Immunolocalization of PTCH protein in odontogenic cysts and tumors

The human patched gene (PTCH) functions in both embryologic development and tumor suppression. PTCH mutations have been found in odontogenic keratocysts. However, the expression and localization of the protein product of the gene have not been determined in odontogenic tumors and cysts. We investigated 68 odontogenic lesions by immunohistochemistry, and compared their PTCH expression with that in basal cell carcinomas. All odontogenic lesions, including two keratocysts with truncating mutations, were positive for PTCH. Different types of lesions had different amounts of staining. Lack of staining was noted in the majority of basal cell carcinomas. Taken together, these data suggest that odontogenic keratocysts arise with heterozygous mutations of the PTCH gene.     

Playing wind instruments as a potential aetiologic cofactor in external cervical resorption: two case reports

AIM: To present two cases of external cervical resorption (ECR) on maxillary incisors, in which the primary aetiologic factor is suggested to be pressure trauma by frequently playing wind instruments. SUMMARY: The exact aetiological spectrum of ECR is still poorly understood. For resorption to occur, a defect in the cementum layer (trigger) is a likely prerequisite. Whilst the mechanism for continuation (stimulus) is still unclear, knowledge of potential predisposing factors is important in assessing patients at risk. Pressure generated by playing wind instruments could present an aetiological factor in ECR because it affects the cervical region of the root surface. The cases that are presented may confirm this hypothesis and the extent of resorption defects is shown by cone-beam computer tomography (CT) and micro-focus CT imaging techniques.     

Synovial chondromatosis of the temporomandibular joint

Synovial chondromatosis is a cartilaginous metaplasia of the mesenchymal remnants of the synovial tissue of the joints. Its main characteristic is the formation of cartilaginous nodules in the synovium and inside the articular space (loose bodies). Synovial chondromatosis mainly affects big synovial joints such as the elbow and knee and is uncommon in the temporomandibular joint. The main symptoms are pain, limitation of jaw movement, crepitation, and inflammation. Diagnosis is made by panoramic radiograph, computed tomography scan, and mainly magnetic resonance imaging. Surgery is the therapeutic choice. The authors describe their experience in the treatment and in the follow up of a patient with unilateral synovial chondromatosis.     

Direction of the mental canal in human mandibles

The direction of the mental canal was calculated in the horizontal and vertical planes with a view to aiding anaesthetic techniques. Based on our data, it is advisable to give the following approximate inclinations to the needle when penetrating the mental canal in anaesthetic procedures: 55 degrees postero-anteriorly in relation to a horizontal plane and 40 degrees latero-medially in relation to a horizontal line tangent to the body of the mandible at the level of the mental foramen.     

Detection of non-cavitated approximal caries lesions in digital images from seven solid-state receptors with particular focus on task-specific enhancement filters. An ex vivo study in human teeth

The aim of this study was to compare detection of non-cavitated approximal caries lesions in images from seven solid-state intraoral digital receptors, with particular focus on two task-specific enhancement filters. One hundred and sixty approximal non-cavitated surfaces were radiographed under standardized conditions using the following seven intraoral solid-state digital receptors: two CMOS systems, Schick CDR-APS, and Kodak RVGui; and five CCD systems: Visualix, VistaRay, Dixi2, Sidexis, and Dr. Suni Plus. The Kodak RVGui digital images were captured with two task-specific, predefined enhancement filters ("dento-enamel" and "periodontal"). Eight observers examined the digital images for the presence or absence of approximal carious lesions. The teeth were subsequently sectioned for histological analysis, which served as the "gold standard" for the radiographic examination and allowed for a calculation of sensitivity, specificity, and overall accuracy. Both RVG modalities obtained the highest sensitivity values, which were significantly higher than with Visualix, Sidexis, and VistaRay images (all P 0.05).     

Reimpianto dentale in soggetto affetto da paralisi cerebrale infantile: problemi di valutazione medico-legale del danno

Objectives

Analysis of the parameters used for the medicolegal assessment of damages in a case of tooth avulsion and replantation in a child with cerebral palsy.

Materials and methods

The authors report a case of traumatic tooth avulsion in a child with cerebral palsy. During recess at school, the girl fell out of her wheelchair, which was being pushed by her schoolmates, and suffered maxillofacial trauma associated with superior incisor avulsion. The tooth was replanted within 60 minutes, but it fell out 6 years later. Because the traumatic event leading to the avulsion had occurred at school, the parents filed a claim for damages with the school's insurance company.

Discussion

The authors review the procedure for arriving at a fair assessment of the damage, based on the child's condition before the trauma and data in the literature on life expectancy in subjects with cerebral palsy and factors affecting the duration of the tooth replants.     

Orthodontic microsurgery: a new surgically guided technique for dental movement

Eight patients with malocclusions were treated with a new orthodontic-surgical technique that reduces the duration of treatment compared to conventional techniques. The monocortical tooth dislocation and ligament distraction (MTDLD) technique combines two different dental movements that work separately but simultaneously on opposite root surfaces. On the root surface corresponding to the direction of movement, vertical and horizontal microsurgical corticotomies are performed around each tooth root with a piezosurgical microsaw to eliminate cortical bone resistance. The immediate application of strong biomechanical forces produces rapid dislocation of the root and the cortical bone together. On the root surface opposite the direction of movement, the force of dislocation produces rapid distraction of ligament fibers. During the osteogenic process that follows, application of normal orthodontic biomechanics achieves the final tooth movement. All eight patients underwent periodontal and radiologic examinations for more than 1 year after treatment. No periodontal defects were observed in any of the patients, including one with a severe malocclusion and a thin periodontal tissue biotype. Compared to traditional orthodontic therapy, the average treatment time with the MTDLD technique in the mandible and maxilla was reduced by 60% and 70%, respectively.     

Save the natural tooth or place an implant? Three periodontal decisional criteria to perform a correct therapy

To perform advanced periodontal therapy to save a natural tooth or to extract it and place an implant-which is best? Several considerations need to be made to make the proper decision. Endodontic conditions, proper reconstruction of a devitalized tooth, and the possibility of correct prosthetic treatment are all factors to be considered. From a strictly periodontal point of view, in the presence of a stable, vital, intact, periodontally involved, single-rooted tooth, a few fundamental criteria need to be considered to make the proper decision. These criteria will be discussed through analysis of therapy outcomes over a period of at least 10 years.