Evaluation of the accuracy of dynamic navigation versus robot-assisted dental implant placement in models with one missing tooth or multiple missing teeth with a free-end: an in vitro study.

Objectives: To assess and compare the accuracy of robot-assisted and dynamic navigation systems for dental implant placement in models with either a single missing tooth or multiple consecutive missing teeth at the distal extension.

Methods: Thirty-two models and 86 implants were utilized. Implant placement was randomly assigned using either a robot-assisted or dynamic navigation system.

Evaluating the accuracy of a novel marker-free registration technique for dynamic computer-assisted implant surgery: An in vitro study.

Objectives: To propose a novel marker-free cusp-and-surface registration (CSR) technique for dynamic computer-assisted implant surgery (dCAIS) and to evaluate its accuracy in vitro.

Methods: Forty implants were inserted into twenty 3D-printed models designed to simulate maxillary anterior partial edentulism, using a dynamic navigation system that employed either the CSR or cusp registration (CR) technique. The CR group employed six reference points on six teeth adjacent to the edentulous ridge as reference structures.

Deep learning-based multimodal CT/MRI image fusion and segmentation strategies for surgical planning of oral and maxillofacial tumors: A pilot study.

Purpose: This pilot study aims to evaluate the feasibility and accuracy of deep learning-based multimodal computed tomography/magnetic resonance imaging (CT/MRI) fusion and segmentation strategies for the surgical planning of oral and maxillofacial tumors.

Materials And Methods: This study enrolled 30 oral and maxillofacial tumor patients visiting our department between 2016 and 2022. All patients underwent enhanced CT and MRI scanning of the oral and maxillofacial region.

Analyses of gingival papilla blood flow via color doppler flow imaging and micro-flow imaging in patients with advanced periodontitis: a clinical pilot study.

Background: Research investigating the potential link between gingival microvascular blood flow and inflammatory status is scarce. This study aims to assess color doppler flow imaging (CDFI) and micro-flow imaging (MFI) as tools for the assessment of gingival papilla blood flow (GPBF) and to examine their diagnostic utility as a noninvasive means of detecting gingival bleeding.

Methods: CDFI and MFI were used to assess the GPBF grade (0-4) of 140 anterior gingival papilla sites in advanced periodontitis patients.

Optimal tooth sectioning using a surgical handpiece and elevator: a finite element study of horizontally deeply impacted mandibular third molars.

Objectives: To conduct a finite element analysis of the impact of different variables on tooth sectioning efficiency and trauma to surrounding tissues when utilizing high-speed surgical handpieces and elevators.

Methods: CBCT data from the horizontally impacted third mandibular molar (M3M) of a patient were utilized to establish digital models of the M3M, adjacent M2M, and surrounding bone. To simulate tooth sectioning, a 3D finite element model was established with the following variables: remaining tooth tissue thickness (1-5 mm), tooth section fissure width (1-3 mm), elevator depth in fissure (2-6 mm), elevator position (buccal, lingual, central), elevator width (2-5 mm), and application of force (rotating, levering).

Effect of mineralized dentin matrix on the prognosis of bone defect and retained root after coronectomy.

Objective: To investigate the impact of mineralized dentin matrix (MDM) on the prognosis on bone regeneration and migration of retained roots after coronectomy.

Materials And Methods: Patients were divided into three groups based on the type of bone graft after coronectomy: Group C (n = 20, collagen), Group T (n = 20, tricalcium phosphate (TCP) + collagen), and Group D (n = 20, MDM + collagen). CBCT scans, conducted immediately and 6 months after surgery, were analyzed using digital software.

Analysis of the aerodynamic characteristics of the upper airway in obstructive sleep apnea patients.

Background/purpose: This study was designed to explore upper airway aerodynamic characteristics in individuals diagnosed with obstructive sleep apnea (OSA) and to evaluate correlations between these characteristics and other anatomical upper airway findings in these patients.

Materials And Methods: This was a retrospective study of 40 OSA patients (22 male, 18 female) who were stratified into groups with mild, moderate, and severe disease based upon overnight polysomnographic (PSG) recording results. Newtom5G cone-beam CT scans (CBCT) were conducted for all patients, and the resultant images were used to reconstruct three-dimensional images of the upper airways which were used to calculate aerodynamic characteristics.

The impacts of registration-and-fixation device positioning on the performance of implant placement assisted by dynamic computer-aided surgery: A randomized controlled trial.

Objectives: To assess the efficacy of dynamic computer-aided surgery (dCAS) in replacing a single missing posterior tooth, we compare outcomes when using registration-and-fixation devices positioned anterior or posterior to the surgical site. Registration is performed on either the anterior or opposite posterior teeth.

Methods: Forty individuals needing posterior single-tooth implant placement were randomly assigned to anterior or posterior registration.

Accuracy of computer-assisted dynamic navigation when performing coronectomy of the mandibular third molar: A pilot study.

