Odontogenic keratocyst and ameloblastoma: radiographic evaluation.

OBJECTIVES: To describe the radiographic features of odontogenic keratocysts (OKCs) and ameloblastomas and to compare the radiographic findings between these 2 lesions. METHODS: Radiographs of OKCs and ameloblastomas were retrospectively reviewed. Location, border, shape, association with impacted tooth, tooth displacement, root resorption, and bone expansion were evaluated. Chi-squared or Fisher's exact tests were used for statistical analysis. A p value < 0.05 was considered to indicate statistical significance. RESULTS: One hundred OKCs and 101 ameloblastomas were reviewed. The ratios of maxilla to mandible were 1:1.4 and 1:9.1 in OKCs and ameloblastomas, respectively. All evaluated features significantly differed between OKCs and ameloblastomas (p ≤ 0.001). Most OKCs showed smooth border (60%) and unilocular shape (82%), while most ameloblastomas showed scalloped border (77.2%) and multilocular shape (68.3%). Association with impacted tooth was found in 47% of OKCs and 18.8% of ameloblastomas. Adjacent tooth displacement was found in 33.7% of OKCs and 55.8% of ameloblastomas. Root resorption was more common in ameloblastomas (66.7%) than in OKCs (7%). Bone expansion was also more common in ameloblastomas (96.3%) than in OKCs (63.6%). CONCLUSION: A unilocular radiolucent lesion with smooth border, no adjacent tooth displacement, no root resorption and causing mild or no bone expansion is suggestive of an OKC rather than an ameloblastoma.

Evaluation of bone formation following the osteotome sinus floor elevation technique without grafting using cone beam computed tomography: a preliminary study.

BACKGROUND: Osteotome sinus floor elevation (OSFE) is used to increase the bone volume at the site of the maxillary sinus through the transalveolar approach. However, there is uncertainty regarding the necessity of the use of grafting material in order to maintain the space for new bone formation. OBJECTIVE: This study aimed to evaluate new bone formation 6 months after osteotome sinus floor elevation without grafting and to evaluate the correlations between residual bone height (RBH), implant protrusion length (IPL), and endo-sinus bone gain (ESBG). MATERIAL AND METHODS: Thirty-one implants (27 patients) from area 14-17 and 24-27 were included in the study. All implants had a history of OSFE without grafting, with cone beam computed tomography (CBCT) taken prior to the surgery. The clinical examination and radiographic examination using CBCT were performed again 6 months after implantation. The RBH, new bone level, ESBG, and IPL were measured. Paired sample t test and Pearson correlation were used to analyze the data. RESULTS: The average RBH before surgery was 7.14 ± 1.07 mm and 6 months after surgery was 8.95 ± 1.17 mm. There was a significant increase in new bone formation in the 6 months following surgery (p < 0.05). The average ESBG and IPL were 1.8 ± 0.79 mm and 2.02 ± 0.73 mm, respectively. There was a significant positive correlation between the IPL and ESBG (p < 0.05) while there was a negative correlation between RBH and ESBG. This study also demonstrates a decrease in the percentage of bone formation in relation to IPL as the IPL increases. The survival rate of the implant was 100%. CONCLUSION: Significant new bone formation can be detected around the implant site 6 months after implantation using OSFE technique without grafting. There is a negative correlation between the RBH and ESBG. While IPL is correlated to ESBG and appears to be the influencing factors of bone formation changes in the maxillary sinus. The preliminary radiographic results suggest that OSFE technique without grafting in combination with optimal IPL can provide sufficient bone height for implant support with a 100% implant survival rate.

Branching patterns of the inferior alveolar canal in a Thai population: a novel classification using cone beam computed tomography.

