Bone Wall Research Articles

The Use of the Facial Sinus Wall as Bone Shell Onlay Graft for Maxillary Posterior Ridge Reconstruction: A Retrospective Case Series.

To evaluate the performance and clinical outcome of vertical and horizontal bone augmentation (VHBA) in posterior maxillary regions combining lateral window sinus floor elevation (LWSFE) with a horizontal bone shell technique applying the maxillary facial sinus wall as a bone plate. In 18 patients, LWSFE was combined with a horizontal bone shield augmentation procedure utilizing the maxillary facial sinus bone wall as a lateral bone plate. Both the sinus cavity and the lateral bone box created were grafted with a mixture of autogenous bone/venous blood and bovine bone mineral. The primary aim was to assess the performance of combined techniques enabling subsequent implant placement. Using radiographic measurements (preoperative, after VHBA, at implant placement, and at follow-up), bone gain/reduction of augmented horizontal ridge width (HRW) and vertical bone height (VBH) were evaluated. Additionally, clinical outcome assessing implant survival/success rate, marginal bone loss (MBL), and implant health (mucositis/peri-implantitis) was evaluated. For the combined VHBA techniques, HRW and VBH increased significantly (p < 0.001) from preoperative 3.5 ± 1.4 mm/3.6 ± 2.1 mm to 9.7 ± 1.9 mm/18.0 ± 1.6 mm post-augmentation. However, HRW and VBH dimensions decreased up to 8.9 ± 1.8 mm/17.1 ± 1.4 mm at implant placement and 8.6 ± 1.7 mm/16.7 ± 1.3 mm at follow-up evaluation (3.8 ± 1.8 years; p < 0.001, respectively). Augmented bone reduction was significantly higher (-7.7%) between the augmentation procedure and implant placement than in the post-implant-placement period (-2.5%). All implants survived (100%) representing peri-implant MBL of -0.9 ± 0.7 mm, pocket depth of 3.4 + 1.8 mm, and prevalences of 5%/0% for peri-implant mucositis/peri-implantitis. The combination of horizontal bone augmentation using local bone shield transfer from the maxillary facial sinus wall with LWSFE enables sufficient reconstruction of maxillary posterior ridge.

The interplay between prehistoric vegetation, climatic fluctuations and anthropogenic activities in Central China

The interaction between climate, hydrological environment, and human activities in prehistoric times has consistently attracted significant interest. However, the process and mechanism of this interaction remain unclear due to a lack of detailed materials that provide information on both human activity and environmental evolution. Here we present a comprehensive dataset of optically stimulated luminescence (OSL) dating and pollen analysis derived from lacustrine facies deposits in the vicinity of the Dongzhao Site in Central China, which is a key region for the origin and development of Chinese civilization. These data have revealed the existence of multiple cycles of environment-human interaction during prehistoric periods. The gradual improvement in the climate and minor fluctuations facilitated the settlement of prehistoric populations in the region, fostering uninterrupted cultural development for millennia since the early Holocene. The increase in population and intensification of human activities significantly affected regional vegetation, resulting in a decrease in the number of trees around 4.0 ka BP. Environmental changes influenced the prehistoric architectural style, resulting in a decrease in houses with “wood bone and mud walls” that were prevalent during the Yangshao periods (7.0–5.0 ka BP) due to a lack of trees. Our research once again highlights the perpetual cycle of interdependence and interaction between natural environments and human activities.

