Roentgeno-oddities

Each month this section will bring to the reader of ORAL SURGERY, ORAL MEDICINE, AND ORAL

PATHOLOGY one or more roentgenograms that demonstrate unusual, unexpected, rare, or bizarre roentgenographic changes. These roentgenograms will be accompanied by an explanation or by words of inquiry regarding the particular change. Please submit 5 by 7 inch glossy black and white prints along with two copies of the description of the case. All material for publication should be submitted to Dr. John W. Preece, Department of Dental Diagnostic Sciences, School of Dentistry, The University of Texas Health Science Center, 7703 Floyd Curl Dr., San Antonio, Texas 78284.

GEMINATION, HYPODONTIA, SUPERNUMERARY TEETH

AND study’ were the most often missing teeth the mandib- ular lateral incisors.

G emination is a rare dental anomaly with strong hereditary characteristics. It appears most frequent- ly as a tooth with a bifid crown, one root, and one pulp canal. It is observed with highest frequency on incisors and canines. Partial anodontia or hypodontia is a rather common condition. Certain teeth, such as the third molars, maxillary lateral incisors, and maxillary and mandibular second premolars, are missing more frequently than others. In only one

Supernumerary canines are extremely rare and are more common in the maxilla than in the mandi- ble.

During oral examination, a 15-year-old Indian patient was observed to have gingivitis, caries, and the absence of some molars due to previous extrac- tions. In the maxillary incisor region, the right lateral incisor had caries and a crown that was wider than normal with a shallow longitudinal groove that divided it incompletely into two equal parts. The

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738 Roentgeno-oddities Oral Surg. December, 1986

number of maxillary teeth, including the extracted ones, was normal. The radiograph showed only one root and one pulp canal. In view of these character- istics, the condition was diagnosed as gemination.

In the mandibular incisor region the “lateral incisors” more closely resembled the shape of canines. Because of their appearance, it is easy to speculate about the possible congenital absence of mandibular lateral incisors and their replacement by supernumerary canines in this patient.

It was not possible to obtain any information

about similar conditions in other members of the patient’s family.

Jose Serrano V., Dr. Odont. Faculty of Odontology

University of Cuenca Cuenca, Ecuador

REFERENCES

I. Niswander JD, Suja KC: Am J Phys Anthropal 21: 569, 1963.

ECTOPIC DEVELOPING MANDIBULAR PREMOLAR

A 5-year-old Latin-American boy reported to the dental service for a complete dental examination. Inspection of the radiographs showed the right man- dibular second premolar positioned distal to the right second primary molar and mesial to the first perma- nent molar (Fig. 1). The developing left mandibular premolars were in normal position.

the first permanent molar erupts. A unilateral band and loop-appliance can be fabricated to ensure space maintenance. It is hoped that the second premolar will shift mesially into proper position.

Robert Steelman, D.M.D. Duane Tinkler, D.D.S., M.S.D.

Venice Kerr, D.D.S.

Planned treatment of this developmental anomaly consists of extracting the second primary molar after

Cyndi Jordan, R.D.H. Department of Pediatrics

University of Texas Health Science Center Dallas, TX

Fig 1.