New method for analysing spatial relationships of facial muscles on MRI: a pilot study

Dysfunction of the facial musculature can have significant physical, social, and psychological consequences. In surgeries such as cleft surgery or craniofacial bimaxillary osteotomies, the perioral facial muscles may be detached or severed, potentially altering their functional vectors and mimicry capabilities. Ensuring correct reconstruction and maintenance of anatomical sites and muscle vectors is crucial in these procedures. However, a standardized method for perioperative assessment of the facial musculature and function is currently lacking. The aim of this study was to develop a workflow to analyse the three-dimensional vectors of the facial musculature using magnetic resonance imaging (MRI) scans. A protocol for localizing the origins and insertions of these muscles was established. The protocol was implemented using the 3DMedX computer program and tested on 7 Tesla MRI scans obtained from 10 healthy volunteers. Inter- and intra-observer variability were assessed to validate the protocol. The absolute intra-observer variability was 2.6 mm (standard deviation 2.0 mm), and absolute inter-observer variability was 2.6 mm (standard deviation 1.5 mm). This study presents a reliable and reproducible method for analysing the spatial relationships and functional significance of the facial muscles. The workflow developed facilitates perioperative assessment of the facial musculature, potentially aiding clinicians in surgical planning and potentially enhancing the outcomes of midface surgery.

Anatomical position of the mandibular condyle after open versus closed treatment of unilateral fractures: A three-dimensional analysis

This study aimed to compare open and closed treatment for unilateral mandibular condyle neck and base fractures by final three-dimensional (3D) condylar position at 6 months follow-up. 3D position was associated with mandibular functioning and pain. A total of 21 patients received open (n = 11) or closed (n = 10) treatment. 3D positions were assessed on cone-beam computed tomography scans. Volume differences, root mean square, translations, and rotations were obtained related to the pursued anatomical position and compared between treatment groups by the Mann-Whitney U test. The 3D position parameters were associated with the maximum interincisal opening (MIO), mixing ability test (MAT), Mandibular Function Impairment Questionnaire (MFIQ), and pain based on Spearman correlation coefficients (rs). Translation in the medial-lateral direction was smaller after open treatment (P = 0.014). 3D position was not associated with the MAT; however, worse position was associated with a smaller MIO. A larger pitch rotation was associated with a worse MFIQ (rs = 0.499, P = 0.025). Volume reduction of the affected condyle was associated with more pain (rs = -0.503, P = 0.020). In conclusion, after unilateral condylar fractures, worse 3D position is associated with a smaller mouth opening and worse patient-reported outcomes. This is independent of the chosen treatment, despite a better anatomical reduction after open treatment.

Bone Regeneration in a Large Animal Model Featuring a Modular Off-the-Shelf Soft Callus Mimetic

Implantation of engineered cartilage with soft callus features triggers remodeling to bone tissue via endochondral bone regeneration (EBR). Thus far, EBR has not progressed to the level of large animals on the axis of clinical translation. Herein, the feasibility of EBR is aimed for a critical-sized defect in a large animal model. Chondrogenesis is first induced in goat-derived multipotent mesenchymal stromal cells (MSCs) by fine-tuning the cellular differentiation process. Through a unique devitalization process, two off-the-shelf constructs aimed to recapitulate the different stages of the transient cartilaginous soft callus template in EBR are generated. To evaluate bone regeneration, the materials are implanted in an adapted bilateral iliac crest defect model in goats, featuring a novel titanium star-shaped spacer. After 3 months, the group at the more advanced differentiation stage shows remarkable regenerative capacity, with comparable amounts of bone regeneration as the autograft group. In contrast, while the biomaterial mimicking the earlier stages of chondrogenesis shows improved regeneration compared to the negative controls, this is subpar compared to the more advanced material. Concluding, EBR is attainable in large animals with a soft callus mimetic material that leads to fast conversion into centimeter-scale bone, which prospects successful implementation in the human clinics.

Clinically Established Temporomandibular Involvement in Adults With Juvenile Idiopathic Arthritis

OBJECTIVE

To study clinical variables defining temporomandibular function in adults with juvenile idiopathic arthritis (JIA) and healthy controls.

METHODS

In this cross-sectional study, the temporomandibular joint (TMJ) screening protocol, mandibular range of motion (MROM), and anterior maximum voluntary bite force (AMVBF) were compared between adults with JIA and healthy controls. Unadjusted and adjusted models with corrections for sex and disease duration were constructed for active maximum interincisal mouth opening (AMIO) and AMVBF.

RESULTS

A total of 100 adults with JIA and 59 healthy adults were included in this study. In adults with JIA, 56% had clinically established TMJ involvement. AMIO was the MROM variable most reduced by TMJ involvement; AMIO was 8.8 mm (95% CI -11.40 to -6.12; P < 0.001) less in adults with JIA with TMJ involvement compared to JIA without TMJ involvement. No differences of AMIO were found between healthy adults and adults with JIA without TMJ involvement (-2.52, 95% CI -5.13 to 0.10; P = 0.06). Male sex was associated with a higher AMIO, and disease duration was associated with a decreased AMIO. Collinearity between the subtype prebiologic era and disease duration was found. AMVBF did not differ between adults with JIA and healthy adults.

CONCLUSION

The high prevalence of clinically established TMJ involvement in adults with JIA indicates the need for awareness of TMJ problems in adults with JIA. TMJ involvement negatively influenced AMIO and should therefore be part of the TMJ screening in adults with JIA. AMVBF seems to have less utility for TMJ screening in adult populations.

[Is there more to hypodontia then missing teeth?]

Dental care professionals regularly see patients with hypodontia. Hypodontia can be acquired, for example through chemotherapy or radiation at a young age, but is hereditary in most patients. Due to an error (pathogenic variant) in one of the many genes that control odontogenesis, the formation of the tooth germ is disrupted at an early stage. The genes involved are not only crucial for tooth development, but they also play an important role in other physical processes. This article provides background information on hypodontia. Based on an inventory of gastrointestinal complaints in patients with hypodontia and a case description of the simultaneous occurrence of a coagulation disorder and hypodontia, the importance of a broad view of this patient group is illustrated. It is concluded that, in addition to a dental assessment, examination of these patients should include a limited physical examination and the medical history of the patient and his close relatives.

Oral functioning after open versus closed treatment of unilateral condylar neck or base fractures: A two-centre controlled clinical trial

BACKGROUND

Oral functioning and rehabilitation in patients after condylar trauma can be measured by objective functional outcomes and patient-reported outcomes. The similarities or differences between these outcomes may contribute to the decision if open treatment (OT) or closed treatment (CT) will obtain the most advantageous results.

OBJECTIVES

The aim of this study was to compare OT versus CT for unilateral condylar mandibular neck or base fractures in a two-centre controlled clinical trial by objective functional outcomes and patient-reported outcomes measured at 6 weeks and 6 months follow-up. Additionally, these outcomes were compared within each group.

METHODS

Patients were enrolled between January 2017 and November 2019. In one centre, patients received OT by extra-oral open reduction and internal fixation. In another centre, patients received CT by maxillomandibular fixation. Objective measurements included the mixing ability test (MAT) and mandibular active range of motion (ROM). Patient-reported outcomes included the mandibular function impairment questionnaire (MFIQ) and visual analogue scale (VAS) for pain. Independent t-tests and Mann-Whitney U-tests were used to determine differences between the treatment groups at 6 weeks and 6 months follow-up. Paired t-tests and Wilcoxon signed rank tests were used to determine differences within each group.

RESULTS

Thirty-three patients were enrolled. No differences were found between the groups treated with OT or CT for MAT, ROM, MFIQ and VAS. Both groups showed functional improvement.

CONCLUSION

Good objective functional outcomes and patient-reported outcomes were achieved with both OT and CT in patients with unilateral condylar mandibular neck or base fractures.

