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Upper cuspid replacement by a fixed partial denture
Fixed p&id
Michael School
C. Kafalias, of Dentistry,
dentures
B.D.S., M.D.S., M&D.* Sydney
University,
Sydney,
Australia
lhere is an attitude of relaxation in treatment planning when the cuspid tooth is available as an abutment for a fixed partial denture. It is probably the tooth most frequently used for this purpose. 1f 2 It has a large, strong, and flattened root with a large periodontal attachment. The cuspid serves as an excellent abutment not only in fixed but also in removable prostheses involving a variety of precise and semiprecise attachments” and complete overlay dentures.4 Provided that adequate endodontic therapy (coupled with apicectomy if necessary) and proper dowel and core procedures have been carried out, it can be used equally well when pulpless. 5 In mouths exhibiting occlusal patterns of “cuspid rise” or “cuspid protection,” the importance of this tooth is even more pronounced. However, there are times when the cuspid tooth has been lost or is missing, and the resulting space cannot be treated orthodontically and must be filled. When this situation arises, the problem is more difficult than usual.
CAUSES OF LOSS The loss of a reasons: ( 1) The extensive caries, or or was congenitally
cuspid tooth can be broadly classified to have resulted for two cuspid tooth had been present and was lost through mishap or (2) the cuspid was extracted because of impaction or malposition missing.
REPLACEMENT Reason 1. When the cuspid is lost as a result of caries or an accident, an attempt should be made to make the pontic functionally and esthetically as similar as possible to the pre-existing tooth. Tooth form and occlusion must be studied carefully. The treatment of choice in this instance should be a fixed partial denture with maximum support at both ends of the pontic. Since the lateral incisor is the weakest tooth in the upper arch and has the smallest amount of periodontal attachment, the occasions are rare when it can be *Senior Lecturer, Department 384
of Operative Dentistry.
Volume Number
31 4
Denture
to replace
upper
cuspid
385
used as the only mesial abutment. The central and lateral incisors have often been prescribed as the mesial abutments. L 2, 6 The first premolar usually has sufficient support to be the distal abutment, but occasionally, the second premolar may have to be added. Another restorative possibility is the use of the first and second premolars as abutments with the cuspid pontic attached as a cantilever.lp 2p 7s* Because of suggested dangers of leverage and rotation due to occlusal forces which may unseat a bridge constructed in this manner, less emphasis has been placed on this method of treatment. Usually, in these instances of cuspid loss, the adjacent teeth have also been lost. Because of this more extensive loss, the resulting space is quite unsuitable for a fixed partial denture. A removable partial denture is indicated under these circumstances. Reason 2. When the cuspid has been lost because of impaction and surgery and the space has been maintained by the deciduous cuspid or when the cuspid is congenitally missing and there is sufficient space, the treatment of choice is not necessarily the one with maximum support at both ends of the pontic. These situations are relatively common. Archer9 lists a number of causes for impacted maxillary cuspids and concludes that the cuspid is the third most frequently impacted tooth, being preceded by the lower third molar and the upper third molar. He also states that the majority of these anomalies are found in women. RohreP has shown that impacted cuspids occur in the maxillae twenty times more frequently than in the mandible. Under these circumstances, the treatment of choice should be the construction of a fixed partial denture using the first and second premolars as retainers with the cuspid pontic attached as a cantilever.
DISCUSSION With the presence of a cuspid tooth, a person becomes accustomed to a certain functional and esthetic situation. The patient often uses the cuspid tooth for breaking the great variety of hard foods available, and any replacement is liable to receive the same treatment. The cuspid plays a leading role in the guidance of mandibular movements and may be the only tooth on that side of the mouth so involved. If such a tooth is lost, through caries or mishap, its replacement must be such that the pontic resembles, as closely as possible, the former state; otherwise the possibility of an unhappy patient and an unsatisfactory result becomes real. The restoration of a cuspid space resulting from impaction or malposition can be accomplished in a different way. The occlusal pattern, prior to construction of a fixed partial denture, is not dependent upon a permanent cuspid tooth. By the correction of any slight occlusal malalignment (such as a small amount of extrusion of the opposing cuspid) and by careful and judicious construction of the pontic, a fixed partial denture can be constructed so that, in lateral and protrusive excursions, contact is maintained more by “group function” eliminating the possibility of full occlusal stress being placed on the pontic alone. Even when there is construction of a slightly smaller pontic, esthetics can only be improved when compared with the original deciduous cuspid or empty space. This will be readily accepted by the patient, and the construction of a prominent cuspid
386
Kafalias
Fig. 1. The space distal to the lateral impacted upper permanent cuspids. slightly rotated with small diastemata. Fig.
2. The
Fig.
3. Partial
Fig.
