A successful implant-supported fixed prosthesis in a patient with osteopetrosis: A clinical report.

Osteopetrosis (marble bone disease) is a family of rare genetic disorders characterized by impaired osteoclast function leading to hyperdense, hypovascular, brittle bone. Typical imaging shows increased bone mass and thickened cortical and trabecular bone. Bones are more prone to fracture and osteomyelitis may develop. When considering dental implant placement in a patient with osteopetrosis, the potential for bony fracture and/or osteomyelitis should be considered along with the decreased likelihood of successful osseointegration because of hypovascularity. This clinical report describes an unusual imaging presentation and successful osseointegration of multiple dental implants supporting an implant-supported fixed mandibular prosthesis with long-term survival.

Osteoblastoma and Osteoid Osteoma of the Mandible: Review of the Literature and Report of Two Cases.

Osteoblastoma and osteoid osteoma are rare benign neoplasms of the jaws. We reviewed current literature surrounding the ongoing debate over similarities and differences of osteoblastoma and osteoid osteoma and present two cases. Both cases are well-demarcated mixed radiodensity mandibular lesions with histological features of osteoblastoma. They exhibit, however, distinctly unique and contrasting clinical and imaging characteristics suggesting that the first case is osteoblastoma and the second is osteoid osteoma. The first case of a 37-year-old male presents with a large, expansile lesion at posterior mandible, surrounded by a thick sclerotic band. Unusual features include significant buccal/lingual expansion, extensive new bone apposition, and soft tissue edema in the masseter muscle. This is in contrast to the second case of a much smaller lesion in a 17-year-old male with history of recent third molar extraction in the left posterior mandible. In this case, CT imaging revealed a circular, nonexpansile lesion with a sclerotic border surrounded by a radiolucent rim. Both patients underwent surgical excision of the lesion with extraction of the adjacent tooth. We discuss herein the distinct clinical and imaging features.

Delayed diagnosis of palatal adenoid cystic carcinoma: Review of diagnostic workup and image features of perineural spread.

OBJECTIVES: Adenoid cystic carcinoma (ACC) is the malignancy most likely to spread perineurally. Delayed diagnosis often leads to undetected perineural spread (PNS). Better understanding of diagnostic processes, clinical and imaging features in ACC may allow earlier diagnoses. MATERIALS AND METHODS: A retrospective records search of the University of Washington Radiology archive identified patients with palatal ACC diagnosis and pre-treatment MDCT and/or MRI. Demographic data, clinical findings, diagnostic workup history and image features including the presence of PNS were recorded. RESULTS: 44 patients met inclusion and exclusion criteria. Symptoms included pain, mass, numbness, and sinonasal congestion. The most common finding on clinical examination was visible or palpable palatal mass. 55% of patients were evaluated by a dentist pre-diagnosis. Most common initial impressions were infection and/or dental disease. PNS was identified in 81.8% of patients, most commonly at pterygopalatine fossa, palatine foramina/canals, Vidian canal, or foramen rotundum. PNS was statistically significantly associated with paresthesia (p = 0.003) but not with tumor size, age, gender, or tobacco history. 44% of patients were diagnosed ≥1 year from initial symptoms, with a mean delay of 18.3 (range < 1-72) months. CONCLUSIONS: This study represents the first analysis of the nature of the diagnostic process of palatal ACC. Majorities of patients were evaluated by a general dentist pre-diagnosis. PNS was identified in a majority of patients and all the patients who presented with paresthesia had evidence of PNS. Despite patients presenting with paresthesia, palatal ACC is often initially misdiagnosed resulting in delayed diagnosis.

Osteoarthritis of the temporomandibular joint and increase of the horizontal condylar angle: a longitudinal study.

OBJECTIVE: Our previous study of patients with unilateral temporomandibular joint (TMJ) osteoarthritis (OA) showed that the affected joints had greater horizontal condylar angle (HCA) compared with the contralateral unaffected joints. However, it was unclear whether the HCA changes preceded or were the result of OA changes. The aim of this longitudinal study was to investigate the relationship between HCA and OA progression. STUDY DESIGN: In total, 127 patients (with or without TMJ disorders) completed baseline and follow-up examinations (average time to follow-up 7.9 years). Generalized estimating equation models were used to account for correlation of observations within the same patients. RESULTS: (1) HCA was greater in OA-affected joints than in unaffected joints (P = .04). (2) Increased HCA at follow-up was associated with change in joint status from no OA to OA. (P = .001). (3) Baseline HCA value alone did not predict future OA diagnosis. (4) All OA changes in fossa/articular eminence morphology, and some combinations of condylar changes, were associated with a greater HCA. (5) OA diagnosis was associated with pain during maximum opening (P = .005) and pain history (P = .002). (6) Aging alone was not correlated with increased HCA. CONCLUSIONS: Clinical progression of OA preceded increases in HCA. HCA alone did not predict OA development.