Osteoinductive calcium phosphate with submicron topography as bone graft substitute for maxillary sinus floor augmentation: A translational study

OBJECTIVES

The aim of this study was the preclinical and clinical evaluation of osteoinductive calcium phosphate with submicron surface topography as a bone graft substitute for maxillary sinus floor augmentation (MSFA).

MATERIAL AND METHODS

A preclinical sheep model of MSFA was used to compare a calcium phosphate with submicron needle-shaped topography (BCPN , MagnetOs Granules, Kuros Biosciences BV) to a calcium phosphate with submicron grain-shaped topography (BCPG ) and autologous bone graft (ABG) as controls. Secondly, a 10-patient, prospective, randomized, controlled trial was performed to compare BCPN to ABG in MSFA with two-stage implant placement.

RESULTS

The pre-clinical study demonstrated that both BCPN and BCPG were highly biocompatible, supported bony ingrowth with direct bone apposition against the material, and exhibited bone formation as early as 3 weeks post-implantation. However, BCPN demonstrated significantly more bone formation than BCPG at the study endpoint of 12 weeks. Only BCPN reached an equivalent amount of bone formation in the available space and a greater proportion of calcified material (bone + graft material) in the maxillary sinus compared to the "gold standard" ABG after 12 weeks. These results were validated in a small prospective clinical study, in which BCPN was found comparable to ABG in implant stability, bone height, new bone formation in trephine core biopsies, and overall clinical outcome.

CONCLUSION

This translational work demonstrates that osteoinductive calcium phosphates are promising bone graft substitutes for MSFA, whereas their bone-forming potential depends on the design of their surface features. Netherlands Trial Register, NL6436.

Reliability and measurement error of anterior maximum voluntary bite force in children with juvenile idiopathic arthritis and healthy children

In children with juvenile idiopathic arthritis (JIA) the temporomandibular joint (TMJ) can be involved. As a consequence, the oral function can be impaired due to joint and/or muscle involvement of the masticatory system with a negative influence on the maximum bite force. The aim of this cross-sectional study was to establish the reliability of AMVBF in children with JIA and healthy children. Children with JIA and healthy children conducted three attempts of AMVBF. The reliability of AMVBF measurement was determined by the intra-class correlation coefficient (ICC) by age, standard error of measurement (SEM), smallest detectable change (SDC), and limits of agreement (LoA). A total of 298 children with JIA and 168 healthy children were examined. The AMVBF measurements showed an good to excellent reliability in children with JIA based on the ICCs corrected for age (0.782-0.979). In healthy children, the reliability was moderate to excellent (0.546-0.999). The SDC in our study indicated that values above 11.4N might be a clinical relevant change over time in children with JIA. The LoA showed a wide spread of variability in both children with JIA (-72.6-44.4N) and healthy children (-79.9-72.8N). The Bland-Altman plots indicated that the differences between the test and retest increased in value proportionally to the biteforce value.

The average three-dimensional face for different sex and age groups in a Dutch population

The increasing use of three-dimensional imaging calls for reference models representing large parts of the population. The aim of this prospective study was to create templates depicting facial maturation in the younger age groups. Healthy Dutch volunteers were captured, without selection of inclusions. Three-dimensional average faces were created using MATLAB, for both genders in four age groups (4-8 years, 8-12 years, 12-16 years, and ≥16 years). Variation within the groups was calculated and depicted on an average face with a green to red colour scale, corresponding to standard deviations between 0 and ≥ 3 mm, respectively. Measurements of the distances of eight peri-oral landmarks were provided as ratios. The statistical analysis was performed using ANOVA and Tukey's test. Three-dimensional reconstructions of the average face and their first principal component were created for each gender and age group. The first principal component comprised the facial width for each group, and the variation of landmarks was low. All ratios showed an increasing trend with increasing age, except for the ratio of philtrum width to mouth width. This study is novel in comparing facial morphology by means of ratios and in creating average faces for the different young age groups. These data provide useful insights into facial maturation, which might be beneficial for facial surgeons.

Long-term masticatory performance and ability following closed treatment for unilateral mandibular condylar neck or base fractures: a cross-sectional study

PURPOSE

The aim of this study was to find explanatory variables for objective and patient-reported long-term masticatory functioning in patients treated with maxillomandibular fixation for unilateral condylar neck or base fractures. These outcomes were compared to healthy control subjects.

METHODS

Patients treated between 1996 and 2013 were enrolled in the study. Objective measurements included the mixing ability test (MAT) for masticatory performance, and range of motion of the mandible. Patient-reported measurements included the mandibular function impairment questionnaire (MFIQ) for masticatory ability, and the visual analogue scale for pain. Healthy subjects were recruited between October 2018 and January 2019, and performed the MAT and MFIQ.

RESULTS

Twenty-one patients and 30 healthy subjects were included. The average follow-up period was 11.67 years. In adjusted regression analysis, the amount of occlusal units (OU) was associated with the MAT (P = 0.020; R² = 0.253) and MFIQ (P = 0.001, R² = 0.454). The MAT outcome was similar in both groups when correcting for OU (P = 0.001; R² = 0.201). The MFIQ was inferior in the patient group (P = 0.001).

CONCLUSION

Long-term masticatory performance was similar in patients with a history of condylar neck or base fracture and healthy subjects; however, masticatory ability was inferior in patients compared to healthy subjects.

Creating Three-Dimensional Templates of Smiling and Pouting Faces for Different Sex- and Age Groups

Smile appearance has a major psychological impact. Orthognathic surgery, which has harmonizing results on skeletal structures, can negatively influence the smile appearance due to soft tissue effects. To enhance the aesthetic effects of orthognathic surgery on soft tissues, reference models for large parts of the hospital’s adherent area are called for. This study aims to create average facial models for different sex and age groups in two facial exercises: maximum closed smile, and pouting. These models were created using coherent point drift and Procrustes algorithms in MATLAB. Principal component analysis was performed, and of 20 surgical landmarks, the in-group variation using standard deviation was calculated. Three distances were analyzed: nasal width, philtral width, and mouth width. To correct for facial size, these distances were analyzed as a ratio of intercanthal width. In total, 328 healthy subjects were included in the study. Subjects were grouped by sex, and in age categories spanning four years each, with an adult group with all ages >16 years. For both smiling and pouting faces, all ratios increased with ageing. These templates and data can benefit facial surgeons, to obtain an expected outcome according to the age of the patient.

Value of cone beam computed tomography for detecting bone invasion in squamous cell carcinoma of the maxilla

OBJECTIVE

To determine the diagnostic value of cone beam computed tomography (CBCT) in detecting bone invasion in maxillary squamous cell carcinoma (MSCC).

STUDY DESIGN

In this retrospective cohort study, preoperative CBCT scans were independently assessed by a single surgeon in imaging assessment 1 (IA 1) and by 1 surgeon with 2 dentists in consensus (IA 2) for the presence of bone invasion in MSCC. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, area under the receiver operating characteristic curve (AUC), and Cohen's κ were calculated. Histopathologic results of resection specimens served as the reference standard.

RESULTS

Of 27 patients, 19 (70%) had proven bone invasion. IA 1 yielded 68.4% sensitivity, 75.0% specificity, 86.7% PPV, 50.0% NPV, 70.4% accuracy, and 0.717 AUC. All results of IA 2 were true-positive and true-negative, resulting in 100% sensitivity, specificity, PPV, NPV, accuracy, and AUC. The assessments differed in 6 cases. Interobserver κ was fair (0.38, 95% CI 0.04-0.72, P = .038). There was a significant association between CBCT detection of bone invasion and extent of surgical treatment (P = .006) CONCLUSIONS: The diagnostic accuracy of CBCT was high but observer-dependent. CBCT examination may be useful in surgical treatment planning.

