Effect of Concentrated Growth Factor on Distraction Osteogenesis of Dental Implant Distractors.

PURPOSE: The periosteum of bone segments can be destroyed during the installation of a dental implant distractor (DID) device, resulting in bone defects on the exposed side of the distraction gap. The purpose of this animal experiment is to explore the application of concentrated growth factor (CGF) in DID surgery, which can induce angiogenesis and osteogenesis and improve osteogenesis defects caused by periosteum loss on the exposed side of bone segments. METHODS: CGF is the latest generation of platelet concentrate. Twenty-four DID devices inserted into the tibias of 8 goats were evenly divided into the CGF and control groups. Following 10 days of distraction and a 12-week consolidation period, all 8 animals were euthanized to retrieve their tibias. The distraction gap between each segment was measured at 5 points, and the average value was taken as the computed tomography (CT) value of the distraction gap at 4, 8, and 12 weeks after distraction. The vascular density and trabecular bone volume of each DID distraction gap were determined and statistically compared between the 2 groups. RESULTS: The CT value of the distraction gap increased gradually in control groups at 4, 8, and 12 weeks after distraction to 319.3 ± 14.6, 449.3 ± 34.4, and 614.0 ± 15.6 HU in the control group and 368.3 ± 8.8, 544.5 ± 12.3, and 661.0 ± 8.1 HU in the CGF group. The trabecular bone volume was 281.7 ± 16.5 and 209.7 ± 21.6 µm2 in the CGF group and control group. The vascular density was 17.7 ± 2.1 and 11.7 ± 1.9 in the CGF group and control group. Statistically significant differences were observed in the CT value (P = .002), vascular density (P = .023), and trabecular bone volume (P = .010) between the CGF and control groups. CONCLUSIONS: The application of an autogenous CGF membrane in DID surgery repaired bone defects caused by osteolysis around osteotomy segments.

A gland-sparing, intraoral sialolithotomy approach for hilar and intraparenchymal multiple stones in the submandibular gland.

Multiple intraglandular sialolithiasis for stones deep in the glandular parenchyma may require submandibulectomies, especially if sialendoscopic facilities are unavailable. We describe a gland-sparing intraoral sialolithotomy approach for both hilar and intraparenchymal multiple sialoliths. Nine patients with obstructive sialadenitis resulting from multiple sialoliths in both the deep hilar region and the submandibular gland parenchyma were selected for this study. Ultrasonography and computer tomography (CT) scans were performed to determine the location, number and sizes of the calculi and the distance between hilar and intraparenchymal sialoliths. All sialoliths were removed via gland-sparing, intraoral sialolithotomy. In all, 27 stones were found in the 9 patients. The hilar and deeper sialoliths were 4.5-11 and 0.8-4.5 mm, respectively, in diameter. The largest distance between the hilar and intraparenchymal sialoliths was 28.3 mm. Sialoliths in the hilar region were excised through an intraoral incision before deeper intraparenchymal stones were eased out of the same incision site. Postoperative follow-up imaging verified complete sialolith removal. Therefore, submandibular gland multiple sialoliths in the hilum and parenchyma can be successfully removed via an intraoral sialolithotomy under general anesthesia, thereby preserving the gland and restoring its secretory function.

Influence of periosteal coverage on distraction osteogenesis with dental implant distractors.

PURPOSE: The continuity and integrity of the enveloping nutritive periosteum can be compromised during installation of a dental implant distractor (DID) device. This novel animal experiment investigated the influence of the periosteum on the bony regenerate in 3 scenarios of periosteal coverage: whole periosteum (WP), half periosteum (HP), and no periosteum (NP). MATERIALS AND METHODS: Twelve goat tibias were vertically osteotomized into 2 segments each and divided into 3 groups (WP, HP, and NP). A DID device was surgically installed onto each segment, followed by 10 days of distraction at a rate of 0.35 mm twice daily. Fluorescence labeling and trabecula count per high-power field (TBC/HPF) measurements were performed and statistically compared across groups. Implant stability quotients (ISQs) of all fixtures were performed. RESULTS: New bone formation occurred sooner in the WP and HP groups than in the NP group under fluoroscopy. The TBC/HPF values showed an obvious but not statistically significant decrease between the WP and HP groups (P = .500), WP and NP groups (P = .157), and HP and NP (P = .077). And the WP group showed no significantly higher ISQ values compared with the HP (P = .712) and NP (P = .958) groups, also between the HP and NP (P = .751) groups. CONCLUSION: Vertical distraction osteogenesis can be performed successfully with the DID to obtain bone of adequate stock and density. However, the enveloping periosteum should be preserved as much as possible during installation of the DID device.

Influence of periosteal coverage on the osteointegration and stability of dental implant distractors.

OBJECTIVES: Dental implant distractors (DID) are an efficacious means of simultaneously augmenting the vertical bony height together with the installation of dental implants. Little is known about their biomechanical properties and osteointegration ability in the free fibula flap, where the periosteum is invariably damaged during the multiple osteotomies required for contouring purposes. MATERIALS AND METHODS: Twenty-four DID devices inserted into the tibias of 12 goats were evenly divided into three groups - whole periosteum (WP), half periosteum (HP), no periosteum (NP). Following 10 days of distraction and a 12 week consolidation period, the animals were euthanized to retrieve all 12 tibias. The bone-implant bonded percentage (BIBP) and removal torques (RTQ) of each fixture were determined and statistically compared across the various groups. RESULTS: A slight decrease in both BIBP and RTQ values was observed across the WP, HP, and NP groups, respectively, with statistically significant differences in the BIBP for the WP and NP groups only. CONCLUSION: We conclude that although an intact periosteum is ideal for the osteointegration of the DID fixture, adequate stability can still be achieved due to the sufficient anchorage accorded by the base screws in the apical cortex.

Submandibular gland mucocele associated with a mixed ranula.

Mucoceles of the submandibular gland are extremely rare pathologic occurrences that present an investigative and management dilemma owing to their clinical indistinguishability from plunging ranulas. Of the few that have been documented, these mucous extravasation cysts involved the submandibular gland alone. We describe perhaps the first case of an extensive submandibular gland mucocele occurring in conjunction with a mixed ranula from the ipsilateral sublingual gland, and discuss the various considerations in the management of such lesions.