Radiographic enlargement of mandibular canal as first feature of non-Hodgkin's lymphoma.

Non-Hodgkin's lymphoma has the propensity to affect non-lymphoid tissue including oral tissue. Primary non-Hodgkin's lymphoma of the mandible mistreated as chronic periodontitis with diffuse enlargement of the mandibular canal and ice-cold numbness is very rarely described in English medical literature. A 57-year-old patient presented with a painful swelling on the left side of the mandible with a clinically chronic periodontitis associated with ice-cold numbness. A panoramic radiograph showed a diffuse uniform enlargement of the mandibular canal. Histological examination showed that the lesion was a primary intraosseous non-Hodgkin's lymphoma of the mandible. Immunohistochemical examination showed a positive reaction for CD20+, Ki-67+. Seven months after chemotherapy the patient was observed for possible life-threatening propagation of the disease. In conclusion, primary (extra-nodal) non-Hodgkin's lymphoma of the mandible usually clinically presents with bone swelling, teeth mobility and neurological disturbance. Radiographic features presenting as diffuse enlargement of the mandibular canal could be considered as non-Hodgkin's lymphoma.

Mandible schwannoma (neurilemmoma) presenting as periapical lesion.

Schwannoma is a benign nerve tumour that originates from Schwann cells, which cover peripheral nerves. Intraosseous schwannoma of the jaw is rare. Primary schwannoma of the mandible presenting as a periapical radiolucency on a non-vital endodontically treated tooth has rarely been referred to in the English medical literature. A rare case of intraosseous schwannoma is reported in a 23-year-old woman. The patient presented clinically with a painful swelling on the right side of the mandible and with a radiologically ill-defined unilocular periapical lesion around the mesial root of the endodontically treated first molar. Surgical treatment involved complete excision of the lesion with a mesial and distal root resection. Histological and immunohistochemical examination showed that the lesion was a primary intraosseous schwannoma of the mandible. Immunohistochemical examination showed a positive and strong reaction for S-100 protein, characteristic of neural tumours. 1 year following surgery, there were no regional recurrences. Radiographically, mandibular intraosseous schwannoma is difficult to differentiate from bone tumours such as ameloblastoma, myxoma, fibrous dysplasia, neurofibroma, central giant cell lesion or periapical lesion, so it should be included in the list of possible periapical pathoses.

[Maxillary osteonecrosis caused by toxic effect of zinc-oxide-eugenol paste].

Zinc-oxide powder mixed with eugenol or cariofillorum oil and sterilized cotton is frequently used in dental practice as surgical bandage for eliminating or dry socket. Osteonecrosis of alveolar bone caused by free eugenol is rare but possible complication. The aim of this paper is to present a patient with maxillary osteonecrosis complicated with maxillary sinusitis caused by a surgical paste of zinc-oxide. A 47-year-old female patient was admitted to our department after unsuccessful treatment of dry socket with a paste of zinc-oxide. Intense use of zinc-oxide paste as bandage over the extraction sockets caused two separately osteonecrosis of maxillary alveolar bone. Surgical resection of necrotic bone, extraction of adjacent teeth and revision surgery of maxillary sinus was treatment of choice. Postoperative course was uneventful and 6 months postoperatively there weren't present further signs of maxillary necrosis. In preparation of a paste of zinc-oxide as surgical bandage it is necessary that all the powder be filled up with intense mixing with liquid. In present case osteonecrosis was caused by free eugenol in surgical zinc-oxide bandage as well as due to the long term and frequently used of zinc-oxide. In resistant dry sockets we recommended combined method of treatment and not only the use of zinc-oxide paste especially if there was no analgesic and therapeutic effects.

Acidity constants of cefetamet, cefotaxime and ceftriaxone; the effect of the substituent at C3 position.

Ionization constants of three cephalosporin antibiotics, cefetamet (CEF), cefotaxime (CFX) and ceftriaxone (CFTR) are determined using pH-potentiometric titrations at I=0.1 M (NaCl) and t=25 degrees C. Cefetamet and cefotaxime have three ionization groups: carboxylic, amide and aminothiazole. Besides those three, ceftriaxone possesses an hydroxytriazinone group as new and additional ionization center. In acid medium two overlapping acid-base processes are occurring with acidity constants being: pK1 2.93 (COOH) and pK2 3.07 (aminothiazole) for cefetamet, and pK1 2.21 (COOH) and pK2 3.15 (aminothiazole) for cefotaxime. In the case of ceftriaxone the situation is even more complicated, three overlapping processes coexist with pK1 2.37 (COOH), pK2 3.03 (aminothiazole) and pK3 4.21 (hydroxytriazinone). Protolysis of amide group is happening in the alkaline medium as completely separated process from those in acid medium. The acidity constants which correspond to amide group are pK3 10.65 (CEF), pK3 10.87 (CFX) and pK4 10.74 (CFTR). The influence of the C3 substituent on the dissociation process of the neighboring ionization group, particularly carboxylic group, was considered. The differences in acidity of CEF, CFX and CFTR (pK1: 2.93, 2.21 and 2.37, respectively) are likely to be caused by the stereoelectronic properties of substituents in the beta-position to the carboxylic group due to the combined inductive, hyperconjugative and resonance effects.