Growth curves for mandibular range of motion and maximum voluntary bite force in healthy children

Mandibular range of motion and bite force are indispensable variables for the evaluation of mandibular function. There are a variety of medical and dental conditions that can negatively affect mandibular function. Values for mandibular range of motion (i.e., active and passive maximum interincisal mouth opening, protrusion, and laterotrusion) and anterior maximum voluntary bite force (AMVBF) in healthy children and adolescents can help in recognizing temporomandibular dysfunction. In this longitudinal study, 169 healthy children aged 6-18 years were included. They were examined at four time points over 1 year. Mixed model analysis was performed to produce growth curves of mandibular range of motion and AMVBF. Average active maximum interincisal mouth opening was significantly higher in boys with 50.0 mm compared to 47.8 mm in girls. Boys also had a significantly higher AMVBF than girls with an average of 169.0 N versus 140.0 N, respectively. Growth curves of active and passive maximum interincisal mouth opening showed an increase with age, albeit levelling off through puberty. The growth curves of AMVBF in girls reach a plateau phase at ages 12-14 years, after which the curve descends; in boys, the AMVBF tended to increase up to 18 years of age, although a slow-down after 14 years of age was noted.

A Novel and Practical Protocol for Three-Dimensional Assessment of Alveolar Cleft Grafting Procedures

OBJECTIVE

To evaluate the reproducibility and accuracy of a new, easy-to-use volumetric assessment of the alveolar cleft.

DESIGN

Twelve cone-beam computed tomography (CBCT) datasets of patients with a unilateral cleft lip, alveolus, and palate were evaluated by two investigators. Residual alveolar cleft calcified volume one year after surgery was analyzed by using standardized landmarks to determine the borders of the cleft defect and semi-automatically segment the alveolar cleft defect.

RESULTS

The Dice-coefficient between observers for the segmented preoperative alveolar cleft defect was 0.81. Average percentage of residual alveolar cleft calcified material was 66.7% one year postoperatively.

CONCLUSIONS

This study demonstrates a reliable and practical semi-automatic three-dimensional volumetric assessment method for unilateral clefts using CBCT.

[Reconstruction of the mandible after loss of the middle segment due to an odontogenic myxoma]

In an 18-year-old boy, the middle segment of the mandible was removed because of a locally aggressive tumour. The reconstruction became infected and was lost, resulting in 2 separately-moving mandible parts and oral disability. For the second reconstruction, skeletal fixation with osteosynthesis plates, dental fixation with a stabilization frame and intermaxillary fixation were used. Preparation for returning the jaws to their original position was facilitated by three-dimensional simulation software. After a successful second reconstruction, an implant-supported removable bridge was eventually placed.

Acceleration of Bone Regeneration Induced by a Soft-Callus Mimetic Material

Clinical implementation of endochondral bone regeneration (EBR) would benefit from the engineering of devitalized cartilaginous constructs of allogeneic origins. Nevertheless, development of effective devitalization strategies that preserves extracellular matrix (ECM) is still challenging. The aim of this study is to investigate EBR induced by devitalized, soft callus-mimetic spheroids. To challenge the translatability of this approach, the constructs are generated using an allogeneic cell source. Neo-bone formation is evaluated in an immunocompetent rat model, subcutaneously and in a critical size femur defect. Living spheroids are used as controls. Also, the effect of spheroid maturation towards hypertrophy is evaluated. The devitalization procedure successfully induces cell death without affecting ECM composition or bioactivity. In vivo, a larger amount of neo-bone formation is observed for the devitalized chondrogenic group both ectopically and orthotopically. In the femur defect, accelerated bone regeneration is observed in the devitalized chondrogenic group, where defect bridging is observed 4 weeks post-implantation. The authors' results show, for the first time, a dramatic increase in the rate of bone formation induced by devitalized soft callus-mimetics. These findings pave the way for the development of a new generation of allogeneic, "off-the-shelf" products for EBR, which are suitable for the treatment of every patient.

A Novel Method for Quantitative Three-Dimensional Analysis of Zygomatico-Maxillary Complex Symmetry

To develop a reliable and accurate method to quantify the symmetry of the zygomaticomaxillary complex (ZMC).

Zygomaticomaxillary complex fracture repair with intraoperative CBCT imaging. A prospective cohort study

The aim of this study was to evaluate the value of intraoperative conebeam computed tomography (CBCT) imaging in the treatment of zygomaticomaxillary complex (ZMC) fractures. A prospective single center cohort study was performed. Included were consecutive patients who underwent surgery for a unilateral ZMC fracture. An intraoperative CBCT scan was performed after reduction of the ZMC fracture. Revision reduction was performed of the ZMC and/or orbital floor (OF) on indication. The preoperative and postoperative asymmetry of the outer surface of the ZMC was measured on digital 3D-models of CBCT scans, using a mirroring and surface-based matching technique. The postoperative asymmetry of the ZMC in the study group was compared to the asymmetry of the ZMC in the control group with healthy individuals. A total of 38 patients with a unilateral ZMC fracture were included. The mean postoperative asymmetry in the study group (1.67 mm, SD 0.89) was less than the mean preoperative asymmetry (2.69 mm, SD 0.95) (paired samples T-test p < 0.01) but showed no statistically significant difference with the mean asymmetry in the healthy control group (1.40 mm, SD 0.54) (independent samples T-test p = 0.31). Revision reduction of the ZMC and/or OF fracture had been performed in 11 cases after malalignment was noted on the intraoperative CBCT. The indication for intraoperative revision reduction was associated with comminuted ZMC fractures and/or fractures with indication for OF reduction (Pearson Chi Square p < 0.01). Within the limitations of the study, intraoperative CBCT imaging seemed to have a positive influence on ZMC fracture treatment, especially in the case of comminuted ZMC fractures and/or fractures with indication for OF treatment.

Gastrointestinal symptoms in patients with isolated oligodontia and a Wnt gene mutation

OBJECTIVE

Since Wnt signaling plays an important role in both tooth agenesis and altered intestine homeostasis, the aim was to compare gastrointestinal symptoms in patients with isolated oligodontia caused by a Wnt pathway gene mutation and controls.

METHODS

A case-control study was designed to compare self-reported gastrointestinal symptoms among patients with isolated oligodontia, caused by a Wnt signaling gene mutation, and fully dentate controls. The Gastrointestinal Symptom Rating Scale (GSRS) was used to assess gastrointestinal symptoms. Prevalence and severity of gastrointestinal symptoms among patients and age- and gender-matched controls were evaluated.

RESULTS

Twenty patients with isolated oligodontia and a pathogenic variant in the wnt pathway genes WNT10A, LRP6, or PAX9 participated. The prevalence of gastrointestinal symptoms was higher in the oligodontia patients compared to their controls (Χ² (1) = 87.33, p = .008). Mean GSRS total scores (p = .011) and domain scores for "abdominal pain" (p = .022), "reflux" (p = .003) and constipation (p = .030) were higher for these oligodontia patients compared to their controls.

CONCLUSION

Gastrointestinal symptoms are more prevalent and more severe in patients with isolated oligodontia and a deficiency in a Wnt pathway-related gene, when compared to controls without tooth agenesis.

Mandibular range of motion in children with juvenile idiopathic arthritis with and without clinically established temporomandibular joint involvement and in healthy children; a cross-sectional study

BACKGROUND

Recognition of temporomandibular joint (TMJ) involvement in children with juvenile idiopathic arthritis (JIA) has gained increasing attention in the past decade. The clinical assessment of mandibular range of motion characteristics is part of the recommended variables to detect TMJ involvement in children with JIA. The aim of this study was to explore explanatory variables for mandibular range of motion outcomes in children with JIA, with and without clinically established TMJ involvement, and in healthy children.

