David Mock

Odontogenic tumors. A demographic study of 759 cases in a Chinese population.

Seven hundred fifty-nine cases of odontogenic tumors retrieved from the files of College of Stomatology, West China University of Medical Sciences were classified according to the World Health Organizations Histological Classification of Odontogenic Tumors and compared with similar reports from other countries. Among these cases, 93.9% of the tumors were benign and 6.1% were malignant. Ameloblastomas predominated (58.6%) with a predilection for the mandible, while odontomas, generally regarded as the most frequent odontogenic tumor in North America, only accounted for 6.7%, the fourth most common tumor in this series. The mandible and the maxilla were divided into eight anatomic regions, and the distribution of each odontogenic tumor type amongst these regions was recorded. The relative incidence of each tumor type, patient age and gender were also compared with data from other selected large series. Geographic differences were noted in the relative incidence of ameloblastoma, odontoma and malignant odontogenic tumors among the Chinese/African, North American and Turkish/German groups. Ameloblastoma and malignant odontogenic tumors are not considered rare in a Chinese population.

An Interfaculty Pain Curriculum: Lessons learned from six years experience

Abstract Minimal pain content has been documented in pre‐licensure curricula and students lack important pain knowledge at graduation. To address this problem, we have implemented and evaluated a mandatory Interfaculty Pain Curriculum (IPC) yearly since 2002 for students (N = 817 in 2007) from six Health Science Faculties/Departments. The 20‐h pain curriculum continues to involve students from Dentistry, Medicine, Nursing, Pharmacy, Physical Therapy, and Occupational Therapy as part of their 2nd or 3rd year program. Evaluation methods based on Kirkpatrick’s model now include evaluation of a Comprehensive Pain Management Plan along with the previously used Pain Knowledge and Beliefs Questionnaire (PKPQ) and Daily Content and Process Questionnaires (DCPQ). Important lessons have been learned and subsequent changes made in this iterative curriculum design based on extensive evaluation over the 6‐year period. Modifications have included case development more relevant to the diverse student groups, learning contexts that are uni‐, inter‐, and multi‐professional, and facilitator development in working with interprofessional student groups. PKBQ scores have improved in all years with a statistically significant average change on correct responses from 14% to 17%. The DCPQ responses have also indicated consistently that most students (85–95%) rated highly the patient panel, expert‐lead clinically focused sessions, and small interprofessional groups. Relevancy and organization of the information presented have been generally rated highly from 80.3% to 91.2%. This curriculum continues to be a unique and valuable learning opportunity as we utilize lessons learned from extensive evaluation to move the pain agenda forward with pre‐licensure health science students.

Atypical facial pain: A retrospective study

Among the most challenging patients seen for evaluation by a health care practitioner are those suffering from the atypical facial pain syndrome. They have almost inevitably been subjected to extensive treatment which either has had no effect on the symptoms or has aggravated them. This article reports a retrospective study of thirty-four randomly selected cases of atypical facial pain that have been seen by a multidisciplinary pain group.

Burning mouth syndrome.

Most clinicians dread seeing the patient presenting with a primary complaint of a burning pain on one or more oral mucosal surfaces. Unlike most other clinical conditions presenting in a dental office, burning mouth syndrome is poorly understood with few evidence based remedies. More recently, advances have been made towards clarifying the possible etiology of the disorder and testing the possible therapeutic modalities available. This article attempts to summarize the “state of the art” today.

Immunohistochemical and histochemical characterization of the mucosubstances of odontogenic myxoma: histogenesis and differential diagnosis.

To discuss the dental origin of odontogenic myxoma and to provide further information for the differential diagnosis between this tumor and myxoid malignant fibrous histiocytoma (MFH) which occasionally occurs in jaw bones, the contents of glycosaminoglycans (GAGs) and proteoglycans (PGs) in the mucosubstances of 15 odontogenic myxomas, 5 myxoid MFH and 3 human fetal tooth germs in the bell stage of development were characterized using histochemical and immunohistochemical methods. Histochemical staining of hyaluronic acid (HA) was undertaken using biotinylated HA binding protein (B-HABP), and immunohistochemical detection was done using a panel of antibodies against chondroitin 6-sulfate (CS-6), chondroitin 4-sulfate (CS-4), dermatan sulfate (DS), keratan sulfate (KS), heparan sulfate (HS), aggrecan, PG-M/versican, decorin and biglycan. In odontogenic myxoma, CS-6, HA and PG-M/versican were observed in the myxomatous matrix of all cases, while KS and HS were seen in none. As for CS-4, DS, aggrecan, decorin and biglycan, only irregular and mild stainings were shown. Consistent and strong positive straining for CS-6, HA and PG-M/versican were seen in dental papilla and provided evidence supporting the origin of this tumor from dental papilla. Except for the constant staining for HA, the myxoid matrix was rarely stained for most GAGs and PGs in myxoid MFH. Immunodetection of CS-6 and PG-M/version with the use of monoclonal antibodies 3-B-3 and 2-B-1 is therefore recommended as a useful tool in differentiating odontogenic myoma from myxoid MFH.