Morphology and thickness of the buccal bone wall of the maxillary central incisors in population: a CBCT study

Morphology and thickness of the buccal bone wall of the maxillary central incisors in population: a CBCT study

Management of Neglected Facial Fracture: A Case Report

Introduction: Neglected fracture occurs where there has been a delay of more than 30 days. The maxillofacial fracture complex is the most common fracture in traffic accidents. The most common maxillofacial fractures are Naso-Orbito-Etmoid (NOE), Lefort fracture, Zygomatic Complex (ZMC), Palate Fracture, and Parasymphysis Fracture. Neglected fractures lead to delayed treatment, worsening conditions, and even disability. Case: A 52-year-old male patient presents with complaints of facial bone fracture after being involved in a motor vehicle accident. CT scan examination showed: Multiple fractures of the bilateral nasal bones, interethmoidal septum, anterior walls of bilateral frontal sinuses, bilateral lamina papyracea of the ethmoid bone, anterior, medial, and lateral walls of bilateral maxillary bones all support Le Fort II. fracture, extending to bilateral dentoalveolar processes, bilateral zygomatic bones, and right mandibular parasymphysis. Case Management: The ORIF technique was used for the upper, middle, and lower face fractures in a preferred order. The palatal reduction and fixation step was frequently the first in this sequence. When proper occlusion was achieved, it was maintained by intermaxillary fixation. Conclusion: There was a significant result in correcting the functional, mastication, and aesthetic of the mid and lower face by using surgical management of facial fractures using ORIF. Keywords: Facial fracture, Neglected fracture, ORIF

Morphological remodeling of the repaired sigmoid sinus bone wall in patients with pulsatile tinnitus after successful surgical reconstruction: an ultra-high-resolution CT study.

Sigmoid sinus wall reconstruction (SSWR) is an effective treatment for pulsatile tinnitus (PT). However, follow-up postoperative imaging manifestations have not been extensively reported. To evaluate the morphological changes in patients with PT after successful SSWR using ultra-high-resolution computed tomography (U-HRCT). Data were retrospectively analyzed from 10 patients with PT who underwent successful SSWR primarily with autologous bone powder. U-HRCT scans were performed within 3 days of surgery and repeated 6 months later. The integrity, relative density, extent, and shape of the repaired wall were analyzed. The chi-square test was used to compare the categorical variables and the Phi (φ) coefficient was used to represent the magnitude of the correlation. Among the 10 patients with PT, 1 (10%) achieved complete coverage of the defect with the residual bone, 8 (80%) had partial coverage, and 1 (10%) showed complete separation. A gap between the repaired wall and residual bone in the initial U-HRCT was linked to incomplete defect coverage in the subsequent U-HRCT scan (P < 0.001, φ = 0.903). The repaired wall shrank from the periphery to the center and the density increased. The repaired wall compressed into the sigmoid sinus retracts over time, reshaping into a naturally curved sigmoid sinus sulcus. Morphological remodeling is a typical characteristic of the repaired sigmoid sinus wall in patients with PT. Short-term incomplete repair may imply incomplete coverage of the defect in the future, but this is not correlated with recurrence.

Prosthetic Soft Tissue Management in Esthetic Implant Restorations, Part I: Presurgical Planning, Implant Placement, and Restoration Timing. A Narrative Review.

This two-part review article delineates various techniques to enhance esthetic outcomes in anterior implant treatments. Part I concentrates on presurgical measures, case selection, implant placement, and restoration timing. Part II discusses post-surgical steps, the temporary restoration phase, the emergence profile contour, abutment types, and impression techniques. A comprehensive search was conducted using Medline/PubMed, Embase, Scopus, and the Cochrane Library. The primary keywords included were "Dental Implants," "Dental Prosthesis, Implant-Supported," "Esthetics, Dental," "Dental Impression Techniques," and "Tissue Management." Initially, 1472 studies were identified, from which 187 were selected based on publication year and title relevance. After removing duplicates, 84 abstracts were reviewed in full text, culminating in 59 studies being thoroughly analyzed. Optimal esthetics in implant restorations are attainable through meticulous treatment planning, precise surgical execution, and systematic restorative steps, ensuring predictable outcomes. Factors such as a thick gingival biotype, an intact facial bone wall, and atraumatic extraction significantly contribute to superior esthetic results. Immediate implant placement combined with immediate provisionalization provides the most predictable outcomes by supporting and maintaining soft tissue architecture. Conversely, delayed implant placement and provisionalization often require extensive manipulation of collapsed soft tissues to achieve desired esthetics.

