Predicting Forefoot-Orthosis Interactions in Rheumatoid Arthritis Using Computational Modelling

Foot orthoses are prescribed to reduce forefoot plantar pressures and pain in people with rheumatoid arthritis. Computational modelling can assess how the orthoses affect internal tissue stresses, but previous studies have focused on a single healthy individual. This study aimed to ascertain whether simplified forefoot models would produce differing biomechanical predictions at the orthotic interface between people with rheumatoid arthritis of varying severity, and in comparison to a healthy control. The forefoot models were developed from magnetic resonance data of 13 participants with rheumatoid arthritis and one healthy individual. Measurements of bony morphology and soft tissue thickness were taken to assess deformity. These were compared to model predictions (99th% shear strain and plantar pressure, max. pressure gradient, volume of soft tissue over 10% shear strain), alongside clinical data including body mass index and Leeds Foot Impact Scale–Impairment/Footwear score (LFIS-IF). The predicted pressure and shear strain for the healthy participant fell at the lower end of the rheumatoid models’ range. Medial first metatarsal head curvature moderately correlated to all model predicted outcomes (0.529 < r < 0.574, 0.040 < p < 0.063). BMI strongly correlated to all model predictions except pressure gradients (0.600 < r < 0.652, p < 0.05). There were no apparent relationships between model predictions and instances of bursae, erosion and synovial hypertrophy or LFIS-IF score. The forefoot models produced differing biomechanical predictions between a healthy individual and participants with rheumatoid arthritis, and between individuals with rheumatoid arthritis. Models capable of predicting subject specific biomechanical orthotic interactions could be used in the future to inform more personalised devices to protect skin and soft tissue health. While the model results did not clearly correlate with all clinical measures, there was a wide range in model predictions and morphological measures across the participants. Thus, the need for assessment of foot orthoses across a population, rather than for one individual, is clear.

Changes in Hard and Soft Tissue During the First 6 Months After Immediate Implant Placement and Provisionalization of a Single Anterior Maxillary Incisor: A Prospective Cohort Study

Background: To evaluate changes in hard and soft tissue during the first 6 months after immediate implant placement and provisionalization (IIPP) of a single maxillary incisor.Methods: Failed maxillary incisors were replaced with IIP implants in 34 patients. Intraoral scans and cone beam computed tomography (CBCT) were performed before and 6 months after IIPP. Changes in soft tissue thickness, soft tissue contour, and hard tissue contour were measured by a three-dimensional superimposition method. The correlations of hard and soft tissue contour changes were assessed.Results: A total of 31 patients completed the study. Soft tissue contour tended to collapse after 6 months. Soft tissue was significantly thickened 1–3 mm below the gingival margin. Correlation analysis showed strong correlations between the hard and soft tissue contour changes at 0–5 mm apical to the implant platform. The mid-facial recession at 6 months was −0.46 ± 0.55 mm.Conclusions: Soft tissue contour collapsed after tooth extraction, regardless of IIPP. Both soft and hard tissue change affected the soft tissue contour change.

The development and testing of Thai facial soft tissue thickness data in three-dimensional computerized forensic facial reconstruction

Forensic facial reconstruction is a useful tool to assist the public in recognizing human remains, leading to positive forensic investigation outcomes. To reproduce a virtual face, facial soft tissue thickness is one of the major guidelines to reach the accuracy and reliability for three-dimensional computerized facial reconstruction, a method that is making a significant contribution to improving forensic investigation and identification. This study aimed to develop a facial soft tissue thickness dataset for a Thai population, and test its reliability in the context of facial reconstruction. Three-dimensional facial reconstruction was conducted on four skulls (2 males and 2 females, with ages ranging between 51 to 60 years). Two main tools of three-dimensional computer animation and modeling software—Blender and Autodesk Maya—were used to rebuild the three-dimensional virtual face. The three-dimensional coordinate ( x, y, z) cutaneous landmarks on the mesh templates were aligned homologous to the facial soft tissue thickness markers on the three-dimensional skull model. The final three-dimensional virtual face was compared to the target frontal photograph using face pool comparison. Four three-dimensional virtual faces were matched at low to moderate levels, ranging from 30% to 70% accuracy. These results demonstrate that the facial soft tissue thickness database of a Thai population applied in this study could be useful for three-dimensional computerized facial reconstruction purposes.