METHODS

This cross-sectional study included children with JIA and healthy children of age 6-18 years. Mandibular range of motion variables included active and passive maximum interincisal opening (AMIO and PMIO), protrusion, laterotrusion, dental midline shift in AMIO and in protrusion. Additionally, the TMJ screening protocol and palpation pain were assessed. Adjusted linear regression analyses of AMIO, PMIO, protrusion, and laterotrusion were performed to evaluate the explanatory factors. Two adjusted models were constructed: model 1 to compare children with JIA and healthy children, and model 2 to compare children with JIA with and without TMJ involvement.

RESULTS

A total of 298 children with JIA and 169 healthy children were included. Length was an explanatory variable for the mandibular range of motion excursions. Each centimeter increase in length increased AMIO (0.14 mm), PMIO (0.14 mm), and protrusion (0.02 mm). Male gender increased AMIO by 1.35 mm. Having JIA negatively influenced AMIO (3.57 mm), PMIO (3.71 mm), and protrusion (1.03 mm) compared with healthy children, while the discrepancy between left and right laterotrusion raised 0.68 mm. Children with JIA and TMJ involvement had a 8.27 mm lower AMIO, 7.68 mm lower PMIO and 0.96 mm higher discrepancy in left and right laterotrusion compared to healthy children.

CONCLUSION

All mandibular range of motion items were restricted in children with JIA compared with healthy children. In children with JIA and TMJ involvement, AMIO, PMIO and the discrepancy between left and right laterotrusion were impaired more severely. The limitation in protrusion and laterotrusion was hardly clinically relevant. Overall, AMIO is the mandibular range of motion variable with the highest restriction (in millimeters) in children with JIA and clinically established TMJ involvement compared to healthy children.

Maximum bite force in children with juvenile idiopathic arthritis with and without clinical established temporomandibular joint involvement and in healthy children: a cross-sectional study

Background

In children with juvenile idiopathic arthritis (JIA), the temporomandibular joint (TMJ) can be involved, resulting in dysfunction of the masticatory system. Bite force is one of the variables that reflects the function of the masticatory system. The aim of this study was to compare maximum bite force in children with JIA, with and without TMJ involvement and with healthy children.

Methods

Children with JIA and healthy children between the ages 6 and 18 were included in this cross‐sectional study. The clinical examination consisted of measuring the anterior maximum voluntary bite force (AMVBF), assessment of the TMJ screening protocol items and TMJ, masseter and temporal muscle palpation pain. Unadjusted linear regression analyses were performed to evaluate the explanatory factors for AMVBF. Two adjusted models were constructed with corrections for age and gender differences: model 1 to compare children with JIA and healthy children and model 2 to compare children with JIA with and without TMJ involvement.

Results

In this cross‐sectional study, 298 children with JIA and 169 healthy children participated. AMVBF was 24 Newton (N) lower in children with JIA, when compared with healthy children (95%CI: −35.5–−12.4, p = .000). When children with JIA also had clinically established TMJ involvement, AMVBF was reduced 42 N (component JIA:−16.78, 95% CI −28.96–−4.59, p = .007 and component TMJ involvement:−25.36, 95% CI −40.08–−10.63, p = .001). Age and male gender increased AMVBF.

Conclusion

Children with JIA had a reduction in the AMVBF compared with healthy children. In children with JIA and clinically established TMJ involvement, AMVBF was more reduced.

Retrospective analysis of clinical outcomes in bilateral cleft lip and palate patients after secondary alveolar bone grafting and premaxilla osteotomy, using a new dento-maxillary scoring system

Evaluation of relevant clinical outcomes in patients with bilateral cleft lip and palate (BCLP) after secondary aveolar bone grafting (SABG) and premaxilla osteotomy (PMO), through the use of a new scoring system. Data were collected retrospectively from all patients with BCLP who were operated on between 2004 and 2014, at the end of follow-up. The treatment protocol consisted of SABG + PMO in patients aged between 9 and 13 years. At the end of follow-up, the following parameters were scored: (un)interrupted dental arch, skeletal sagittal relationship, bone height using the Bergland/Abyholm criteria, and the presence of postoperative fistula. These parameters were combined to produce a dento-maxillary scoring system, giving a final score between 1 and 10. For statistical analysis, the independent t-test was used. Of 55 children, 45 were suitable for analysis. The mean age at time of surgery was 12.0 years (8.9-16.4 yrs), and the mean follow-up time was 11.7 years (5.8-15.8 yrs). The average number of surgeries executed under general anesthesia was 6 (range: 3-11). The average dento-maxillary score in this patient cohort was 7.6 (1-10; median: 8). Among these patients, 31 had an uninterrupted dental arch; the average Bergland/Abyholm score was 2.07; 30 patients exhibited an Angle class I incisor relationship; and, in 38 cases, the oronasal communication was closed after SABG + PMO treatment. A significant effect of fistulas was seen on dento-maxillary score (p = 0.001). Specifically, a significant effect of fistulas was seen on interrupted dental arch (p = 0.002) and on Bergland/Abyholm score (p = 0.037). The proposed dento-maxillary scoring system is a straightforward tool that can be used to describe and analyze the amount of dento-maxillary rehabilitation at the end of the treatment. Persistence of oronasal fistulas in patients with BCLP has a significant impact on interruption of the dental arch, and can influence dental results at the end of the second decade.

Endochondral Bone Regeneration by Non-autologous Mesenchymal Stem Cells

Mimicking endochondral bone formation is a promising strategy for bone regeneration. To become a successful therapy, the cell source is a crucial translational aspect. Typically, autologous cells are used. The use of non-autologous mesenchymal stromal cells (MSCs) represents an interesting alternative. Nevertheless, non-autologous, differentiated MSCs may trigger an undesired immune response, hampering bone regeneration. The aim of this study was to unravel the influence of the immune response on endochondral bone regeneration, when using xenogeneic (human) or allogeneic (Dark Agouti) MSCs. To this end, chondrogenically differentiated MSCs embedded in a collagen carrier were implanted in critical size femoral defects of immunocompetent Brown Norway rats. Control groups were included with syngeneic/autologous (Brown Norway) MSCs or a cell-free carrier. The amount of neo-bone formation was proportional to the degree of host-donor relatedness, as no full bridging of the defect was observed in the xenogeneic group whereas 2/8 and 7/7 bridges occurred in the allogeneic and the syngeneic group, respectively. One week post-implantation, the xenogeneic grafts were invaded by pro-inflammatory macrophages, T lymphocytes, which persisted after 12 weeks, and anti-human antibodies were developed. The immune response toward the allogeneic graft was comparable to the one evoked by the syngeneic implants, aside from an increased production of alloantibodies, which might be responsible for the more heterogeneous bone formation. Our results demonstrate for the first time the feasibility of using non-autologous MSC-derived chondrocytes to elicit endochondral bone regeneration in vivo. Nevertheless, the pronounced immune response and the limited bone formation observed in the xenogeneic group undermine the clinical relevance of this group. On the contrary, although further research on how to achieve robust bone formation with allogeneic cells is needed, they may represent an alternative to autologous transplantation.

Feasibility of CT quantification of intratumoural 166Ho-microspheres

Background

Microspheres loaded with radioactive ¹⁶⁶Ho (¹⁶⁶Ho-MS) are novel particles for radioembolisation and intratumoural treatment. Because of the limited penetration of β radiation, quantitative imaging of microsphere distribution is crucial for optimal intratumoural treatment. Computed tomography (CT) may provide high-resolution and fast imaging of the distribution of these microspheres, with lower costs and widespread availability in comparison with current standard single-photon emission tomography (SPECT) and magnetic resonance imaging. This phantom study investigated the feasibility of CT quantification of ¹⁶⁶Ho-MS.

Methods

CT quantification was performed on a phantom with various concentrations of HoCl and Ho-MS to investigate the CT sensitivity and calibrate the CT recovery. ¹⁶⁶Ho-MS were injected into ex vivo tissues, in VX-2 cancer-bearing rabbits, and in patients with head-neck cancer, to demonstrate sensitivity and clinical visibility. The amount of Ho-MS was determined by CT scanning, using a density-based threshold method and compared with a validated ¹⁶⁶Ho SPECT quantification method.

