Objective: To investigate the influence of increasing the occlusal vertical dimension (iOVD) on the fibre-type distribution and ultrastructure of deep masseter of rat at different ages.
Design: A total of forty-eight male Wistar rats were divided into two groups according to age: 'teenage' group (n=24, 1.5 months) and 'young adult' group (n=24, 8 months). Both the teenage and the young adult rats were then randomly divided into the control group (n=12) and the experimental group (n=12). The occlusal vertical dimensions of the rats in the experimental groups were increased by placing composite resin on all maxillary molars. The fibre-type distribution and ultrastructure of the deep masseter were subsequently observed on day 7 and day 14 after iOVD.
Results: In the teenage experimental group, the proportion of type IIa fibres increased, while the proportion of type IIb and type IIx fibres decreased by day 7 after iOVD (P<0.05). However, no significant fibre phenotype transformation was observed in the young adult experimental group until day 14 after iOVD. In addition, the proportion of type IIa in the teenage experimental group was higher than that of the young adult experimental group on day 7 and 14 (P<0.05). Under the transmission electron microscope, muscle fibre reconstruction and the compensatory increase in the number and volume of mitochondria appeared earlier in the teenage experimental group. The cellular traumatic reaction was less than that in the young adult experimental group.
Conclusion: The teenage rat alters masseter muscle structure to a slower phenotype earlier and to a greater degree than that of the young adult rat when increasing the occlusal vertical dimension.
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http://dx.doi.org/10.1016/j.archoralbio.2016.10.031 | DOI Listing |
J Prosthet Dent
January 2025
Associate Professor, Department of Clinical Science, College of Dentistry, Ajman University, Ajman City, United Arab Emirates.
Statement Of Problem: Different factors affect 3-dimensionally (3D) printed resin products. However, evidence on the effect of the print orientation on resin dental devices is lacking.
Purpose: The purpose of this systematic review and meta-analysis was to assess the impact of print orientation on the properties and accuracy of 3D printed implant surgical guides, occlusal devices, clear orthodontic retainers, and aligners.
J Indian Prosthodont Soc
January 2025
Department of Prosthodontics, Chhattisgarh Dental College and Hospital, Rajnandgaon, Chhattishgarh, India.
Aim: The aim of this study was to compare the marginal accuracy of polyetheretherketone (PEEK) and zirconia copings fabricated using computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and to assess the impact of their material properties on accuracy when produced with a 4-axis milling system under controlled conditions.
Settings And Design: The study employed an in vitro design with a stainless steel die model featuring a 6 mm axial wall height, a 6-degree total occlusal convergence, and a radial shoulder finish line.
Materials And Methods: Thirty stone dies were created from silicone impressions of the metal die and poured using type-IV dental stone.
J Dent
December 2024
Faculty of Dentistry, Aydin Adnan Menderes University, Aydin, Turkey. Electronic address:
Objective: To evaluate volumetric changes over time in teeth treated with the Hall Technique (HT) and their opposing teeth. Secondary aims included assessing occluso-vertical dimension (OVD), temporomandibular joint (TMJ) function, and children's treatment perceptions.
Methods: Twenty-eight children (5-9 years-old) requiring HT treatment for one first primary molar were recruited.
Br J Oral Maxillofac Surg
November 2024
Department of Oral and Maxillofacial Surgery, Hospital for Rehabilitation of Craniofacial Anomalies/USP (HRAC/USP), Bauru, Sao Paulo, Brazil.
This study aims to evaluate the post-surgical stability of patients with cleft lip and palate that underwent maxillary advancement surgery. The study was conducted by means of cephalometric analysis of the soft tissues in digital radiographs acquired preoperatively, immediate postoperatively and six months after surgery using Dolphin Imaging 11.5 software.
View Article and Find Full Text PDFBMC Oral Health
December 2024
Faculty of Dentistry, Department of Orthodontics, Ondokuz Mayıs University, Atakum, Samsun, 55139, Turkey.
Background: This retrospective study aimed to investigate the relationships between the radiographic features of impacted maxillary canines (IMCs) and traction duration and the factors affecting treatment success.
Methods: Pre-treatment panoramic radiographs and patient records of 121 consecutive patients with IMCs were analyzed. The measurements included the angle of the IMC with the midline (α-angle), the horizontal position of the IMC relative to the adjacent teeth (S-Sector), the distance from the IMC to the occlusal plane (d-distance), the apex position of the IMC (A), and the vertical height of the IMC relative to the adjacent lateral tooth (V).
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