Orthodontic treatment of’ectopic eruption of lower lateral incisors Seppo
Jlrvinen,
Kuopio,
Finland
Dr. odont.*
E
ctopic eruption has been defined as eruption of a permanent tooth which takes place in such a manner that partial or total resorption of the root(s) of an adjacent deciduous tooth results. Most of the ectopically erupted teeth have been found to be lower lateral incisors.’ The degree of the displacement varies from milder forms to the condition in which the canine and lateral incisor are transposed, and in most cases of severe deviation the etiologic factors are unknown; early loss of the deciduous canines and retention of the deciduous lateral incisors seem to be the results rather than the causes of the ectopic eruption, and the mesial displacement of the permanent canine apparently lacks significance as an etiologic factor. 2 The prognosis for ectopically erupted lower lateral incisors is poor in cases of severe deviation, and extraction of the displaced tooth is the final treatment in most of the cases.2* B Case
report
A girl aged 8 years 6 months was sent for orthodontic treatment. The case history and the visual examination showed early loss of the lower first deciduous molars and the lower right deciduous canine. The eruption of the permanent lower lateral incisors was ectopic, the left lateral incisor being distal to the deciduous canine. The lower left deciduous lateral incisor was retained. The occlusal relationship was neutral. An orthopantomogram (Panorex) (Fig. I) showed transposition of the permanent lower left lateral incisor and the unerupted permanent canine. In the upper jaw the unerupted permanent left lateral incisor was rotated and located distal to the deciduous lateral incisor. Since there was sufficient space for the accommodation of the teeth, extraction of the permanent lower left lateral incisor was not indicated. On the other hand, the alignment of this tooth in its correct position in the arch did not seem to be possible. The lower left deciduous canine was extracted and a fixed appliance was used to move the permanent left lateral incisor into the place of the extracted tooth and to align the right lateral incisor in its correct position. About 3 years later (Fig. 2) the permanent lower left canine erupted between the central and lateral incisors and the right canine erupted in its correct position in the arch. The occlusal relationships are satisfactory, and the slight esthetic disharmony may be corrected by shaping the canine to resemble an incisor. In the upper jaw the left lateral incisor has been aligned in its correct position with a fixed appliance. *Department
31”
of Dentistry,
University
of Kuopio
0002-9416/78/0374-0318$00.30/O
0
1978 The C. V. Mosby Co.
Volume 74 Number 3
Ectopic
eruption
of lower lateral
incisors
319
Fig. 1. An otthopantomogram (Panorex) taken at the age of 8 years 8 months shows ectopic eruption of the lower lateral incisors and mesial displacement of the lower left canine. The deciduous left lateral incisor is retained, and the deciduous first molars and the right canine are missing.
Fig. 2. A new or@topantomogram taken at the age of 11 years 9 months. The lower left lateral incisor has been moved into the place of the mesially displaced canine. The lower right canine is erupting in its correct place and the left canine is erupting between the central and lateral incisors.
Discussion Tuverson4 has presented a treatment procedure in which canines are used to replace missing upper lateral incisors, and Newman” developed another one in which canines take the place of missing lower incisors. An analogous procedure is presented here. In cases with severe crowding the extraction of a displaced incisor may be the best form of treatment. When there is sufficient or excess space, the absence of an incisor can lead to the need for prosthetic treatment or to progressive problems in orthodontic treatment. In such cases, the procedure described here seems to be the method of choice for treating incisor-canine transposition.
Am. J. Orthcd. September 1978 REFERENCES I. O’Meara, W. F.: Ectopic eruption pattern in selected permanent teeth, J. Dent. Res. 41: 607-616, 1962. 2. Taylor, G. S., and Hamilton, M. C.: Ectopic eruption of lower lateral incisors, J. Dent. Child. 38: 282-284, 1971. 3. Schaad, T. D., and Thompson. H. E.: Extreme ectopic eruption of the lower permanent lateral incisor, AM. J. ORTHOD. 66: 280-286, 1974. 4. Tuverson, D. L.: Orthodontic treatment using canines in place of missing lateral incisors, AM. J. ORTHOD. 58:
109-127,
5. Newman, 53:482-49 70101
1970.
G. V.: Congenitally I, 1967.
Kuopio
10, Postilokero
missing
mandibular
incisors:
Treatment
procedures,
AM.
J. ORTHOD.
138
At about five years of age the first permanent molars commence to crowd their way into the arches between the bases of the deciduous arches on one side, and the rami and tuberosities on the other. Nature, apparently conscious of the forceful influences of this eruptive process toward an interstitial forward movement of the entire deciduous denture, has provided the deciduous molars with broad spreading roots so as to take a sufficiently firm and immovable hold of their surroundings to successfully combat this force. . . Note also how perfectly nature under normal conditions has timed this eruptive stage to prevent that possibility which she so evidently fortifies herself against, and at the same time to take advantage of the general developing forces of eruption. Under the needs of increasing age for greater masticating facilities, she (Nature) starts the eruption of the first permanent molars at a time when the strong phalanx of the deciduous denture is there, or should be there, to resist the forward pressure of these erupting teeth; nor does she commence it before there is nearly enough room by growth for those large teeth back of the temporary set; nor before the alveolar surroundings of the deciduous roots are developed to comparative stability; nor does she wait until the temporary molar roots have become weakened by resorption from the eruptive forces of the premolars. (Case, Calvin S.: Dental Orthopedia and Correction of Cleft Palate: Etiologic Influences of Deciduous and Erupting Teeth With Principles of Treatment, Chicago, 1921, Ft. Ft. Donnelley & Sons, pp. 30-31.)