Greater mandibular horizontal condylar angle is associated with temporomandibular joint osteoarthritis.

BACKGROUND: Research using magnetic resonance imaging analysis has shown that internal temporomandibular joint derangement is associated with significantly greater horizontal condylar angle. However, the association between osteoarthritic (OA) bony changes as shown on computed tomography and horizontal condylar angle has never been evaluated. OBJECTIVE: To investigate the relationship between mandibular condylar angle and OA degenerative changes. STUDY DESIGN: This is a retrospective study using cone beam computed tomography images and reports from 60 patients with unilateral OA degenerative changes and 43 control patients with no OA-affected joints. RESULTS: Condylar angles in the joints of control patients and the unaffected joints in OA patients were not significantly different. The mean horizontal condylar angle in the unilaterally OA-affected joints (29.5° ± 10.5°) was larger than in the contralateral unaffected joints (22.5° ± 7.7°) (P < .001). In the OA-affected joints, flattening and erosion of the articular eminence was associated with a greater condylar angle (P < .05). CONCLUSIONS: Moderate to severe degenerative temporomandibular joint change is associated with greater horizontal condylar angle.

Mandibular inferior cortical bone thickness on panoramic radiographs in patients using bisphosphonates.

OBJECTIVE: The goal of this study was to detect dimensional changes in the mandibular cortical bone associated with bisphosphonate (BP) use and to correlate measurements of the cortical bone with the cumulative dose of BPs. STUDY DESIGN: Mandibular inferior cortical bone thickness (MICBT) was measured under the mental foramen on panoramic radiographs of patients with and without bisphosphonate-related osteonecrosis of the jaws (BRONJ) taking BPs and controls. RESULTS: Patients with BRONJ had the highest mean MICBT (6.81 ± 1.35 mm), compared with patients without BRONJ taking BPs (5.44 ± 1.09 mm) and controls (4.79 ± 0.85 mm) (P < .01). Mean MICBT of patients with BRONJ was significantly higher than that of patients without BRONJ taking BPs. There was a correlation between MICBT and cumulative dose of zolendronate. CONCLUSIONS: Measurement of MICBT on panoramic radiographs is a potentially useful tool for the detection of dimensional changes associated with BP therapy.

De novo synthesis of PCR templates for the development of SARS diagnostic assay.

A novel coronavirus was identified as the cause for severe acute respiratory syndrome (SARS). The complete sequence of SARS genome has provided an opportunity for the development of molecular diagnostic assays. To restrain further outbreak of SARS, the World Health Organization has posted several pairs of polymerase chain reaction (PCR) primers for early diagnosis and urged more research to be done on PCR protocols. Here we report a strategy for the de novo synthesis of PCR templates complimentary to the SARS virus genome, which has the advantage of working on PCR templates without concern about viral infection and also has the advantage that it can be used by those who do not have access to the SARS virus. This highly efficient and safe strategy for obtaining SARS gene fragments is useful for the development of PCR assays, as well as for the preparation of reliable positive controls for PCR testing kits.

Mandibular cortical bone evaluation on cone beam computed tomography images of patients with bisphosphonate-related osteonecrosis of the jaw.

OBJECTIVES: The objective of this study was to develop a technique for detecting cortical bone dimensional changes in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ). STUDY DESIGN: Subjects with BRONJ who had cone-beam computed tomography imaging were selected, with age- and gender-matched controls. Mandibular cortical bone measurements to detect bisphosphonate-related cortical bone changes were made inferior to mental foramen, in 3 different ways: within a fixed sized rectangle, in a rectangle varying with the cortical height, and a ratio between area and height. RESULTS: Twelve BRONJ cases and 66 controls were evaluated. The cortical bone measurements were significantly higher in cases than controls for all 3 techniques. The bone measurements were strongly associated with BRONJ case status (odds ratio 3.36-7.84). The inter-rater reliability coefficients were high for all techniques (0.71-0.90). CONCLUSIONS: Mandibular cortical bone measurement is a potentially useful tool in the detection of bone dimensional changes caused by bisphosphonates.

Sequential roles of Brg, the ATPase subunit of BAF chromatin remodeling complexes, in thymocyte development.

T cells develop through distinct stages directed by a series of signals. We explored the roles of SWI/SNF-like BAF chromatin remodeling complexes in this process by progressive deletion of the ATPase subunit, Brg, through successive stages of early T cell development. Brg-deficient cells were blocked at each of the developmental transitions examined. Bcl-xL overexpression suppressed cell death without relieving the developmental blockades, leading to the accumulation of Brg-deleted cells that were unexpectedly cell cycle arrested. These defects resulted partly from the disruptions of pre-TCR and potentially Wnt signaling pathways controlling the expression of genes such as c-Kit and c-Myc critical for continued development. Our studies indicate that BAF complexes dynamically remodel chromatin to propel sequential developmental transitions in response to external signals.