4. The
small
amount
veneer fixed
partial
of lower
crown
incisors resulted The lateral and
cuspid
extrusion
preparations
dentures
four
have years
after
from surgical removal of deciduous and central
is easily been
made
incisors
are
thin,
intact,
and
corrected. on the premolar
teeth.
completion.
will not be necessary. The cantilever type of bridge suggested is, therefore, more than a mere possibility in these situations. Other factors which may contribute in the decision to construct a cantilever bridge should be noted. Both central and lateral incisors may be short rooted, thin, slightly rotated, free of lesions or restorations, or have a diastema between them, or another bridge may be present using one or both of them as abutments. Special care is necessary. A favorable occlusion should exist or be produced before treatment is commenced. An older patient may be more suitable, because the teeth are more stable, and the lessening effect of oblique occlusal forces due to attrition existsG, i The preparations of the abutment teeth must be as classical as possible; the type of retainers should depend upon the condition of the abutment teeth. Maximum retention should be attained, and adequate crown length is necessary, but indiscriminate tooth reduction is not recommended as there is no way to replace sound labial or buccal enamel estheticahy and with periodontal compatibility. Veneered gold crownsll or partial veneer crowns are the retainers of choice.‘, 8 The directional movement of abutment teeth supporting a cantilever type of restoration can be reasonably predicted. Therefore, the amount and location of the bony support for each abutment are critical diagnostic factors in contemplating this type of restoration.ll* I2
Volume Numhrl
31 4
Denture
to replace
upper
cuspid
387
CLINICAL EVALUATION AND RESULTS Six bridges of the cantilever type were constructed using the criteria presented as a guide and have been in place for periods ranging from one to four years. The patients’ ages varied from 20 to 35 years, Six-month evaluations of each prosthesis were made. The only adjustment necessary was a slight occlusal correction for working side lateral movement on two bridges; both corrections were made at the first six-month evaluation. An example is that of a 20-year-old woman with bilateral impaction of the upper cuspids (Figs. 1 to 4). Deciduous cuspids maintained the space until the impacted permanent teeth were surgically removed.
SUMMARY The replacement of a maxillary cuspid by a fixed prosthesis, though difficult, can be satisfactorily achieved. A careful evaluation of the case and the reason for loss will help in determining the treatment plan. The use of a fixed prosthesis employing the first and second bicuspids as abutments with the cuspid pontic attached as a cantilever is suggested where the maxillary cuspid has been lost as a result of impaction or malposition or is congenitally missing.
References 1. Tylman, S. D., Brumfield, R. C., Moulton, G. H., and Tylman, S. G.: Theory and Practice of Crown and Bridge Prosthodontics, ed. 5, St. Louis, 1965, The C. V. Mosby Company, pp. 244-246. 2. Myers, G. E.: Textbook of Crown and Bridge Prosthodontics, St. Louis, 1969, The C. V. Mosby Company, pp. 149-161. 3. Preiskel, H. W.: Precision Attachments in Dentistry, London, 1968, Henry Kimpton. C. H.: The Physiologic Basis 4. Loiselle, R. J., Crum, R. J., Rooney, G. E., and Stuever, for the Overlay Denture, J. PROSTHET. DENT. 28: 4-12, 1972. 5. Kafalias, M. Cl.: Abutment Preparation in Crown and Bridge, Aust. Dent. J. 14: 1-7, 1969. 6. Johnston, J. F., Phillips, R. W., and Dykema, R. W.: Modern Practice in Crown and Bridge Prosthodontics, ed. 3, Philadelphia, 1971, W. B. Saunders Company, pp. 539-540. 7. Antonoff, S. J.: The Status of Cantilever Bridges, N. Y. State Dent. J. 38: 275-281, 1972. 8. Ewing, J. E.: Re-evaluation of the Cantilever Principle, J. PROSTHET. DENT. 7: 78-92, 1957. 9. Archer, W. H.: Oral Surgery, Philadelphia, 1961, W. B. Saunders Company, p. 145. 10. Rohrer, A.: Displaced and Impacted Canines, a Radiographic Research, Int. J. Orthod., Oral Surg. Radio]. 15: 1002-1020, 1929. 11. Schweitzer, J. M., Schweitzer, R. D., and Schweitzer, J.: Free-end Pontics Used on Fixed Partial Dentures, J. PROSTHET. DENT. 20: 120-138, 1968. 12. Henderson, D., Blevins, W. R., Wesley, R. C., and Seward, T. : Cantilever Type of Posterior Fixed Partial Dentures: A Laboratory Study, J. PROSTHET. DENT. 24: 47-67, 1970. FACULTY
OF DENTISTRY
THE UNIVERSITY 2 CHALMERS ST. SYDNEY, N.S.W. AUSTRALIA
2010
OF SYDNEY
Michael School
C. Kafalias, of Dentistry,
dentures
B.D.S., M.D.S., M&D.* Sydney
University,
Sydney,
Australia
lhere is an attitude of relaxation in treatment planning when the cuspid tooth is available as an abutment for a fixed partial denture. It is probably the tooth most frequently used for this purpose. 1f 2 It has a large, strong, and flattened root with a large periodontal attachment. The cuspid serves as an excellent abutment not only in fixed but also in removable prostheses involving a variety of precise and semiprecise attachments” and complete overlay dentures.4 Provided that adequate endodontic therapy (coupled with apicectomy if necessary) and proper dowel and core procedures have been carried out, it can be used equally well when pulpless. 5 In mouths exhibiting occlusal patterns of “cuspid rise” or “cuspid protection,” the importance of this tooth is even more pronounced. However, there are times when the cuspid tooth has been lost or is missing, and the resulting space cannot be treated orthodontically and must be filled. When this situation arises, the problem is more difficult than usual.
