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The combination syndrome: A literature review
The combination syndrome: A literature review Sigvard Palmqvist, LDS, Odont Dr,a Gunnar E. Carlsson, LDS, Odont Dr, Dr Odont hc,b and ¨ wall, LDS, Odont Dr, Dr Med hcc Bengt O School of Dentistry, University of Copenhagen, Copenhagen, Denmark; and School of Dentistry, Go¨teborg University, Go¨teborg, Sweden Although combination syndrome is recognized by many clinicians, documented observations seem to be rare. The aim of this article was to critically review the literature regarding combination syndrome to evaluate the evidence for this concept. A search of the dental literature with Medline/PubMed through July 2002, focusing on the combination syndrome and related features, was undertaken and combined with a hand search of older references and textbooks on removable prosthodontics. (J Prosthet Dent 2003;90:270-5.)
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oss of bone of the anterior edentulous maxilla when opposed by natural mandibular anterior teeth is 1 of several features of the combination syndrome. Although recognized by many clinicians, documented observations seem to be rare. The Glossary of Prosthodontic Terms1 defines combination syndrome as “the characteristic features that occur when an edentulous maxilla is opposed by natural mandibular anterior teeth, including loss of bone from the anterior portion of the maxillary ridge, overgrowth of the tuberosities, papillary hyperplasia of the hard palatal mucosa, extrusion of mandibular anterior teeth, and loss of alveolar bone and ridge height beneath the mandibular removable partial denture bases, also called anterior hyperfunction syndrome.” Ellsworth Kelly2 was the first person to use the term “combination syndrome.” He followed a small group of patients wearing a complete maxillary denture opposed by mandibular anterior teeth and a distal extension distal removable partial denture (RPD). Of the 6 patients followed up for 3 years, all showed a reduction of the anterior bone in the maxilla along with enlarged tuberosities. For 5 patients there was an increased bone level of the tuberosities. Kelly2 blamed the mandibular RPD and the lack of a posterior seal in the maxillary denture for these changes. He discussed “excessive bony resorption under the mandibular removable partial denture bases” but provided no values. Kelly2 discussed various possibilities to avoid combination syndrome, including extraction of the mandibular teeth, but did not advocate this solution. Instead, he proposed using the roots of anterior mandibular teeth to support an overdenture. He also mentioned the option of using endodontic ima
Professor emeritus, Department of Prosthetic Dentistry, University of Copenhagen. b Professor emeritus, Department of Prosthetic Dentistry, Go¨teborg University. c Professor and Chair, Department of Prosthetic Dentistry, University of Copenhagen. 270 THE JOURNAL OF PROSTHETIC DENTISTRY
plants to preserve questionable roots for support in the posterior part of the mandible. A few years later, further characteristics were added to the combination syndrome: loss of vertical dimension of occlusion, occlusal plane discrepancy, anterior spatial repositioning of the mandible, poor adaptation of the prostheses, epulis fissuratum, and periodontal changes.3 However, these changes are not generally associated with combination syndrome. In spite of his emphasis on the negative role of the mandibular RPD, Kelly2 wrote: “The early loss of bone from the anterior part of the maxillary jaw is the key to the other changes of the combination syndrome.” This view was previously published in The American TextBook of Prosthetic Dentistry4 in 1907 in the following manner: “One of the most commonly observed cases of this sort (localized adsorption) is that in which a full upper plate denture is antagonized only by six or eight lower natural teeth, there being no teeth posterior to this point, adsorption of the alveolar process in the maxilla in front occurring as a result of the undue pressure on it.” Clinicians have recognized a number of the aforementioned features in some patients, but documented observations are rare. About 25 years after the publication of Kelly’s2 article, a review of sequelae of treatment with complete dentures argued that there was a lack of evidence for the combination syndrome.5 Today, accepting the principle of evidence-based dentistry, a critical review of the documentation behind the concept of “combination syndrome” seems warranted. The aim of this article was to evaluate the evidence for this concept.
LITERATURE REVIEW A search of medical and dental literature through July 2002 was undertaken by use of Medline/PubMed. The focus of the search was on combination syndrome and related features such as alveolar bone loss, bone resorption, maxillary tuberosities, denture stomatitis, and maxillary abnormalities, all combined with removable partial denture variables. Along with the articles found VOLUME 90 NUMBER 3
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in Medline/PubMed, those found by a hand search of older references were also considered. In addition, some common textbooks on removable prosthodontics were scrutinized for additional documentation.
Residual ridge resorption— general aspects After extraction of teeth, a remodeling process of the alveolar bone occurs, including bone resorption and a changed contour.6,7 The loss of bone in the maxilla was reported to be less if an immediate denture technique was used compared with a healing period without denture.8,9 For the mandible, no difference or a smaller difference in resorption rate during this initial stage was found between the immediate technique and a healing period without denture.9,10 After the initial remodeling phase, there is continuous bone resorption under denture bases. It is inevitable and has been called “a major oral disease entity.”11 The initial prosthetic technique probably has no long-term influence on residual ridge resorption, which is more pronounced in the mandible than in the maxilla and has been demonstrated to occur for up to 30 years.11-14 Bone resorption under dentures can affect not only the alveolar bone but also, in some situations, the basal bone.11-13 However, great individual differences have been noted, and factors other than the wearing of removable dentures may be involved in the resorption process.15-17 There are clear indications and little doubt that the removable denture plays an important causative role in the bone resorption process. This is supported by studies showing significant differences in residual alveolar bone between edentulous subjects wearing or not wearing removable dentures.18,19 Subjects not wearing dentures had more remaining bone. In groups of patients who had been wearing complete mandibular dentures for different lengths of time, the continuous bone resorption stopped in the areas distal to the mandibular foramina after the patients had been provided with fixed prostheses supported by implants placed anterior to the foramina.20 In another study, a fixed implant-supported prosthesis of the same design produced bone apposition in the posterior parts of the mandible, whereas an overdenture supported by 2 implants resulted in a continuous resorption of the same areas.21 Moreover, animal studies have shown that continuous pressure from an experimental denture caused bone resorption when exceeding a threshold value, and that the resorbed bone was not reshaped when pressure was discontinued.22-24
Maxillary ridge resorption in relation to mandibular status Mandibular natural teeth with or without RPD. Bone resorption in the anterior part of the edentulous maxilla, the main feature of the “combination syndrome,” has been the subject of many clinical reports and some inSEPTEMBER 2003
