title: Agenesis of a mandibular canine: a case report.
abstract: BACKGROUND
  Hypodontia is one of the most common developmental anomalies in man. The most frequently missing tooth is the third molar. Agenesis of canine in the secondary dentition is rarely reported .
  
  
  OBJECTIVE
  To report a very rare form of missing tooth in the secondary dentition due to agenesis.
  
  
  METHODS
  A 49-year Nigerian male consulted with a desire to have a dental check-up. Extra- and intr-oral exminations were carried out. Following observation of a a missing tooth orthopanthomograph was carried out. with a missing lower right canine. All other teeth were well formed and have all erupted into the oral cavity.
  
  
  RESULTS
  There was no history of systemic disease or family history of oligodontia and was generally well. Systemic examination was essentially normal. Intra oral examination revealed that he had full complement of teeth but for a missing lower right canine. There was a gap of about 2mm between the lower right lateral incisor and the lower right first premolar and a buccal displacement of the upper left second molar as well as a carious lesion on the upper first left molar. The orthopanthomograph showed that the tooth was not within the mandible in this patient.
  
  
  CONCLUSIONS
  The cause of the aplasia resulting in this rare condition is not clear but may be due to inadequate secretion of some of the signaling molecules or localized absence of their receptors in the ectomesenchye destined to differentiate into the right canine tooth.
authors.affiliation: Department of Restorative Dentistry, College of Medicine, University of Ibadan, Nigeria.
authors.forename: O O
authors.initials: OO
authors.lastname: Dosumu
authors.forename: B F
authors.initials: BF
authors.lastname: Adeyemi
authors.forename: B M
authors.initials: BM
authors.lastname: Kolude
mesh_terms: D000848:Anodontia / Q000150:complications*; D001641:Bicuspid; D003481:Cuspid / Q000002:abnormalities*; D019229:Dentition, Permanent; D006801:Humans; D008297:Male; D008334:Mandible; D008875:Middle Aged; D011862:Radiography, Panoramic