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SELECTIONS FROM THE CURRENT LITERATURE
JOURNALSCAN
SELECTIONS FROM THE CURRENT LITERATURE
Compiled by Michael L. Barnett, DDS
ORAL PATHOLOGY
Clinicopathological study and treatment outcomes of 121 cases of ameloblastomas Fregnani ER, da Cruz Perez DE, de Almeida OP, et al. Int J Oral Maxillofac Surg 2010;39(2):145-149.
he authors conducted a retrospective study to compile the clinical, radiographic and histopathological findings for all ameloblastomas seen at a single Brazilian hospital in a 50-year period. They identified 121 patients with confirmed ameloblastoma lesions after reviewing data from patients’ records and archived histologic slides. They found that the majority (72 percent) of patients were white, with a slight predominance of females (53 percent), and that the ages ranged from 2 to 82 years (mean age, 33.2 years). With respect to lesion location, the authors found that the majority (89 percent) of lesions were located in the mandible, with most of these in the posterior region and only 9 percent located anteriorly, and that all but one of the maxillary lesions were in the posterior region as well. Their review of the records indicated that the patients’ chief complaints were swelling, pain or both in the involved area and that 113 lesions were classified as solid, seven as unicystic and one as peripheral. Furthermore, the authors found that the majority (62 percent) of the lesions appeared multilocular
T
on radiographs, with 65 percent showing expansion and 25 percent showing discontinuity of the vestibular bone plate, the lingual bone plate or both; the basal bone plate showed expansion or discontinuity in 40 and 13 percent of lesions, respectively. The 113 solid ameloblastomas were treated with segmental resection (47 lesions), bone curettage followed by cryotherapy (47 lesions) or bone curettage alone (19 lesions); all of the unicystic lesions were treated with curettage or curettage and cryotherapy. The authors found that the mean follow-up period was 9.7 years, during which 27 patients experienced a recurrence of their lesions, 25 of whom had solid ameloblastoma and two of whom had unicystic lesions. They noted that lesions that appeared multilocular on radiographs were 3.02 times more likely to recur than were unilocular lesions and, moreover, that controversy remains concerning the treatment criteria and protocols for managing solid ameloblastomas. Significance. Although ameloblastomas are relatively rare, they compose 13 to 58 percent of all odontogenic tumors, according to data cited by the authors.1 Because the majority of ameloblastomas are located in the posterior mandible, a site of other lesions that also may appear as radiolucencies, these tumors should be considered in the differential diagnosis of such lesions. 1. Reichart PA, Phillipsen HP, eds. Odontogenic tumors and allied lesions. London: Quintessence; 2004.
JADA, Vol. 141
http://jada.ada.org
Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
May 2010
569
J O U R N A L S C A N
ORAL ONCOLOGY
Chromosomal numerical aberrations in apparently normal oral mucosa of heavy smokers affected by lung cancer Shani T, Onn A, Kabha A, et al. Oral Oncol 2010;46(2):96-99.
