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Extreme resorption of the mandible: a case report
Journal of Dentistry, 5, No. 1, 1977, pp. 73-75. Printed in Great Britain
Extreme resorption of the mandible: a case report P. Panoussopoulous, DOS* Royal Dental Hospital o f London
ABSTRACT
A patient who used an unusual material to make his lower denture more comfortable is reported. The serious consequences that arose, together with evidence from the literature, suggest that patients should be warned that they should at no time interfere with their dentures but return to their dentist for advice and treatment. INTRODUCTION
Alveolar bone is formed during the development and eruption of the teeth. After their loss it slowly disappears. The speed and degree of this process vary considerably from one individual to another, and the occurrence of almost completely resorbed mandibular alveolar bone is not uncommon. The factors that influence the pattern, rate and degree of this process are not completely understood, but it has been suggested (Atwood, 1971; Atwood and Coy, 1971) that the following are important: (a) the amount, density and state of health of the alveolar bone as well as metabolic factors, (b) the preservation of the buccal plate of cortical bone at the t~nne of extractions, (c) the functional load that is transmitted to the bone and (d) details of design o f the dentures which are used. Considerable importance has been attached to the last factor. It has been established that gross errors in the construction of dentures and specifically an increase in the occlusal vertical dimension (Terry et al., 1967) do produce bone resorption, and the larger the error, the greater is the resorption that may occur, particularly if the patient continues to use the dentures despite the initial discomfort which he experiences. It is not uncommon for patients who have uncomfortable dentures and who do not wish to return to their dentist for adjustment to tamper with their dentures themselves. They usually resort to the various home reliner materials which are commercially available. When a home reliner material is applied to the dentures and placed in the mouth, there is a noticeable increase in the vertical relation of occlusion and also changes in the relative position of the denture bases to the supporting bone (Means, 1964). In addition to the increased vertical dimension, an error in centric jaw relation will, in all likelihood, be introduced. The most common sequela of this self-treatment is bone resorption. The following case report is an example of gross resorption of the mandible following the use o f a home reliner for a complete lower denture. This involved not only the residual ridge but also the major part of the basal bone so that only a very thin strip of cortical bone remained. *Present address: Clinical Assistant Professor, Removable Ptosthodontics, University of Missouri-Kansas City, School of Dentistry, Kansas City, Missouri.
74
Journal of Dentistry, Vol. 5/No. I
Fig. I. Fitting surface of the lower denture.
Fig. 2. Labiobuccal surface of the lower denture.
Fig. 3. Denture-bearing area of the mandible which
Fig. 4. Panoramic X-ray showing minimal amount of bone remaining in the mandible. Note the inferior dental canal openings on the anterior border of the mandibular remus.
has a deep depression instead of the alveolar ridge.
CASE REPORT A man aged 79 years presented at the Prosthetic Clinic of the Royal Dental Hospital School o f London with the request that he be supplied with a new set of dentures. The patient had been edentulous for 20 years and had had two sets of dentures in this period. He proudly announced that he had bought his present set o f dentures 10 years ago second-hand, and when he found that the lower denture was unsatisfactory he carried out extensive alterations himself. He used as a relining material plastic from a plastic flower pot. This he cut into small pieces and allowed it to soften in hot water. The pieces of soft plastic were then applied to the impression surface and polished surfaces of the lower denture and smoothed down with a f'mger. The upper and lower dentures were inserted into the mouth while the plastic was soft and pliable and the teeth were brought into occlusion. When the patient felt that the plastic had moulded itself to the mouth the dentures were removed and the procedure repeated until he was satisfied with the fit of the lower denture. After the plastic had hardened the dentures were inserted and used continually. At the present examination it was noted that the lower base was grossly underextended (Fig. 1) and that, with the exception of the teeth, the whole lower denture appeared to be made of a dark red-brown material and the surfaces were very rough (Fig. 2). The vertical dimension of occlusion and centric relation were acceptable. It is probable that this situation had arisen by the mandible undergoing resorption to compensate for what was a greatly increased vertical relation o f occlusion. The maxillary ridge was well-shaped and covered with healthy mucosa. In place o f the mandibular ridge, however, there was a trough-like depression in the mandible where the base of the lower denture fitted (F/g. 3). The mucosa covering the mand~le was thin and generally inflamed, but no ulcer or hyperplasia was evident and the patient did not complain o f soreness or discomfort. A panoramic X-ray was taken to discover the amount of residual bone (F/g. 4). From this it was evident that on the right side a minimal amount of bone o f 1 mm thickness was present. On the left side the
Panoussopoulous: Resorption of the mandible
75
Fig. 5. Right lateral oblique X-ray verifying the extreme degree of resorption.
