Search Results (24)

Pressures applied to horses via nosebands are of growing concern. The current study applied noseband pressure to the head of a dead horse. Pressure sensors were placed on the left nasal bone to record pressures as the noseband was progressively tightened. Tightness increased as predicated by holes in the strap of the noseband (as supplied) through eight steps from two fingers’ space, assessed using the standard International Society for Equitation Science Taper Gauge through to zero space. Sensors were also placed at the midline frontal plane and intra-orally at the level of the second premolar tooth. A strain gauge integrated into the noseband recorded tensions within the noseband at each tightness level, and a digital taper gauge under the noseband recorded forces on the face. Pressures at the left nasal bone rose to 403 kPa, while those at the frontal nasal plane reached 185 kPa. Pressures rose rapidly once the noseband was tightened at the equivalent of 1.4 fingers’ space under the noseband. These findings may help to explain cases of bone and skin damage at the noseband location and indicate the need to ensure that nosebands can accommodate more than the equivalent of 1.4 fingers beneath them in the nasal midline. Given that pressures are expected to rise from those reported here when horses wear bits, locomote, and when the reins are under tension, we conclude that the traditional provision of two fingers’ space should be retained. Full article

Background: Mucostatic impressions have been always indicated in thin, sharp, or flabby ridges, and have been addressed for their beneficial effect on long-term residual ridge stability. Nonetheless, a purely mucostatic impression was not possible until intraoral scans became available. This provides an option for digital removable denture which is biologically sensible but might reduce retention in comparison with a mucocompressive impression with border molding. On the other hand, pressure applied to the mucosa may have harmful effects on the long-term residual ridge stability, causing higher resorption and ultimately reduced denture retention. Hence, the possibility to merge mucostatics and mucocompressive philosophies would be a clinically and biologically sensible option for oral rehabilitation in aging populations where patients will potentially wear dentures for longer periods. This possibility is demonstrated in this technical report with a cast-free digital workflow. Technique: Baseplates for occlusion rims, closely adapted to the mucosa, were designed on intraoral scans of edentulous arches and, once 3D-printed, used to register maxillomandibular relations and information for tooth arrangement, as well as to perform border molding. Occlusion rims were then scanned and, within the 3Shape Dental System 2024 software program, the intaglio surfaces of their baseplates were segmented and inverted to obtain the digital master casts which incorporated the precise reproduction of the molded borders. Then, denture design was performed and manufactured; no limitations regarding manufacturing options are applicable to the presented technique. Conclusions: The potential benefits (i.e., improved retention in the initial period after denture delivery and the preservation of tissues) of the presented digital cast-free workflow, based on merging mucostatic and mucocompressive philosophies to obtain dentures with a mucostatic intaglio surface and functional borders, are sensible clinical outcomes which recommend the clinical application of the technique, although further validation, especially in the long term, is required. Full article

The absence of interdental papillae in dental prosthetics often leads to unsatisfactory esthetic outcomes, such as black triangles and elongated clinical crowns. While previous research has demonstrated that papillae can regenerate in a coronal direction, the underlying mechanisms remain incompletely understood. Several theories have been proposed to explain this phenomenon, but no clear cause–effect relationship has been established among the various factors involved in spontaneous papilla growth around implants. This study aims to identify and classify the factors influencing this process. Various potential contributors were analyzed, including adjacent elements, buccal–lingual papilla width, contact point position, convergent neck design, crown overcontour, intraoral negative pressure, and others. To systematically organize these factors, a modified Overton Window and a mind map were employed. The factors were categorized as cause-related, essential, or influencing based on the collective opinion of the research group following a comprehensive review of the relevant literature. In the absence of clear evidence supporting a definitive cause–effect relationship, Occam’s Razor (the principle of parsimony) was applied to identify the most plausible cause-related factors. Full article

Introduction: Mandibular complete dentures often pose challenges due to anatomical and functional limitations. Impression techniques, including functional, mucostatic, compressive, selective pressure, and neutral zone methods, play a crucial role in achieving stability and retention. In 1999, Abe introduced the Suction Effective Mandibular Complete Denture (SEMCD) technique, revolutionizing mandibular denture retention by incorporating functional extensions and achieving a peripheral seal even in the presence of mobile soft tissues. Case report: An 87-year-old male presented to a private dental clinic with the chief complaint that his current lower complete denture lacked retention and stability. Intraoral examination revealed a severely resorbed mandibular edentulous ridge with movable retromolar pads and a prominent spongy lingual area. This case report describes the integration of Abe’s concepts into a digital workflow, using a single-step intraoral scanning technique and digital design software to fabricate a mandibular denture with enhanced retention and stability. Conclusions: This approach minimizes the number of clinical steps involved, improves patient comfort, and achieves predictable outcomes, highlighting the utility of digital technologies in modern prosthodontics. Full article