Orthodontists in forensic facial approximation (FFA): current inter-disciplinary perspective

Forensic odontology has contributed significantly in forensic investigations and involves various branches of dentistry including orthodontics. The current communication presents evidence-based perspective highlighting synergistic union of different specialties for Forensic Facial Approximation (FFA). It brings forth commonality in principles of anthropology, forensic science, anthropometry, anatomy, paleontology, forensic odontology, with orthodontics, used in FFA. Various attributes and skills of orthodontists’ aid in dental and skull profiling and the corresponding sex, age, and ethnicity-based soft tissue assessments for facial soft tissue thickness (FSTT), may aid a life-like appearance. They can assist hard tissue profiling by their expertise in growth of skeletal and soft tissue, along with the evolutionary trends in occlusion, and diet formulations. Their knowledge in identifying teeth patterns, dental/skeletal jaw relationships, cranial/facial indices, vertical/horizontal facial proportions, can help prepare skull for orientation and reconstruction. The dental, photographic, and radiographic records maintained by orthodontists and general dentists are instrumental in data retrieval, used in various software, clinical, or research areas. These can provide normative values for comparative analysis or facial recreation. The orthodontists can also assist anthropologists and forensic specialists in the virtual reconstructions due to their ease in using latest digital technologies including three-dimensional (3D) facial scan, stereo-photogrammetry, 3D printing, automated soft-tissue landmarks, growth, and age predictions. Thus, the current study established the commonality in concepts of various forensic disciplines with orthodontics, which can strengthen both forensic on-field facial approximations and hard/soft tissue research to further enhance the accuracy of contemporary digital software used in FFA.

Relationship of tissue dimensions and three captive bolt placements on cadaver heads from mature swine (Sus scrofa domesticus) > 200 kg body weight

Three penetrating captive bolt (PCB) placements were tested on cadaver heads from swine with estimated body weight (BW) >200 kg (sows = 232.9 ± 4.1 kg; boars = 229.3 ± 2.6 kg). The objectives were to determine tissue depth, cross-sectional brain area, visible brain damage (BD), regions of BD, and bolt-brain contact; and determine relationships between external head dimensions and tissue depth at each placement. A Jarvis PAS – Type P 0.25R PCB with a Long Stunning Rod Nosepiece Assembly and 3.5 gr power loads was used at the following placements on heads from 111 sows and 46 boars after storage at 2-4° C for approximately 62 h before treatment: FRONTAL (F) – 3.5 cm superior to the optic orbits at midline, TEMPORAL (T) – at the depression posterior to the lateral canthus of the eye within the plane between the lateral canthus and the base of the ear, or BEHIND EAR (BE) – directly caudal to the pinna of the ear on the same plane as the eyes and targeting the middle of the opposite eye. For sows, the bolt path was in the plane of the brain for 42/42 (100%, 95% CI: 91.6-100.0%) F heads, 39/40 (97.5%, 95% CI: 86.8-99.9%) T heads, and 34/39 (87.5%, 95% CI: 72.6-95.7%) BE heads; for the heads that could reliably be assessed for BD damage was detected in 25/26 (96.2%, 95% CI: 80.4-99.9%) F heads, 24/35 (68.6%, 95% CI: 50.7-83.2%) T heads, and 5/40 (12.5%, 95% CI: 4.2-26.8%) BE heads. For boars, the bolt path was in the plane of the brain for 17/17 (100.0%, 95% CI: 80.5-100.0%) F heads, 18/18 (100.0%, 95% CI: 81.5-100.0%) T heads, and 14/14 (100.0%, 95% CI: 76.8-100.0%) BE heads; damage was detected in 11/12 (91.7%, 95% CI: 61.5-99.8%) F heads, 2/15 (13.3%, 95% CI: 1.7-40.5%) T heads, and 7/14 (50.0%, 95% CI: 23.0-77.0%) BE heads. Tissue depth was reported as mean ± standard error followed by 95% one-sided upper reference limit (URL). For sows, total tissue thickness was different (P < 0.05) between placements (F: 52.7 ± 1.0 mm, URL: 64.1 mm; T: 69.8 ± 1.4 mm, URL: 83.9 mm; BE: 89.3 ± 1.5 mm, URL: 103.4 mm). In boars, total tissue thickness was different (P < 0.05) between placements (F: 41.2 ± 2.1 mm, URL: 56.3 mm; T: 73.2 ± 1.5 mm, URL: 83.4 mm; BE: 90.9 ± 3.5 mm, URL: 113.5 mm). For swine > 200 kg BW, F placement may be more effective than T or BE due to less soft tissue thickness, which may reduce concussive force. The brain was within the plane of bolt travel for 100% of F heads with brain damage for 96.2% and 91.7% of F sow and boar heads, respectively.