BUCCAL FAT PAD LIFT : A TECHNICAL NOTE

The buccal fat pad is largely involved to close oro-antral communication (OAC) . The implant rehabilitation of the maxillary posterior area after OAC is a surgical challenge. The difficulty of this rehabilitation remains in the absence of a lateral and crestal bone wall. The buccal fat pad lift was performed under general anaesthesia. This involved lifting the buccal fat pad and the sinus mucosa, which they were fused and filled the gap with a biomaterial. The osteogenic properties of the environment will enable osseointegration of the biomaterial. This technique requires a relevant surgical experience. It is a reliable and valid surgical solution to rehabilitate the maxillary posterior area for dental implant placement.

Micro-XCT analysis of anatomical features and dimensions of the incisive canal: implications for dental implant treatment in the anterior maxilla

BackgroundThis study used micro-focus X-ray Computed Tomography (micro-XCT) to examine the anatomical differences and dimensions of the maxillary incisive canal (MIC) in a South African population. The accurate imaging yielded dependable results that support earlier research and enhance anterior maxilla surgery planning. Furthermore, these anatomical features are compared between various racial and gender groupings in the study.MethodsUsing a micro-XCT scanner, 108 human cadaver skulls from the Pretoria Bone Collection were scanned and included in the study. Advanced volume rendering software was employed for measuring the MIC length, diameter, shape, and the buccal bone wall measurements in relation to the MIC.ResultsSignificant anatomical variation in the size and shape of the MIC was identified in the population, with variations seen between racial and gender groups. The incisive foramen (ICO) mean diameter was 6.61 mm, and the MIC length varied from 4.96 to 20.10 mm. There were significant differences in the buccal alveolar bone height between different ethnic groups and gender. Regarding morphological patterns in coronal and sagittal views, single canals were more common in the black population while Y-shaped canals were more common in the white population. The study also introduced a new metric by measuring the mean distances between teeth #11 and #21 and the ICO (1.83 mm and 1.88 mm respectively).ConclusionsThe complex anatomical differences of the MIC in a South African population were clarified. Clinicians should be aware of tooth sockets in near proximity to the MIC and perform accurate preoperative assessment using sophisticated 3-D imaging and preferable guided implant placement in the anterior maxilla.

Optimizing surgical approaches for lacrimal gland adenoid cystic carcinoma to minimize cross-organ invasion.

To evaluate the outcomes of eye-sparing surgery for lacrimal gland adenoid cystic carcinoma and the impact on tumor recurrence and orbital integrity. The study enrolled four patients with recurrent lacrimal gland adenoid cystic carcinoma. The outcome focused on the relevance of the integrity of the lateral orbital wall to the occurrence of extraorbital metastasis in the local recurrence of lacrimal gland adenoid cystic carcinoma. Three patients underwent eye-sparing surgery via lateral orbitotomy without postoperative radiotherapy, and one patient who underwent eye-sparing surgery via sub-brow approach. These four patients all demonstrated a recurrence involving the invasion of extraorbital tissues as metastatic form through surgical bone seams. Preserving intact orbital bone tissue is crucial for mitigating direct cross-organ metastasis of lacrimal gland adenoid cystic carcinoma. The findings suggest avoiding the lateral orbitotomy approach with no or limited orbital bone wall invasion.

Postcranial anatomy of Dsungaripterus weii (Pterosauria: Ornithocheiroidea) from the Lower Cretaceous of Wuerho, China

