The A.B.F.O. study of third molar development and its use as an estimator of chronological age.

Radiographs depicting third molars (M3s) have been used to estimate chronological age in juvenile and adult suspects, but accuracy of the method has been in question. This study provides age benchmarks for American whites (age range: 14 to 24 years) based on cases (n = 823) drawn from diplomates of the American Board of Forensic Odontologists in the United States and Canada. Maxillary M3 formation was slightly advanced over mandibular M3s, and root formation occurred earlier in males than females. Mean and median ages for M3 formation are tabled using Demirjian's eight-grade classification. Regression formulas and empirical probabilities are provided relative to the medicolegal question of whether an individual is at least 18 years of age. The M3 is the most variable tooth in the dentition, but situations arise where M3 formation is the only usable datum for age estimation.

Methods for physical stabilization of ashed teeth in incinerated remains.

Methods for physically stabilizing the extremely fragile ashed teeth that are often encountered in incinerated human remains were investigated. Results of a questionnaire sent to forensic anthropologists and forensic odontologists disclosed that, for these two groups, the most popular methods currently used are impregnation with a solution of polyvinyl acetate or application of cyanoacrylate cement, respectively. In addition, extracted human teeth were incinerated in the laboratory and impregnated with commercially available preparations of either cyanoacrylate cement, clear acrylic spray paint, hair spray, spray furniture varnish, clear fingernail polish, quick-setting epoxy cement, Duco household cement, polyvinyl acetate polymer in acetone, or self-curing clear dental acrylic resin. Every substance tested successfully stabilized the incinerated teeth. Clear acrylic spray paint was judged the most efficacious overall because of its ease of application, availability, inexpensiveness, and rapidity of setting.

Oral ulcerations.

Ulcerations are common occurrences in the mouth. Causes include physical trauma, radiation, chemical injury, and microbial infection (bacterial, viral, and fungal). Some ulcerations, such as recurrent aphthous stomatitis, Behçet's syndrome, and erythema multiforme, are of uncertain etiology, whereas others (eg, pemphigus, pemphigoid) are apparently of immunologic origin. Malignant neoplasms also may present as ulcerations. Because the natural history and treatment varies with the diagnosis, the practitioner should become familiar with the clinical appearance of the various types of ulcerations so that appropriate treatment can be instituted.

Natal primary molar: case report.

The case of an immature natal maxillary first primary molar is reported. Natal molars are rare occurrences, the present instance being only the eighteenth reported case. Clinical and histologic examination revealed that the tooth was rootless, incompletely mineralized, and acutely inflamed. Subsequent radiographs showed that the tooth was actually the primary first molar.

Oral anomalies in the neonate, by race and gender, in an urban setting.

A broad range of developmental anomalies and morphologic variants may occur in the oral cavity of the newborn. Because many of these are transient (e.g.: palatal and alveolar cysts, lymphangioma), self-correcting with age, conventional assessments of older children can yield significantly altered trait incidences. A total of 500 normal full-term newborns (blacks and whites) were assessed by standardized criteria for 11 oral conditions, in addition to collating data on maternal conditions (age, gravidity, tobacco and alcohol use). Leukoedema and median alveolar notches were significantly more common in blacks, whereas palatal cysts were 2.5 times as likely to occur in whites. Ankyloglossia, three times as common in males, was the one trait to exhibit a significant predilection by gender. Low maternal age (less than 20 years) significantly enhanced the risk of alveolar lymphangioma in these data.

Dental transplants: discussion and case report.

A 21-year-old Chinese male patient presented to an urban dental clinic with a transplanted molar, which had been removed from a human cadaver. The tooth was in occlusal function for three years, stable, and without mobility. Radiographs of the tooth showed root resorption and apparent ankylosis. Individual transplantation of human teeth has been considered surgical dental treatment of an empirical nature for centuries. Two types of human tooth transplantation are usually considered in the dental literature. An allotransplantation or allograft is a transplantation of tissue (tooth) between different individuals of identical species. An autotransplantation or autograft is a transplantation of tissue within the same individual (obviously within the same species). Replacement of an avulsed tooth, while technically an autograft is considered a replantation, rather than a transplant. Tooth transplantations in the late 20th century are usually performed in developing third world countries, where patient dental education is minimal, and the cost of more technology based forms of tooth replacement (prosthodontics, synthetic implants) are economically prohibitive. Transplantation of permanent teeth is rarely seen in the United States in the 1990's due to the use of titanium implants, although pediatric, adolescent, and disabled patients, especially those with limited incomes, could benefit from the re-introduction of dental transplants.