The Vertical Soft Tissue Thickness and Subcrestal Implant Placement as Factors for Peri-implant Crestal bone Stability

Aim The aim of this prospective study was to determine the influence of vertical soft tissue thickness on bone level changes in platform-switched implants placed eqicrestally or subcrestally and restored with screw-retained or cement-retained restorations. Methods Platform-switched bone-level implants were placed in a single stage manner in the posterior mandibular region. Implant sites were divided into thick (control) and thin (test) vertical soft tissue groups. The implants in the control group were placed equicrestally. The implant sites from the control group were randomly allocated to receive equicrestally or subcrestally placed implants. Bone remodeling/loss was radiographically measured at baseline, three months postoperatively and six months after delivery of final prosthetic restoration. Results The mean crestal bone loss values three months postoperatively and six months post prosthetic restoration were higher in sites with thin versus sites with thick gingiva. In implant sites with thin gingiva, subcrestally placed implants presented less bone loss than eqicrestally placed implants. Conclusion Platform switched implants are prone to more bone loss when they are placed in sites with thin soft tissue, regardless of the type of final restoration (screw-retained or cement-retained). Subcrestal placement of platform-switched implants can prevent crestal bone loss in sites with vertical soft tissue thickness < 3 mm.

Evaluation of Ultrasound Guided Measurement of Anterior Neck Soft Tissue Thickness in Predicting Difficult Laryngoscopy in Obese Patients

Background: The incidence of unanticipated difficult airway is 14.3-17.5% in obese. Preoperative difficult airway prediction is important to avoid postoperative morbidity and mortality. USG guided measurement of anterior neck soft tissue thickness can be used to predict difficult laryngoscopy in obese patients and we thus undertook this study to determine the role of USG guided measurement of anterior neck thickness at the level of vocal cords in difficult laryngoscopy prediction. Methods: Sixty obese patients (BMI≥30kg/m2), 18-70 years of age of either sex, were included. Anterior neck soft tissue thickness was measured by ultrasound as the distance from the skin to the anterior commissure of vocal cord. Neck circumference was measured at mid neck just below the laryngeal prominence with the subjects standing upright and facing forward with shoulders relaxed. Thyromental distance, sternomental distance, Mallampatti score and neck circumference were also recorded. Results: The cut off values of BMI (46.94 kg/m2), neck circumference (41.5 cm) and anterior neck soft tissue thickness (22.1mm). Four patients in the morbidly obese and 80% of the superobese patients had a difficult laryngoscopy. Sixteen (26.67%) patients had an anterior neck soft tissue thickness of >22.1mm. Of these, 11 (91.67%) patients had difficult laryngoscopy while one (8.33%) patient with anterior neck soft tissue thickness ≤ 22.1mm had difficult laryngoscopy (P<0.05). There was also significant association between neck circumference and BMI. Conclusion: The USG guided measurement of anterior neck soft tissue thickness, BMI and neck circumference can reliably predict difficult laryngoscopy in obese patients.