Objectives: The study represents a preliminary evaluation of the accuracy of the dynamic navigation system (DNS) in coronectomy of the mandibular third molar (M3M).

Methods: The study included participants with an impacted M3M near the inferior alveolar canal. The coronectomy planes were designed before the surgery using cone-beam computed tomography (CBCT) imaging data and then loaded into the DNS program.

Accuracy of different registration areas using active and passive dynamic navigation systems in dental implant surgery: An in vitro study.

Objectives: To gauge the relative accuracy of the use of passive and active dynamic navigation systems when placing dental implants, and to determine how registration areas affect the performance of these systems.

Materials And Methods: Eighty implants were assigned to be placed into 40 total resin mandible models missing either the left or right first molars using either passive or active dynamic navigation system approaches. U-shaped tube registration devices were fixed in the edentulous site for 20 models each on the left or right side.

Analysis of the accuracy of a dynamic navigation system when performing dental implant surgery with transcrestal sinus floor elevation: A pilot study.

Background/purpose: The success of transcrestal sinus floor elevation (TSFE) is primarily reliant upon the experience of the surgeon owing to the limited operative visibility. To evaluate the accuracy associated with the use of a dynamic navigation system when conducting posterior maxilla implant surgery with TSFE.

Materials And Methods: Twenty-eight implants were placed in 28 patients requiring implantation in the posterior maxilla via a TSFE approach.

The use of shear wave elastography to monitor changes in gingival elasticity associated with initial periodontal therapy in patients with advanced periodontitis: A prospective pilot study.

Background/purpose: Gingival tissue firmness cannot be objectively assessed or monitored in real-time in existing examinations. This study was designed to examine the potential utility of shear wave elastography (SWE) as a means of evaluating and monitoring gingival inflammation in an effort to assess the effects of initial periodontal therapy in patients with advanced periodontitis.

Materials And Methods: This pilot study included analyses of 66 sites in 6 advanced periodontitis patients.

Accuracy of automatic and manual dynamic navigation registration techniques for dental implant surgery in posterior sites missing a single tooth: A retrospective clinical analysis.

Objectives: To assess the relative accuracy of manual (U-shaped tube) and automatic (two-in-one) dynamic navigation registration techniques for implant surgery performed in posterior sites missing one tooth.

Materials And Methods: This study included 58 partially edentulous patients with 58 implants, including 31 and 27 in the manual and automatic groups. Deviations between the planned and actual implant placement were assessed.

A registration-and-fixation approach with handpiece adjustment for dynamic navigation in dental implant surgery.

The deviations between the preoperative (planned) and postoperative (actual) positions of dental implants have always been of a major concern in dental implant surgery. Dynamic computer-aided implant surgery (dCAIS) systems have been used to achieve optimal implant positioning. The method of registration is indeed an important factor that affects the implanting accuracy.

Enantioselective Ni/N-Heterocyclic Carbene-Catalyzed Redox-Economical Coupling of Aldehydes, Alkynes, and Enones for Rapid Construction of Acyclic All-Carbon Quaternary Stereocenters.

Acyclic quaternary carbon stereocenters exist widely in natural products and bioactive molecules, but their enantioselective construction remains a prominent challenge. In particular, multicomponent enantioselective couplings of simple precursors to acyclic all-carbon quaternary stereocenters are very rare. We describe herein an N-heterocyclic carbene (NHC)-Ni catalyzed redox-economical three-component reaction of aldehydes, alkynes, and enones that proceeds in a highly chemo-, regio-, and enantioselective manner.

Regio- and Enantioselective C-H Cyclization of Pyridines with Alkenes Enabled by a Nickel/N-Heterocyclic Carbene Catalysis.

Annulated pyridines are ubiquitous scaffolds in many bioactive molecules. A highly regio- and enantioselective Ni(0)-catalyzed endo-selective C-H cyclization of pyridines with alkenes has been developed. An unprecedented enantioselective C-H activation at pyridyl 3- or 4-positions was enabled by bulky chiral N-heterocyclic carbene ligands.

Costochondral Graft in Young Children With Hemifacial Microsomia.

Patients with severely hypoplastic mandibles usually require condylar reconstruction. This study aimed to describe costochondral graft (CCG) for condylar reconstruction and report subsequent outcomes of these grafts in young children with Pruzansky/Kaban type IIB and type III mandibular hypoplasia. This study included 4 young children with type IIB and type III hemifacial microsomia treated with CCG to reconstruct the condyle at the Department of Oral and Maxillofacial Surgery in our hospital from March 2008 to March 2014.

Primary neuroendocrine carcinoma in oral cavity: two case reports and review of the literature.

Neuroendocrine carcinoma (NEC) is a tumor that occurs in different locations, particularly the lungs and larynx. The oral cavity is a rare site for a primary NEC. This report describes 2 cases of primary NEC in the oral cavity.