Virtual Three-Dimensional Model Analysis in the Assessment of the Maxillary and Mandibular Donor Sites on Cone-Beam Computed Tomography Images.

Using the Mimics software to assess the maxillary and mandibular donor sites on cone-beam computed tomography (CBCT) images. This cross-sectional study was conducted on 80 CBCT scans. Data in DICOM format were transferred to the Mimics software version 21, and a maxillary and a mandibular mask according to cortical and cancellous bones were virtually created for each patient based on Hounsfield units (HUs). Three-dimensional models were reconstructed, and boundaries of donor sites, including mandibular symphysis, ramus, coronoid process, zygomatic buttress, and maxillary tuberosity, were defined. Virtual osteotomy was conducted on the 3D models to harvest bone. The volume, thickness, width, and length of harvestable bone from each site were quantified by the software. Data were analyzed by independent t-test, one-way ANOVA, and Tukey's test (alpha = 0.05). The greatest harvestable bone volume and length differences were observed between ramus and tuberosity (P < 0.001). The maximum and minimum harvestable bone volumes were found in symphysis (1753.54 mm3) and tuberosity (84.99 mm3). The greatest difference in width and thickness was noted between the coronoid process and tuberosity (P < 0.001) and symphysis and buttress (P < 0.001), respectively. Harvestable bone volume from tuberosity, length, width, volume from symphysis, and volume and thickness from the coronoid process was significantly greater in males (P < 0.05). The harvestable bone volume was the highest in symphysis, followed by ramus, coronoid, buttress, and tuberosity. The harvestable bone length and width were the highest in the symphysis and coronoid process, respectively. Maximum harvestable bone thickness was found in symphysis.

Low-level laser and management of common complications after the mandibular third molar surgery: A double-blind randomized clinical trial.

Background: There are controversies on the analgesic and anti-inflammatory effects of low-level laser therapy on pain, edema, and trismus after mandibular third molar extraction surgery. This study aimed to evaluate the efficacy of low-level laser therapy (LLLT) on discomforts occurring after the mandibular wisdom tooth removal. Materials and Methods: This double-blind, split-mouth design, randomized clinical trial study was performed on 36 healthy controls with bilateral symmetrical mandibular third molar referred to the Department of Oral and Maxillofacial Surgery of Dental Faculty from January to November 2019. After surgical extraction, the laser group underwent laser (Ga-Al-As diode laser, 808 nm, 200 mW) intraorally and extraorally just after surgery and 24 h after surgery. For the placebo group, the handpiece was inserted without laser irradiation. The pain level was assessed by Baker Wong scale at 2, 4, 6, 12, 24, 36, 48, and 60 h postoperatively, and the edema and the extent of mouth opening were examined before surgery, at the 1st and 7th days after surgery. The data were collected and analyzed by SPSS at the significant level of 0.05. Results: The statistical analysis of 32 participants' data (laser group: n = 32, placebo group: n = 32) indicated that the mean score of pain in 3 days after surgery in the interventional group was significantly lower than the score of the placebo group (P < 0.001). Furthermore, the swelling and the extent of the mouth opening differed significantly between the two groups at 1st and 7th days after the procedure (P < 0.001). Conclusion: Our findings showed that the LLLT had beneficial effects on the management of pain, edema, and trismus following after 3rd molar extraction surgery.

Periosteal reaction as a crucial radiographic finding for desmoplastic fibroma of the jaw bone in children: A case report.

This report presents the case of a 5-year-old boy with a hard swelling on the right side of the mandible body. An important point of this case is that the primary imaging finding was fine spicules in the inferior border of the mandible on panoramic radiography without significant changes in bone density. Cone-beam computed tomography views revealed a lytic lesion on the lingual side of the right mandibular body with the destruction of the lingual cortex and periosteal reaction from the midline to the first molar area. Careful attention to this radiographic finding in the primary stage in the absence of other significant imaging findings, particularly in children, could result in the early diagnosis of desmoplastic fibroma. Therefore, a better prognosis can be expected following early surgical treatment.

Post-COVID mucormycosis osteomyelitis and its imaging manifestations in the North of Iran: case series.