he concept of “field cancerization” suggests that the entire mucosa of the aerodigestive tract in smokers is at increased risk of developing malignant lesions, insofar as this tissue is exposed to the carcinogenic compounds in tobacco products. Aneuploidy, an alteration (increase) in chromosome number, is found in the nonmalignant and premalignant bronchial and oral epithelium of smokers. The authors conducted a study to determine the prevalence of aneuploid cells in samples obtained from normal-appearing oral mucosa of smokers who had lung cancer, smokers who did not have lung cancer and people who had never smoked. They enrolled 152 participants older than 40 years who had clinically normal oral mucosa, 59 of whom were heavy smokers who did not have lung cancer, 31 of whom were heavy smokers who had lung cancer and 62 of whom were nonsmokers. They obtained two oral samples from each patient (from the posterior lateral border of the tongue and from the buccal mucosa); they used a disposable brush with hard nylon fibers to brush the surface mucosa with rotary movements and light pressure to harvest cells from all epithelial layers. To assess chromosome number, the authors selected two chromosomes, numbers 2 and 8, which they noted was based on results of their previous studies investigating aneuploid cells in oral premalignant lesions. They used a fluorescent in situ hybridization method that detected chromosomes 2 and 8 with green and red signals, respectively, and calculated the percentage of cells with more than two signals for each of the chromosomes. The authors found no differences between buccal mucosa and tongue samples. As a result of statistical analysis, they showed that in comparison with those who had never smoked, a high proportion of the heavy smokers with and without lung cancer had more than 2 percent aneuploid cells (odds ratio [OR] = 3.62, 95 percent confidence interval [CI] = 0.942-20.411) and that the proportion was significantly higher among the heavy smokers with lung cancer (OR = 5.74, 95 percent CI = 1.164-36.447, P = .015). The authors noted that the results of this
T
570
JADA, Vol. 141
http://jada.ada.org
study suggest that heavy smokers have a detectable chromosomal instability in the oral mucosal epithelium and that the presence of aneuploid cells in normal-appearing oral mucosa might be used to identify smokers at higher risk of developing cancer. However, the validity of this finding as a screening tool needs to be established in a longitudinal clinical study. Significance. The relatively high prevalence of oral cancer and its association with tobacco smoking has led to efforts to find factors, or biomarkers, with which to identify people especially susceptible to developing this disease. This has led to studies of putative factors in accessible fluids, such as blood and saliva, as well as to studies of tissue from potential lesion sites such as the investigation reported here. While the validation of biomarkers requires rigorous documentation, it might be anticipated that as biomedical research progresses, the goal of identifying people at risk of developing disease will be realized. ORAL RADIOLOGY
Prevalence of mucosal abnormalities of the maxillary sinus and their relationship to dental disease in panoramic radiography: results from the Health 2000 Health Examination Survey Vallo J, Suominen-Taipale L, Huumonen S, et al. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109(3):e80-e87.
he authors conducted this study to determine the prevalence of maxillary sinus changes and the extent to which these changes are associated with pathological dental findings. They used data from a nationally representative sample of adults, 30 years or older, in Finland. After training to calibrate their radiographic interpretation, oral radiologists reviewed panoramic radiographs with at least one clearly visible maxillary sinus from 5,021 participants, whose mean age was 51.7 years. They categorized their maxillary sinus findings in three groups: mucosal thickening (a 3to 6-millimeter–thick noncorticated radiopaque band following the bony wall of the sinus); mucosal antral cyst (a smooth, noncorticated, dome-shaped radiopaque mass rising from the floor or wall of the sinus); or other pathological findings. For dental findings, they recorded the presence of periapical lesions, the extent of horizontal and vertical bone loss, and the presence and adequacy of endodontic treatments. They
T
May 2010
Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
J O U R N A L S C A N
observed maxillary sinus mucosal changes in 19 percent of participants, with findings more common in men (27 percent) than in women (13 percent). They reported that the most frequent finding was mucosal thickening, which they saw in 12 percent of participants, with mucosal antral cysts seen in 7 percent of participants; the former was apparent most often in people aged 40 to 49 years, whereas antral cysts were found most often in younger age groups. The authors conducted statistical analyses and found that while participants with periapical lesions, periodontal bone loss or furcation involvement had a significantly higher risk (3.1-fold to 6.3-fold) of having mucosal thickening than that of edentulous participants, there was no difference between participants who had teeth without dental pathology and edentulous participants. The association between dental pathology and the presence of mucosal antral cysts was lower. The authors noted that maxillary mucosal changes generally are not symptomatic, although large antral cysts have been associated with nasal stuffiness, a sensation of facial fullness, paresthesias and pain or soreness on palpation. Consequently, in the case of a patient who has pain in the facial region with no other obvious cause, the clinician should consider maxillary sinus changes. Significance. The radiographic changes of the maxillary sinus described in this study are seen not infrequently on routine dental radiographs. This study provides data that will help clinicians in interpreting the findings and establishing a differential diagnosis and treatment plan. GENE THERAPY
Salivary epithelial cells: an unassuming target site for gene therapeutics Perez P, Rowzee AM, Zheng C, et al. (published online ahead of print Feb. 26, 2010). Int J Biochem Cell Biol.