ABSTRACT Ornithocheiroidea was a globally diverse group of pterosaurs during the Cretaceous. However, well-documented ornithocheiroids are highly derived, hampering our understanding on the morphological evolution of this clade. Dsungaripterus weii Young, 1964 from the Lower Cretaceous Tugulu Group (Valanginian) of the Junggar Basin is an iconic early member of Ornithocheiroidea. Dsungaripterus is known from numerous three-dimensionally preserved specimens, ranging from isolated bones to partially articulated individuals. Here we provide a comprehensive description of the postcranium of Dsungaripterus. We find that Dsungaripterus has many autapomorphies in the postcranial skeleton parallelling its unique skull, including the asynchronous fusion between the sacrum and pelvis and a posterodorsal fossa of the humerus with a paper-thin bone wall. Dsungaripterus also displays some plesiomorphic features of Ornithoecheiroidea, for example, limb bones with relatively thick bone walls, variably reduced pneumatic features in cervical vertebrae and appendicular skeletons, absence of spinoprezygapophyseal and spinopostzygapophyseal ridges in middle-series cervical vertebrae, at least one metacarpal articulating with the distal syncarpal, and a distally displaced adductor ridge on the femur. Additionally, Dsungaripterus possesses some unexpected features possibly convergent with other members of Ornithocheiroidea. Although the postcranial skeletons of Dsungaripterus are represented by osteologically mature specimens, notable morphological variation is present. Functional reconstructions of several aspects of the postcranial skeleton of Dsungaripterus are elucidated, including the arrangement of the metacarpophalangeal region during terrestrial locomotion. Niche partitioning between the two dsungaripterids from the Tugulu Group of Wuerho, Dsungaripterus and Noripterus, is supported by their distinct dentitions, neck morphology, and limb proportions.

Prognostic significance of malignant pleural effusions in patients with advanced luminal B breast cancer

BackgroundThough the survival of breast cancer (BC) patients with malignant pleural effusion (MPE) has been studied, this has not been specifically studied in the luminal B subtype. Therefore, this study investigated the characteristics and survival of luminal B-BC patients presenting with MPE.MethodsWe retrospectively analyzed 141 patients diagnosed with postoperative advanced Luminal B breast cancer, including 54 cases with MPE and 87 cases without MPE at the Tianjin Cancer Hospital from January 2012 to January 2015. We assessed the clinical characteristics between the groups.ResultsThe mean age of all patients was 47 years, with no significant difference between the two groups. Altogether, 29 (33%), 24 (28%), 28 (32%), 45 (52%), and 10 (11%) patients had lung, liver, bone, lymph node, and chest wall metastases, respectively. In addition. The difference in overall survival between the two groups was not significant (P>0.05). However, cox regression analysis showed that only the tumor clinical stage at initial diagnosis was related to short overall survival. Further, we conducted a subgroup analysis and found that the higher the clinical stage at initial diagnosis in age < 50 years patients, the shorter the overall survival, while age > 50 years patients was not. (P < 0.05).ConclusionsThere was no difference in the overall survival between luminal B-BC patients with MPE and those without. Clinical stages at initial diagnosis were an independent prognostic factor for age < 50 years luminal B BC with MPE overall survival. Our results may help clinicians make positive decisions regarding personalized treatment of luminal B-BC with MPE.

Orbital injuries: aspects of forensic medical examination in assessing the severity of harm caused to human health