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vestigations of series of patients. No longitudinal study with the extraction of the anterior maxillary teeth as the starting point and randomly chosen mandibular status exists. Most studies comprise only small groups of patients. However, some cautious conclusions may be drawn by comparing results from available studies of various designs. Most studies have used radiographic cephalometry for measurement of residual ridge height. With this technique, 1 study7 compared bone resorption of the anterior maxilla in patients wearing a complete maxillary denture with different mandibular status: (1) mandibular complete denture; (2) anterior mandibular teeth and a Class I mandibular RPD; and (3) natural mandibular teeth only. No statistically significant differences were found between these groups. However, the smallest resorbed area of the maxillary residual ridge, calculated from the radiographs for the period between 6 months and 5 years after extraction, was noted for group 3 (natural teeth only). Grouping the subjects with complete dentures together with those with natural teeth including molars, and comparing them with a group having only anterior teeth (with or without an RPD) showed slightly greater bone resorption in the latter group which was significantly different (P⬍.05). However, there were considerable individual variations in the extent of the changes in all groups. In a 21-year follow-up of the same patients, the individual variations were still very large, and there was no support for systematic development of “combination syndrome.”13 At the same center, other groups of patients with a maxillary complete denture and various prosthodontic solutions for the partially edentulous mandible were also followed.25,26 The first group had no posterior teeth and no RPD; the second group had a Class I mandibular RPD; the third group had an RPD retained by a bar splint uniting crowns, primarily on the canines. Over a 5-year period there was a significant reduction of the measured height of the anterior maxillary bone in the first 2 groups with similar mean values for both groups. In the bar splint group no significant reduction in bone height was noted in the anterior maxilla. When evaluating the horizontal dimension and calculating the anterior bone area of the maxillary residual ridge on the radiographs, a reduction was noted in all groups without significant differences between them. Only small and statistically insignificant changes in the bone height of the edentulous maxilla were found during a 5-year observation period in a patient group where the complete maxillary denture was opposed by a bar-retained mandibular RPD.27 The bone resorption under complete maxillary dentures was also studied during a 5-year period in patients wearing either a conventional complete mandibular denture or an overdenture supported by roots of the mandibular canines.28 Similar values were noted for both groups. An earlier longitudi271
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nal study over 7 years found no significant difference in maxillary bone resorption in patients wearing a complete maxillary denture opposed by either a complete mandibular denture or natural teeth and a removable partial denture, even if somewhat higher values were noted in the latter group.29 Examination records were reviewed in 150 consecutive denture patients at a dental school with regard to “prevalence of symptoms associated with combination syndrome.”30 All patients had a maxillary complete denture; however, the mandibular status differed. “Maxillary anterior alveolar bone loss” was nearly nonexistent in the group with complete mandibular dentures as well as in the group with natural dentition including bilateral molars. In groups with unilateral or bilateral missing molars, different percentages of maxillary anterior bone loss were noted. However, the authors found no significant difference related to whether the patients wore an RPD or not. This might partly be explained by the small number of subjects in these 2 groups. In fact, the highest percentage of “maxillary anterior alveolar bone loss” (56%) was noted for the group wearing a Class I mandibular RPD. The authors listed 5 changes “most consequential to denture wearing and most difficult to correct”: maxillary anterior bone loss, mandibular posterior bone loss, maxillary alveolar ridge canting, tuberosity enlargement, and hypermobile maxillary residual ridge. All of these changes were prevalent in less than 7% of the total sample but were found in 24% of the patients with a bilateral distal-extension RPD. It should be noted, however, that this was not an epidemiologic study of a random sample, but findings in patients at a dental school. Further, all variables presented in the article were dichotomous, and the criteria were not clarified to the readers. No epidemiologic study of the combination syndrome was found. Mandibular implant-supported or -retained prostheses. An Australian implant center reported on anterior bone resorption beneath complete maxillary dentures when opposed by implant-supported mandibular prostheses.31,32 The situation with a mandibular overdenture supported by 2 bar-connected implants resembled the situation with natural anterior teeth and an RPD. Maxillary changes similar to the combination syndrome, anterior bone loss in the maxilla, and “posterior loss of occlusal contact were observed.”31 The situation with a fixed implant-supported prosthesis in the mandible32 “did not appear to promote a condition similar to combination syndrome.” However, “loss of posterior occlusal contact” was also observed in these patients. The anterior bone loss under a maxillary complete denture has also been studied when the mandibular overdenture was supported by a transmandibular implant with 4 posts penetrating the mandibular crest between the mental foramina.33,34 Some changes consistent with signs associated with combination syndrome 272
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were noted33 but maxillary bone resorption was smaller compared with that reported by Kelly2 in the situation with remaining anterior teeth and a Class I mandibular RPD. According to the authors, a possible explanation of these improved results could be that implants do not supra-erupt as natural teeth do.34 Using panoramic radiographs, Jacobs et al35 followed up 3 groups of patients, all with a complete maxillary denture. In the mandible, 1 group had a complete denture, another group an implant-retained overdenture, and the third group had a fixed implant-supported prosthesis. The most pronounced annual bone resorption in the maxilla was noted in the complete denture group and was statistically significant compared with the overdenture group. Bone resorption in the fixed implantsupported prosthesis group demonstrated values in between the other 2 groups that were not significantly different from the other groups. The masticatory forces and deformation of the maxillary complete denture during function have been studied in patients with either a complete denture or a fixed implant-supported prosthesis in the mandible.36 The results showed a marked improvement in “chewing ability” after implant treatment, as indicated by changes in measured masticatory forces. However, no significantly increased levels of loading were measured by the strain gauges placed in the maxillary dentures. The conclusion was that there should be no increased risk of failure or complications associated with loading clinically with the type of fixed implant-supported prostheses that were studied. In another study of a group of patients with implantsupported overdentures in the mandible, frequent midline fractures of the opposing maxillary complete denture was noted, indicating an increase in denture deformation during function.37 However, this finding has not been confirmed in more recent studies.38-40 Regarding changes of the edentulous maxilla in complete denture wearers, there are also several studies in which radiographs have not been used but measurements have been performed on casts.41-43 The relevance of these studies concerning bone resorption can be questioned, and they are not included in this review.
Enlargement of the tuberosities In a study of denture patients treated at a dental school,30 “tuberosity elongation” was found in 5% of patients with complete dentures in both jaws. In patients with bilaterally missing mandibular molars, “tuberosity elongation” was found in 22% of those wearing a removable partial denture and in 56% of those with no RPD. The groups were small, and the study was not longitudinal, indicating that no conclusions can be drawn about the development of the noted “elongations.” VOLUME 90 NUMBER 3
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Papillary hyperplasia of the hard palate’s mucosa Epidemiologic studies of mucosal changes in denture wearers mostly report low percentage figures for “papillary hyperplasia of the hard palatal mucosa,” also called “papillomatous stomatitis.”44,45 No study was found focusing specifically on changes in the maxillary mucosa with respect to the mandibular dentition status.
Extrusion of mandibular anterior teeth Kelly demonstrated extrusion of the mandibular anterior teeth in all 6 patients with combination syndrome followed up for 3 years by means of profile radiographs.2 The amount of extrusion varied between 1.0 and 1.5 mm. No other reports have been found regarding extrusion of mandibular anterior teeth in combination with a complete maxillary denture and a mandibular RPD.