he authors wrote this review to provide an update on studies being conducted that ultimately could lead to the use of salivary glands for
T
gene therapy in systemic disorders. They noted that while salivary glands typically are thought to produce proteins and secrete them into the saliva, studies have shown that they can secrete proteins into the blood stream as well and, thereby, can have both an exocrine and an endocrine function. In view of the demonstrated endocrine function, the authors conducted studies of in situ gene transfer to salivary glands for gene therapy in systemic disorders. They discussed salivary gland development, the vectors used for gene transfer and the secretory pathways for transgenic proteins. Finally, they provided examples of successes of gene therapy in eliciting the secretion of transgenic therapeutic proteins in animal models in both saliva and blood. For the former, they cited the production of therapeutic levels of histatin 3 in rats that are effective against fluconazole-resistant Candida in vitro and the salivary augmentation of keratinocyte growth factor at levels sufficient to prevent severe oral mucositis in an irradiated murine model. For the latter, they cited the production and secretion of human erythropoietin, human parathyroid hormone and human growth hormone after gene transfer to mouse or rat submandibular glands. Although gene therapy to correct singleprotein deficiency disorders has promise, the authors noted that the secretory pathway for the glands’ endocrine function is not predictable and that, consequently, proteins intended for systemic distribution actually may be secreted into saliva with a severely attenuated effect. Further investigation into the cellular biology underlying the sorting pathways likely will help to overcome this difficulty. Significance. This study further illustrates the universality of biomedical research and the interconnections between the tissues and organs of the mouth and those of the remainder of the body. ■ Dr. Barnett is a clinical professor, Department of Periodontics/ Endodontics, School of Dental Medicine, University at Buffalo, The State University of New York. Disclosure. Dr. Barnett did not report any disclosures.
JADA, Vol. 141
http://jada.ada.org
Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
May 2010
571
SELECTIONS FROM THE CURRENT LITERATURE
Compiled by Michael L. Barnett, DDS
ORAL PATHOLOGY
Clinicopathological study and treatment outcomes of 121 cases of ameloblastomas Fregnani ER, da Cruz Perez DE, de Almeida OP, et al. Int J Oral Maxillofac Surg 2010;39(2):145-149.
he authors conducted a retrospective study to compile the clinical, radiographic and histopathological findings for all ameloblastomas seen at a single Brazilian hospital in a 50-year period. They identified 121 patients with confirmed ameloblastoma lesions after reviewing data from patients’ records and archived histologic slides. They found that the majority (72 percent) of patients were white, with a slight predominance of females (53 percent), and that the ages ranged from 2 to 82 years (mean age, 33.2 years). With respect to lesion location, the authors found that the majority (89 percent) of lesions were located in the mandible, with most of these in the posterior region and only 9 percent located anteriorly, and that all but one of the maxillary lesions were in the posterior region as well. Their review of the records indicated that the patients’ chief complaints were swelling, pain or both in the involved area and that 113 lesions were classified as solid, seven as unicystic and one as peripheral. Furthermore, the authors found that the majority (62 percent) of the lesions appeared multilocular
T
on radiographs, with 65 percent showing expansion and 25 percent showing discontinuity of the vestibular bone plate, the lingual bone plate or both; the basal bone plate showed expansion or discontinuity in 40 and 13 percent of lesions, respectively. The 113 solid ameloblastomas were treated with segmental resection (47 lesions), bone curettage followed by cryotherapy (47 lesions) or bone curettage alone (19 lesions); all of the unicystic lesions were treated with curettage or curettage and cryotherapy. The authors found that the mean follow-up period was 9.7 years, during which 27 patients experienced a recurrence of their lesions, 25 of whom had solid ameloblastoma and two of whom had unicystic lesions. They noted that lesions that appeared multilocular on radiographs were 3.02 times more likely to recur than were unilocular lesions and, moreover, that controversy remains concerning the treatment criteria and protocols for managing solid ameloblastomas. Significance. Although ameloblastomas are relatively rare, they compose 13 to 58 percent of all odontogenic tumors, according to data cited by the authors.1 Because the majority of ameloblastomas are located in the posterior mandible, a site of other lesions that also may appear as radiolucencies, these tumors should be considered in the differential diagnosis of such lesions. 1. Reichart PA, Phillipsen HP, eds. Odontogenic tumors and allied lesions. London: Quintessence; 2004.