Background: Forensic examination plays a key role in establishing the severity of injuries, especially of orbital trauma, which can lead to serious consequences, including vision loss. Examination of forensic reports associated with orbital trauma provides valuable information about the nature of the injuries, their prevalence, and factors influencing the severity of the injury. Aim: Analysis of the possibilities of an interdisciplinary approach based on the presence of a full ophthalmological status and computed tomography data of the skull in conducting a forensic medical examination of living persons and in the final qualification of the degree of harm to health in orbital injuries. Materials and methods: An analysis of 37 completed forensic medical examinations of living persons with orbital injuries who were treated in multidisciplinary hospitals in Moscow was carried out. The forensic medical examination was carried out in the Bureau of Forensic Medical Examination of the Moscow Health Department. In 23 cases, the ophthalmological status was assessed at periods from 1 week to 6 months after the injury. In all cases (n = 37; 100%), computed tomography of the facial and cerebral skull was performed. The age of the victims at the time of injury ranged from 12 to 82 years (average 39.7 ± 9.2 years). There were 29 adults among the victims (78.3%), 8 children (21.6%). In terms of gender distribution, there was a significant male predominance — 27 men (73%) versus 10 women (27%). Results: According to the results of the analysis of forensic medical reports, polytrauma with the simultaneous presence of several severe injuries to various organs and systems, combined with orbital trauma, was recorded in 12 victims (32.4%). A combination of traumatic brain injury and orbital injury without involvement of other organs and systems was detected in 9 victims (24.3%), isolated orbital trauma — in 13 people (35.1%), isolated injury of two orbits simultaneously — in 3 victims (8.1%). From the conclusions of forensic experts, it follows that in 89% of cases, the bone walls of the orbits, formed by the frontal, ethmoid and sphenoid bones, as well as the upper jaw, were damaged, which could subsequently lead to damage to the globe, optic nerve and other orbital structures. Damage to the soft tissue of the orbits with globe contusion was noted in 11% of cases. In 3 cases (n = 3; 8.1%), moderate harm to health was determined based on significant persistent loss of general ability to work. In 14 cases (n = 14; 37.8%), it was not possible to focus on the acuteness of the injured globe before the traumatic episode, due to the fact that the victims had no documented visits to an ophthalmologist before the injury. Conclusions: To objectively assess of the orbital trauma and determine the degree of harm to human health, it is necessary to have a full ophthalmological status, including such clinical and instrumental criteria as visual acuteness, presence or absence of ophthalmoplegia and globe dystopia, as well as computed tomography data of the skull, which must be presented in the primary medical documentation.

Comparative Histological Analysis of Dentine-Derived Tooth Grafts in Maxillary vs Mandibular Socket Preservation: A Retrospective Study of 178 Cases.

(1) Background: In recent years, there has been a growing interest in tooth-derived materials as valuable alternatives to synthetic biomaterials for preventing alveolar ridge dimensional changes. This study aimed to evaluate the histological and clinical differences between alveolar ridge preservation procedures in the maxilla and mandible using demineralized dentin treated with Tooth Transformer®. (2) Methods: A total of 178 patients in good general health were enrolled, with 187 post-extractive sockets lacking buccal and/or palatal bone walls. Alveolar socket preservation procedures and histological evaluations were performed. The sites were divided into two groups: Group A (99 mandibular samples) and Group B (108 maxillary samples). After 5 months (±1 month), single bone biopsies were performed for histologic and histomorphometric analysis. (3) Results: Clinical outcomes demonstrated a good healing of hard and soft tissues with an effective maintenance of bone architecture in both groups. Histomorphometric analysis revealed a total bone volume of 50.33% (±14.86) in Group A compared to 43.53% (±12.73) in Group B. The vital new bone volume was 40.59% (±19.90) in Group A versus 29.70% (±17.68) in Group B, with residual graft dentin material volume at 7.95% (±9.85) in Group A compared to 6.75% (±9.62) in Group B. (4) Conclusions: These results indicate that tooth-derived material supports hard tissue reconstruction by following the structure of the surrounding bone tissue. A 6.8% difference observed between the maxilla and mandible reflects the inherent disparities in natural bone structures in these regions. This suggests that the bone regeneration process after tooth extraction adheres to an anatomical functional pattern that reflects the specific bone characteristics of each area, thus contributing to the preservation of the morphology and functionality of the surrounding bone tissue.

A large pterosaur from the Middle Jurassic (lower Bajocian) of Rutland, United Kingdom

An incomplete, but large hollow bone is identified as pterosaurian on account of its pneumatic nature, thin bone wall, palaeohistology and the characteristic surface texture of the peridermal bone. Despite being incomplete it is tentatively identified as a ?left ulna, and is remarkable for its size. Coming from the lower Middle Jurassic Lincolnshire Limestone Formation of Rutland, eastern England, this is the first record anywhere in the World of a Bajocian pterosaur, and probably the first pterosaur recorded from Rutland. It is most likely from Discites to Laeviuscula zones part of the lower Bajocian succession, and represents one of the largest Jurassic pterosaurs yet recorded, with a wingspan tentatively estimated at between 3.5 and 4.0 m. The taxonomic identity of the new specimen is uncertain, but it is likely allied to the Pterodactyloidea on account of its size, although presently it remains Pterosauria fam. et gen., et sp. indet.