Background: Cheiloscopy, a forensic technique based on the uniqueness of labial traces, has traditionally relied on analog methods. While simple, these methods present significant limitations in terms of precision and reproducibility. The introduction of 3D technology, specifically high-resolution optical scanners, represents a pivotal advancement in overcoming these challenges. Objective: This pilot study aimed to explore the feasibility and potential advantages of 3D cheiloscopy in forensic science by analyzing its precision and repeatability compared to traditional analog methods. Methods: Two participants were selected as a pilot sample, and their lip impressions were captured using both analog techniques and a high-resolution intraoral scanner (Medit i700). A total of 40 samples were collected, equally distributed among operators with varying levels of experience. Surface deviation analysis was performed to compare the methods. Results: The 3D models demonstrated greater uniformity and resolution compared to the analog impressions, which were more prone to errors caused by material quality or operator pressure. Surface deviation analysis showed an average similarity of 70%, with a standard deviation of 0.229 mm. The digital methods also significantly reduced operator-dependent variability. Conclusions: This pilot study highlights the potential of 3D cheiloscopy to improve precision and standardization in forensic applications. While the small sample size limits the generalizability of the findings, the results provide a foundation for further research with larger and more diverse datasets. Future studies should explore the capability of 3D cheiloscopy to accurately match individuals and further validate its applicability in forensic and clinical contexts. Full article

In our previous article, we observed and measured a spontaneous growth in the coronal direction of the keratinized tissues present around implants. This growth involved both free margins and interdental papillae, and we indicated our hypothesis on the probable cause of this still-unexplained phenomenon. The growth of oral soft tissues involves several other structures, such as the linea alba and tongue indentation. Our idea holds that growth of these tissues is generated by the negative intraoral pressure created in the oral phase of swallowing and the subsequent resting position, which through the resulting suction causes a shift of these soft structures in the gaps around the dental crowns. Other hypotheses have been suggested in the past to understand this phenomenon of soft tissue growth, which still lacks data supporting etiological evidence. The purpose of this article is to thoroughly analyze and verify our model by comparing the clinical observations with citations and examples from the literature, combined with notions of physiology, biology, and physics that help in clarifying these events. To better explain the mechanisms of oral soft tissue growth, photographs of clinical cases paradigmatic of the phenomenon are shown. Full article

Closing a recurrent oroantral fistula (OAF) that occurs at an infected sinus augmentation site is a challenge for clinicians. The recurrent OAF has a detrimental impact on bone regeneration and subsequent implant placement. This case report includes three cases in which sinus graft infection and OAF occurred after maxillary sinus augmentation (MSA). In these cases, treatments to control sinus infection were performed using an otolaryngologist; then, intraoral interventions comprising mucosal flap procedures, bone grafts, and barrier membrane applications were performed 2–5 times by oral surgeons. Nevertheless, OAF recurred persistently. The failure to stop OAF recurrence may be due to the inability to effectively block air pressure at the OAF site. Following a comprehensive debridement of the infected tissue at the previous sinus augmentation site, a pouch was created through sinus mucosal elevation. The perforated sinus mucosa at the OAF site was covered with a non-resorbable membrane in one case and with resorbable collagen membranes in the other two cases, followed by bone grafting within the pouch. Lastly, this procedure was completed by blocking the entrance of the pouch with a cortical bone shell graft and a resorbable collagen membrane. The cortical bone shell graft, obstructing the air pressure from the nasal cavity, facilitated bone formation, and, ultimately, allowed for implant placement. Within the limitations of the present case report, the application of a guided bone regeneration technique involving a cortical bone shell graft and a barrier membrane enabled the closure of the recurrent OAF and subsequent implant placement. Full article