JADA, Vol. 141
http://jada.ada.org
Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
May 2010
569
J O U R N A L S C A N
ORAL ONCOLOGY
Chromosomal numerical aberrations in apparently normal oral mucosa of heavy smokers affected by lung cancer Shani T, Onn A, Kabha A, et al. Oral Oncol 2010;46(2):96-99.
he concept of “field cancerization” suggests that the entire mucosa of the aerodigestive tract in smokers is at increased risk of developing malignant lesions, insofar as this tissue is exposed to the carcinogenic compounds in tobacco products. Aneuploidy, an alteration (increase) in chromosome number, is found in the nonmalignant and premalignant bronchial and oral epithelium of smokers. The authors conducted a study to determine the prevalence of aneuploid cells in samples obtained from normal-appearing oral mucosa of smokers who had lung cancer, smokers who did not have lung cancer and people who had never smoked. They enrolled 152 participants older than 40 years who had clinically normal oral mucosa, 59 of whom were heavy smokers who did not have lung cancer, 31 of whom were heavy smokers who had lung cancer and 62 of whom were nonsmokers. They obtained two oral samples from each patient (from the posterior lateral border of the tongue and from the buccal mucosa); they used a disposable brush with hard nylon fibers to brush the surface mucosa with rotary movements and light pressure to harvest cells from all epithelial layers. To assess chromosome number, the authors selected two chromosomes, numbers 2 and 8, which they noted was based on results of their previous studies investigating aneuploid cells in oral premalignant lesions. They used a fluorescent in situ hybridization method that detected chromosomes 2 and 8 with green and red signals, respectively, and calculated the percentage of cells with more than two signals for each of the chromosomes. The authors found no differences between buccal mucosa and tongue samples. As a result of statistical analysis, they showed that in comparison with those who had never smoked, a high proportion of the heavy smokers with and without lung cancer had more than 2 percent aneuploid cells (odds ratio [OR] = 3.62, 95 percent confidence interval [CI] = 0.942-20.411) and that the proportion was significantly higher among the heavy smokers with lung cancer (OR = 5.74, 95 percent CI = 1.164-36.447, P = .015). The authors noted that the results of this
T
570
JADA, Vol. 141
http://jada.ada.org
study suggest that heavy smokers have a detectable chromosomal instability in the oral mucosal epithelium and that the presence of aneuploid cells in normal-appearing oral mucosa might be used to identify smokers at higher risk of developing cancer. However, the validity of this finding as a screening tool needs to be established in a longitudinal clinical study. Significance. The relatively high prevalence of oral cancer and its association with tobacco smoking has led to efforts to find factors, or biomarkers, with which to identify people especially susceptible to developing this disease. This has led to studies of putative factors in accessible fluids, such as blood and saliva, as well as to studies of tissue from potential lesion sites such as the investigation reported here. While the validation of biomarkers requires rigorous documentation, it might be anticipated that as biomedical research progresses, the goal of identifying people at risk of developing disease will be realized. ORAL RADIOLOGY
Prevalence of mucosal abnormalities of the maxillary sinus and their relationship to dental disease in panoramic radiography: results from the Health 2000 Health Examination Survey Vallo J, Suominen-Taipale L, Huumonen S, et al. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109(3):e80-e87.