Feasibility of Immediate, Early and Delayed Implant Placement for Single Tooth Replacement in the Premaxilla: A Retrospective Cone-Beam Computed Tomography Study of 100 Cases.

To assess the feasibility of immediate (IIP), early (EIP) and delayed implant placement (DIP) for single tooth replacement in the premaxilla on the basis of the complete indication area of each approach in routine practice. Data from 100 patients (59 women, 41 men, all Caucasians) aged between 19 and 81 years old (mean age 51.71) who had been consecutively treated with a single implant in the premaxilla (13-23) in one private periodontal practice were retrospectively collected. Demographic data, diagnostic information and linear measurements were extracted from patient files and CBCTs. The feasibility of IIP, EIP and DIP was assessed for all cases by both authors, based on the following criteria: availability of apical bone, position of the tooth in relation to the morphology of the alveolar process, buccal bone morphology and presence of midfacial recession. The reasons for not being able to perform an approach, and the viable alternatives for each approach were secondary outcomes. DIP was considered to have been preceded by alveolar ridge preservation (ARP). Ninety-two patients could be treated by means of IIP, EIP or DIP. In eight patients none of these approaches were possible as they required bone augmentation prior to implant placement. Fifty-two patients (95% CI: 42%-62%) could by treated with IIP, 58 (95% CI: 48%-67%) with EIP and 88 (95% CI: 80%-93%) with DIP. The feasibility proportions of IIP and EIP were significantly lower than the one of DIP (p < 0.001). All patients who could be treated with IIP could also be treated with EIP or DIP. Lack of apical bone for implant anchorage was the main reason for not being able to perform IIP and EIP. Complete loss of the buccal bone wall and the need for bone augmentation prior to implant placement were the reasons for not being able to perform DIP. From the results of this retrospective CBCT analysis, DIP is nearly always possible in contrast to IIP and EIP. Therefore, and since it is much easier than IIP and EIP, inexperienced clinicians should mainly focus on ARP and DIP in clinical practice deferring IIP and EIP until more surgical skills have been acquired.

A Randomized Controlled Trial on the Timing of Soft-Tissue Augmentation in Immediate Implant Placement: Hard-Tissue Changes and Clinical Outcome.

To assess the impact of the timing of soft-tissue augmentation (STA) on mean buccal bone changes following immediate implant placement (IPP) in the anterior maxilla. Patients with a failing tooth and intact buccal bone wall in the anterior maxilla (15-25) were enrolled in this randomized controlled trial. Following single IIP and socket grafting, they were randomly allocated to the control group (immediate STA performed during the same surgical procedure) or the test group (delayed STA performed 3 months later). Implants were placed with a surgical guide and immediately restored with an implant-supported provisional crown. Changes in bone dimensions were assessed using superimposed CBCT images taken prior to surgery and at 1-year follow-up. Clinical outcomes were registered at 1-year follow-up. Twenty patients were randomized to each group (control: 16 females, 4 males, mean age 57.6; test: 9 females, 11 males, mean age 54.2). Ten patients in the control group and 13 patients in the test group had a thick bone wall phenotype. Estimated marginal mean horizontal buccal bone loss at 1 mm below the implant shoulder was -0.553 and -0.898 mm for the control and test group, respectively. The estimated mean difference of 0.344 mm in favour of the control group was not significant (95% CI: -0.415 to 1.104; p = 0.363). Also at all other horizontal and vertical levels, no significant differences could be observed between the groups. The combination of socket grafting and STA enabled counteraction of any buccal soft-tissue loss (≥ 0 mm) at 1 mm below the implant shoulder in 82% of the patients in the control group and in 75% of the patients in the test group (p = 1.000). The clinical outcome was favourable in both groups, yet implants in the control group demonstrated slightly less marginal bone loss (median difference 0.20 mm; 95% CI: 0.00-0.44; p = 0.028). In patients with an intact and mainly thick buccal bone wall in the anterior maxilla, the timing of STA following IIP had no significant impact on mean buccal bone loss. ClinicalTrials.gov identifier: NCT05537545.

