title: The impact of premature birth on the permanent tooth size of incisors and first molars.
abstract: BACKGROUND
  Scientific evidence is insufficient to answer the question of whether premature birth causes altered tooth-crown dimensions.
  
  
  OBJECTIVE
  To evaluate permanent tooth-crown dimensions in prematurely born children and to compare the findings with full-term born controls.
  
  
  METHODS
  Preterm children of 8-10 years of age were selected from the Swedish Medical Birth Register. One group consisted of 36 extremely preterm children (born before the 29th gestational week); the other group included 37 very preterm children (born during gestational weeks 29-32). The preterm children were compared with 41 matched full-term born children. Clinical examination and study casts were performed on all children. Permanent maxillary and mandibular first molars, central incisors, and laterals were measured with a digital sliding caliper on study casts. The tooth-crowns were measured both mesio-distal and bucco-lingual.
  
  
  RESULTS
  Both the mesio-distal and bucco-lingual measurements in the maxillary and mandibular first molars had a significantly smaller width in the extremely preterm group compared with the full-term group. The central incisors and lower laterals were significantly smaller mesio-distally in the extremely preterm group compared to the full-term group. A reduction in tooth size of 4-9% was found between the extremely preterm group and the full-term group for both boys and girls. The maxillary first molars and mandibular left first molar were also smaller mesio-distally in the extremely preterm group compared to the very preterm group. The results indicate that the more preterm the birth, the smaller the tooth-crown dimensions. Independent of gestational age girls had generally smaller teeth than boys.
  
  
  CONCLUSIONS
  Premature birth is associated with reduced tooth-crown dimensions of permanent incisors and first molars.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Sebha university, Sebha, Libya.|Department of Orthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Eman
authors.initials: E
authors.lastname: Ebrahim
authors.affiliation: Department of Orthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Liselotte
authors.initials: L
authors.lastname: Paulsson
mesh_terms: D002648:Child; D019229:Dentition, Permanent; D005260:Female; D005865:Gestational Age; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology / Q000254:growth & development*; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology / Q000254:growth & development; D008963:Molar / Q000033:anatomy & histology / Q000254:growth & development*; D009811:Odontometry / Q000379:methods; D047928:Premature Birth / Q000473:pathology / Q000503:physiopathology*; D019228:Tooth Crown / Q000033:anatomy & histology / Q000254:growth & development