Bone resorption under mandibular RPD bases Continuous bone resorption in the mandible posterior to the remaining anterior teeth has been demonstrated in 2 groups of patients wearing different types of Class I mandibular RPDs, whereas no change of the bone level in the posterior region was noted for the group not wearing an RPD.25,26 In patients who received mandibular implant-supported fixed prostheses, bone resorption in the posterior part of the mandible practically ceased.20 This result has been confirmed in recent studies, some even reporting bone apposition in the posterior areas when a fixed implant-supported prosthesis was used.21,46 Most follow-up studies of removable partial dentures have not included measurement of bone resorption beneath the distal extension bases.47-50 For example, the longitudinal study over 25 years by Bergman et al49 provides no information on this point. However, it may be indirectly concluded that there were considerable changes of the supporting tissues judging from the frequent relining of the RPDs during the first 10 years.48 Kelly2 provided values for the resorption in the edentulous maxilla but not for the posterior, edentulous parts of the mandible. A study of patients with a complete maxillary denture opposed by a mandibular distal extension RPD retained by an anterior bar revealed more bone resorption in the posterior mandible than in the maxilla.27
DISCUSSION Dorland’s Illustrated Medical Dictionary51 defines “syndrome” as “a set of symptoms which occur together; the sum of signs of any morbid state; a symptom complex.” “Combination syndrome” is not included among hundreds of syndromes listed in the dictionary. From this review of the literature it seems obvious that SEPTEMBER 2003
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“combination syndrome” does not meet the criteria to be included in such a list. In a review of the literature, the authors have found no epidemiologic study of “combination syndrome.” Compared with the main feature, “loss of bone from the anterior portion of the edentulous maxilla,” findings such as “papillary hyperplasia of the hard palatal mucosa” seem to be rare.44,45 Enlarged tuberosities may also have other causes than those described by Kelly2 as part of the combination syndrome. Enlarged tuberosities are often seen together with supraerupted maxillary molars. In situations where mandibular molars have been lost, the opposing maxillary molars may supraerupt together with the alveolar process.52 The supraeruption may create enlarged tuberosities without influence of a denture. Not surprisingly, no randomized controlled trials (RCTs) on combination syndrome were found. A review of U.S. prosthodontic journals showed that less than 2% of 3631 articles published over a 10-year period could be classified as RCTs.53 A more extensive review up to the end of year 2000 identified 92 RCTs in prosthodontics, but none related to combination syndrome.54 Perhaps somewhat more surprising, is that there seems to be no prospective study of the “combination syndrome” in spite of the fact that many people have been provided with a complete maxillary denture opposed by anterior mandibular teeth with or without a Class I mandibular RPD. A long-term 21-year study of patients wearing complete maxillary dentures provided no support for a systematic development of the “combination syndrome.”13 This does not mean that the observations made by Kelly2 were false. In the title of his article, he emphasized the negative role of the mandibular RPD. The same view was expressed by Keltjens et al,55 who found the traditional treatment for an edentulous maxilla opposed by a partially edentulous mandible with a complete denture and a Class I mandibular RPD to be “fundamentally inadequate.” The authors also suggested use of implants for distal support. Loss of established posterior occlusal contacts has been discussed as an important factor in relation to the combination syndrome.30 However, loss of occlusal contacts can be attributed not only to bone resorption under mandibular distal extension bases but also to wear of the artificial denture teeth, as well as to changes in position of the anterior mandibular teeth. It can be speculated that such changes in occlusion facilitate parafunctional activities such as clenching and thereby increase the pressure on the maxillary anterior alveolar bone. This speculative theory fits well with the result that patients who had been provided with Class I mandibular RPDs had development of more signs and symptoms of temporomandibular disorders over a 5-year period compared with a matched group of patients treated with cantilevered fixed partial dentures.56 It is also compatible with results from in vivo measurements showing that 273
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a fixed implant-supported prosthesis in the mandible opposing a complete maxillary denture improved the “chewing ability” but did not increase the levels of loads transferred to the denture base.36 Loss of alveolar bone and residual ridge height beneath the mandibular removable partial denture bases was included in the combination syndrome by Kelly.2 Reviewed articles have shown greater bone loss in the mandible associated with an RPD compared with when no RPD or a fixed prostheses supported by anterior implants was provided.20,21,25,26,46 Compared with cantilevered fixed partial dentures, conventional Class I mandibular RPDs have been shown to cause more carious lesions, more plaque and gingivitis, as well as more signs and symptoms of temporomandibular disorders.56,57 The poor biologic outcome with Class I mandibular RPDs constitutes a strong indirect support for the “shortened dental arch” concept,58,59 indicating that missing posterior teeth should not necessarily be replaced. It has been convincingly demonstrated that dentitions consisting of only anterior and premolar teeth can meet oral functional demands in most situations.60-63 Also in patients with dentitions associated with the combination syndrome (edentulous maxilla, bilaterally missing mandibular posterior teeth) it seems reasonable to adopt the shortened dental arch concept. This view is also in agreement with the well-documented excellent long-term results with fixed mandibular prostheses supported by implants placed between the mental foramina and opposing maxillary complete dentures.64,65
SUMMARY Bone resorption of the anterior part of the edentulous maxilla in association with remaining anterior mandibular teeth has been the subject of a limited number of studies of acceptable quality, but the results have not been conclusive. No epidemiologic study of the various features related to combination syndrome has been published. There is no evidence that a mandibular removable partial denture can prevent the development of the events described. On the basis of this review of the literature it may therefore be concluded that the “combination syndrome” does not meet the criteria to be accepted as a medical syndrome. The single features associated with the “combination syndrome” exist but to what extent or in which combinations has not been clarified. REFERENCES 1. The glossary of prosthodontic terms. J Prosthet Dent 1999;81:39-110. 2. Kelly E. Changes caused by a mandibular removable partial denture opposing a maxillary complete denture. J Prosthet Dent 1972;27:140-50. 3. Saunders TR, Gillis RE Jr, Desjardins RP. The maxillary complete denture opposing the mandibular bilateral distal-extension partial denture: treatment considerations. J Prosthet Dent 1979;41:124-8.
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4. Turner CR. The human dental mechanism; its structures, functions, and relations. Changes in the jaws following the loss of teeth. In: Turner CR, editor. The American text-book of prosthetic dentistry. London: Henry Kimpton; 1907. p. 230-92. 5. Carlsson GE. Clinical morbidity and sequelae of treatment with complete dentures. J Prosthet Dent 1998;79:17-23. 6. Carlsson GE, Thilander H, Hedegard B. Histologic changes in the upper alveolar process after extractions with or without insertion of an immediate full denture. Acta Odontol Scand 1967;25:21-43. 7. Carlsson GE, Bergman B, Hedegard B. Changes in contour of the maxillary alveolar process under immediate dentures. A longitudinal clinical and x-ray cephalometric study covering 5 years. Acta Odontol Scand 1967; 25:45-75. 8. Wictorin L. Bone resorption in cases with complete upper denture. Acta Radiol 1964;228 (Suppl):1-97. 9. Johnson K. A study of the dimensional changes occurring in the maxilla following closed face immediate denture treatment. Aust Dent J 1969;14: 370-6. 10. Carlsson GE, Persson G. Morphologic changes of the mandible after extraction and wearing of dentures. A longitudinal, clinical, and x-ray cephalometric study covering 5 years. Odontol Rev 1967;18:27-54. 11. Atwood DA. Reduction of residual ridges: a major oral disease entity. J Prosthet Dent 1971;26:266-79. 12. Tallgren A. The continuing reduction of residual alveolar ridges in complete denture wearers: a mixed-longitudinal study covering 25 years. J Prosthet Dent 1972;27:120-32. 13. Bergman B, Carlsson GE. Clinical long-term study of complete denture wearers. J Prosthet Dent 1985;53:56-61. 14. Jackson RA, Ralph WJ. Continuing changes in the contour of the maxillary residual alveolar ridge. J Oral Rehabil 1980;7:245-8. 15. Carlsson GE, Haraldson T. Fundamental aspects of mandibular atrophy. In: Worthington P, Branemark PI, editors. Advanced osseointegration surgery: maxillofacial applications. Chicago: Quintessence Publishing; 1992. p. 109-18. 16. Xie Q, Ainamo A, Tilvis R. Association of residual ridge resorption with systemic factors in home-living elderly subjects. Acta Odontol Scand 1997;55:299-305. 17. Xie Q, Narhi TO, Nevalainen JM, Wolf J, Ainamo A. Oral status and prosthetic factors related to residual ridge resorption in elderly subjects. Acta Odontol Scand 1997;55:306-13. 18. Campbell RL. A comparative study of the resorption of the alveolar ridges in denture-wearers and non-denture wearers. J Am Dent Assoc 1960;60: 143-53. 19. Jozefowicz W. The influence of wearing dentures on residual ridges: a comparative study. J Prosthet Dent 1970;24:137-44. 20. Sennerby L, Carlsson GE, Bergman B, Warfvinge J. Mandibular bone resorption in patients treated with tissue-integrated prostheses and in complete-denture wearers. Acta Odontol Scand 1988;46:135-40. 21. Wright PS, Glantz PO, Randow K, Watson RM. The effects of fixed and removable implant-stabilised prostheses on posterior mandibular residual ridge resorption. Clin Oral Implants Res 2002;13:169-74. 22. Mori S, Sato T, Hara T, Nakashima K, Minagi S. Effect of continuous pressure on histopathological changes in denture-supporting tissues. J Oral Rehabil 1997;24:37-46. 23. Ohara K, Sato T, Imai Y, Hara T. Histomorphometric analysis of bone dynamics in denture supporting tissue under masticatory pressure in rat. J Oral Rehabil 2001;28:695-701. 24. Imai Y, Sato T, Mori S, Okamoto M. A histomorphometric analysis on bone dynamics in denture supporting tissue under continuous pressure. J Oral Rehabil 2002;29:72-9. 25. Carlsson GE, Ragnarson N, Astrand P. Changes in height of the alveolar process in edentulous segments. A longitudinal clinical and radiographic study of full upper denture cases with residual lower anteriors. Odontol Tidskr 1967;75:193-208. 26. Carlsson GE, Ragnarson N, Astrand P. Changes in height of the alveolar process in edentulous segments. II. A longitudinal clinical and radiographic study over 5 years of full upper denture patients with residual lower anteriors. Sven Tandlak Tidskr 1969;62:125-36. 27. Uctasli S, Hasanreisoglu U, Iseri H. Cephalometric evaluation of maxillary complete, mandibular fixed-removable partial prosthesis: a 5-year longitudinal study. J Oral Rehabil 1997;24:164-9. 28. Crum RJ, Rooney GE Jr. Alveolar bone loss in overdentures: a 5-year study. J Prosthet Dent 1978;40:610-3.
