FURTHER CASES ILLl~STRA’l’l~C TIIR ILL-EFFECTS TO THE MAXILLARY ARCH OF THE LOSS OF I\ThNDIBl!LAR TEETH”

C ASE 1.-Female. aged nineteen )-ears, (‘lass 1 mslocclusiou. At the age of sixteen and one-half years, j 1 was extracted because it

was badly rotated : from the history, probably one of the approximal surfaces present.ed labially. Since thr removal of this toot,11 the paGent thinks t,hc maxillary laterals have become more tinsightly, particularly the left one, which rests on the lomcr lil). It, would seem that this C'iISe originally was an example of some c~nntrac%ion of both a rchrs, rcprc~sentf4 ill the mandibular by severe rotation of 011~ incisor, ant1 in thr, maxillary arch by labial owlnsiotr

Fig. 1

of the lateral incisors, but not sufficient 10 direct att.ention to it. In all prob- ability the loss of the mandibular tooth has allowed the mandibular arch to become, smaller (and the alignment to remain good) ; am1 when it contracted. the maxillary arch contracted also, but as there was no loss of a tooth, a crowding-in this particular case an increased crowdiirg-is to be expected (particularly if there is any facility for this to occurs e.g., incorrect approximal contact as in this case between 2 1 / and / 1 2); and is shown by the increased

.------; labioclination of 2 1 2, now safficient to be unsightly (Fig. 1). -- It would be interesting to know whether there would have been any

collapse of the maxillary a,rch had this a.rch been normal and the approximal contact of all the teeth correct. It would also be interesting to know whether a more satisfactory result would have been obtained had a maxillary lateral incisor been removed when a mandibular central incisor was taken out, or even ----

*Transactions of British Society for the Study of Orthdontics, 1933.

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a maxillary central incisor, a.s was done in a case shown by Mr. A. L. Packham in 1926.” The general condition of the mouth was excellent.

CASE 2.-Male, aged fourteen years, Class II, division 1, an almost typical example.

The arch is good: the general condition of the mouth is good, except that 6 1 6 have lost their crowns entirely through caries and only the roots remain, with consequent reduction in the space occupied by the crowns. A typical feature of the case is that 1 ] is considerably labial to the alignment ._ of the remaining maxillary teeth (Fig. 2) ; the arrangment of the other maxillary anterior teeth is typical of this malocclusion. The mother reports that the position of the maxillary central incisor is getting worse. This would only seem to he possible if the nlandiblll;rr arch is becoming smaller. which it may

Fig. 2.

quite well be doing as a result of the loss of the crowns of 6 1 6: the roots of these teeth were removed shortly after the impressions were taken.

DISCUSSION

The PwA-T~&& asked Mr. Chapman whether he was doing any treatment for that ease, which was very similar to the case of the doctor’s daughter which he himself had shown. He would take the maxillary first or second premolar to compensate to some extent for the 108s of the two mandibular molars, and to restore the balance which was lacking. If he did this he would get an easy result in the next six months.

Mr. Packham thanked Mr. Chapman for showing, by his communication, in a yet clearer light the difficulties which attended the practice of orthodontics by the extraction of teeth. It had always seemed to the speaker since he had worked on the subject that the practice of orthodontics was extremely difficult in any case; its practice by the extraction of teeth was even more difficult. It was very hard to know what was going to happen after the ex- tractions had been carried out. Even if Mr. Chapman had emphasized that note alone, the society would have learned a great deal from his communication.

*Packham. A. L.: “A Case Showinr Tooth Moremcnt.” Trans. British Society for the Study of Orthodontics, 1926, pase 40.