On the use of intraoperative 3D-RX C-arm imaging in orthognathic surgery: a prospective non-consecutive case series study.

CONTEXT: Segment and osteosynthesis malposition resulting in patients' complaints (mainly about asymmetries) are encountered in orthofacial/orthognathic surgery. OBJECTIVE, DESIGN, AND SETTING: We planned to investigate the usefulness of intraoperative three-dimensional (3D) imaging concerning positioning and fixation of bone segments and osteosynthesis in orthognathic/orthofacial surgery. We performed a prospective study of non-consecutive cases. All patients receiving a bimaxillary osteotomy, genioplasty, and their combinations were included in the study from May 2016 to May 2020. Unilateral and bilateral sagittal split osteotomies were excluded. There were no gender and age limitations. All were intraoperatively examined using the BV Pulsera 3D-RX System (Philips Medical, Eindhoven, The Netherlands). The outcome variables were the percentage of revisions of segment positioning and osteosynthesis. Predictor variables were age, gender, type of surgery, timing (pre- and post-imaging), and surgeon experience (senior vs assistant). RESULTS: Forty female and twenty-two male patients were included (mean age 25.25 years ± 7.52 and 29.1 years ± 12.6 respectively). We evaluated 27 genioplasties and 34 Le Fort "type-I" osteotomies. Indications for segment repositioning and redo-osteosynthesis increased after intraoperative imaging as compared to operator's clinical judgment before intraoperative imaging (95% confidence interval; p < .001 and p = .002 respectively). CONCLUSION: Suboptimal positioning and fixation of bone segments or osteosynthesis were more apparent with 3D imaging. In addition, some satisfactory cases were also revised for an optimal outcome. As a result, surgeons were prompted to more revisions than judged necessary without intraoperative imaging.

Surface wear in a custom manufactured temporomandibular joint prosthesis.

The wear of a novel temporomandibular joint (TMJ) prosthesis was evaluated in an animal model. The prosthesis consisted of an additively manufactured titanium alloy (Ti6 Al4 V) mandibular condyle and glenoid fossa created through selective laser melting, with a machined vitamin E-enriched ultra-high molecular weight polyethylene (UHMWPE) surface attached to the fossa. Thirteen TMJ prosthesis were implanted in sheep, six of which had condylar heads coated with HadSat® diamond-like carbon (H-DLC). Euthanasia took place after 288 days, equaling 22 years of human mastication. Linear and volumetric wear analysis of the fossa was performed by optical scanning. The condylar head surfaces were assessed by scanning electron and confocal laser microscopy. The average linear UHMWPE wear, when combined with the coated condyle, was 0.67 ± 0.28 mm (range: 0.34-1.15 mm), not significantly differing (p = .3765, t-test) from the non-coated combination average (0.88 ± 0.41 mm; range: 0.28-1.48 mm). The respective mean volumetric wear volumes were 25.29 ± 11.43 mm3 and 45.85 ± 22.01 mm3 , not significantly differing (p = .1448, t-test). Analysis of the coated condylar surface produced a mean Ra of 0.12 ± 0.04 µm and Sa of 0.69 ± 0.07 µm. The non-coated condylar surface measured a mean Ra of 0.28 ± 0.17 µm and Sa of 2.40 ± 2.08 µm. Both Sa (p = .0083, Mann-Whitney U test) and Ra (p = .0182, Mann-Whitney U test), differed significantly. The prosthesis exhibits acceptable wear resistance and addition of the H-DLC-coating significantly improved long-term condylar surface smoothness.

Lateral pterygoid muscle enthesis reconstruction in total temporomandibular joint replacement: An animal experiment with radiological correlation.

A novel total temporomandibular joint replacement (TMJR) was developed with CADskills BV (Ghent, Belgium), aiming to achieve reinsertion of the (LPM) onto a scaffold in the implant. In order to investigate the possibility of reinsertion of the LPM, an animal experiment was conducted. An in vivo sheep experiment was conducted, which involved implanting sheep with a TMJR. Clinical parameters were recorded regularly and computed tomography (CT) scan images of two randomly selected sheep per scan were made at 1, 3, and 6 months. After 9.5 months, the sheep were euthanized, and CT scans of all animals were performed in order to evaluate the LPM's enthesis. A total of 13 sheep were implanted with a TMJR. One sheep was used as a sham. Radiographs revealed four outcome types of enthesis reconstruction. In four sheep, there was no reconstruction between the implant and the LPM. In three sheep, there was a purely soft tissue connection of 0.5-0.9 mm (average 0.7 mm) between the ostectomized bony LPM insertion and the implant's lattice structure. A combination of partial bony and partial soft tissue enthesis attachment (0.3-0.5 mm, average 0.4 mm) was found in three sheep. A bony ingrowth of the enthesis into the scaffold occurred in two sheep. A secondary bony connection between the mandible and the insertion of the LPM was found in 10 of 13 sheep. Four fossa components were found to be displaced, yet TMJ function remained in these ewes. The heterotopic ossification that was seen may be a confounding factor in these results. This in vivo experiment showed promising results for improving the current approach to TMJR with the possibility of restoring the laterotrusive function. The fossa displacement was considered to be due to insufficient fixation and predominant laterotrusive force not allowing for proper osseointegration. Further optimization of the reattachment technique, scaffold position and surface area should be done, as well as trials in humans to evaluate the effect of proper revalidation.

Extended Total Temporomandibular Joint Replacement with Occlusal Adjustments: Pitfalls, Patient-reported Outcomes, Subclassification, and a New Paradigm.