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29. Tallgren A. The effect of denture wearing on facial morphology. A 7-year longitudinal study. Acta Odontol Scand 1967;25:563-92. 30. Shen K, Gongloff RK. Prevalence of the “combination syndrome” among denture patients. J Prosthet Dent 1989;62:642-4. 31. Lechner SK, Mammen A. Combination syndrome in relation to osseointegrated implant-supported overdentures: a survey. Int J Prosthodont 1996; 9:58-64. 32. Gupta S, Lechner SK, Duckmanton NA. Maxillary changes under complete dentures opposing mandibular implant-supported fixed prostheses. Int J Prosthodont 1999;12:492-7. 33. Maxson BB, Powers MP, Scott RF. Prosthodontic considerations for the transmandibular implant. J Prosthet Dent 1990;63:554-8. 34. Barber HD, Scott RF, Maxson BB, Fonseca RJ. Evaluation of anterior maxillary alveolar ridge resorption when opposed by the transmandibular implant. J Oral Maxillofac Surg 1990;48:1283-7. 35. Jacobs R, van Steenberghe D, Nys M, Naert I. Maxillary bone resorption in patients with mandibular implant-supported overdentures or fixed prostheses. J Prosthet Dent 1993;70:135-40. 36. Stafford D, Glantz PO, Lindqvist L, Strandman E. Influence of treatment with osseointegrated mandibular bridges on the clinical deformation of maxillary complete dentures. Swed Dent J Suppl 1985;28:117-35. 37. Haraldson T, Jemt T, Stalblad PA, Lekholm U. Oral function in subjects with overdentures supported by osseointegrated implants. Scand J Dent Res 1988;96:235-42. 38. Sadowsky SJ. Mandibular implant-retained overdentures: a literature review. J Prosthet Dent 2001;86:468-73. 39. Chaffee NR, Felton DA, Cooper LF, Palmqvist U, Smith R. Prosthetic complications in an implant-retained mandibular overdenture population: initial analysis of a prospective study. J Prosthet Dent 2002;87:40-4. 40. Watson GK, Payne AG, Purton DG, Thomson WM. Mandibular overdentures: comparative evaluation of prosthodontic maintenance of three different implant systems during the first year of service. Int J Prosthodont 2002;15:259-66. 41. Carlsson GE. Measurements on casts of the edentulous maxilla. Odontol Revy 1966;17:386-402. 42. Abrams H, Kopczyk RA, Kaplan AL. Incidence of anterior ridge deformities in partially edentulous patients. J Prosthet Dent 1987;57:191-4. 43. Narhi TO, Geertman ME, Hevinga M, Abdo H, Kalk W. Changes in the edentulous maxilla in persons wearing implant-retained mandibular overdentures. J Prosthet Dent 2000;84:43-9. 44. MacEntee MI. The prevalence of edentulism and diseases related to dentures—a literature review. J Oral Rehabil 1985;12:195-207. 45. MacEntee MI, Glick N, Stolar E. Age, gender, dentures and mucosal disorders. Oral Diseases 1998;4:32-6. 46. Murphy WM, Absi EG, Gregory MC, Williams KR. A prospective 5-year study of two cast framework alloys for fixed implant-supported mandibular prostheses. Int J Prosthodont 2002;15:133-8. 47. Carlsson GE, Hedegard B, Koivumaa KK. Late results of treatment with partial dentures. An investigation by questionnaire and clinical examination 13 years after treatment. J Oral Rehabil 1976;3:267-72. 48. Bergman B, Hugoson A, Olsson CO. Caries, periodontal and prosthetic findings in patients with removable partial dentures: a ten-year longitudinal study. J Prosthet Dent 1982;48:506-14. 49. Bergman B, Hugoson A, Olsson CO. A 25 year longitudinal study of patients treated with removable partial dentures. J Oral Rehabil 1995;22: 595-9. 50. Vermeulen AH, Keltjens HM, van’t Hof MA, Kayser AF. Ten-year evaluation of removable partial dentures: survival rates based on retreatment, not wearing and replacement. J Prosthet Dent 1996;76:267-72.
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51. Dorland WA. Dorland’s illustrated medical dictionary. 29th ed. Philadelphia: WB Saunders; 2000. p. 1748-71. 52. Compagnon D, Woda A. Supraeruption of the unopposed maxillary first molar. J Prosthet Dent 1991;66:29-34. 53. Dumbrigue HB, Jones JS, Esquivel JF. Developing a register for randomized controlled trials in prosthodontics: results of a search from prosthodontic journals published in the United States. J Prosthet Dent 1999;82: 699-703. 54. Jokstad A, Esposito M, Coulthard P, Worthington HV. The reporting of randomized controlled trials in prosthodontics. Int J Prosthodont 2002;15: 230-42. 55. Keltjens HM, Kayser AF, Hertel R, Battistuzzi PG. Distal extension removable partial dentures supported by implants and residual teeth: considerations and case reports. Int J Oral Maxillofac Implants 1993;8:208-13. 56. Budtz-Jorgensen E, Isidor F. A 5-year longitudinal study of cantilevered fixed partial dentures compared with removable partial dentures in a geriatric population. J Prosthet Dent 1990;64:42-7. 57. Jepson NJ, Moynihan PJ, Kelly PJ, Watson GW, Thomason JM. Caries incidence following restoration of shortened lower dental arches in a randomized control trial. Br Dent J 2001;191:140-4. 58. Kayser AF. Shortened dental arches and oral function. J Oral Rehabil 1981;8:457-62. 59. Kayser AF. Teeth, tooth loss and prosthetic appliances. In: Owall B, Kayser AF, Carlsson GE, editors. Prosthodontics: principles and management strategies. London: Wolfe Publishing; 1996. p. 35-48. 60. Witter DJ, De Haan AF, Ka¨ yser AF, Van Rossum GM. A 6-year follow-up study of oral function in shortened dental arches. Part II: Craniomandibular dysfunction and oral comfort. J Oral Rehabil 1994;21:353-66. 61. Allen PF, Witter DF, Wilson NH, Kayser AF. Shortened dental arch therapy: views of consultants in restorative dentistry in the United Kingdom. J Oral Rehabil 1996;23:481-5. 62. Witter DJ, van Palenstein Heldermann WH, Creugers NH, Kayser AF. The shortened dental arch concept and its implications for oral health care. Community Dent Oral Epidemiol 1999;27:249-58. 63. Witter DJ, Creugers NH, Kreulen CM, de Haan AF. Occlusal stability in shortened dental arches. J Dent Res 2001;80:432-6. 64. Lindquist LW, Carlsson GE, Jemt T. A prospective 15-year follow-up study of mandibular fixed prostheses supported by osseointegrated implants. Clinical results and marginal bone loss. Clin Oral Implants Res 1996;7: 329-36. 65. Wennerberg A, Carlsson GE, Jemt T. Influence of occlusal factors on treatment outcome: a study of 109 consecutive patients with mandibular implant-supported fixed prostheses opposing maxillary complete dentures. Int J Prosthodont 2001;14:550-5. Reprint requests to: DR GUNNAR E. CARLSSON DEPARTMENT OF PROSTHETIC DENTISTRY FACULTY OF ODONTOLOGY, GO¨ TEBORG UNIVERSITY BOX 450, SE 405 30 GO¨ TEBORG SWEDEN FAX: 46-31-773-3193 E-MAIL: [email protected] Copyright © 2003 by The Editorial Council of The Journal of Prosthetic Dentistry. 0022-3913/2003/$30.00 ⫹ 0 doi:10.1016/S0022-3913(03)00471-2
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oss of bone of the anterior edentulous maxilla when opposed by natural mandibular anterior teeth is 1 of several features of the combination syndrome. Although recognized by many clinicians, documented observations seem to be rare. The Glossary of Prosthodontic Terms1 defines combination syndrome as “the characteristic features that occur when an edentulous maxilla is opposed by natural mandibular anterior teeth, including loss of bone from the anterior portion of the maxillary ridge, overgrowth of the tuberosities, papillary hyperplasia of the hard palatal mucosa, extrusion of mandibular anterior teeth, and loss of alveolar bone and ridge height beneath the mandibular removable partial denture bases, also called anterior hyperfunction syndrome.” Ellsworth Kelly2 was the first person to use the term “combination syndrome.” He followed a small group of patients wearing a complete maxillary denture opposed by mandibular anterior teeth and a distal extension distal removable partial denture (RPD). Of the 6 patients followed up for 3 years, all showed a reduction of the anterior bone in the maxilla along with enlarged tuberosities. For 5 patients there was an increased bone level of the tuberosities. Kelly2 blamed the mandibular RPD and the lack of a posterior seal in the maxillary denture for these changes. He discussed “excessive bony resorption under the mandibular removable partial denture bases” but provided no values. Kelly2 discussed various possibilities to avoid combination syndrome, including extraction of the mandibular teeth, but did not advocate this solution. Instead, he proposed using the roots of anterior mandibular teeth to support an overdenture. He also mentioned the option of using endodontic ima
Professor emeritus, Department of Prosthetic Dentistry, University of Copenhagen. b Professor emeritus, Department of Prosthetic Dentistry, Go¨teborg University. c Professor and Chair, Department of Prosthetic Dentistry, University of Copenhagen. 270 THE JOURNAL OF PROSTHETIC DENTISTRY
