Virtual planning, guided surgery, and digital prosthodontics in the treatment of extended mandible chondrosarcoma.

Chondrosarcoma is among the most common primary bone tumors in adults. In the mandible, chondrosarcoma is a very uncommon malignant cartilage-producing tumor. This case report shows how virtual planning combined with other digital technologies may improve masticatory function rehabilitation in patients with enlarged mandibular chondrosarcoma. The present study reports a case of a 52-year-old male patient who was initially diagnosed with a mandible chondroma, which was successfully excised with no evidence of malignant transformation. Nevertheless, the patient's symptoms recurred after 10 years, and a subsequent diagnosis of mandible chondrosarcoma was established, prompting the need for subtotal mandible resection and reconstruction with a fibula-free flap. Following a healing period, the patient underwent dental implant surgery to restore the mandibular dental arch, which was performed utilizing computer-aided design and computer-aided manufacturing technology, with fully guided implant placement facilitated by virtual planning. In this case report, the implant position data merging process is described from the digital impression and control model to ensure optimal passive fit of the full-arch zirconia prosthesis and discuss the importance of occlusal adjustments to avoid technical and biological complications. Virtual planning and digital technologies are crucial for the effective management of mandibular defects, allowing for accurate treatment and complete restoration of mandibular function. Their use leads to improved patient outcomes and quality of life. As technology advances, their importance in treating complex medical conditions is only expected to grow.

Influence of Kennedy class and number of implants on the accuracy of dynamic implant navigation: An in vitro study using an X-ray free evaluation methodology.

OBJECTIVES: The aim of this in vitro study was to evaluate the accuracy of fully guided dynamic implant navigation surgery in Kennedy I, II, and III class dental arch defects with two different implant designs, using an X-ray free evaluation method. METHODS: Polyurethane resin maxillary models simulated posterior edentulous defects. Four cone beam computed tomography (CBCT) scans and four intraoral (IOS) scans were obtained for each model and a digital wax-up with the correct implant positions was made. The accuracy of implant positions was evaluated using an IOS-based X-ray-free method (3Shape). Four deviation characteristics were evaluated: insertion point, depth deviation, horizontal and angle deviation. RESULTS: The insertion point deviation measures ranged from 0.19 mm to 1.71 mm. Depth (s) and (u) deviations ranged from -1.47 mm to 0.74 mm and from 0.02 mm to 1.47 mm, respectively. Horizontal deviation ranged from 0.09 mm to 1.37 mm. CONCLUSIONS: There is a tendency of a decreasing insertion point deviation for an increasing number and distribution area of the teeth (increasing Kennedy class number). Kennedy class II and distal implant position had the most influence for the higher deviations. CLINICAL SIGNIFICANCE: Dynamic implant guidance provides accurate spacing, angulation, depth and position of the implants. It is important to understand how the number of missing teeth and implant design could influence the accuracy of dynamic implant navigation. Thus, it is important to evaluate factors influencing the accuracy of dynamic systems by using a X-ray-free post-operative method and to overcome the limitations of providing multiple CBCT scans.

Conservative management of large mandibular dentigerous cysts with a novel approach for follow up: Two case reports.

BACKGROUND: Dentigerous cysts are odontogenic cysts of the jaws accounting for approximately 24% of all epithelium-lined jaw cysts. Rarely, these cysts can become extremely large causing additional symptoms, while challenging treatment. This article represents a novel approach for radiological treatment follow up of large dentigerous cysts. MATERIAL AND METHODS: Dentigerous cysts were treated by marsupialization, using dedicated obturators and enucleation of the cyst afterwards. Teeth vitality in the lesion was regularly assessed by laser doppler flowmetry, follow-up of lesion regression was accomplished using semi-automatic radiographic analysis of bone healing quantification. RESULTS: Cystic marsupialization by means of the obturator resulted in a number of advantages compared to a conventional approach: lower risk of spontaneous fracture of the mandible, anatomical structure preservation, mandibular canal identification and preservation of tooth vitality as measured by intraoral laser doppler flowmetry. Notwithstanding that a 1-year follow-up panoramic image could not visualize a remnant bone defect nor cystic lesion recurrence, 3D-CBCT based semi-automated bone quantification could only demonstrate an increase of 46% of mineralized bone volume one year after surgery. Bone healing typically occurred starting from the periphery of the original lesion towards the inner core. CONCLUSIONS: The presently reported cystic marsupialization was useful as a preliminary treatment for subsequent enucleation. 3-D CBCT based objective quantification of the bone volume and healing can provide new insights in lesion healing in general and more particular in the outcome of specific diagnostic and therapeutic challenges.