Deciduous teeth normally erupt at approximately 6 months of age. Natal teeth are teeth found at birth, while neonatal teeth are ones that erupt within the first month of life. They are nearly always prematurely erupted deciduous teeth, with maturity degree corresponding with the infant’s age. This means that approximately 5/6 of the crown is developed, while the root is not yet formed or its development is incomplete or defective, resulting with their mobility (1). Both types are rare occurrences, yet the earliest known reports date back to antiquity. Titus Livius, a Roman historian from the 1^st century BC, commented on the cases of infants born with erupted teeth as an omen of future calamities (2), while his contemporary, Plinius the Elder forecast fortune awaited boys born with teeth, whereas misfortune – girls (3, 4). Famous historical figures who are known to have been born with natal teeth include Hannibal, Richard III, Louis XIV, cardinal Richelieu and Napoleon Bonaparte (2).

The reported incidence of natal and neonatal teeth varies largely depending on the type of studies and the size of the studied group, ranging from 1:2000 to 1:4000 (2). Massler et Savara have estimated the incidence of natal teeth at 1 per 2000 births (5), Bodenhoff et Gofin at 1 per 3000 (3), while Szymańska-Jachimczak based on her 10-year observation period found it to be 1 per 4844 neonates delivered in Warsaw hospitals (6). The majority of authors cite higher incidence of natal and neonatal teeth in girls. The teeth are most commonly prematurely erupted deciduous teeth, not supernumerary or predeciduous teeth, which in fact account for less than 10% of all natal and neonatal teeth (7). Typically, they are mandibular central incisors, however there have also been reports of prematurely erupted molars (8).

The exact aetiology of the phenomenon in question remains elusive. Superficial positioning of the tooth germ on the alveolar bone, increased osteoblastic activity in the area of the tooth germ associated with bone remodelling processes, endocrine diturbances such as hyperactive thyroid or pituitary gland, family history and inheritance pattern of an autosomal dominant trait, vitamin deficiency, malnutrition/undernourishment, PCB exposure, infections, injuries and febrile episodes suffered during pregnancy have all been suggested as possible underlying causes (2, 9-12). The presence of natal and neonatal teeth may be found in many multiple defect syndromes and congenital defects, including Ellis-van-Creveld syndrome, Gorlin syndrome, Hallermann-Streiff syndrome, Pierre Robin syndrome, Struge-Weber syndrome, Jadassohn-Lewandowski syndrome, Kabuki syndrome, Meckel-Gruber syndrome, Opitz syndrome, Pallister-Hall syndrome, Pfeiffer syndrome, Rubinstein-Taybi syndrome, Sotos syndrome and Wiedemann-Rautenstrauch syndrome (2, 9, 10). They are also sometimes present in children with uni- and bilateral orofacial clefts, in which case the teeth are lateral incisors in the region of the cleft (13, 14).

The aim of the study was to discuss the cases of natal and neonatal teeth treated at the Department of Paediatric Dentistry of the Medical University of Łódź.

In the years 2013-2016, 5 infants (including 4 boys and 1 girl) were treated at our Department for natal (3 patients) or neonatal (2 patients) teeth. This paper discusses management of each of the cases.

On 8.02.2013, parents with a male neonate 10 days old were admitted for consultation. The boy had been delivered 3 weeks ahead of his due date, at 3300 g. The reason for the dental appointment was the presence of natal teeth, which were mandibular central incisors 71 and 81 (ISO 3950 notation), tooth mobility (TM) Grade 2. The mother reported nursing problems due to sore nipples and the baby’s reluctance to suckle. Soft tissues around the teeth and on the ventral surface of the tongue showed inflammation. Because of the risk for swallowing or aspirating the teeth into the respiratory tract, as well as the problems with proper breastfeeding and the evident inflammation of oral tissues, extraction was necessary. The procedure was performed in topical anaesthesia administered with lidocaine spray placed on a sterile cotton roll. The teeth had no roots, the crowns were underdeveloped, and the enamel was hypomineralized. A follow-up examination on 24.04.2016 revealed presence of primary dentition complete except for the removed natal teeth 71 and 81 (fig. 1). The patient was referred for orthodontic treatment.