Multiple canalicular adenomasA case report and review of the literature

The canalicular adenoma is an uncommon, benign salivary gland tumor that most frequently occurs in the upper lip. Rarely, it manifests itself clinically and histologically as a multifocal lesion, a feature not generally seen with other intraoral salivary gland tumors. Here we report a case of canalicular adenoma that manifested itself with 13 clinically discrete tumor masses involving the upper lip and anterior buccal mucosa. In addition to the clinical nodules, there were microscopic foci of tumor cells in the adjacent normal-appearing salivary gland tissue surrounding the tumors. This article also reviews previously reported multifocal canalicular adenomas and discusses their features, emphasizing differences in the reported growth patterns of this unusual tumor.

Sensory and affective components of orofacial pain: is it all in your brain?

In this paper, we shall review several chronic orofacial pain conditions with emphasis on those that are essentially refractory to treatment. We shall present a review of current and past literature that describes the various pain phenomena as well as their underlying central mechanisms. New data concerning refractory pain will be used to underscore the importance of central processing of pain, with particular emphasis on neuropsychological and cognitive function and capacity that may play important roles in pain processing and maintenance of the pain state. Further, neurophysiological data showing that the anterior cingulate cortex (ACC) and other structures in the brain may play key roles in modulation of chronic pain will also be discussed. Although peripheral triggering events surely play an important role in initiating pain, the development of chronic and, in particular, refractory pain may depend on changes or malfunctions in the central nervous system. These changes may be quite subtle and require sophisticated approaches, such as functional MRI, to study them, as is now being done. New findings obtained therefore may lead to more rational and reliable treatment for orofacial pain.

Proliferative activity of calcifying odontogenic cysts as evaluated by proliferating cell nuclear antigen labeling index

The calcifying odontogenic cyst (COC) presents with diverse hlstologlcal features; thus, several subclasslfl‐cations have been proposed. To evaluate the slgnlficance of the various histological features and subtypes of COC from the perspectlve of proliferative activity, the proliferating cell nuclear antigen (PCNA) labellng index (LI; the percentage of positive nuclei) was assessed immunohistochemlcally in 25 cases of COC (21 benign and four malignant). All of the benign cases were of the cystic variety and further subclas‐sified into non‐proliferative subtype (NPS; four cases); proliferative subtype (PS; eight cases); and COC associated with odontoma (COCaO, nlne cases). The PCNA U of the mallgnant COC (65.2 ± 5.6) was slgnlflcantly higher than that of the benlgn COC (11.6 ± 9.0; P = 0.002). Non‐proliferative subtype (6.8 ± 2.8) showed the lowest PCNA LI and PS (17.2 ± 11.2) the highest of among the three subtypes of benign cystic COC (P = 0.028). In nine cases of COCaO, six showed epithelial lining of the non‐proliferative type as NPS and the other three had lining wlth proliferative features as PS. The PCNA LI of the latter COCaO group (14.3 ± 6.6) was significantly higher than that of the former (6.1 ± 4.3; P = 0.05), as Seen between PS and NPS. These results demonstrate that PCNA LI is a possible parameter for differentiating mallgnant COC from benign COC and, whatever the subtypes, the proliferative features In the lining are the main factor influencing the prollferatlng actlvity of COC.

Chondrometaplasia involving the temporomandibular joint.

The pathogenesis of chondrometaplasia is discussed and a case of a single loose body in the temporomandibular joint is presented, with radiologic observations, operative findings, and histologic studies.

Familial amelodentinal dysplasia

T here are few abnormalities of tooth development that affect both the mesodermal and ectodermal dental components. Regional odontodysplasia is such a condition, in which the teeth are malformed, discolored, and have short roots, open apices, and wide pulp chambers. The eruption of the dentition is delayed, and often teeth remain unerupted. This condition affects one segment of teeth, as a rule, although cases of extensive involvement have been reported. Chaudhry and associates’ reported a case extensively involving three quadrants, and Herman and MOSS* reported involvement of all four quadrants, although the diagnosis in the latter case has been questioned.3 Although many possible causes of odontodysplasia have been suggested, no specific cause has been confirmed. The causes that have been discussed in the literature include somatic mutation,‘,4 local circulatory disorders,5 irradiation4v 6* ’ local trauma,4* 6, 7 infection,*+ *. 9 metabolic disturbances,4s ’ nutritional deficiency? 7 local ischemia? ‘O and hyperpyrexia,” 7. A genetic basis has been suggested, but thus far there have not been any reports of a familial pattern.” There have also been sporadic reports of abnormalities of enamel and dentin associated with other genetic abnormalities. I2 Suzuki and co-workers’3 reported a case of opalescent dentin with associated enamel defects; however, the characteristics of the dentin were consistent with odontogenesis imperfecta and the patient’s father had the characteristic dental changes. Recently, Nakata and colleaguesr4 reported amelogenesis imperfecta associated with a dysplasia of dentin in the interradicular area of teeth in two sisters, offspring of a consanguineous marriage. They also noted retarded tooth eruption in these cases. We are reporting two cases of a developmental abnormality of both mesodermal and ectodermal components of teeth, affecting, to some extent, the entire dentitions of two siblings. Fig. 1. Case 1. Clinical photograph showing partially erupted teeth with attrition of incisal surfaces.