CAUSES OF LOSS The loss of a reasons: ( 1) The extensive caries, or or was congenitally
cuspid tooth can be broadly classified to have resulted for two cuspid tooth had been present and was lost through mishap or (2) the cuspid was extracted because of impaction or malposition missing.
REPLACEMENT Reason 1. When the cuspid is lost as a result of caries or an accident, an attempt should be made to make the pontic functionally and esthetically as similar as possible to the pre-existing tooth. Tooth form and occlusion must be studied carefully. The treatment of choice in this instance should be a fixed partial denture with maximum support at both ends of the pontic. Since the lateral incisor is the weakest tooth in the upper arch and has the smallest amount of periodontal attachment, the occasions are rare when it can be *Senior Lecturer, Department 384
of Operative Dentistry.
Volume Number
31 4
Denture
to replace
upper
cuspid
385
used as the only mesial abutment. The central and lateral incisors have often been prescribed as the mesial abutments. L 2, 6 The first premolar usually has sufficient support to be the distal abutment, but occasionally, the second premolar may have to be added. Another restorative possibility is the use of the first and second premolars as abutments with the cuspid pontic attached as a cantilever.lp 2p 7s* Because of suggested dangers of leverage and rotation due to occlusal forces which may unseat a bridge constructed in this manner, less emphasis has been placed on this method of treatment. Usually, in these instances of cuspid loss, the adjacent teeth have also been lost. Because of this more extensive loss, the resulting space is quite unsuitable for a fixed partial denture. A removable partial denture is indicated under these circumstances. Reason 2. When the cuspid has been lost because of impaction and surgery and the space has been maintained by the deciduous cuspid or when the cuspid is congenitally missing and there is sufficient space, the treatment of choice is not necessarily the one with maximum support at both ends of the pontic. These situations are relatively common. Archer9 lists a number of causes for impacted maxillary cuspids and concludes that the cuspid is the third most frequently impacted tooth, being preceded by the lower third molar and the upper third molar. He also states that the majority of these anomalies are found in women. RohreP has shown that impacted cuspids occur in the maxillae twenty times more frequently than in the mandible. Under these circumstances, the treatment of choice should be the construction of a fixed partial denture using the first and second premolars as retainers with the cuspid pontic attached as a cantilever.
DISCUSSION With the presence of a cuspid tooth, a person becomes accustomed to a certain functional and esthetic situation. The patient often uses the cuspid tooth for breaking the great variety of hard foods available, and any replacement is liable to receive the same treatment. The cuspid plays a leading role in the guidance of mandibular movements and may be the only tooth on that side of the mouth so involved. If such a tooth is lost, through caries or mishap, its replacement must be such that the pontic resembles, as closely as possible, the former state; otherwise the possibility of an unhappy patient and an unsatisfactory result becomes real. The restoration of a cuspid space resulting from impaction or malposition can be accomplished in a different way. The occlusal pattern, prior to construction of a fixed partial denture, is not dependent upon a permanent cuspid tooth. By the correction of any slight occlusal malalignment (such as a small amount of extrusion of the opposing cuspid) and by careful and judicious construction of the pontic, a fixed partial denture can be constructed so that, in lateral and protrusive excursions, contact is maintained more by “group function” eliminating the possibility of full occlusal stress being placed on the pontic alone. Even when there is construction of a slightly smaller pontic, esthetics can only be improved when compared with the original deciduous cuspid or empty space. This will be readily accepted by the patient, and the construction of a prominent cuspid
386
Kafalias
Fig. 1. The space distal to the lateral impacted upper permanent cuspids. slightly rotated with small diastemata. Fig.
2. The
Fig.
3. Partial
Fig.