plants to preserve questionable roots for support in the posterior part of the mandible. A few years later, further characteristics were added to the combination syndrome: loss of vertical dimension of occlusion, occlusal plane discrepancy, anterior spatial repositioning of the mandible, poor adaptation of the prostheses, epulis fissuratum, and periodontal changes.3 However, these changes are not generally associated with combination syndrome. In spite of his emphasis on the negative role of the mandibular RPD, Kelly2 wrote: “The early loss of bone from the anterior part of the maxillary jaw is the key to the other changes of the combination syndrome.” This view was previously published in The American TextBook of Prosthetic Dentistry4 in 1907 in the following manner: “One of the most commonly observed cases of this sort (localized adsorption) is that in which a full upper plate denture is antagonized only by six or eight lower natural teeth, there being no teeth posterior to this point, adsorption of the alveolar process in the maxilla in front occurring as a result of the undue pressure on it.” Clinicians have recognized a number of the aforementioned features in some patients, but documented observations are rare. About 25 years after the publication of Kelly’s2 article, a review of sequelae of treatment with complete dentures argued that there was a lack of evidence for the combination syndrome.5 Today, accepting the principle of evidence-based dentistry, a critical review of the documentation behind the concept of “combination syndrome” seems warranted. The aim of this article was to evaluate the evidence for this concept.
LITERATURE REVIEW A search of medical and dental literature through July 2002 was undertaken by use of Medline/PubMed. The focus of the search was on combination syndrome and related features such as alveolar bone loss, bone resorption, maxillary tuberosities, denture stomatitis, and maxillary abnormalities, all combined with removable partial denture variables. Along with the articles found VOLUME 90 NUMBER 3
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in Medline/PubMed, those found by a hand search of older references were also considered. In addition, some common textbooks on removable prosthodontics were scrutinized for additional documentation.
Residual ridge resorption— general aspects After extraction of teeth, a remodeling process of the alveolar bone occurs, including bone resorption and a changed contour.6,7 The loss of bone in the maxilla was reported to be less if an immediate denture technique was used compared with a healing period without denture.8,9 For the mandible, no difference or a smaller difference in resorption rate during this initial stage was found between the immediate technique and a healing period without denture.9,10 After the initial remodeling phase, there is continuous bone resorption under denture bases. It is inevitable and has been called “a major oral disease entity.”11 The initial prosthetic technique probably has no long-term influence on residual ridge resorption, which is more pronounced in the mandible than in the maxilla and has been demonstrated to occur for up to 30 years.11-14 Bone resorption under dentures can affect not only the alveolar bone but also, in some situations, the basal bone.11-13 However, great individual differences have been noted, and factors other than the wearing of removable dentures may be involved in the resorption process.15-17 There are clear indications and little doubt that the removable denture plays an important causative role in the bone resorption process. This is supported by studies showing significant differences in residual alveolar bone between edentulous subjects wearing or not wearing removable dentures.18,19 Subjects not wearing dentures had more remaining bone. In groups of patients who had been wearing complete mandibular dentures for different lengths of time, the continuous bone resorption stopped in the areas distal to the mandibular foramina after the patients had been provided with fixed prostheses supported by implants placed anterior to the foramina.20 In another study, a fixed implant-supported prosthesis of the same design produced bone apposition in the posterior parts of the mandible, whereas an overdenture supported by 2 implants resulted in a continuous resorption of the same areas.21 Moreover, animal studies have shown that continuous pressure from an experimental denture caused bone resorption when exceeding a threshold value, and that the resorbed bone was not reshaped when pressure was discontinued.22-24
Maxillary ridge resorption in relation to mandibular status Mandibular natural teeth with or without RPD. Bone resorption in the anterior part of the edentulous maxilla, the main feature of the “combination syndrome,” has been the subject of many clinical reports and some inSEPTEMBER 2003
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vestigations of series of patients. No longitudinal study with the extraction of the anterior maxillary teeth as the starting point and randomly chosen mandibular status exists. Most studies comprise only small groups of patients. However, some cautious conclusions may be drawn by comparing results from available studies of various designs. Most studies have used radiographic cephalometry for measurement of residual ridge height. With this technique, 1 study7 compared bone resorption of the anterior maxilla in patients wearing a complete maxillary denture with different mandibular status: (1) mandibular complete denture; (2) anterior mandibular teeth and a Class I mandibular RPD; and (3) natural mandibular teeth only. No statistically significant differences were found between these groups. However, the smallest resorbed area of the maxillary residual ridge, calculated from the radiographs for the period between 6 months and 5 years after extraction, was noted for group 3 (natural teeth only). Grouping the subjects with complete dentures together with those with natural teeth including molars, and comparing them with a group having only anterior teeth (with or without an RPD) showed slightly greater bone resorption in the latter group which was significantly different (P⬍.05). However, there were considerable individual variations in the extent of the changes in all groups. In a 21-year follow-up of the same patients, the individual variations were still very large, and there was no support for systematic development of “combination syndrome.”13 At the same center, other groups of patients with a maxillary complete denture and various prosthodontic solutions for the partially edentulous mandible were also followed.25,26 The first group had no posterior teeth and no RPD; the second group had a Class I mandibular RPD; the third group had an RPD retained by a bar splint uniting crowns, primarily on the canines. Over a 5-year period there was a significant reduction of the measured height of the anterior maxillary bone in the first 2 groups with similar mean values for both groups. In the bar splint group no significant reduction in bone height was noted in the anterior maxilla. When evaluating the horizontal dimension and calculating the anterior bone area of the maxillary residual ridge on the radiographs, a reduction was noted in all groups without significant differences between them. Only small and statistically insignificant changes in the bone height of the edentulous maxilla were found during a 5-year observation period in a patient group where the complete maxillary denture was opposed by a bar-retained mandibular RPD.27 The bone resorption under complete maxillary dentures was also studied during a 5-year period in patients wearing either a conventional complete mandibular denture or an overdenture supported by roots of the mandibular canines.28 Similar values were noted for both groups. An earlier longitudi271