Results

In the phantom, a near perfect linearity (least squares R² > 0.99) between HU values and concentration of ¹⁶⁶Ho was found. Ex vivo tissue experiments showed an excellent correlation (r = 0.99, p < 0.01) between the dose calibrator, SPECT, and CT imaging. CT recovery was on average 86.4% ex vivo, 76.0% in rabbits, and 99.1% in humans.

Conclusion

This study showed that CT-based quantification of Ho microspheres is feasible and is a high-resolution alternative to SPECT-based determination of their local distribution.

Low skeletal muscle mass is a strong predictive factor for surgical complications and a prognostic factor in oral cancer patients undergoing mandibular reconstruction with a free fibula flap

BACKGROUND

Fibula free flaps (FFF) are effective in accomplishing successful reconstruction for segmental defects of the mandible. Potential risk factors for FFF complications have been described in previous research, e.g. age, comorbidity and smoking. Low skeletal muscle mass (SMM) has shown to be an emerging predictive factor for complications and prognostic factor for survival in head and neck cancer. This study aims to identify the predictive and prognostic value of low SMM for surgical FFF related complications, postoperative complications and survival in patients who underwent mandibular reconstruction with FFF after oral cavity cancer resection.

MATERIALS AND METHODS

A retrospective study was performed between 2002 and 2018. Pre-treatment SMM was measured at the level of the third cervical vertebra and converted to SMM at the level of the third lumbar vertebra (L3). SMM at the level of L3 was corrected for squared height. Low SMM was defined as a lumbar skeletal muscle index (LSMI) below 43.2 cm²/m².

RESULTS

78 patients were included, of which 48 (61.5%) had low SMM. Low SMM was associated with an increased risk of FFF related complications (HR 4.3; p = 0.02) and severe postoperative complications (Clavien-Dindo grade III-IV) (HR 4.0; p = 0.02). In addition low SMM was a prognosticator for overall survival (HR 2.4; p = 0.02) independent of age at time of operation, ACE-27 score and TNM stage.

CONCLUSION

Low SMM is a strong predictive factor for FFF reconstruction complications and other postoperative complications in patients undergoing FFF reconstruction of the mandible. Low SMM is also prognostic for decreased overall survival.

Inflammatory pseudotumour of the alveolar process of the maxilla as clinical manifestation of IgG4-related disease: a case report and literature review

IgG4-related disease (IgG4-RD) is an uncommon immune-mediated condition considered to be a systemic disease, described in multiple organ systems. IgG4-RD that involves the maxillary and sinonasal region is rare. This report presents a very rare presentation of IgG4-RD in the maxillary alveolar process. The patient presented with left-sided facial pain, headache, and mobility and loss of teeth. The first biopsy and resection specimen reports were inconclusive and showed a non-specific chronic inflammatory process. After the third resection, the diagnosis was finally established through findings that satisfied the 2012 consensus criteria for IgG4-RD. Consequently high doses of oral corticosteroids and azathioprine were given, tapered over a total period of 36 months. Weaning is still in progress, but no recurrence was observed after 34 months. A review of the English-language literature was performed, which identified seven cases of IgG4-RD with maxillary and sinonasal involvement. Cases were excluded from the review if there was any doubt that they met the consensus statement on the pathology.

Reproducibility and construct validity of the utrecht mixing ability Test to obtain masticatory performance outcome in patients with condylar mandibular fractures

OBJECTIVE

This study assessed the test-retest reproducibility of the Utrecht mixing ability test (MAT) and the construct validity of the MAT in relation to the Mandibular Function Impairment Questionnaire (MFIQ) in patients with mandibular condylar fractures.

MATERIAL AND METHODS

Twenty-six patients treated for a mandibular condylar fracture participated in this clinimetric study; all patients performed the MAT twice. Simultaneously the MFIQ was conducted. Test-retest reliability and construct validity were assessed using the intra-class correlation coefficient (ICC) and Spearman correlation, respectively.

RESULTS

The ICC of the MAT was 0.906 (95% CI: 0.801-0.957), which indicates an excellent reliability. A weak correlation of 0.386 (P = .052) between the first MAT and the overall outcome of the MFIQ was found. A significant moderate correlation of 0.401 (P = .042) was found between the retest of the MAT and the overall outcome of the MFIQ. One question on the MFIQ (about yawning) showed a moderate positive correlation of 0.569 (P = .002) and 0.416 (P = .034) for the MAT test and retest, respectively.

CONCLUSION

The MAT is an easy test to use in follow-up of patients. The test-retest reliability of this test is excellent in condylar trauma patients. As the validity of the MAT and the MFIQ could not be confirmed, the MFIQ may be an addition to patient's feedback about the rehabilitation process of their mandibular functioning.

Layer-specific cell differentiation in bi-layered vascular grafts under flow perfusion

Bioengineered grafts have the potential to overcome the limitations of autologous and non-resorbable synthetic vessels as vascular substitutes. However, one of the challenges in creating these living grafts is to induce and maintain multiple cell phenotypes with a biomimetic organization. Our biomimetic grafts with heterotypic design hold promises for functional neovessel regeneration by guiding the layered cellular and tissue organization into a native-like structure. In this study, a perfusable two-compartment bioreactor chamber was designed for the further maturation of these vascular grafts, with a compartmentalized exposure of the graft's luminal and outer layer to cell-specific media. We used the system for a co-culture of endothelial colony forming cells and multipotent mesenchymal stromal cells (MSCs) in the vascular grafts, produced by combining electrospinning and melt electrowriting. It was demonstrated that the targeted cell phenotypes (i.e. endothelial cells (ECs) and vascular smooth muscle cells (vSMCs), respectively) could be induced and maintained during flow perfusion. The confluent luminal layer of ECs showed flow responsiveness, as indicated by the upregulation of COX-2, KLF2, and eNOS, as well as through stress fiber remodeling and cell elongation. In the outer layer, the circumferentially oriented, multi-layered structure of MSCs could be successfully differentiated into vSM-like cells using TGFβ, as indicated by the upregulation of αSMA, calponin, collagen IV, and (tropo)elastin, without affecting the endothelial monolayer. The cellular layers inhibited diffusion between the outer and the inner medium reservoirs. This implies tightly sealed cellular layers in the constructs, resulting in truly separated bioreactor compartments, ensuring the exposure of the inner endothelium and the outer smooth muscle-like layer to cell-specific media. In conclusion, using this system, we successfully induced layer-specific cell differentiation with a native-like cell organization. This co-culture system enables the creation of biomimetic neovessels, and as such can be exploited to investigate and improve bioengineered vascular grafts.

A Versatile Biosynthetic Hydrogel Platform for Engineering of Tissue Analogues

For creating functional tissue analogues in tissue engineering, stem cells require very specific 3D microenvironments to thrive and mature. Demanding (stem) cell types that are used nowadays can find such an environment in a heterogeneous protein mixture with the trade name Matrigel. Several variations of synthetic hydrogel platforms composed of poly(ethylene glycol) (PEG), which are spiked with peptides, have been recently developed and shown equivalence to Matrigel for stem cell differentiation. Here a clinically relevant hydrogel platform, based on PEG and gelatin, which even outperforms Matrigel when targeting 3D prevascularized bone and liver organoid tissue engineering models is presented. The hybrid hydrogel with natural and synthetic components stimulates efficient cell differentiation, superior to Matrigel models. Furthermore, the strength of this hydrogel lies in the option to covalently incorporate unmodified proteins. These results demonstrate how a hybrid hydrogel platform with intermediate biological complexity, when compared to existing biological materials and synthetic PEG-peptide approaches, can efficiently support tissue development from human primary cells.

Tongue function and its influence on masticatory performance in patients treated for oral cancer: a five-year prospective study

Purpose

The purpose of this study was to observe the impact of oral oncological treatment, including the recovery of several tongue functions (force, mobility, and sensory functions), and to determine the influence of these functions on masticatory performance.

