23 Persistent primary teeth
The owner was concerned that ‘she has too many teeth’. She had a poor appetite and would not eat anything other than grilled chicken, cut into small pieces. The case was referred to us for management.
ORAL EXAMINATION – CONSCIOUS
The dog disliked having her face handled. She was tiny (weight 1.8 kg) and difficult to restrain adequately. A cursory conscious examination was performed, which revealed the following:
ORAL EXAMINATION – UNDER GENERAL ANAESTHETIC
A thorough oral and dental examination, including investigating periodontal parameters, was performed. All findings were noted on the dental record sheet.
In summary, examination under general anaesthesia identified the following:
Figure 23.1 Incisor occlusion. The permanent upper incisors were fully erupted caudal to the persistent primary upper incisors. The primary lower incisors had been exfoliated and the permanent counterparts were fully erupted and occluding between the rows of upper incisors.
Figure 23.2 Canine occlusion. The permanent upper canines were erupting in front of the persistent primary canine bilaterally, thus closing the diastema where the permanent lower canines should occlude. Note the severe gingivitis (reddening, swelling and spontaneous haemorrhage of the gingival margin).
Radiographs were taken of all persistent primary canine teeth (to determine the anatomy of the primary tooth, and the position and stage of development of the permanent counterpart).
The primary teeth were fully developed with closed apices. All permanent teeth were in early development (around half of total root length formed for incisors, around one-third of the total root length formed for the canines and around two-thirds of the estimated total root length for the premolars).