4. The
small
amount
veneer fixed
partial
of lower
crown
incisors resulted The lateral and
cuspid
extrusion
preparations
dentures
four
have years
after
from surgical removal of deciduous and central
is easily been
made
incisors
are
thin,
intact,
and
corrected. on the premolar
teeth.
completion.
will not be necessary. The cantilever type of bridge suggested is, therefore, more than a mere possibility in these situations. Other factors which may contribute in the decision to construct a cantilever bridge should be noted. Both central and lateral incisors may be short rooted, thin, slightly rotated, free of lesions or restorations, or have a diastema between them, or another bridge may be present using one or both of them as abutments. Special care is necessary. A favorable occlusion should exist or be produced before treatment is commenced. An older patient may be more suitable, because the teeth are more stable, and the lessening effect of oblique occlusal forces due to attrition existsG, i The preparations of the abutment teeth must be as classical as possible; the type of retainers should depend upon the condition of the abutment teeth. Maximum retention should be attained, and adequate crown length is necessary, but indiscriminate tooth reduction is not recommended as there is no way to replace sound labial or buccal enamel estheticahy and with periodontal compatibility. Veneered gold crownsll or partial veneer crowns are the retainers of choice.‘, 8 The directional movement of abutment teeth supporting a cantilever type of restoration can be reasonably predicted. Therefore, the amount and location of the bony support for each abutment are critical diagnostic factors in contemplating this type of restoration.ll* I2
Volume Numhrl
31 4
Denture
to replace
upper
cuspid
387
CLINICAL EVALUATION AND RESULTS Six bridges of the cantilever type were constructed using the criteria presented as a guide and have been in place for periods ranging from one to four years. The patients’ ages varied from 20 to 35 years, Six-month evaluations of each prosthesis were made. The only adjustment necessary was a slight occlusal correction for working side lateral movement on two bridges; both corrections were made at the first six-month evaluation. An example is that of a 20-year-old woman with bilateral impaction of the upper cuspids (Figs. 1 to 4). Deciduous cuspids maintained the space until the impacted permanent teeth were surgically removed.
SUMMARY The replacement of a maxillary cuspid by a fixed prosthesis, though difficult, can be satisfactorily achieved. A careful evaluation of the case and the reason for loss will help in determining the treatment plan. The use of a fixed prosthesis employing the first and second bicuspids as abutments with the cuspid pontic attached as a cantilever is suggested where the maxillary cuspid has been lost as a result of impaction or malposition or is congenitally missing.
References 1. Tylman, S. D., Brumfield, R. C., Moulton, G. H., and Tylman, S. G.: Theory and Practice of Crown and Bridge Prosthodontics, ed. 5, St. Louis, 1965, The C. V. Mosby Company, pp. 244-246. 2. Myers, G. E.: Textbook of Crown and Bridge Prosthodontics, St. Louis, 1969, The C. V. Mosby Company, pp. 149-161. 3. Preiskel, H. W.: Precision Attachments in Dentistry, London, 1968, Henry Kimpton. C. H.: The Physiologic Basis 4. Loiselle, R. J., Crum, R. J., Rooney, G. E., and Stuever, for the Overlay Denture, J. PROSTHET. DENT. 28: 4-12, 1972. 5. Kafalias, M. Cl.: Abutment Preparation in Crown and Bridge, Aust. Dent. J. 14: 1-7, 1969. 6. Johnston, J. F., Phillips, R. W., and Dykema, R. W.: Modern Practice in Crown and Bridge Prosthodontics, ed. 3, Philadelphia, 1971, W. B. Saunders Company, pp. 539-540. 7. Antonoff, S. J.: The Status of Cantilever Bridges, N. Y. State Dent. J. 38: 275-281, 1972. 8. Ewing, J. E.: Re-evaluation of the Cantilever Principle, J. PROSTHET. DENT. 7: 78-92, 1957. 9. Archer, W. H.: Oral Surgery, Philadelphia, 1961, W. B. Saunders Company, p. 145. 10. Rohrer, A.: Displaced and Impacted Canines, a Radiographic Research, Int. J. Orthod., Oral Surg. Radio]. 15: 1002-1020, 1929. 11. Schweitzer, J. M., Schweitzer, R. D., and Schweitzer, J.: Free-end Pontics Used on Fixed Partial Dentures, J. PROSTHET. DENT. 20: 120-138, 1968. 12. Henderson, D., Blevins, W. R., Wesley, R. C., and Seward, T. : Cantilever Type of Posterior Fixed Partial Dentures: A Laboratory Study, J. PROSTHET. DENT. 24: 47-67, 1970. FACULTY
OF DENTISTRY
THE UNIVERSITY 2 CHALMERS ST. SYDNEY, N.S.W. AUSTRALIA
2010
OF SYDNEY