Mucormycosis is an invasive fungal infection that usually affects patients with immunocompromised conditions. In the context of the COVID-19 pandemic and the following corticosteroid therapy, mucormycosis prevalence has increased. The situation may be more complicated with some underlying diseases such as diabetes mellitus. In addition, due to the vicinity of maxillary bone to the nasal cavity and paranasal sinuses, which are the main routes for the infection to spread, dentists, maxillofacial radiologists, and surgeons may be the first to encounter these patients. Post-COVID mucormycosis osteomyelitis is one of the complications of this infection Bone destruction and the erosion or breach of cortical boundaries of the maxilla and the bone structures in the vicinity of paranasal sinuses are the most critical radiographic findings of post-covid osteomyelitis. Herein, there are some cases of post-covid mucormycosis osteomyelitis involving the maxillary and other facial bones.

Efficacy of cone-beam computed tomography with modified gray-scale range versus digital periapical radiography for the assessment of bone-implant interface gaps.

OBJECTIVES: To compare the efficacy of digital periapical (PA) radiography with cone-beam computed tomography (CBCT) by altering the gray-scale range for the detection of bone-implant interface gaps. METHODS: Titanium implants were placed in 52 blocks of bovine rib such that 42 had no gaps and served as the control group. The implants were subsequently placed in the same blocks with 0.25 mm increase in the osteotomy size to serve as the test group. The remaining 10 blocks were used for random arrangement of the test and control blocks within a fabricated wax arch. CBCT with change in the gray-scale range and digital PA were obtained and evaluated by two observers regarding the presence/absence of gaps. The two imaging modalities were compared by the receiver operating characteristic (ROC) curve, Kappa and McNemar tests (α = 0.05). RESULTS: PA and CBCT showed moderate agreement for gap detection (k = 0.60). There were no significant differences in the area under the ROC curve (AUC) between CBCT and PA (P = 0.45). The frequency of correct diagnoses on PA radiographs was significantly higher in the test group (P = 0.016), while not significant on the CBCT images (P = 0.344). PA showed higher sensitivity (100%) compared to CBCT (83.33%). However, the specificity of CBCT (92.86%) was greater than that of PA (83.33%). CONCLUSIONS: Certain gray-scale ranges in CBCT enhance the assessment of bone-implant interface which brings the accuracy of CBCT closer to digital PA radiography as the modality of choice.

Evaluation of the nasopalatine canal with cone-beam computed tomography in an Iranian population.

BACKGROUND: Implant placement plays a vital role in oral rehabilitation following loss of the incisors. Thus, having knowledge of anatomical variations of adjacent neurovascular structures especially the nasopalatine canal (NPC) is essential. Due to the lack of basic information in Iran about the morphology of this canal and the probability of its variety in different populations, this study was designed on an Iranian population. MATERIALS AND METHODS: In this descriptive study, we selected cone-beam computed tomography images of 198 patients comprising of 98 males and 100 females in two dental groups (edentulous or dentate). The shape of the nasopalatine foramen and the form of the canal in axial views were assessed. Then, the canal height and its diameter at the palatal, middle and nasal levels in cross-sectional images were measured. The available bone in the buccal and palatal sides of the canal was assessed. Data analysis was carried out using a Chi-square test and an independent t-test (P ≤ 0.05). RESULTS: The majority of the samples (81.8%) presented a single foramen. Cylindrical shape (57.6%) was the most frequently detected canal form. The mean of the estimated canal height was 12.84 ± 2.88 mm. The canal diameter at the palatal level between the sexes and dental groups showed statistically significant differences. CONCLUSION: In our investigated population, the NPC form was mainly cylindrical with a single opening foramen. The mean of the canal height was higher than that found in other populations. Furthermore, the canal diameter in the edentulous group was greater than that observed in the other group.

Assessment of growth activity in the mandibular condyles by single-photon emission computed tomography (SPECT).

BACKGROUND: Unilateral condylar hyperplasia can lead to marked and disfiguring changes in the face and occlusion. A method of determining side-to-side differences in condylar activity is an important step in managing this condition. AIMS: To determine the growth activity in normal mandibular condyles and to devise an index of side-to-side differences in condylar activity in different individuals. METHODS: Thirty eight patients, ranging from 13 to 34 years, who were undergoing skeletal scintigraphy for a variety of conditions agreed to participate in this study. No subjects had clinical or radiographic signs of mandibular hyperplasia. After injection of 25 mci Tc99 the uptake by the right and left mandibular condyles was measured and the side-to-side differences used to calculate an index. RESULTS: The maximum side-to-side differences were 6.2 per cent (Right side versus left side: 53.1 per cent and 46.9 per cent respectively) in the male patients and 5.7 per cent in the female patients (Right side versus Left side: 52.85 per cent and 47.15 per cent respectively). CONCLUSIONS: The variation in growth activity in normal right and left mandibular condyles was less than 6.2 per cent.