Aesthetic Outcomes of Early Occlusal Loaded SLA Dental Implants with Hydroxyl Ion Modified Surface—A 12 Months Prospective Study

Background: Many efforts have been made recently to arrange a newer, more hydrophilic and more osteoconductive implant surface. One of the possible options in this matter is modification with hydroxyl ion. Materials and Methods: Forty implants with the diameters 3.5 and 4.0 mm were inserted as a single missing tooth restoration protocol in the frontal aspect of the maxilla. All implants were loaded early in a 4 week period. Prior to and during the surgery, the following indices were considered: height of keratinized tissue, the thickness of soft tissue, and the initial level of bone tissue. After 12 months, the implant and the tissues in its direct vicinity were evaluated once more with the following indices: marginal bone loss (MBL), height of keratinized tissue (HKT), probing pocket depth (PPD), pink and white aesthetics scores (PES, WES), as well as pain sensations combined with the procedure (VAS). All results were related to the diameter of the implant and thickness of periodontal biotype. Results: High aesthetic outcomes were reported regardless of soft tissue thickness and implant diameter. The VAS score was higher for the 4.0 implant group, and the thickness of soft tissue had no influence on VAS. In case of implantation in thin or soft tissue, higher MBL levels were reported (0.26 mm), while in case of a thick phenotype, MBL was 0.06 mm. Conclusions: Hydrophilic surface implants can be used for a protocol of early functional occlusal loading. The initial thickness of soft tissue does not influence aesthetic outcomes and does not raise pain perception, although it may elevate crestal bone resorption.

A computerized facial approximation method for archaic humans based on dense facial soft tissue thickness depths

Facial approximation (FA) is a common tool used to recreate the possible facial appearance of a deceased person based on the relationship between soft tissue and the skull. Although this technique has been primarily applied to modern humans in the realm of forensic science and archaeology, only a few studies have attempted to produce FAs for archaic humans. This study presented a computerized FA approach for archaic humans based on the assumption that the facial soft tissue thickness depths (FSTDs) of modern living humans are similar to those of archaic humans. Additionally, we employed geometric morphometrics (GM) to examine the geometric morphological variations between the approximated faces and modern human faces. Our method has been applied to the Jinniushan (JNS) 1 archaic human, which is one of the most important fossils of the Middle Pleistocene, dating back to approximately 260,000 BP. The overall shape of the approximated face has a relatively lower forehead and robust eyebrows; a protruding, wider, and elongated middle and upper face; and a broad and short nose. Results also indicate skull morphology and the distribution of FSTDs influence the approximated face. These experiments demonstrate that the proposed method can approximate a plausible and reproducible face of an archaic human.

Evaluation of facial soft tissue thickness in asymmetric mandibular deformities after orthognathic surgery

Objectives The purpose of this study was to compare differences in facial soft tissue thickness in three-dimensional (3D) images before and after orthognathic surgery in patients with skeletal Class III malocclusion and to obtain a better understanding of the relationship between hard and soft tissue changes after surgery. Materials and method The present retrospective study included 31 patients with skeletal Class III malocclusion with mandibular chin deviation greater than 4 mm who had undergone cone-beam computed tomography before and 6 months after surgery. Seven bilateral points were established. Measurements were taken from software-generated multiplanar reconstructions. The predictor variables were timing (pre- and postoperatively) and side (deviated vs. nondedicated). A regression model and correlation analysis were conducted for statistical analysis. Results The difference of bilateral facial soft tissue thickness was statistically significantly different between deviated and nondeviated sides (P < 0.05), with lower values observed on the deviated side. The soft tissue thickness has become nearly symmetric at local regions of the lower thirds of the face after orthognathic surgery. However, most measurements showed a negative correlation between changes in soft tissue thickness and changes in bone tissues. Conclusions Skeletal Class III malocclusion with facial asymmetry is accompanied by differences in soft tissue thickness when comparing Dev and N-Dev sides of the posterior region of the mandible, where soft tissues are thinner on the Dev side. Soft tissue thickness can compensate for or camouflage the underlying asymmetric mandible. In addition, the asymmetric soft tissue thickness on the lower third of the face can be partially improved by orthognathic surgery, but the amount of soft tissue thickness change is not consistent with that of hard tissue positional change.