Materials and methods

Masticatory performance and tongue force, mobility, and sensory functions were determined in 123 patients with oral cavity cancer. The assessments were performed 4 weeks before treatment and 4 to 6 weeks, 6 months, 1 year, and 5 years after treatment. Generalized estimation equations and mixed model analyses were performed, correcting for previously identified factors in the same population.

Results

A significant deterioration in tongue mobility and sensory function was observed in patients with mandible and tongue and/or floor-of-mouth tumors. Better tongue force and sensory function (thermal and tactile) positively influenced masticatory performance, and this effect was stronger where fewer occlusal units were present. The effect of both the tongue force and maximum bite force was weaker in dentate patients in comparison with patients with full dentures. A web-based application was developed to enable readers to explore our results and provide insight into the coherence between the found factors in the mixed model.

Conclusions

Tongue function deteriorates after oral oncological treatment, without statistically significant recovery. Adequate bite and tongue forces are especially important for patients with a poor prosthetic state. Patients with sensory tongue function deficits especially benefit from the presence of more occluding pairs.

Incidence of complications in secondary alveolar bone grafting of bilateral clefts with premaxillary osteotomy: a retrospective cohort study

OBJECTIVE

To evaluate factors affecting incidence of complications after secondary alveolar bone grafting with premaxillary osteotomy (SABG + PO) in children with complete bilateral cleft of lip and palate (BCLP).

MATERIALS AND METHODS

Data were collected from children with BCLP treated with SABG + PO from 2004 to 2014 at our institute. Preoperative parameters included age, donor site, race, gingival health, bone quality around cleft-related teeth, premaxilla position, graft timing, presence of canines in the cleft, and presence of deciduous teeth around the cleft area. Logistic regression and the chi-squared test were used to assess correlations and the incidence of complications.

RESULTS

In the 64 patients, a significant correlation was found between complication rate and timing of bone grafting with respect to early versus late SABG + PO (p = 0.041), age > 12 years (p = 0.011; odds ratio (OR) 5.9; 95% confidence interval (CI) 1.49-23.93), malposition of the premaxilla (p = 0.042; OR 3.3; 95% CI 1.04-10.13), and preoperative bone quality around cleft-related teeth (p = 0.005; OR 5.3; 95% CI 1.6-17.2).

CONCLUSIONS

The timing of SABG + PO is essential, as early SABG + PO is associated with fewer complications. A malpositioned premaxilla and poor bone quality around cleft-related teeth are associated with more complications. Therefore, preoperative orthodontic repositioning of the malpositioned premaxilla before SABG + PO should be considered.

CLINICAL RELEVANCE

Analysis of treatment protocols and complications for BCLP patients underscores that proper timing of SABG + PO and correct premaxilla repositioning help reduce complications.

[Bimaxillary osteotomy for obstructive sleep apnoea]

Bimaxillary osteotomy for obstructive sleep apnoea Objective To gain insight into postoperative results of bimaxillary osteotomy in patients with obstructive sleep apnoea (OSA). Design Retrospective patient series. Method All patients with OSA who had undergone a bimaxillary osteotomy in the Amphia Hospital in Breda in the Netherlands in the past 4 years were eligible for inclusion. The primary outcome measures were the apnoea-hypopnoea index (AHI), a decrease in symptoms and the success of the operation. Results In the past 4 years, 22 patients with OSA underwent a bimaxillary osteotomy in the Amphia Hospital in Breda. We further analysed data from 18 patients. All patients had a normal to moderately elevated BMI. 94.1% had a complete absence or a marked decline in symptoms postoperatively. In 23.5% the cure was complete (AHI < 5/h) and treatment was successful in 52.9% of the patients (> 50% reduction in AHI and AHI < 20/h). The average AHI decreased from 38/h preoperatively to 11/h postoperatively. Conclusion Bimaxillary osteotomy is currently often regarded as a final treatment option for patients with OSA. Even in these patients with a relatively complex condition the results of the operation are relatively good. For treatment providers it is important to recognise patients who might benefit from a bimaxillary osteotomy, such as patients with OSA and retrognathia.

Articular soft tissue injuries associated with mandibular condyle fractures and the effects on oral function

The majority of studies debating the optimization of treatment for condylar mandibular fractures focus on the bony aspect first. However, fractures of the mandibular condyle may go together with soft tissue injury of the temporomandibular joint. An electronic literature search for this topic was undertaken. Assessment of quality was carried out using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Sixteen articles were included in this review. The reviewed literature showed that intracapsular fractures and dislocated condylar fractures result in more severe injuries. Serious injury to the disc and capsule of the temporomandibular joint is a contributing factor towards development of complications after closed treatment. The results of this review give an overview of the published studies focusing on articular soft tissue injuries caused by condylar mandibular fractures. Additionally, an overview of the magnetic resonance imaging (MRI) settings used to detect these injuries is provided. Until now, the relation between soft tissue injuries and type of condylar trauma and their influence on clinical outcome has been insufficiently investigated. Before considering reduction of soft tissues next to reduction of the fracture, more research is needed into the impact of soft tissue injuries on oral functioning, in which a uniform classification is used.

Effect of donor variation on osteogenesis and vasculogenesis in hydrogel cocultures

To introduce a functional vascular network into tissue-engineered bone equivalents, human endothelial colony forming cells (ECFCs) and multipotent mesenchymal stromal cells (MSCs) can be cocultured. Here, we studied the impact of donor variation of human bone marrow-derived MSCs and cord blood-derived ECFCs on vasculogenesis and osteogenesis using a 3D in vitro coculture model. Further, to make the step towards cocultures consisting of cells derived from a single donor, we tested how induced pluripotent stem cell (iPSC)-derived human endothelial cells (iECs) performed in coculture models. Cocultures with varying combinations of human donors of MSCs, ECFCs, or iECs were prepared in Matrigel. The constructs were cultured in an osteogenic differentiation medium. Following a 10-day culture period, the length of the prevascular structures and osteogenic differentiation were evaluated for up to 21 days of culture. The particular combination of MSC and ECFC donors influenced the vasculogenic properties significantly and induced variation in osteogenic potential. In addition, the use of iECs in the cocultures resulted in prevascular structure formation in osteogenically differentiated constructs. Together, these results showed that close attention to the source of primary cells, such as ECFCs and MSCs, is critical to address variability in vasculogenic and osteogenic potential. The 3D coculture model appeared to successfully generate prevascularized constructs and were sufficient in exceeding the ~200 μm diffusion limit. In addition, iPSC-derived cell lineages may decrease variability by providing a larger and potentially more uniform source of cells for future preclinical and clinical applications.

Masticatory function and related factors after oral oncological treatment: A 5-year prospective study

BACKGROUND

Chewing ability is often compromised in patients with oral cancer. The aim of this study was to identify which factors affect masticatory performance in these patients.

METHODS

Patients with primary oral cancer were assessed for up to 5 years after primary treatment. Healthy controls were assessed once. A mixed-model analysis was performed, with masticatory performance as outcome measure.

RESULTS

A total of 123 patients were included in the study. Factors positively associated with masticatory performance were number of occlusal units (OU), having functional dentures, and maximum mouth opening (MMO). The impact of tumor location and maximum bite force (MBF) differed per assessment moment. Masticatory performance declined for up to 1 year but recovered at 5 years after treatment.

CONCLUSION

Masticatory performance in patients treated for oral cancer is affected by MBF, MMO, number of OU, and dental status. These should be the focus of posttreatment therapy.

