32: Poor quality first permanent molars

32 Poor quality first permanent molars

Summary

Lisa is 9 years old. Her mother has brought her to your surgery because her new permanent teeth at the back of her mouth are brown and there are white and brown patches on her new incisors. What has caused these discolorations? How may they be treated?

History

Lisa has complained that for the past few months the teeth have been painful on eating hot and cold foods. The pain is of 1–2 minutes’ duration. Toothbrushing also has caused sensitivity at the back of the mouth. There has been no pain on biting and eating foods. Very recently Lisa felt that one of the back teeth especially has started to crumble. Her mother has also noticed this when she has helped with brushing.

Lisa has not required any analgesics for the discomfort caused by her teeth.

Medical history

Lisa is a healthy child who has never been in hospital.

Dental history

Lisa and her family are regular dental attenders. The family all have a low caries risk. Lisa has no restorations in her primary dentition. She used a children’s toothpaste (500 ppm) until recently and is now using the same adult toothpaste as her parents (1450 ppm).

Examination

Intraoral examination revealed that all four first permanent molars (FPMs) were hypomineralized with areas of brown, rough enamel. In addition there were areas of hypoplasia where the enamel had chipped away, exposing the underlying dentine. The maxillary molars were the worst affected by hypoplasia. image had a large amalgam restoration. In addition some white and brown hypomineralized areas were visible on the labial surfaces of the newly erupted upper and lower permanent central incisors (Figs 32.1 and 32.2).
‘Hypomineralized’ is the name given to enamel when it has a reduced mineral content.
‘Hypoplasia’ is the name applied when there is a reduced thickness of enamel.
Upper and lower arches were uncrowded. Space assessed from the distal of 2’s to mesial of 6’s in each quadrant was 21.5 mm in the lower arch and 22 mm in each upper arch quadrant. On average, 21 mm and 22 mm are required for these distances in the lower and upper arches, respectively.
The incisor relationship was just Class I on image; the molar relationship was Class I bilaterally.
image

Fig. 32.1 Hypomineralized and hypoplastic upper first permanent molars.

image

Fig. 32.2 Hypomineralized upper and lower permanent incisors.

image Do you think that the enamel hypomineralization and hypoplasia noted on the first permanent molars and the permanent incisors follows a chronological pattern? If so, at what time was the affected enamel formed?

Yes, it is possible that there is a chronological pattern. The cusp tips of the first permanent molars begin mineralizing from the eighth month of pregnancy. The cusp tips of the incisors and cuspids (canines) from about 3 months of age (the upper lateral incisor slightly later at 10–12 months). Mineralization dates for the permanent dentition are given in Table 32.1.

Table 32.1 Mineralization times for the permanent dentition

Tooth Mineralization begins (months)
Upper  
Central incisor 3–4
Lateral incisor 10–12
Canine 4–5
First premolar 18–21
Second premolar 24–27
First molar At birth
Second molar 30–36
Third molar 84–108
Lower  
Central incisor 3–4
Lateral incisor 3–4
Canine 4–5
First premolar 21–24
Second premolar 27–30
First molar At birth
Second molar 30–36
Third molar 96–120

Key point

Mineralization of FPM commences around birth.

image What specific questions would you like to ask Lisa’s mother?

Pre-natal./>

Related posts:

  1. 27: Facial swelling and dental abscess
  2. 39: Gingival bleeding and enlargement
  3. 3: Absent upper lateral incisors
  4. 6: Palatal canines
  5. 14: Posterior crossbite
  6. 2: Unerupted upper central incisor

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Jan 2, 2015 | Posted by in Orthodontics | Comments Off on 32: Poor quality first permanent molars

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