CONTEXT: Alloplastic temporomandibular joint (TMJ) replacement is a treatment strategy for segmental mandibular defects with occlusal abnormalities. AIMS: To describe our experience with extended total TMJ replacement (eTMJR) by reporting operative obstacles, complications, and patient-reported outcomes, as well as to suggest a subclassification system and paradigm shift. SETTING AND DESIGN: University hospital and private clinic; case series with retrospective follow-up. METHODS AND MATERIALS: Five patients (6 eTMJRs) were followed for more than 1 year after surgery. Patient-reported outcomes were assessed using FACE-Q™ "Satisfaction with Outcome" questionnaires (sum and corresponding transformed Rasch scores). STATISTICAL ANALYSIS: Descriptive analyses were performed. RESULTS: Problems were related to contralateral mandibular osteotomy healing (if performed), keying the prosthetic condyle into the fossa component, intra- and postoperative prosthetic lag, and intraoperative proper establishment of the occlusion when unilateral replacement was performed. Patients reported high satisfaction with the outcome, with a mean Rasch score of 89.2/100. CONCLUSIONS: Unilateral eTMJR obstacles related to three-dimensional rotational repositioning of the remaining mandible. We suggest a paradigm shift, considering primary alloplastic replacement instead of microvascular osseous transplantation for reconstruction when radiotherapy is not required. This can avoid donor site morbidity and long reconstructive surgery. An autologous osseous transplant is still available in case of implant failure. A subclassification system is proposed for eTMJR, which accounts for contour corrections, occlusal adjustments, and simultaneous contralateral mandibular osteotomy.

Total Temporomandibular Joint Replacement: Stick to Stock or Optimization by Customization?

PURPOSE: This article aims to compare the difference in postoperative results in patients treated with either a patient-specific (PSI) or a stock temporomandibular total joint replacement system. MATERIALS AND METHODS: The investigators performed a systematic review concerning postoperative results after placement of either a stock total joint replacement system or a PSI. PubMed Central, Web of Science, Cochrane Library Plus, Wiley Online Library, and EMBASE were used to conduct this search. All articles up to August 15, 2018, were scrutinized. All included articles were nonrandomized cohort studies. Maximal mouth opening (MMO) and Visual Analog Scale (VAS) scores for pain and diet before and after surgery were evaluated. The Methodological Index for NonRandomized Studies scale was used for quality assessment. Weighted mean difference was calculated and pooled by meta-analysis using random-effect models. RESULTS: The search identified 1581 articles, of which 15 were included. The average risk of bias was low. Both systems achieved significant increases in MMO and decreased VAS pain scores at 1, 2, and 3 years after surgery. No significant difference was found between the system types. Both achieved significant improvements in dietary VAS scores, with a more significant improvement for stock implants. CONCLUSIONS: Due to the lack of detailed diagnostic evaluation tools allowing proper start-point categorization, there is a significant risk for selection bias in the pooled data. The PSI is more frequently chosen for cases with more significant joint degeneration, skewing postoperative results. A patient-fitted implant can provide significant operative and patient-centered advantages over a stock implant, which will likely be confirmed when observational cohort studies have included indications like the ones for stock prostheses. Furthermore, while current US Food and Drug Administration-approved stock implants contain cobalt -chromium -molybdenum, the newly manufactured PSI are made of titanium alloy, diminishing the risks of morbidity and implant failure.

Postoperative Physiotherapy After Open Temporomandibular Joint Surgery: A 3-Step Program.

PURPOSE: This study aimed to ascertain the value of postoperative physiotherapy after open temporomandibular joint (TMJ) surgery and provide a usable approach for practitioners. MATERIALS AND METHODS: The authors performed a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines of literature concerning the results of postoperative physiotherapy after open TMJ surgery to evaluate its effect on rehabilitation. PubMed Central, Web of Science, Cochrane Library Plus, CINAHL, and EMBASE were used to conduct this search and all articles up to April 1, 2018 (total, 675 articles) were included. Risk of bias in nonrandomized controlled trials (non-RCTs) and other observational studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS) scale. The Cochrane Collaboration's tool was used for evaluating RCTs. Maximal mouth opening (MMO) before and after surgery was evaluated, as was the physiotherapeutic protocol used during the postoperative period. Evaluation of lateral movement and pain also was included, if this information was provided. RESULTS: Initially, 675 articles were found, 6 of which were included after screening. Risk of bias was found to be unclear in the included RCTs and rather high in comparative and noncomparative articles. Three studies concluded that patients who received postoperative physiotherapy had a significantly larger increase in MMO (P < .05) compared with patients who did not receive any postoperative physiotherapy. No difference in lateral movement was found (P > .05). Mean visual analog scale pain score was significantly lower in patients who were treated with physiotherapy according to 2 of the included articles (P < .05). CONCLUSIONS: Based on the current scientific literature included in this systematic review, it can be concluded physiotherapy after open TMJ surgery plays an important role in achieving good postoperative results. The authors provide a scheme for its effective use.

Autologous Fat Grafting in Total Temporomandibular Joint Replacement Surgery.

CONTEXT: Alloplastic temporomandibular joint replacement. AIMS: To search for evidence for the use of periprosthetic autologous fat transplantation. SETTING AND DESIGN: Systematic review. MATERIALS AND METHODS: We searched in PubMed Central, Elsevier ScienceDirect Complete, Wiley Online Library Journals, Ovid Lippincott Williams and Wilkins, and Cochrane Library plus Results. Six studies reported improved results with the use of autologous fat graft (AFG) in patients treated with a total joint replacement, mainly about increased mobility. Three studies involved patients from the same surgeon with increased inclusions and increased follow-up period. A 1997 study by Wolford showed a significant difference in heterotopic bone formation between patients treated with AFG, compared to those who were not, indicating the potential and usefulness of AFG. CONCLUSION: A prospective multicenter randomized controlled trial of this promising concept is warranted before justifying common application because of the added morbidity and the questionable advantage.