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nal study over 7 years found no significant difference in maxillary bone resorption in patients wearing a complete maxillary denture opposed by either a complete mandibular denture or natural teeth and a removable partial denture, even if somewhat higher values were noted in the latter group.29 Examination records were reviewed in 150 consecutive denture patients at a dental school with regard to “prevalence of symptoms associated with combination syndrome.”30 All patients had a maxillary complete denture; however, the mandibular status differed. “Maxillary anterior alveolar bone loss” was nearly nonexistent in the group with complete mandibular dentures as well as in the group with natural dentition including bilateral molars. In groups with unilateral or bilateral missing molars, different percentages of maxillary anterior bone loss were noted. However, the authors found no significant difference related to whether the patients wore an RPD or not. This might partly be explained by the small number of subjects in these 2 groups. In fact, the highest percentage of “maxillary anterior alveolar bone loss” (56%) was noted for the group wearing a Class I mandibular RPD. The authors listed 5 changes “most consequential to denture wearing and most difficult to correct”: maxillary anterior bone loss, mandibular posterior bone loss, maxillary alveolar ridge canting, tuberosity enlargement, and hypermobile maxillary residual ridge. All of these changes were prevalent in less than 7% of the total sample but were found in 24% of the patients with a bilateral distal-extension RPD. It should be noted, however, that this was not an epidemiologic study of a random sample, but findings in patients at a dental school. Further, all variables presented in the article were dichotomous, and the criteria were not clarified to the readers. No epidemiologic study of the combination syndrome was found. Mandibular implant-supported or -retained prostheses. An Australian implant center reported on anterior bone resorption beneath complete maxillary dentures when opposed by implant-supported mandibular prostheses.31,32 The situation with a mandibular overdenture supported by 2 bar-connected implants resembled the situation with natural anterior teeth and an RPD. Maxillary changes similar to the combination syndrome, anterior bone loss in the maxilla, and “posterior loss of occlusal contact were observed.”31 The situation with a fixed implant-supported prosthesis in the mandible32 “did not appear to promote a condition similar to combination syndrome.” However, “loss of posterior occlusal contact” was also observed in these patients. The anterior bone loss under a maxillary complete denture has also been studied when the mandibular overdenture was supported by a transmandibular implant with 4 posts penetrating the mandibular crest between the mental foramina.33,34 Some changes consistent with signs associated with combination syndrome 272
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were noted33 but maxillary bone resorption was smaller compared with that reported by Kelly2 in the situation with remaining anterior teeth and a Class I mandibular RPD. According to the authors, a possible explanation of these improved results could be that implants do not supra-erupt as natural teeth do.34 Using panoramic radiographs, Jacobs et al35 followed up 3 groups of patients, all with a complete maxillary denture. In the mandible, 1 group had a complete denture, another group an implant-retained overdenture, and the third group had a fixed implant-supported prosthesis. The most pronounced annual bone resorption in the maxilla was noted in the complete denture group and was statistically significant compared with the overdenture group. Bone resorption in the fixed implantsupported prosthesis group demonstrated values in between the other 2 groups that were not significantly different from the other groups. The masticatory forces and deformation of the maxillary complete denture during function have been studied in patients with either a complete denture or a fixed implant-supported prosthesis in the mandible.36 The results showed a marked improvement in “chewing ability” after implant treatment, as indicated by changes in measured masticatory forces. However, no significantly increased levels of loading were measured by the strain gauges placed in the maxillary dentures. The conclusion was that there should be no increased risk of failure or complications associated with loading clinically with the type of fixed implant-supported prostheses that were studied. In another study of a group of patients with implantsupported overdentures in the mandible, frequent midline fractures of the opposing maxillary complete denture was noted, indicating an increase in denture deformation during function.37 However, this finding has not been confirmed in more recent studies.38-40 Regarding changes of the edentulous maxilla in complete denture wearers, there are also several studies in which radiographs have not been used but measurements have been performed on casts.41-43 The relevance of these studies concerning bone resorption can be questioned, and they are not included in this review.
Enlargement of the tuberosities In a study of denture patients treated at a dental school,30 “tuberosity elongation” was found in 5% of patients with complete dentures in both jaws. In patients with bilaterally missing mandibular molars, “tuberosity elongation” was found in 22% of those wearing a removable partial denture and in 56% of those with no RPD. The groups were small, and the study was not longitudinal, indicating that no conclusions can be drawn about the development of the noted “elongations.” VOLUME 90 NUMBER 3
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Papillary hyperplasia of the hard palate’s mucosa Epidemiologic studies of mucosal changes in denture wearers mostly report low percentage figures for “papillary hyperplasia of the hard palatal mucosa,” also called “papillomatous stomatitis.”44,45 No study was found focusing specifically on changes in the maxillary mucosa with respect to the mandibular dentition status.
Extrusion of mandibular anterior teeth Kelly demonstrated extrusion of the mandibular anterior teeth in all 6 patients with combination syndrome followed up for 3 years by means of profile radiographs.2 The amount of extrusion varied between 1.0 and 1.5 mm. No other reports have been found regarding extrusion of mandibular anterior teeth in combination with a complete maxillary denture and a mandibular RPD.
Bone resorption under mandibular RPD bases Continuous bone resorption in the mandible posterior to the remaining anterior teeth has been demonstrated in 2 groups of patients wearing different types of Class I mandibular RPDs, whereas no change of the bone level in the posterior region was noted for the group not wearing an RPD.25,26 In patients who received mandibular implant-supported fixed prostheses, bone resorption in the posterior part of the mandible practically ceased.20 This result has been confirmed in recent studies, some even reporting bone apposition in the posterior areas when a fixed implant-supported prosthesis was used.21,46 Most follow-up studies of removable partial dentures have not included measurement of bone resorption beneath the distal extension bases.47-50 For example, the longitudinal study over 25 years by Bergman et al49 provides no information on this point. However, it may be indirectly concluded that there were considerable changes of the supporting tissues judging from the frequent relining of the RPDs during the first 10 years.48 Kelly2 provided values for the resorption in the edentulous maxilla but not for the posterior, edentulous parts of the mandible. A study of patients with a complete maxillary denture opposed by a mandibular distal extension RPD retained by an anterior bar revealed more bone resorption in the posterior mandible than in the maxilla.27
DISCUSSION Dorland’s Illustrated Medical Dictionary51 defines “syndrome” as “a set of symptoms which occur together; the sum of signs of any morbid state; a symptom complex.” “Combination syndrome” is not included among hundreds of syndromes listed in the dictionary. From this review of the literature it seems obvious that SEPTEMBER 2003
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“combination syndrome” does not meet the criteria to be included in such a list. In a review of the literature, the authors have found no epidemiologic study of “combination syndrome.” Compared with the main feature, “loss of bone from the anterior portion of the edentulous maxilla,” findings such as “papillary hyperplasia of the hard palatal mucosa” seem to be rare.44,45 Enlarged tuberosities may also have other causes than those described by Kelly2 as part of the combination syndrome. Enlarged tuberosities are often seen together with supraerupted maxillary molars. In situations where mandibular molars have been lost, the opposing maxillary molars may supraerupt together with the alveolar process.52 The supraeruption may create enlarged tuberosities without influence of a denture. Not surprisingly, no randomized controlled trials (RCTs) on combination syndrome were found. A review of U.S. prosthodontic journals showed that less than 2% of 3631 articles published over a 10-year period could be classified as RCTs.53 A more extensive review up to the end of year 2000 identified 92 RCTs in prosthodontics, but none related to combination syndrome.54 Perhaps somewhat more surprising, is that there seems to be no prospective study of the “combination syndrome” in spite of the fact that many people have been provided with a complete maxillary denture opposed