OBJECTIVE: This aim of this study was to determine the prevalence and branching patterns of the inferior alveolar canal (IAC) in premolar and molar areas using cone beam computed tomography (CBCT). METHOD AND MATERIALS: CBCT volumes from partially or fully edentulous premolar and molar areas were investigated retrospectively. The presence of such branches with their patterns, sides, and areas, as well as the sex of the patient, were recorded by two observers and analyzed statistically. The branching patterns were initially classified into three types: A, superior type; B, forward type; and C, plexus type. During the investigation, an additional type was found in the premolar area and was classified as type D, an anterior extension type. RESULTS: In total, 243 mandibular sites in 176 subjects were included. Among them, 106 sites displayed branches (43.62%). In the premolar area, most branches were of the anterior extension type (D, 33%), followed by the superior and plexus types (A and C, respectively, 29%), and the forward type (B, 9%). In the molar area, the plexus type was the most common finding (C, 39%), followed by the superior type (A, 32%) and the forward type (B, 29%). Branches in the molar area were significantly more frequent in men than in women (P = .011). CONCLUSION: IAC branches with four branching patterns in the premolar and molar areas are not rare and could be detected by CBCT. Clinicians should be aware of these branches during surgical procedures concerning the posterior mandible.

The retromolar canal and its variations: Classification using cone beam computed tomography.

OBJECTIVE: To determine the prevalence of the retromolar canal and its various patterns using cone beam computed tomography (CBCT). METHOD AND MATERIALS: CBCT images with the presence of mandibular third molars from August 2013 to May 2015 were retrospectively investigated. The presence of retromolar canal, its patterns, sides, as well as gender were evaluated by two observers. The pattern of retromolar canal was initially classified into three types: Type A, superior type; Type B, radicular-retromolar type; and Type C, dental type. During the investigation, two additional types were found and further classified: Type D, plexus type; and Type E, forward type. The distribution of retromolar canals between genders and sides was statistically analyzed with Pearson's chi-square test. RESULTS: A total of 201 mandibular sites in 156 subjects (99 women, 57 men) were included. Among them, 128 sites had retromolar canals (63.68%). The presence of retromolar canal was not statistically related to gender or side. Most of the retromolar canals were the radicular-retromolar type (Type B, 38.10%), followed by the superior type (Type A, 29.93%), dental type (Type C, 19.73%), plexus type (Type D, 6.80%), and forward type (Type E, 5.44%). CONCLUSION: There was a high frequency of retromolar canals and these could be classified into five patterns. The clinician should be aware of this anatomical structure when performing surgical procedures involving the retromolar area.

Application of a new chair-side method for the harvest of mesenchymal stem cells in a patient with nonunion of a fracture of the atrophic mandible--a case report.

PURPOSE: This case report describes a new clinical method for chair-side processing of a cell mixture which contains mesenchymal stem cells (MSCs) which was applied for the first time in the treatment of a nonunion of an atrophic fractured mandible. METHODS: Bone marrow was aspirated and a corticocancellous bone graft was harvested from the iliac crest of a 56-year-old woman with medical comorbidities and a fracture of the atrophic mandible. The fracture was stabilized with a reconstruction bone plate, and mononuclear cells including MSCs were concentrated by centrifugation and applied in combination with a particulate bone transplant. A sample of the grafted cells was characterized by flow cytometric analysis and by their ability to differentiate into various cell types. RESULTS: The fracture healed uneventfully. No complications occurred during the 4-month follow-up. CONCLUSION: Adding MSCs is a feasible alternative to enhance bone healing. This chair-side method requires little training and no cell laboratory support.

Complicated late mandibular fracture following third molar removal.

Mandibular fractures are a rare complication after third molar removal. Symptoms show a wide variance. Treatment options range from prescription of a soft diet to surgical treatment by open reduction and internal fixation. This article describes a patient who presented a late mandibular fracture following third molar removal. The fracture was not detectable in radiographs at the time of fracture. Six weeks after the reported cracking noise, the patient presented a mandibular fracture with associated osteomyelitis. Treatment by open reduction and internal fixation and autologous iliac crest graft was performed via a submandibular approach. The delayed diagnosis of this pathologic fracture demonstrates the necessity of repeated radiologic controls to prevent osteomyelitis when a fracture is suspected.