Blood oxygen saturation (SpO₂) is an essential indicator of a patient’s general condition. However, conventional measurement methods have some issues such as time delay and interference by ambient light. Improved measurement methods must be developed, and there are no reports on intraoral measurements of SpO₂ using wearable devices. Therefore, we aimed to establish an intraoral SpO₂ measurement method for the first time. Twelve healthy adults participated in this study. The following steps were taken: (1) to identify the optimal measurement location, mid-perfusion index (PI) values were measured at six places on the mucosa of the maxilla, (2) to validate the optimal measurement pressure, PI values were obtained at different pressures, and (3) using the proposed mouthpiece device, SpO₂ values in the oral cavity and on the finger were analyzed during breath-holding. The highest PI values were observed in the palatal gingiva of the maxillary canine teeth, with high PI values at pressures ranging from 0.3 to 0.8 N. In addition, changes in SpO₂ were detected approximately 7 s faster in the oral cavity than those on the finger, which is attributed to their proximity to the heart. This study demonstrates the advantage of the oral cavity for acquiring biological information using a novel device. Full article

Although digital impression using an intraoral scanner (IOS) has been applied for removable partial denture (RPD) fabrication, it is still unclear how the morphology of a residual ridge recorded by digital impression would differ from that recorded by conventional impression. This in vivo study investigated the morphological difference in the recorded residual ridge between digital and conventional impressions. Vertical and horizontal displacements (VD and HD) in residual ridges recorded by digital and conventional impressions were assessed in 22 participants (15 female; mean age 78.2 years) based on the morphology of the tissue surface of in-use RPD. Additionally, the mucosal thickness of the residual ridge was recorded using an ultrasound diagnostic device. VD and HD were compared using the Wilcoxon signed-rank test, and the correlation of mucosal thickness with VD and HD was analyzed using Spearman’s ρ. The VD of digital impression was significantly greater than that of a conventional impression (p = 0.031), while no significant difference was found in HD (p = 0.322). Meanwhile, the mucosal thickness showed no significant correlation with the recorded morphology of the residual ridge, regardless of the impression techniques. It was concluded that the digital impression would result in a greater displacement in the height of the residual ridge from the morphology of in-use RPD than the conventional impression. Full article

The Tübingen Palatal Plate (TPP) is a minimally invasive yet highly effective functional orthodontic treatment for upper airway obstruction in infants with Robin Sequence (RS). It consists of a palatal plate to cover the cleft and a velar extension that shifts the root of the tongue forward. We review our practical experience with this approach. First, upon admission, our local orthodontists perform an (3-D) intraoral scan of the maxilla. Based on the scan data, the TPP is manufactured in a semi-digital workflow. The length and angulation of its extension is checked via awake laryngoscopy and the effectiveness confirmed by a sleep study. Plates are kept in place by adhesive cream. When inserting the TPP, the tip of the tongue must be visible. Next, metal fixation bows should be secured to the forehead using tape and elastic bands. Plates are removed daily for cleaning, and the oral mucosa is then checked for pressure marks. Feeding training (initially only via finger feeding) may even start before plate insertion. Breathing often normalizes immediately once the plate is inserted. For isolated RS, we have never had to perform a tracheostomy. This has largely been possible through our highly dedicated and competent team, particularly the nursing staff, and the early involvement of parents. Full article

The intelligent tongue control system is of great significance for assisting the independent life of patients with a limb disability. In order to more accurately control the assisted living equipment of incompetent patients and solve the power-loss problem of the intelligent tongue control system, this research designs a non-invasive pressure sensor array for tongue touch signal detection in the oral cavity and proposes a tongue control system based on RSIC-V edge computing. The system converts the tongue touch pressure data into specific control instructions on the edge of the RSIC-V chip and transmits them to the receiver, thus reducing the transmission of data. This study takes control of the wheelchair motor as the test object. In the experiment, the speed response time test, the center click task, and the power consumption experiment are carried out, whose results show that the adaptive fuzzy PID control algorithm has good robustness in the system; when the DC motor with a given speed of 750 r/min reaches the steady state, its rise time is 0.108 s and the adjustment time is 0.59 s. The dynamic power consumption of the non-intrusive intraoral stand-alone tongue control system proposed in this paper is found to be 3.745 MW, which is 11.5% lower than the total power consumption of the sTD system. Full article