by anterior mandibular teeth with or without a Class I mandibular RPD. A long-term 21-year study of patients wearing complete maxillary dentures provided no support for a systematic development of the “combination syndrome.”13 This does not mean that the observations made by Kelly2 were false. In the title of his article, he emphasized the negative role of the mandibular RPD. The same view was expressed by Keltjens et al,55 who found the traditional treatment for an edentulous maxilla opposed by a partially edentulous mandible with a complete denture and a Class I mandibular RPD to be “fundamentally inadequate.” The authors also suggested use of implants for distal support. Loss of established posterior occlusal contacts has been discussed as an important factor in relation to the combination syndrome.30 However, loss of occlusal contacts can be attributed not only to bone resorption under mandibular distal extension bases but also to wear of the artificial denture teeth, as well as to changes in position of the anterior mandibular teeth. It can be speculated that such changes in occlusion facilitate parafunctional activities such as clenching and thereby increase the pressure on the maxillary anterior alveolar bone. This speculative theory fits well with the result that patients who had been provided with Class I mandibular RPDs had development of more signs and symptoms of temporomandibular disorders over a 5-year period compared with a matched group of patients treated with cantilevered fixed partial dentures.56 It is also compatible with results from in vivo measurements showing that 273
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a fixed implant-supported prosthesis in the mandible opposing a complete maxillary denture improved the “chewing ability” but did not increase the levels of loads transferred to the denture base.36 Loss of alveolar bone and residual ridge height beneath the mandibular removable partial denture bases was included in the combination syndrome by Kelly.2 Reviewed articles have shown greater bone loss in the mandible associated with an RPD compared with when no RPD or a fixed prostheses supported by anterior implants was provided.20,21,25,26,46 Compared with cantilevered fixed partial dentures, conventional Class I mandibular RPDs have been shown to cause more carious lesions, more plaque and gingivitis, as well as more signs and symptoms of temporomandibular disorders.56,57 The poor biologic outcome with Class I mandibular RPDs constitutes a strong indirect support for the “shortened dental arch” concept,58,59 indicating that missing posterior teeth should not necessarily be replaced. It has been convincingly demonstrated that dentitions consisting of only anterior and premolar teeth can meet oral functional demands in most situations.60-63 Also in patients with dentitions associated with the combination syndrome (edentulous maxilla, bilaterally missing mandibular posterior teeth) it seems reasonable to adopt the shortened dental arch concept. This view is also in agreement with the well-documented excellent long-term results with fixed mandibular prostheses supported by implants placed between the mental foramina and opposing maxillary complete dentures.64,65
SUMMARY Bone resorption of the anterior part of the edentulous maxilla in association with remaining anterior mandibular teeth has been the subject of a limited number of studies of acceptable quality, but the results have not been conclusive. No epidemiologic study of the various features related to combination syndrome has been published. There is no evidence that a mandibular removable partial denture can prevent the development of the events described. On the basis of this review of the literature it may therefore be concluded that the “combination syndrome” does not meet the criteria to be accepted as a medical syndrome. The single features associated with the “combination syndrome” exist but to what extent or in which combinations has not been clarified. REFERENCES 1. The glossary of prosthodontic terms. J Prosthet Dent 1999;81:39-110. 2. Kelly E. Changes caused by a mandibular removable partial denture opposing a maxillary complete denture. J Prosthet Dent 1972;27:140-50. 3. Saunders TR, Gillis RE Jr, Desjardins RP. The maxillary complete denture opposing the mandibular bilateral distal-extension partial denture: treatment considerations. J Prosthet Dent 1979;41:124-8.
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4. Turner CR. The human dental mechanism; its structures, functions, and relations. Changes in the jaws following the loss of teeth. In: Turner CR, editor. The American text-book of prosthetic dentistry. London: Henry Kimpton; 1907. p. 230-92. 5. Carlsson GE. Clinical morbidity and sequelae of treatment with complete dentures. J Prosthet Dent 1998;79:17-23. 6. Carlsson GE, Thilander H, Hedegard B. Histologic changes in the upper alveolar process after extractions with or without insertion of an immediate full denture. Acta Odontol Scand 1967;25:21-43. 7. Carlsson GE, Bergman B, Hedegard B. Changes in contour of the maxillary alveolar process under immediate dentures. A longitudinal clinical and x-ray cephalometric study covering 5 years. Acta Odontol Scand 1967; 25:45-75. 8. Wictorin L. Bone resorption in cases with complete upper denture. Acta Radiol 1964;228 (Suppl):1-97. 9. Johnson K. A study of the dimensional changes occurring in the maxilla following closed face immediate denture treatment. Aust Dent J 1969;14: 370-6. 10. Carlsson GE, Persson G. Morphologic changes of the mandible after extraction and wearing of dentures. A longitudinal, clinical, and x-ray cephalometric study covering 5 years. Odontol Rev 1967;18:27-54. 11. Atwood DA. Reduction of residual ridges: a major oral disease entity. J Prosthet Dent 1971;26:266-79. 12. Tallgren A. The continuing reduction of residual alveolar ridges in complete denture wearers: a mixed-longitudinal study covering 25 years. J Prosthet Dent 1972;27:120-32. 13. Bergman B, Carlsson GE. Clinical long-term study of complete denture wearers. J Prosthet Dent 1985;53:56-61. 14. Jackson RA, Ralph WJ. Continuing changes in the contour of the maxillary residual alveolar ridge. J Oral Rehabil 1980;7:245-8. 15. Carlsson GE, Haraldson T. Fundamental aspects of mandibular atrophy. In: Worthington P, Branemark PI, editors. Advanced osseointegration surgery: maxillofacial applications. Chicago: Quintessence Publishing; 1992. p. 109-18. 16. Xie Q, Ainamo A, Tilvis R. Association of residual ridge resorption with systemic factors in home-living elderly subjects. Acta Odontol Scand 1997;55:299-305. 17. Xie Q, Narhi TO, Nevalainen JM, Wolf J, Ainamo A. Oral status and prosthetic factors related to residual ridge resorption in elderly subjects. Acta Odontol Scand 1997;55:306-13. 18. Campbell RL. A comparative study of the resorption of the alveolar ridges in denture-wearers and non-denture wearers. J Am Dent Assoc 1960;60: 143-53. 19. Jozefowicz W. The influence of wearing dentures on residual ridges: a comparative study. J Prosthet Dent 1970;24:137-44. 20. Sennerby L, Carlsson GE, Bergman B, Warfvinge J. Mandibular bone resorption in patients treated with tissue-integrated prostheses and in complete-denture wearers. Acta Odontol Scand 1988;46:135-40. 21. Wright PS, Glantz PO, Randow K, Watson RM. The effects of fixed and removable implant-stabilised prostheses on posterior mandibular residual ridge resorption. Clin Oral Implants Res 2002;13:169-74. 22. Mori S, Sato T, Hara T, Nakashima K, Minagi S. Effect of continuous pressure on histopathological changes in denture-supporting tissues. J Oral Rehabil 1997;24:37-46. 23. Ohara K, Sato T, Imai Y, Hara T. Histomorphometric analysis of bone dynamics in denture supporting tissue under masticatory pressure in rat. J Oral Rehabil 2001;28:695-701. 24. Imai Y, Sato T, Mori S, Okamoto M. A histomorphometric analysis on bone dynamics in denture supporting tissue under continuous pressure. J Oral Rehabil 2002;29:72-9. 25. Carlsson GE, Ragnarson N, Astrand P. Changes in height of the alveolar process in edentulous segments. A longitudinal clinical and radiographic study of full upper denture cases with residual lower anteriors. Odontol Tidskr 1967;75:193-208. 26. Carlsson GE, Ragnarson N, Astrand P. Changes in height of the alveolar process in edentulous segments. II. A longitudinal clinical and radiographic study over 5 years of full upper denture patients with residual lower anteriors. Sven Tandlak Tidskr 1969;62:125-36. 27. Uctasli S, Hasanreisoglu U, Iseri H. Cephalometric evaluation of maxillary complete, mandibular fixed-removable partial prosthesis: a 5-year longitudinal study. J Oral Rehabil 1997;24:164-9. 28. Crum RJ, Rooney GE Jr. Alveolar bone loss in overdentures: a 5-year study. J Prosthet Dent 1978;40:610-3.