he authors conducted this study to determine the prevalence of maxillary sinus changes and the extent to which these changes are associated with pathological dental findings. They used data from a nationally representative sample of adults, 30 years or older, in Finland. After training to calibrate their radiographic interpretation, oral radiologists reviewed panoramic radiographs with at least one clearly visible maxillary sinus from 5,021 participants, whose mean age was 51.7 years. They categorized their maxillary sinus findings in three groups: mucosal thickening (a 3to 6-millimeter–thick noncorticated radiopaque band following the bony wall of the sinus); mucosal antral cyst (a smooth, noncorticated, dome-shaped radiopaque mass rising from the floor or wall of the sinus); or other pathological findings. For dental findings, they recorded the presence of periapical lesions, the extent of horizontal and vertical bone loss, and the presence and adequacy of endodontic treatments. They
T
May 2010
Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
J O U R N A L S C A N
observed maxillary sinus mucosal changes in 19 percent of participants, with findings more common in men (27 percent) than in women (13 percent). They reported that the most frequent finding was mucosal thickening, which they saw in 12 percent of participants, with mucosal antral cysts seen in 7 percent of participants; the former was apparent most often in people aged 40 to 49 years, whereas antral cysts were found most often in younger age groups. The authors conducted statistical analyses and found that while participants with periapical lesions, periodontal bone loss or furcation involvement had a significantly higher risk (3.1-fold to 6.3-fold) of having mucosal thickening than that of edentulous participants, there was no difference between participants who had teeth without dental pathology and edentulous participants. The association between dental pathology and the presence of mucosal antral cysts was lower. The authors noted that maxillary mucosal changes generally are not symptomatic, although large antral cysts have been associated with nasal stuffiness, a sensation of facial fullness, paresthesias and pain or soreness on palpation. Consequently, in the case of a patient who has pain in the facial region with no other obvious cause, the clinician should consider maxillary sinus changes. Significance. The radiographic changes of the maxillary sinus described in this study are seen not infrequently on routine dental radiographs. This study provides data that will help clinicians in interpreting the findings and establishing a differential diagnosis and treatment plan. GENE THERAPY
Salivary epithelial cells: an unassuming target site for gene therapeutics Perez P, Rowzee AM, Zheng C, et al. (published online ahead of print Feb. 26, 2010). Int J Biochem Cell Biol.
he authors wrote this review to provide an update on studies being conducted that ultimately could lead to the use of salivary glands for
T
gene therapy in systemic disorders. They noted that while salivary glands typically are thought to produce proteins and secrete them into the saliva, studies have shown that they can secrete proteins into the blood stream as well and, thereby, can have both an exocrine and an endocrine function. In view of the demonstrated endocrine function, the authors conducted studies of in situ gene transfer to salivary glands for gene therapy in systemic disorders. They discussed salivary gland development, the vectors used for gene transfer and the secretory pathways for transgenic proteins. Finally, they provided examples of successes of gene therapy in eliciting the secretion of transgenic therapeutic proteins in animal models in both saliva and blood. For the former, they cited the production of therapeutic levels of histatin 3 in rats that are effective against fluconazole-resistant Candida in vitro and the salivary augmentation of keratinocyte growth factor at levels sufficient to prevent severe oral mucositis in an irradiated murine model. For the latter, they cited the production and secretion of human erythropoietin, human parathyroid hormone and human growth hormone after gene transfer to mouse or rat submandibular glands. Although gene therapy to correct singleprotein deficiency disorders has promise, the authors noted that the secretory pathway for the glands’ endocrine function is not predictable and that, consequently, proteins intended for systemic distribution actually may be secreted into saliva with a severely attenuated effect. Further investigation into the cellular biology underlying the sorting pathways likely will help to overcome this difficulty. Significance. This study further illustrates the universality of biomedical research and the interconnections between the tissues and organs of the mouth and those of the remainder of the body. ■ Dr. Barnett is a clinical professor, Department of Periodontics/ Endodontics, School of Dental Medicine, University at Buffalo, The State University of New York. Disclosure. Dr. Barnett did not report any disclosures.
JADA, Vol. 141
http://jada.ada.org
Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
May 2010
571