(1) Background: This study aims to evaluate the occlusal force distribution across different quadrants during the placement of orthodontic retainers fabricated using a biocompatible material via digital design. (2) Materials and Methods: A cohort of 21 patients in the retention phase following orthodontic treatment was included in this study. Intraoral scans were obtained using Trios color (3Shape). For retainer fabrication, the splint studio module of the 3Shape design software was utilized. Occlusal evaluation was performed using T-Scan Novus (Tekscan). The Kolmogorov–Smirnov test, Wilcoxon signed ranks test, and Mann–Whitney U test were used for statistical analysis. (3) Results: The digital design set evenly distributed contacts on all occluding surfaces. These contacts, uniform in area, turned out to be uneven in pressure: right distal—37.14%, right frontal—11.4%, left frontal—11.46%, and left distal—39.99%. (4) Conclusions: The results of the study indicate that the digital design workflow has the capability to achieve uniform contact distribution by area. However, despite the achievement of uniform contact distribution, the study found that there was an unequal distribution of occlusal forces. Specifically, the distal sections of the teeth experienced significantly higher loading compared to the frontal sections. Full article

Lip augmentation procedures have become gradually more popular and common due to cultural tendencies and an increasing association of the appearance of the lips with both beauty and youth. Different dermal fillers have been proposed for lip augmentation—such as collagen, calcium hydroxylapatite, hyaluronic acid, and polylactic acid—which are used as temporary fillers. The present case report describes the histopathologic and clinical management of one case of HA filler migrating into the intraoral cheek, which caused discomfort by intraoral swelling. There is also a review of the relevant literature. A female patient, V.A., 34 years old, smoker, no allergies to drug and food substances, came to our attention. The patient was referred to the Department of Innovative Technology in Medicine and Dentistry of the University “G. D’Annunzio” of Chieti-Pescara in Italy by her dentist for the removal of a mass present in the right cheek. The clinical examination of the patient revealed a single mobile mass mimicking a soft tissue tumor in the right anterior cheek. The mass was palpable and approximately 2 cm long and was causing pain and swelling. The mucosa appeared healthy without ulcers. The filler, which had migrated into the cheek, was removed by reaching it with a scalped blade. The material was stored immediately in 10% buffered formalin and processed for histological analysis. The literature search was carried out in accordance with the criteria of the PICO guidelines. Observed histologically, the filler was surrounded by fibroblasts and a few inflammatory cells and giant cells without granuloma formation. The clinical diagnosis was swelling and discomfort caused by chewing trauma, while the histological examination excluded discomfort due to a foreign body reaction caused by the HA used for a lip augmentation procedure. In conclusion, the high-pressure and high-volume filler injections probably caused a detachment of the tissues, with the orbicularis oris muscle concurrently acting as a pump and moving the HA implant, causing migration to the area with low-density tissue such as the cheek. Full article

In addition to mandibular advancement devices, dental expansion appliances are an important clinical approach for achieving an increased intra-oral space that promotes airflow and lessens the frequency or severity of apneic events in patients diagnosed with obstructive sleep apnea (OSA). It has been thought that dental expansion in adults must be preceded by oral surgery; however, in this paper, we examine the results of a new technique for slow maxillary expansion without any surgical procedures. The palatal expansion device, DNA (Daytime-Nighttime Appliance), was reviewed in this retrospective study, particularly regarding its effects on measurements of transpalatal width, airway volume, and apnea-hypopnea indices (AHI) as well as its common modalities and complications. The DNA effectively reduced AHI by 46% (p = 0.00001) and significantly increased both airway volume and transpalatal width (p < 0.00001). After DNA treatment, 80% of patients showed some improvement in AHI scores with 28% of patients having their OSA symptoms completely resolved. Compared to the use of mandibular appliances, this approach is intended to create a sustained improvement in airway management that can reduce or eliminate dependence on continuous positive airway pressure (CPAP) or other OSA treatment devices. Full article

Technological advancements are enabling new applications within biomedical engineering. As a connection point between the outer environment and the human system, the oral cavity offers unique opportunities for sensing technologies. This paper systematically reviews the performance of measurement systems tested in the human oral cavity. Performance was defined by metrics related to accuracy and agreement estimation. A comprehensive search identifying human studies that reported on the accuracy or agreement of intraoral sensors found 85 research papers. Most of the literature (62%) was in dentistry, followed by neurology (21%), and physical medicine and rehabilitation (12%). The remaining papers were on internal medicine, obstetrics, and aerospace medicine. Most of the studies applied force or pressure sensors (32%), while optical and image sensors were applied most widely across fields. The main challenges for future adoption include the lack of large human trials, the maturity of emerging technologies (e.g., biochemical sensors), and the absence of standardization of evaluation in specific fields. New research should aim to employ robust performance metrics to evaluate their systems and incorporate real-world evidence as part of the evaluation process. Oral cavity sensors offer the potential for applications in healthcare and wellbeing, but for many technologies, more research is needed. Full article