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29. Tallgren A. The effect of denture wearing on facial morphology. A 7-year longitudinal study. Acta Odontol Scand 1967;25:563-92. 30. Shen K, Gongloff RK. Prevalence of the “combination syndrome” among denture patients. J Prosthet Dent 1989;62:642-4. 31. Lechner SK, Mammen A. Combination syndrome in relation to osseointegrated implant-supported overdentures: a survey. Int J Prosthodont 1996; 9:58-64. 32. Gupta S, Lechner SK, Duckmanton NA. Maxillary changes under complete dentures opposing mandibular implant-supported fixed prostheses. Int J Prosthodont 1999;12:492-7. 33. Maxson BB, Powers MP, Scott RF. Prosthodontic considerations for the transmandibular implant. J Prosthet Dent 1990;63:554-8. 34. Barber HD, Scott RF, Maxson BB, Fonseca RJ. Evaluation of anterior maxillary alveolar ridge resorption when opposed by the transmandibular implant. J Oral Maxillofac Surg 1990;48:1283-7. 35. Jacobs R, van Steenberghe D, Nys M, Naert I. Maxillary bone resorption in patients with mandibular implant-supported overdentures or fixed prostheses. J Prosthet Dent 1993;70:135-40. 36. Stafford D, Glantz PO, Lindqvist L, Strandman E. Influence of treatment with osseointegrated mandibular bridges on the clinical deformation of maxillary complete dentures. Swed Dent J Suppl 1985;28:117-35. 37. Haraldson T, Jemt T, Stalblad PA, Lekholm U. Oral function in subjects with overdentures supported by osseointegrated implants. Scand J Dent Res 1988;96:235-42. 38. Sadowsky SJ. Mandibular implant-retained overdentures: a literature review. J Prosthet Dent 2001;86:468-73. 39. Chaffee NR, Felton DA, Cooper LF, Palmqvist U, Smith R. Prosthetic complications in an implant-retained mandibular overdenture population: initial analysis of a prospective study. J Prosthet Dent 2002;87:40-4. 40. Watson GK, Payne AG, Purton DG, Thomson WM. Mandibular overdentures: comparative evaluation of prosthodontic maintenance of three different implant systems during the first year of service. Int J Prosthodont 2002;15:259-66. 41. Carlsson GE. Measurements on casts of the edentulous maxilla. Odontol Revy 1966;17:386-402. 42. Abrams H, Kopczyk RA, Kaplan AL. Incidence of anterior ridge deformities in partially edentulous patients. J Prosthet Dent 1987;57:191-4. 43. Narhi TO, Geertman ME, Hevinga M, Abdo H, Kalk W. Changes in the edentulous maxilla in persons wearing implant-retained mandibular overdentures. J Prosthet Dent 2000;84:43-9. 44. MacEntee MI. The prevalence of edentulism and diseases related to dentures—a literature review. J Oral Rehabil 1985;12:195-207. 45. MacEntee MI, Glick N, Stolar E. Age, gender, dentures and mucosal disorders. Oral Diseases 1998;4:32-6. 46. Murphy WM, Absi EG, Gregory MC, Williams KR. A prospective 5-year study of two cast framework alloys for fixed implant-supported mandibular prostheses. Int J Prosthodont 2002;15:133-8. 47. Carlsson GE, Hedegard B, Koivumaa KK. Late results of treatment with partial dentures. An investigation by questionnaire and clinical examination 13 years after treatment. J Oral Rehabil 1976;3:267-72. 48. Bergman B, Hugoson A, Olsson CO. Caries, periodontal and prosthetic findings in patients with removable partial dentures: a ten-year longitudinal study. J Prosthet Dent 1982;48:506-14. 49. Bergman B, Hugoson A, Olsson CO. A 25 year longitudinal study of patients treated with removable partial dentures. J Oral Rehabil 1995;22: 595-9. 50. Vermeulen AH, Keltjens HM, van’t Hof MA, Kayser AF. Ten-year evaluation of removable partial dentures: survival rates based on retreatment, not wearing and replacement. J Prosthet Dent 1996;76:267-72.
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51. Dorland WA. Dorland’s illustrated medical dictionary. 29th ed. Philadelphia: WB Saunders; 2000. p. 1748-71. 52. Compagnon D, Woda A. Supraeruption of the unopposed maxillary first molar. J Prosthet Dent 1991;66:29-34. 53. Dumbrigue HB, Jones JS, Esquivel JF. Developing a register for randomized controlled trials in prosthodontics: results of a search from prosthodontic journals published in the United States. J Prosthet Dent 1999;82: 699-703. 54. Jokstad A, Esposito M, Coulthard P, Worthington HV. The reporting of randomized controlled trials in prosthodontics. Int J Prosthodont 2002;15: 230-42. 55. Keltjens HM, Kayser AF, Hertel R, Battistuzzi PG. Distal extension removable partial dentures supported by implants and residual teeth: considerations and case reports. Int J Oral Maxillofac Implants 1993;8:208-13. 56. Budtz-Jorgensen E, Isidor F. A 5-year longitudinal study of cantilevered fixed partial dentures compared with removable partial dentures in a geriatric population. J Prosthet Dent 1990;64:42-7. 57. Jepson NJ, Moynihan PJ, Kelly PJ, Watson GW, Thomason JM. Caries incidence following restoration of shortened lower dental arches in a randomized control trial. Br Dent J 2001;191:140-4. 58. Kayser AF. Shortened dental arches and oral function. J Oral Rehabil 1981;8:457-62. 59. Kayser AF. Teeth, tooth loss and prosthetic appliances. In: Owall B, Kayser AF, Carlsson GE, editors. Prosthodontics: principles and management strategies. London: Wolfe Publishing; 1996. p. 35-48. 60. Witter DJ, De Haan AF, Ka¨ yser AF, Van Rossum GM. A 6-year follow-up study of oral function in shortened dental arches. Part II: Craniomandibular dysfunction and oral comfort. J Oral Rehabil 1994;21:353-66. 61. Allen PF, Witter DF, Wilson NH, Kayser AF. Shortened dental arch therapy: views of consultants in restorative dentistry in the United Kingdom. J Oral Rehabil 1996;23:481-5. 62. Witter DJ, van Palenstein Heldermann WH, Creugers NH, Kayser AF. The shortened dental arch concept and its implications for oral health care. Community Dent Oral Epidemiol 1999;27:249-58. 63. Witter DJ, Creugers NH, Kreulen CM, de Haan AF. Occlusal stability in shortened dental arches. J Dent Res 2001;80:432-6. 64. Lindquist LW, Carlsson GE, Jemt T. A prospective 15-year follow-up study of mandibular fixed prostheses supported by osseointegrated implants. Clinical results and marginal bone loss. Clin Oral Implants Res 1996;7: 329-36. 65. Wennerberg A, Carlsson GE, Jemt T. Influence of occlusal factors on treatment outcome: a study of 109 consecutive patients with mandibular implant-supported fixed prostheses opposing maxillary complete dentures. Int J Prosthodont 2001;14:550-5. Reprint requests to: DR GUNNAR E. CARLSSON DEPARTMENT OF PROSTHETIC DENTISTRY FACULTY OF ODONTOLOGY, GO¨ TEBORG UNIVERSITY BOX 450, SE 405 30 GO¨ TEBORG SWEDEN FAX: 46-31-773-3193 E-MAIL: [email protected] Copyright © 2003 by The Editorial Council of The Journal of Prosthetic Dentistry. 0022-3913/2003/$30.00 ⫹ 0 doi:10.1016/S0022-3913(03)00471-2
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