Investigation of the extent of post-extraction bone contraction and remodeling after 4 months. A prospective pilot study

ObjectivesTo investigate the correlation between the serum levels of 25(OH)D and the resorption of the alveolar bone walls and regeneration of the alveolar space after tooth extraction. Methods14 adults in need of extraction of hopeless teeth were enrolled. An intraoral digital impression was performed, and each patient was tested to assess serum vitamin D levels. Subsequently, extraction of teeth and contextual guided bone regeneration was performed using porcine origin graft material and a resorbable collagen membrane to covert the defect. After 4 months, an impression was taken, and the model was scanned using a professional scanner for lab. At the same time, a cone beam computed tomography was performed to plan implant insertion through fully digital computer guided surgery. Bone was collected to perform histological and histomorphometric analysis. Pre and postoperative scans were compared using a specific software to estimate the volumetric changes. Tests were applied to investigate the relationship between the different predictor variables and the outcome variables. Results14 patients were divided in 3 groups depending on the serum Vit-D levels, identifying three ranges corresponding to low (lower than 20), medium (between 20 and 30), and optimal vitamin D levels (higher than 30). Volumetric contraction after extraction was observed for all patients, without any significant difference between the groups. Focusing on the post-extraction regeneration, patients belonging to the group with lower levels of Vit-D displayed lower and more disorganized levels of bone. Immunohistochemistry analysis showed that Col1A1 and Osteocalcin had no physiological alteration. Osteopontin could be identified near the external surface of bone tissue granules. Runx2 signals were detected near the margins of bone trabeculae. ConclusionsSerum vit-D levels do not appear to influence the extent of post-extraction bone contraction; on the contrary, they seem to influence the post-extraction regeneration. Clinical SignificanceVit D serum levels may influence the regenerative aspect during post-extraction turn-over. This might suggest controlling and (in case of low levels) recommend Vit D supplement in the patient diet in case of extraction.

Study on the influence of cortical bone heterogeneity on the spatio-temporal distribution of drilling temperature

The degree of thermal damage during cortical bone drilling is an important factor in determining the success rate of surgery and postoperative recovery time. In this study, high and low feed rate drilling experiments are carried out on bovine femoral cortical bone by chisel edge thinning drill. Combined with the characterization of cortical bone tissue structure and the measurement results of important thermal property parameters, the potential impact mechanisms of cortical bone heterogeneity on the spatio-temporal distribution of drilling temperature and thermal damage are analyzed. The temperature rise rate and overheating duration at different distances from the hole wall in cortical bone drilling under different feed rates are also compared. The experimental results show that the specific heat gradually increases and the thermal conductivity gradually decreases from the periosteum to the endosteum. The hole wall temperature and thermal diffusion of cortical bone with different tissue structures are different under high and low feed rates. The closer to the cortical bone endosteum, the lower the drilling temperature, thermal diffusion and thermal damage area. This is not only related to the contact time between the drill bit and the hole wall of cortical bone with different tissue structures, but also closely related to the heterogeneous structure of cortical bone. In addition, it is found that in high feed rate cortical bone drilling, the temperature rise rate at different positions from the hole wall is higher and the overheating duration is shorter.