Biphasic calcium phosphate with submicron surface topography in an Ovine model of instrumented posterolateral spinal fusion

As spinal fusions require large volumes of bone graft, different bone graft substitutes are being investigated as alternatives. A subclass of calcium phosphate materials with submicron surface topography has been shown to be a highly effective bone graft substitute. In this work, a commercially available biphasic calcium phosphate (BCP) with submicron surface topography (MagnetOs; Kuros Biosciences BV) was evaluated in an Ovine model of instrumented posterolateral fusion. The material was implanted stand-alone, either as granules (BCPgranules) or as granules embedded within a fast-resorbing polymeric carrier (BCPputty) and compared to autograft bone (AG). Twenty-five adult, female Merino sheep underwent posterolateral fusion at L2-3 and L4-5 levels with instrumentation. After 6, 12, and 26 weeks, outcomes were evaluated by manual palpation, range of motion (ROM) testing, micro-computed tomography, histology and histomorphometry. Fusion assessment by manual palpation 12 weeks after implantation revealed 100% fusion rates in all treatment groups. The three treatment groups showed a significant decrease in lateral bending at the fusion levels at 12 weeks (P < 0.05) and 26 weeks (P < 0.001) compared to the 6 week time-point. Flexion-extension and axial rotation were also reduced over time, but statistical significance was only reached in flexion-extension for AG and BCPputty between the 6 and 26 week time-points (P < 0.05). No significant differences in ROM were observed between the treatment groups at any of the time-points investigated. Histological assessment at 12 weeks showed fusion rates of 75%, 92%, and 83% for AG, BCPgranules and BCPputty, respectively. The fusion rates were further increased 26 weeks postimplantation. Similar trends of bone growth were observed by histomorphometry. The fusion mass consisted of at least 55% bone for all treatment groups 26 weeks after implantation. These results suggest that this BCP with submicron surface topography, in granules or putty form, is a promising alternative to autograft for spinal fusion.

The impact of immune response on endochondral bone regeneration

Tissue engineered cartilage substitutes, which induce the process of endochondral ossification, represent a regenerative strategy for bone defect healing. Such constructs typically consist of multipotent mesenchymal stromal cells (MSCs) forming a cartilage template in vitro, which can be implanted to stimulate bone formation in vivo. The use of MSCs of allogeneic origin could potentially improve the clinical utility of the tissue engineered cartilage constructs in three ways. First, ready-to-use construct availability can speed up the treatment process. Second, MSCs derived and expanded from a single donor could be applied to treat several patients and thus the costs of the medical interventions would decrease. Finally, it would allow more control over the quality of the MSC chondrogenic differentiation. However, even though the envisaged clinical use of allogeneic cell sources for bone regeneration is advantageous, their immunogenicity poses a significant obstacle to their clinical application. The aim of this review is to increase the awareness of the role played by immune cells during endochondral ossification, and in particular during regenerative strategies when the immune response is altered by the presence of implanted biomaterials and/or cells. More specifically, we focus on how this balance between immune response and bone regeneration is affected by the implantation of a cartilaginous tissue engineered construct of allogeneic origin.

The association between a mixing ability test and patient reported chewing ability in patients treated for oral malignancies

Introduction

Mastication has been assessed in several ways in the past. Both patients reported and objective assessment methods have been developed. The University Medical Center (UMC) Utrecht has developed a mixing ability test (MAT) using a two‐coloured wax tablet. The present study investigates the association between the mixing ability test and a chewing related questionnaire in patients treated for oral malignancies.

Patients and methods

In a cohort study, patients treated for oral malignancies were assessed 4‐6 weeks before and 4‐6 weeks after treatment, as well as 6 months, 1 year and 5 years after treatment. The mixing ability test was assessed using 10 and 20 chewing strokes and was compared to seven questions about several aspects of mastication. Regression analysis was performed and density plots were drawn for statistical analysis.

Results

One hundred and twenty‐three patients were included in this study. The questionnaire was less predictive for the 10‐chewing stroke test and the test was less discriminatory for different food types than the 20‐chewing stroke mixing ability test. Three questions about the ability to chew solid, soft and thickened liquid food types were found to be significantly predictive for the 20‐chewing stroke test. Threshold values on the mixing ability index were around 20 for the ability to chew solid food types and 24 for soft food types.

Conclusion

The 10‐chewing stroke mixing ability test is less suitable than 20‐chewing strokes for patients with and treated for oral cancer. The 20‐chewing stroke mixing ability test has a fair association with self‐reported outcomes.

Preventing hypoesthesia after a buccal plate fracture in a sagittal split procedure: A technical note

If during a sagittal split osteotomy a buccal plate fracture occurs, it inevitably results in a time-consuming procedure with, in many cases, hypoesthesia of the mental region as a consequence of manipulation of the inferior alveolar nerve. We would like to present a novel technique to solve a (threatening) buccal plate fracture that is quick and easy to perform, and has thus far not resulted in hypoesthesia.

A novel digital workflow to manufacture personalized three-dimensional-printed hollow surgical obturators after maxillectomy

Partial or complete resection of the maxilla during tumour surgery causes oronasal defects, leading to oral-maxillofacial dysfunction, for which the surgical obturator (SO) is an important treatment option. Traditional manufacturing of SOs is complex, time-consuming, and often results in inadequate fit and function. This technical note describes a novel digital workflow to design and manufacture a three-dimensional (3D)-printed hollow SO. Registered computed tomography and magnetic resonance imaging images are used for gross tumour delineation. The produced RTStruct set is exported as a stereolitography (STL) file and merged with a 3D model of the dental status. Based on these merged files, a personalized and hollow digital SO design is created, and 3D printed. Due to the proper fit of the prefabricated SO, a soft silicone lining material can be used during surgery to adapt the prosthesis to the oronasal defect, instead of putty materials that are not suitable for this purpose. An STL file of this final SO is created during surgery, based on a scan of the relined SO. The digital workflow results in a SO weight reduction, an increased fit, an up-to-date digital SO copy, and overall easier clinical handling.

Early and late complications in the reconstructed mandible with free fibula flaps

Background and Objectives

Evaluation of mandibular reconstructions with free fibula flaps. Identification of factors associated with major recipient site complications, that is, necessitating surgical intervention under general anaesthesia.

Methods

Seventy‐nine reconstructions were included. The following factors were analyzed: fixation type, number of osteotomies, site of defect (bilateral/unilateral), surgeon, sex, ASA classification, continuous smoking, pathological N‐stage, age, defect size, flap ischemic time, and postoperative radiotherapy. Proportional hazards regression was used to test the effect on the time between reconstruction and intervention.

Results

Sixty‐nine (87%) of the 79 fibula flaps were successful at the last follow‐up. Forty‐eight major recipient site complications occurred in 41 reconstructions. Nineteen complications required surgical intervention within six weeks and were mostly vascular problems, necessitating immediate intervention. These early complications were associated with defects crossing the midline, with an estimated relative risk of 5.3 (CI 1.1‐20, P = 0.01). Twenty‐nine complications required surgical intervention more than 6 weeks after the reconstruction. These late complications generally occurred after months or years, and were associated with smoking, with an estimated relative risk of 2.8 (CI 1.0‐8.3, P = 0.05).

Conclusions

Fibula flaps crossing the midline have a higher risk of early major recipient site complications than unilateral reconstructions. Smoking increases the risk of late complications.

Microstructured β-Tricalcium Phosphate Putty Versus Autologous Bone for Repair of Alveolar Clefts in a Goat Model

For the first time it was demonstrated that an osteoinductive calcium phosphate-based putty is effective in the restoration of complex maxillofacial defects. In these defects, adequate mechanical confinement by multiple bony walls and osteoconduction from multiple surfaces are usually lacking. This study compares the efficacy of a microstructured beta-tricalcium phosphate (β-TCP) putty with autologous bone for the repair of alveolar cleft defects. A total of 10 Dutch milk goats were operated on in a split-mouth study design in which two-wall bony alveolar clefts were created and successively repaired with autologous bone (the gold standard) at one side and β-TCP putty at the other. After 24 weeks of implantation, histomorphometric and micro-computer tomography analyses proved that the β-TCP putty group showed equal bone quality and volume to clefts reconstructed with autologous bone. In addition, surgical handling of the putty is superior to the use of calcium phosphates in a granular form. Therefore, the results of this study open a clear trajectory for the clinical use of β-TCP putty in the reconstruction of the alveolar cleft and other challenging two-wall bony defects.

