complications, rendering orthognathic surgery more effective and safer. This study evaluated the relevance of virtual surgical planning in assessing the displacement of the proximal segments after virtual distal segment repositioning, for predicting bony interferences between the segments and thus avoiding related intra- and postoperative surgical complications. The presence of interferences between the distal and proximal segments was compared between virtually predicted (computer-assisted simulation surgery, Dolphin software) and real cases in 100 consecutive patients diagnosed with dentofacial deformities who underwent orthognathic surgery with mandibular repositioning (using a short lingual osteotomy (SLO)). The results indicated that clockwise rotation of the mandible was the mandibular movement most prone to segment interference. Furthermore, virtual planning was sensitive (100%) but had low specificity (51.6%) in predicting proximal and distal segment interferences. This low specificity was due to the software-based automated design of the mandibular osteotomy, where the length of the distal segment was longer than the real SLO, and the mandibular ramus sagittal split was located just behind Spix's spine. Thus, more precise simulated osteotomies are needed to further validate the accuracy of virtual planning for this purpose.