Dental odontomas: a retrospective study of 104 cases.

An odontoma refers to any tumor of odontogenic origin. Three distinct types of odontomas have been distinguished in the dental literature: complex, compound, and ameloblastic fibro-odontoma. Odontomas are usually associated with overly retained primary and unerupted permanent teeth. The exact etiology of odontomas is unknown, but local trauma, infection, inheritance, and genetic mutation have been postulated as possible causes of odontomas. Studies have found that males are more likely than females to have odontomas, with most frequent occurrence in the second decade of life. One hundred four biopsy reports with a diagnosis of odontoma were analyzed for age, race, gender, location, pre-operative diagnosis, and postoperative laboratory findings. Most odontomas occurred in the 11-20 age group, with Caucasians predominating. The majority were located in the maxilla, and 85 percent were correctly diagnosed clinically by the attending dentist prior to confirmation by histologic pathology reports of the biopsy specimens. The vast majority were compound odontomas (64.4%) with complex odontomas comprising 31.0% of the total lesions. No ameloblastic fibro-odontomas were diagnosed.

Tobacco use and dental disease.

The previously cited Indiana University School of Dentistry teaching monograph, "The Impact of Tobacco Use and Cessation on Nonmalignant and Precancerous Oral and Dental Diseases and Conditions," reviewed over 800 articles and concluded that tobacco use is strongly associated with many dental and oral mucosal diseases, and may contribute to others. Our study of a relatively small sample of 200 patients, of whom 33 percent were tobacco users, found statistically significant data correlating tobacco use with a higher Decayed, Missing and Filled Index (a measurement of caries and tooth loss experience of patients) and relating periodontal bone loss to smokeless tobacco use. And, while this investigation did not find a statistically significant correlation between smoking and periodontitis severity, there was a data trend in that direction. Conclusions about tooth loss in the Indiana monograph were limited to smokers; however, there was an association of ST use with gingival recession, which can become quite severe in the area in which the smokeless tobacco is placed. It might be theorized that the significantly larger number of missing teeth among ST users in our study is associated with the generally poor oral hygiene and less sophisticated outlook on health care that tobacco users often display. Indeed, of the 65 denture wearers in our study, 7.7 percent were ST users and 40.0 percent were tobacco users of some type. In view of the large amount of data in the scientific literature associating tobacco with dental diseases as summarized by the Indiana monograph, and the position of several groups such as the American Cancer Society that tobacco is one of the risk factors most associated with intraoral cancer, it would appear that dentists have a vested professional interest in promoting tobacco use cessation among their patients. Dentists should take every reasonable opportunity to persuade patients to discontinue the tobacco habit, thus preventing life-threatening malignancies as well as dental diseases.

The dos and don'ts of an oral mucosal biopsy performed by the general dentist.

The recognition of a pathologic entity is only the first step in the chain of events which must be performed for accurate diagnoses and appropriate patient management. Other steps include selection of the type of biopsy to be performed; proper biopsy technique, instrumentation and specimen handling; appropriate fixation; detailed documentation; and postoperative patient instructions. If the clinician performs each step carefully and correctly, the patient is ensured of receiving an accurate diagnosis in the shortest possible period of time.

Dinitrochlorobenzene contact hypersensitivity in the hamster cheek pouch.

Stimulation of cell mediated immunity has been reported to be effective in bringing about clinical regression of carcinomas. The purpose of this pilot study was to investigate the possibility of introducing cell mediated immunity into an experimental animal-chemical carcinogenesis system (dimethylbenzanthracene-hamster cheek pouch) to serve as a model for the study of immunotherapy of oral cancer in humans. Contact hypersensitivity to dinitrochlorobenzene (DNCB) was induced in 17 Syrian hamsters via the abdominal skin. After secondary application of the allergen to the cheek pouch, local gross and histologic characteristics indicative of delayed hypersensitivity were observed. Control animals that had received only a primary or a secondary challenge with DNCB essentially showed no change. This study demonstrates that the buccal pouch of the Syrian hamster is capable of manifesting contact hypersensitivity to DNCB.