Gelatin-Methacryloyl Hydrogels: Towards Biofabrication-Based Tissue Repair

Research over the past decade on the cell-biomaterial interface has shifted to the third dimension. Besides mimicking the native extracellular environment by 3D cell culture, hydrogels offer the possibility to generate well-defined 3D biofabricated tissue analogs. In this context, gelatin-methacryloyl (gelMA) hydrogels have recently gained increased attention. This interest is sparked by the combination of the inherent bioactivity of gelatin and the physicochemical tailorability of photo-crosslinkable hydrogels. GelMA is a versatile matrix that can be used to engineer tissue analogs ranging from vasculature to cartilage and bone. Convergence of biological and biofabrication approaches is necessary to progress from merely proving cell functionality or construct shape fidelity towards regenerating tissues. GelMA has a critical pioneering role in this process and could be used to accelerate the development of clinically relevant applications.

Watchful waiting of the neck in early stage oral cancer is unfavourable for patients with occult nodal disease

For cT1/2N0 oral squamous cell carcinoma (OSCC), treatment of the neck is a matter of debate. Two treatment strategies were evaluated in this study: selective neck dissection (SND) and watchful waiting (WW). One hundred and twenty-three SND patients and 70 WW patients with cT1/T2N0M0 OSCC of the tongue, floor of mouth, or buccal mucosa were analysed retrospectively. Extracapsular spread (ECS), 3-year overall survival (OS), and disease-specific survival (DSS) were determined. Twenty-nine percent of SND patients and 13% of WW patients had occult nodal disease. WW-N+ patients showed thicker tumours as compared to WW-N0 patients (5mm vs. 2mm, P=0.02). WW-N+ patients showed significantly more ECS as compared to SND-N+ patients (56% vs. 14%, P=0.016) and had a significantly worse 3-year DSS than SND-N+ patients (56% vs. 82%, P=0.02). For T1 OSCCs, a watchful waiting policy is acceptable if tumour thickness proves to be <4mm. Otherwise, an additional treatment of the neck is advised, since WW-N+ patients show more ECS, with a worse DSS than SND-N+ patients.

Management of the premaxilla in the treatment of bilateral cleft of lip and palate: what can the literature tell us?

Objective

In the treatment of bilateral cleft lip and palate (BCLP) patients, there is discussion about the management of the position of the premaxilla. This literature analysis summarises the literature on managing this condition.

Materials and methods

A PubMed, Embase and Cochrane Library search was conducted resulting in 4465 articles which were screened on title and abstract.

Results

Seventy-one articles were available in full text, 16 of which were included in this literature analysis. We searched on keywords timing and technique, complications, growth of the maxilla and results after bone grafting the alveolar process. This literature analysis has shown that there are various ways to correct the position of the premaxilla. These can be divided into primary, early, late secondary and tertiary intervention before the age of 8 years, between the ages of 8 and 12 years and older than 12 years. Correction is done with surgery, orthodontics or a combination, with or without bone grafting.

Conclusions

An osteotomy of the premaxilla in combination with secondary alveolar bone grafting appears to be the most successful technique. Combining early secondary alveolar bone grafting with osteotomy creates more room to ensure a watertight closure of the nasal mucosa resulting in fewer postoperative complications. Before surgery, the orthodontist should try to optimise the position of the premaxilla for its surgical correction prior to bone grafting.

Clinical relevance

The treatment of BCLP patients is still based on experience and expert opinions. This literature analysis tries to give a summery on how to handle the protruded and displaced premaxilla.

Predictive factors for premature loss of Martin 2.7 mandibular reconstruction plates

Mandibular reconstruction with a plate, with or without a vascularised free (bone) flap, is commonly used to treat patients with a segmental mandibular defect. Common complications are loosening of the osteosynthesis screws, malposition, intraoral or extraoral exposure, or infection. To define prognostic factors for premature loss of such plates and improve future planning, we designed a retrospective study of all patients operated on between 2005 and 2011 for reconstruction of a mandibular segmental defect with a reconstruction plate with or without a free vascularised (bone) flap. Prognostic factors collected from medical records were the patient's age, sex, and American Society of Anesthesiologists (ASA) grade; treatment with radiotherapy; whether they had diabetes or smoked; the site of the mandibular defect; whether there was a dental occlusion; the number of screws used on each side, and the use of a free vascularised (bone) flap; and whether the diagnosis was of oral cancer, benign tumour, or trauma. One hundred patients were included, 79 with oral cancer, 19 with benign tumours, and 2 with trauma. In 20 patients the Martin 2.7 reconstruction plate failed. Diabetes and smoking were significant prognostic factors for premature loss of the reconstruction plate with a hazard ratio of 2.95 (95% CI 1.068-8.172), p value=0.04, for diabetes, and 2.42 (95% CI 1.006-5.824), p value=0.05, for smoking. Smokers and diabetic patients have a higher risk of failure after mandibular reconstruction with a 2.7 reconstruction plate.

The influence of a Le Fort I impaction and advancement osteotomy on smile using a modified alar cinch suture and V-Y closure: a prospective study

A previous report from the authors' department showed that a modified alar cinch suture combined with a muco-musculo-periosteal V-Y closure (mACVY) improves nasolabial mobility. To test if the improvements were equal to the range of nasolabial mobility in non-dysgnathic persons, a prospective study was carried out in 56 patients: 31 with mACVY, 25 with simple closing sutures (SCS) and 18 non-operated, angle class I volunteers. Standardized full facial frontal photographs, taken immediately preoperatively and 18 months postoperatively were used. The landmarks, alare, crista philtri and cheilion were analysed. The test has a standard deviation of 0.9 mm. Intra-group changes, paired t-test, and inter-group differences, unpaired t-test (p<0.05) were statistically analysed. The results show significant preoperative differences in nasolabial mobility compared with the control group, for both groups. Postoperative mobility improved in both groups, but significantly with mACVY with horizontal movement of cheilion and alare, and the vertical movement of crista philtri and less so for the vertical movement of crista philtri with SCS. Postoperative inter-group differences in mobility were small and significant for SCS vs the control group. It can be concluded that using mACVY improves orofacial movement to the level of normal class I volunteers.

A prospective study on the effect of modified alar cinch sutures and V-Y closure versus simple closing sutures on nasolabial changes after Le Fort I intrusion and advancement osteotomies

PURPOSE

The purpose of this study was to determine whether a modified alar cinch suture and V-Y closure (mACVY) have a beneficial effect on labial form after Le Fort I intrusion and advancement osteotomies and whether they result in excessive upward nasal tip rotation. Both are possible effects compared with simple closing sutures (SCS).

PATIENTS AND METHODS

A prospective study was carried out on 56 patients, 31 with mACVY and 25 with SCS. Lateral cephalograms taken immediately before and 18 months after operation were used, measuring horizontal and vertical changes of the following landmarks: anterior and posterior nasal spine, A-point, incision superior, pronasale, subnasale, labiale superior, and stomion superior, as well as angular changes of sella-nasion-pronasale, and changes in upper vermilion exposure. Statistical analysis was performed on intragroup, paired t test, and intergroup differences, unpaired t test (P < .05).

RESULTS

The horizontal and vertical changes of labiale superior were significantly larger for mACVY versus SCS, and the angle sella-nasion-pronasale increased in mACVY versus SCS. However, no significant difference was found for vertical changes of the nasal tip. Upper vermilion exposure increased with mACVY versus SCS.

CONCLUSION

mACVY has a beneficial effect on labial form, and excessive upward rotation of the nasal tip is prevented.