thickness of residual bone was 2 mm. Right and left lateral oblique and lateral skull X-rays were taken to verify this (Fig. 5). The inferior dental canal was seen to open on the anterior border of the ramus and the inferior dental' nerve emerged from this opening and could be felt to be lying on the surface of the mandible under the mucosa. It was thought that owing to the extreme degree of resorption there was a strong likelihood of a pathological fracture of the mandible, but bone grafting was contraindicated because of the patient's age and general physical condition. It was therefore decided to construct new dentures which were as fully extended as possible so as to spread the forces of mastication over a wider area of bone, and to reduce the occlusal area and thus the transmitted masticatory forces (Beam, 1972). While the new dentures were under construction the patient was advised not to use his old lower denture. Following minor adjustments du]ing the first 2 weeks after insertion of the new dentures the patient reported that he was completely comfortable. The patient will be reviewed every 6 months and further X-rays will be taken at yearly intervals to check for changes in the mandible. COMMENT Frail mandibles occur more frequently in later life when surgical intervention is contraindicated. However, in spite of extremely poor support available, correctly designed dentures which distribute and transmit the forces of mastication optimally are well tolerated. Acknowledgement I am grateful to the Photographic Department of the Royal Dental Hospital of London for the illustrations.
REFERENCES Atwood D. A. (19"71) Reduction of residual ridges: a major oral disease entity. Y. Prosthet. Dent. 26, 2 6 6 - 2 7 9 . Atwood D. A. and Coy W. A. (1971) Clinical, cephalometric, and densitometric study of reduction of residual ridges. J. Prosthet. Dent. 26, 2 8 0 - 2 9 5 . Beam E. M. (1972) Some masticatory force patterns produced by full denture wearers. Dent. Pract. Dent. Rec. 22, 3 4 2 - 3 4 6 . Means C. R. (1964) The home reliner materials: the significance of the problem. ?. Prosthet. Dent. 14, 1 0 8 6 - 1 0 9 0 . Terry J. M., Lutes M. and EUinger C. (1967) Do-it-yourself denture reline materials: a contourator study. J. Prosthet. Dent. 18, 3 1 - 3 8 .
Extreme resorption of the mandible: a case report P. Panoussopoulous, DOS* Royal Dental Hospital o f London
ABSTRACT
A patient who used an unusual material to make his lower denture more comfortable is reported. The serious consequences that arose, together with evidence from the literature, suggest that patients should be warned that they should at no time interfere with their dentures but return to their dentist for advice and treatment. INTRODUCTION
Alveolar bone is formed during the development and eruption of the teeth. After their loss it slowly disappears. The speed and degree of this process vary considerably from one individual to another, and the occurrence of almost completely resorbed mandibular alveolar bone is not uncommon. The factors that influence the pattern, rate and degree of this process are not completely understood, but it has been suggested (Atwood, 1971; Atwood and Coy, 1971) that the following are important: (a) the amount, density and state of health of the alveolar bone as well as metabolic factors, (b) the preservation of the buccal plate of cortical bone at the t~nne of extractions, (c) the functional load that is transmitted to the bone and (d) details of design o f the dentures which are used. Considerable importance has been attached to the last factor. It has been established that gross errors in the construction of dentures and specifically an increase in the occlusal vertical dimension (Terry et al., 1967) do produce bone resorption, and the larger the error, the greater is the resorption that may occur, particularly if the patient continues to use the dentures despite the initial discomfort which he experiences. It is not uncommon for patients who have uncomfortable dentures and who do not wish to return to their dentist for adjustment to tamper with their dentures themselves. They usually resort to the various home reliner materials which are commercially available. When a home reliner material is applied to the dentures and placed in the mouth, there is a noticeable increase in the vertical relation of occlusion and also changes in the relative position of the denture bases to the supporting bone (Means, 1964). In addition to the increased vertical dimension, an error in centric jaw relation will, in all likelihood, be introduced. The most common sequela of this self-treatment is bone resorption. The following case report is an example of gross resorption of the mandible following the use o f a home reliner for a complete lower denture. This involved not only the residual ridge but also the major part of the basal bone so that only a very thin strip of cortical bone remained. *Present address: Clinical Assistant Professor, Removable Ptosthodontics, University of Missouri-Kansas City, School of Dentistry, Kansas City, Missouri.