External auditory canal cholesteatoma in children: clinical manifestations

PurposeThe purpose of this study was to explore the characteristics of external auditory canal cholesteatoma (EACC) among children and to describe its radiological findings on high-resolution computed tomography (CT) of the temporal bone in order to improve the diagnostic accuracy of primary EACC.MethodsThe clinical records and CT imaging features of 44 patients who were diagnosed with EACC between January 2017 and May 2022 at Shenzhen Children’s Hospital were retrospectively reviewed. Clinical features, including external auditory canal wall findings, hearing damage, symptoms and physical examination findings, were analysed against the level of lesion involvement. The correlation between different types of EACC and the incidence of different clinical symptoms was analysed, and the degree of hearing impairment and the rate of bone wall destruction were examined using CT.ResultsThe mean age at EACC onset was 9.02 ± 3.15 years, and the mean age at onset for EACC involving the right ear was older than that of EACC involving the left ear (P < 0.05). There were 44 patients (46 ears), including 10 ears with type I EACC, 23 ears with type II EACC, and 13 ears with type III EACC. Conductive hearing loss was the main type of hearing impairment observed among EACC patients. There were differences in types I, II and III EACC in terms of hearing impairment; specifically, there was a significant difference in moderate hearing impairment between type II and type III EACC patients (P < 0.05). The four most common symptoms were otorrhea, otalgia, itching and bleeding. The incidence of itching symptoms was greater in type I EACC than the incidence of otorrhea, and the incidence of otorrhea symptoms in type II and type III EACC was significantly greater than that in type I EACC(P < 0.05). There were no significant differences in the fracture rates of the anterior, posterior, superior or inferior walls of the external auditory canal within or between type II and type III EACC patients (P > 0.05). The failure rate of scute damage was significantly higher in type III EACC patients than in type II EACC patients (P < 0.05).ConclusionThe presence of otorrhea and hearing loss as well as the identification of granulation tissue during otoscopy suggest the need for a temporal bone CT scan. This imaging modality can aid in the early detection and accurate classification of EACC, thereby guiding the selection of appropriate surgical interventions and greatly assisting in preventing further progression of hearing impairment.

Immediate single-tooth implant placement in bony defect sites: A 10-year randomized controlled trial.

It is unclear whether an intact buccal bony plate is a prerequisite for immediate implant placement in postextraction sockets. The aim of this 10-year randomized controlled trial was to compare peri-implant soft and hard tissue parameters, esthetic ratings of, and patient-reported satisfaction with immediate implant placement in postextraction sockets with buccal bony defects ≥5mm in the esthetic zone versus delayed implant placement after alveolar ridge preservation. Patients presenting a failing tooth in the esthetic region and a buccal bony defect ≥5mm after an extraction were randomly assigned to immediate (Immediate Group, n=20) or delayed (Delayed Group, n=20) implant placement. The second-stage surgery and provisional restoration placement occurred 3months after implant placement in both groups, followed by definitive restorations 3months thereafter. During a 10-year follow-up period, marginal bone levels (primary outcome), buccal bone thickness, soft tissue parameters, esthetics, and patient-reported satisfaction were recorded. The mean marginal bone level change was -0.71±0.59mm and -0.36±0.39mm in the Immediate Group and the Delayed Group after 10years (p=0.063), respectively. The secondary outcomes were not significantly different between both groups. Marginal bone level changes, buccal bone thickness, clinical outcomes, esthetics, and patients' satisfaction following immediate implant placement, in combination with bone augmentation in postextraction sockets with buccal bony defects ≥5mm, were not statistically different to those following delayed implant placement after ridge preservation in the esthetic zone. Immediate implant placement in case of a failing tooth is a favorable treatment option for patients because it considerably shortens treatment time and the number of surgical treatments. The question is if an intact buccal bone wall is necessary for immediate implant placement. A 10-year study was performed in which 20 patients with a failing tooth in the frontal region of the upper jaw were treated with immediate implant placement and were compared with 20 patients in whom a more conventional treatment strategy was followed in which the failing tooth was first removed and the bone gap restored and the implant placed in a second step. After a 10-year follow-up period, it appeared that the bone around the implant was very stable, gums were healthy, and patients were very satisfied with the result. There was no difference between the two treatment procedures. Such results mean that professionals can discuss the procedure with the patient and apply the individual's preference.