Jlrvinen,
Kuopio,
Finland
Dr. odont.*
E
ctopic eruption has been defined as eruption of a permanent tooth which takes place in such a manner that partial or total resorption of the root(s) of an adjacent deciduous tooth results. Most of the ectopically erupted teeth have been found to be lower lateral incisors.’ The degree of the displacement varies from milder forms to the condition in which the canine and lateral incisor are transposed, and in most cases of severe deviation the etiologic factors are unknown; early loss of the deciduous canines and retention of the deciduous lateral incisors seem to be the results rather than the causes of the ectopic eruption, and the mesial displacement of the permanent canine apparently lacks significance as an etiologic factor. 2 The prognosis for ectopically erupted lower lateral incisors is poor in cases of severe deviation, and extraction of the displaced tooth is the final treatment in most of the cases.2* B Case
report
A girl aged 8 years 6 months was sent for orthodontic treatment. The case history and the visual examination showed early loss of the lower first deciduous molars and the lower right deciduous canine. The eruption of the permanent lower lateral incisors was ectopic, the left lateral incisor being distal to the deciduous canine. The lower left deciduous lateral incisor was retained. The occlusal relationship was neutral. An orthopantomogram (Panorex) (Fig. I) showed transposition of the permanent lower left lateral incisor and the unerupted permanent canine. In the upper jaw the unerupted permanent left lateral incisor was rotated and located distal to the deciduous lateral incisor. Since there was sufficient space for the accommodation of the teeth, extraction of the permanent lower left lateral incisor was not indicated. On the other hand, the alignment of this tooth in its correct position in the arch did not seem to be possible. The lower left deciduous canine was extracted and a fixed appliance was used to move the permanent left lateral incisor into the place of the extracted tooth and to align the right lateral incisor in its correct position. About 3 years later (Fig. 2) the permanent lower left canine erupted between the central and lateral incisors and the right canine erupted in its correct position in the arch. The occlusal relationships are satisfactory, and the slight esthetic disharmony may be corrected by shaping the canine to resemble an incisor. In the upper jaw the left lateral incisor has been aligned in its correct position with a fixed appliance. *Department
31”
of Dentistry,
University
of Kuopio
0002-9416/78/0374-0318$00.30/O
0
1978 The C. V. Mosby Co.
Volume 74 Number 3
Ectopic
eruption
of lower lateral
incisors
319
Fig. 1. An otthopantomogram (Panorex) taken at the age of 8 years 8 months shows ectopic eruption of the lower lateral incisors and mesial displacement of the lower left canine. The deciduous left lateral incisor is retained, and the deciduous first molars and the right canine are missing.
Fig. 2. A new or@topantomogram taken at the age of 11 years 9 months. The lower left lateral incisor has been moved into the place of the mesially displaced canine. The lower right canine is erupting in its correct place and the left canine is erupting between the central and lateral incisors.
Discussion Tuverson4 has presented a treatment procedure in which canines are used to replace missing upper lateral incisors, and Newman” developed another one in which canines take the place of missing lower incisors. An analogous procedure is presented here. In cases with severe crowding the extraction of a displaced incisor may be the best form of treatment. When there is sufficient or excess space, the absence of an incisor can lead to the need for prosthetic treatment or to progressive problems in orthodontic treatment. In such cases, the procedure described here seems to be the method of choice for treating incisor-canine transposition.
Am. J. Orthcd. September 1978 REFERENCES I. O’Meara, W. F.: Ectopic eruption pattern in selected permanent teeth, J. Dent. Res. 41: 607-616, 1962. 2. Taylor, G. S., and Hamilton, M. C.: Ectopic eruption of lower lateral incisors, J. Dent. Child. 38: 282-284, 1971. 3. Schaad, T. D., and Thompson. H. E.: Extreme ectopic eruption of the lower permanent lateral incisor, AM. J. ORTHOD. 66: 280-286, 1974. 4. Tuverson, D. L.: Orthodontic treatment using canines in place of missing lateral incisors, AM. J. ORTHOD. 58:
109-127,
5. Newman, 53:482-49 70101
1970.
G. V.: Congenitally I, 1967.
Kuopio
10, Postilokero
missing
mandibular
incisors:
Treatment
procedures,
AM.
J. ORTHOD.
138
At about five years of age the first permanent molars commence to crowd their way into the arches between the bases of the deciduous arches on one side, and the rami and tuberosities on the other. Nature, apparently conscious of the forceful influences of this eruptive process toward an interstitial forward movement of the entire deciduous denture, has provided the deciduous molars with broad spreading roots so as to take a sufficiently firm and immovable hold of their surroundings to successfully combat this force. . . Note also how perfectly nature under normal conditions has timed this eruptive stage to prevent that possibility which she so evidently fortifies herself against, and at the same time to take advantage of the general developing forces of eruption. Under the needs of increasing age for greater masticating facilities, she (Nature) starts the eruption of the first permanent molars at a time when the strong phalanx of the deciduous denture is there, or should be there, to resist the forward pressure of these erupting teeth; nor does she commence it before there is nearly enough room by growth for those large teeth back of the temporary set; nor before the alveolar surroundings of the deciduous roots are developed to comparative stability; nor does she wait until the temporary molar roots have become weakened by resorption from the eruptive forces of the premolars. (Case, Calvin S.: Dental Orthopedia and Correction of Cleft Palate: Etiologic Influences of Deciduous and Erupting Teeth With Principles of Treatment, Chicago, 1921, Ft. Ft. Donnelley & Sons, pp. 30-31.)
