A radiographic survey of agenesis of the third molar: A panoramic study

A rare find of a maxillary third molar with five roots: a case report of an unusual morphology

Third molars are frequently absent or impacted; their unpredictable prevalence and morphology, with frequent anatomical variations, is a challenge for the practitioner. The number of roots of the upper third molars vary from one to five, but five roots upper third molars' cases are extremely rare. The case reported here is of a normotrophic male patient, with no significant general medical history, having extracted an impacted maxillary upper molar, with an unusual position and dimensions and five completely separated formed roots, orientated in diverse directions. It highlights the importance of using the correct surgical technique, without excessive pressure, for avoiding the fracture of the maxillary tuberosity, the displacement of the molar into the pterygopalatine fossa or the opening of the maxillary sinus, especially in the absence of good quality imagistic information like cone-beam computed tomography. The case presented in this paper is very rare and highlights the significance of anatomical knowledge, which is mandatory for managing these cases, to avoid trauma, accidents, and complications and to maintain an optimal time of extraction, since such variations occur, and the conventional radiographs do not offer enough data to clarify the diagnosis.

Evaluation of third molar agenesis associated with hypodontia and oligodontia in turkish pediatric patients

Purpose

To evaluate the association between third molar (M3) agenesis and hypodontia and oligodontia in pediatric patients by using panoramic radiography.

Materials and methods

Panoramic radiographs of 1,471 patients (899 females; 572 males) and 5,884 teeth were retrospectively evaluated. The age and gender of the patients were recorded. Patients ages 9-15 years old were included in the study. The mean age was 12.76. The agenesis of M3 teeth and the relationship between M3 agenesis and hypodontia and oligodontia were recorded according to findings from the upper and lower jaw, in both the right and left locations, along with the number of M3 with agenesis. Data were analyzed using chi-square and McNemar tests (p<0.05).

Results

A total of 1,319 (89.7%) patients had all M3 teeth present in the mouth, while the other 152 (10.3%) had congenital agenesis in one or more teeth. The number of teeth in which M3 agenesis was seen, in order of the number of missing M3 teeth, the percentages were 2.6% for one, 2.4% for two, 1.0% for three and 4.3% for four missing teeth.Hypodontia was detected in 37 patients and oligodontia was detected in 3 patients.

Conclusion

The prevalence of M3 agenesis varies from one population to another. Two of the dental anomalies associated with M3 agenesis are hypodontia and oligodontia. In this study, M3 agenesis varied in terms of region and gender; hypodontia was also significantly higher in patients with missing mandibular M3.