O.O. Jaiyeoba and J.U. Ifesanya

Department of Child Oral Health, University College Hospital, Ibadan.


Multiple supernumerary molars are rare and are usually detected on routine radiological investigations. Supernumerary molars could occur as paramolars or distomolars. Occurrence of distomolars in children is reported to be a rare occurrence. In this report of 3 cases, bilateral maxillary and mandibular impacted fourth molars were observed as incidental findings on orthopanthomograms in children between the ages of 12 and 15 years.

Keywords: Supernumerary teeth, Supernumerary molars, Distomolars, Fourth molars


Dr. O.O. Jaiyeoba
Child Oral Health Department,
University College Hospital,


Supernumerary teeth are teeth in excess of the normal number. They may be found either in the anterior or posterior region where they may be fused to the third molars.1-2 They may be single or multiple in number. They may be unilateral or bilateral in location occurring in one or both jaws. In terms of shape, they could be conical, composite odontoma or tuberculate. They may also have anatomical shape of naturally occurring teeth in which case they are called supplemental teeth. They may be erupted or unerupted.3,4 There is generally a higher prevalence of supernumerary molars in the maxilla with values as high as between 75-88.9%, and they are often unilateral and impacted.5-6 Grimanis et al. reported that there is no gender difference in the prevalence of supernumerary molars5 while some other studies found that males were more often affected.7,8

The exact aetiology of supernumerary teeth is unknown though suggestions have been made that they may result from reversion or due to aberrations during embryological formation resulting in hyperactivity of the permanent or primary dental lamina.7,9 It was also suggested that they may result from division of a developing tooth germ giving rise to development of multiple individual teeth.5,10

Supernumerary teeth in the molar region are either paramolars or distomolars. Paramolars are found adjacent (Buccal or palatal) to the molar teeth and are usually off the dental arch whereas, distomolars are found distal to the third molars and are generally in line with the dental arch.11 Distomolars appear rudimentary more commonly in the maxilla or as supplemental teeth more commonly in the mandible.5,12 Here, we describe the clinical and radiographic characteristics of 3 patients with maxillary and mandibular distomolars.

Case 1
A 15-year old male presented at the Orthodontics Clinic of the University College Hospital, Ibadan with a complaint of having proclined maxillary incisors which he noticed about a month before presentation. There was no contributory medical history. He appeared healthy with no features suggestive of any syndrome. Intraoral examination revealed all teeth present except the third molars. An assessment of Angles class II subdivision right complicated by; increased overjet of eight millimetres, mild spacing on both upper and lower anterior segments, incisal class II relationship and increased overbite was made. He was asked to take an orthopantomogram as part of plans for orthodontic treatment. This however revealed impacted third molars and distomolars in all quadrants. He had extractions of these third molars and distomolars done under general anaesthesia. Postoperative follow up to two months revealed satisfactory healing with no complications. He is however yet to commence orthodontic treatment.