Symmetrical agenesis of the mandibular third molars and agenesis of other teeth in a Japanese orthodontic population

Abstract

This study was conducted to investigate the association between symmetrical agenesis of the mandibular third molars and agenesis of other teeth in Japanese orthodontic patients. A sample of 64 patients with symmetrical agenesis of the mandibular third molars and without agenesis of the maxillary third molars was selected as the third molar agenesis group. In addition, 585 patients with all 4 third molars were selected as controls. The main materials examined for diagnosis of tooth agenesis were panoramic radiographs. The prevalence rate of tooth agenesis was compared between the groups using the chi-squared or Fisher's test, and the odds ratio. Significantly increased occurrence of overall agenesis of the maxillary lateral incisors, and overall and symmetrical agenesis of other teeth including the maxillary and mandibular second premolars and mandibular first molars were observed in the patients with symmetrical agenesis of the mandibular third molars and without agenesis of the maxillary third molars. Irrespective of the presence or absence of symmetrical agenesis of the mandibular third molars, no significant differences in the prevalence rates of overall or symmetrical agenesis of other teeth and specific teeth were noted between the sexes or between the right and left sides of the jaws in the patients without maxillary third molar agenesis. (J Oral Sci 58, 171-176, 2016) Keywords: tooth agenesis; symmetrical agenesis of the mandibular third molars; incisor agenesis; second premolar agenesis; first molar agenesis.

Association between skeletal morphology and agenesis of all four third molars in Japanese orthodontic patients

“…This minimum age of 14 years was based on the suggestion of Garn and Lewis [ 7 ] that the upper age limit for M3 agenesis is 14 years. Some studies have adopted a maximum age of 21 years [ 2 , 22 , 23 ]. The adaptation is based on the fact that eruption of M3s begins at 14–21 years of age [ 21 ].…”

Panoramic Radiographic Assessment of Agenesis of Mandibular Third Molars: A Hospital Based Study in Eastern Nepal

“…16 Likewise, studies conducted by Hirakata et al and Sanpei et al has shown association between agenesis of any other teeth when there was presence of bilateral agenesis of mandibular or maxillary third molars. 22,23 Regarding the limitation of the study, one major concern with this study is the lack of random sampling, which was avoided to prevent unnecessary radiographic exposure to the patients.…”

Methods of treatment of premolar agenesis: a literature review

“…Na rycinie 5 przedstawiono zastosowanie autotransplantacji górnych M3 w leczeniu agenezji PM2 w żuchwie. Istotne ograniczenie może dodatkowo stanowić stosunkowo wysoka częstość występowania agenezji M3 (20-30%) (26) oraz współistniejąca agenezja innych zębów (75)(76)(77)(78)(79).…”