74
Journal of Dentistry, Vol. 5/No. I
Fig. I. Fitting surface of the lower denture.
Fig. 2. Labiobuccal surface of the lower denture.
Fig. 3. Denture-bearing area of the mandible which
Fig. 4. Panoramic X-ray showing minimal amount of bone remaining in the mandible. Note the inferior dental canal openings on the anterior border of the mandibular remus.
has a deep depression instead of the alveolar ridge.
CASE REPORT A man aged 79 years presented at the Prosthetic Clinic of the Royal Dental Hospital School o f London with the request that he be supplied with a new set of dentures. The patient had been edentulous for 20 years and had had two sets of dentures in this period. He proudly announced that he had bought his present set o f dentures 10 years ago second-hand, and when he found that the lower denture was unsatisfactory he carried out extensive alterations himself. He used as a relining material plastic from a plastic flower pot. This he cut into small pieces and allowed it to soften in hot water. The pieces of soft plastic were then applied to the impression surface and polished surfaces of the lower denture and smoothed down with a f'mger. The upper and lower dentures were inserted into the mouth while the plastic was soft and pliable and the teeth were brought into occlusion. When the patient felt that the plastic had moulded itself to the mouth the dentures were removed and the procedure repeated until he was satisfied with the fit of the lower denture. After the plastic had hardened the dentures were inserted and used continually. At the present examination it was noted that the lower base was grossly underextended (Fig. 1) and that, with the exception of the teeth, the whole lower denture appeared to be made of a dark red-brown material and the surfaces were very rough (Fig. 2). The vertical dimension of occlusion and centric relation were acceptable. It is probable that this situation had arisen by the mandible undergoing resorption to compensate for what was a greatly increased vertical relation o f occlusion. The maxillary ridge was well-shaped and covered with healthy mucosa. In place o f the mandibular ridge, however, there was a trough-like depression in the mandible where the base of the lower denture fitted (F/g. 3). The mucosa covering the mand~le was thin and generally inflamed, but no ulcer or hyperplasia was evident and the patient did not complain o f soreness or discomfort. A panoramic X-ray was taken to discover the amount of residual bone (F/g. 4). From this it was evident that on the right side a minimal amount of bone o f 1 mm thickness was present. On the left side the
Panoussopoulous: Resorption of the mandible
75
Fig. 5. Right lateral oblique X-ray verifying the extreme degree of resorption.
thickness of residual bone was 2 mm. Right and left lateral oblique and lateral skull X-rays were taken to verify this (Fig. 5). The inferior dental canal was seen to open on the anterior border of the ramus and the inferior dental' nerve emerged from this opening and could be felt to be lying on the surface of the mandible under the mucosa. It was thought that owing to the extreme degree of resorption there was a strong likelihood of a pathological fracture of the mandible, but bone grafting was contraindicated because of the patient's age and general physical condition. It was therefore decided to construct new dentures which were as fully extended as possible so as to spread the forces of mastication over a wider area of bone, and to reduce the occlusal area and thus the transmitted masticatory forces (Beam, 1972). While the new dentures were under construction the patient was advised not to use his old lower denture. Following minor adjustments du]ing the first 2 weeks after insertion of the new dentures the patient reported that he was completely comfortable. The patient will be reviewed every 6 months and further X-rays will be taken at yearly intervals to check for changes in the mandible. COMMENT Frail mandibles occur more frequently in later life when surgical intervention is contraindicated. However, in spite of extremely poor support available, correctly designed dentures which distribute and transmit the forces of mastication optimally are well tolerated. Acknowledgement I am grateful to the Photographic Department of the Royal Dental Hospital of London for the illustrations.
REFERENCES Atwood D. A. (19"71) Reduction of residual ridges: a major oral disease entity. Y. Prosthet. Dent. 26, 2 6 6 - 2 7 9 . Atwood D. A. and Coy W. A. (1971) Clinical, cephalometric, and densitometric study of reduction of residual ridges. J. Prosthet. Dent. 26, 2 8 0 - 2 9 5 . Beam E. M. (1972) Some masticatory force patterns produced by full denture wearers. Dent. Pract. Dent. Rec. 22, 3 4 2 - 3 4 6 . Means C. R. (1964) The home reliner materials: the significance of the problem. ?. Prosthet. Dent. 14, 1 0 8 6 - 1 0 9 0 . Terry J. M., Lutes M. and EUinger C. (1967) Do-it-yourself denture reline materials: a contourator study. J. Prosthet. Dent. 18, 3 1 - 3 8 .