顎堤条件からみたリンガライズドオクルージョンの選択

Purpose : This study examined the functional efficacy of complete dentures with full balanced occlusion or lingualized occlusion in patients with different degrees of residual ridge resorption.Materials and Methods : To compare the residual ridge condition among the five subjects, the alveolar ridge height and supporting area under the denture were measured. Experimental upper and lower complete dentures were fabricated with interchangeable molars and were used by the study subject for two months prior to the functional analyses. To estimate denture function, electromyography (EMG), mandibular kinesiography (MKG), and pressure distribution under the denture while tapping and masticating peanuts were investigated.Results : The EMG results suggested that subjects with poor residual ridge condition may benefit from lingualized occlusion for more efficient mastication. The MKG results suggested that, in subjects with poor ridge condition, mastication tends to be unstable with a full balanced denture, but that widening of the mandibular path that destabilizes the denture is reduced with a lingualized denture. The results of pressure measurement suggested that when lingualized occlusion is provided for patients with a poor residual ridge condition, the occlusal pressure is transmitted mostly at the lingual side of the residual ridge, leading to efficient denture function.Conclusion : A sufficient lingualized occlusion effect was obtained in subjects with a poor alveolar ridge condition. The following indexes were examined as the criteria for applying lingualized occlusion. The ratio of the residual alveolar ridge must be 0.5 or less, and the area of the supporting base of the denture must be 2, 000 mm2 or less.

Tooth position in relation to the denture base foundation

PurposeA lingualized occlusion (LO) for complete dentures reduces lateral inferences and occlusal force contacts and direction; thus, LO is theorized to be more suitable for patients with compromised ridges than fully bilateral balanced articulation (FBBA). However, no studies have yet provided evidence to support LO in edentate patients with compromised alveolar ridges. The purpose of this study was to compare LO and FBBA in edentulous individuals with compromised ridges. MethodsSixty edentulous individuals were randomly allocated into groups and received dentures with either LO or FBBA. Following delivery, several denture-related satisfaction variables were measured using 100mm visual analogue scales; oral health-related quality of life (OHRQoL) was also assessed using the Oral Health Impact Profile (OHIP). Sub-group analyses of the effect of moderate and severe mandibular bone loss were also carried out. ResultsNo significant differences were detected between LO and FBBA with the primary outcome. At 6 months, participants with severely atrophied mandibles and FBBA rated their satisfaction with retention of mandibular dentures significantly lower than those with LO (median LO: 86, FBBA: 58.5, p=0.03). They also had significantly lower OHRQoL for the domain of Pain (median LO: 4, FBBA: 5, p=0.02). General satisfaction and total OHIP scores significantly improved between baseline and 6 months only for the LO subjects with severely atrophied mandibles (satisfaction: p=0.003, OHIP total score: p=0.0007). ConclusionsThe results indicate that the LO occlusal scheme with hard resin artificial teeth is more efficient for patients with severely resorbed mandibular ridges.

Background: Magnetic attachment can be used as a retentive devices in overdenture technique in prostheses. The magnets are attached with remaining root structure transfer the occlusal load to the bone through the periodontal ligament of retained roots and then prevent resorption of the alveolar ridge. Alvelar ridge plays an important role for the retention and stability of the denture as they will support the denture base. Magnetic assembly consist of magnet and coping with a keeper on the remaining tooth structure since magnetic attachment can provide support, stability and retention. Purpose: The purpose of this case report was to report magnetic attachment retained complete overdenture design and fabrication as a preserve to alveolar bone height to achieve retention and stability of the denture. Case: A 69 years old female patient, a baker and private English teacher with partial edentulous ridge came to Dental Hospital of Airlangga University asked for dentures. Clinical examination shown a complete edentulous in the upper jaw and partial edentulous in the lower jaw. The remaining teeth were 33, 34, 35, 43 and 44. 33 and 35 are chronic gangrene radix, 35 shown a slightly mobility. 34 non vital, 44 and 45 are vital with moderate resorption. Case management : All the left teeth in the lower jaw were consulted for endodontic treatment. Magnetic attachment retained complete overdenture was choosen for the lower jaw and complete denture for the upper jaw. The remaining teeth in the lower jaw kept the alveolar ridge from resorption and the magnet provided extra retention for the complete overdenture. Discussion: Overdentures supported by magnet attachment achieved greater satisfaction, gives better retention and stability for the denture. On the other side, the natural abutment teeth in overdentures preserved better proprioception and psychologically beneficial as the patient had not undergone extraction. As a conclusion, overdenture supported by magnetic attachment can be used to increase support, retention and stability especially in the lower jaw and also prevent further alveolar ridge resorption. Conclusion: Overdenture supported by magnetic attachment can be used to increase retention and the residual root also prevent further alveolar ridge resorption.

Background:Following tooth extraction, alveolar ridge resorption, particularly in the mandible, is a chronic, progressive process that can extend beyond the alveolar ridge in severe cases. Research indicates that despite its dense structure, the mandibular ridge is highly susceptible to this type of resorption. This study aimed to evaluate mandibular ridge resorption following complete denture therapy over a six-month to one-year period, assessing changes at the masticatory centre and mental foramen. Differences between patients with complete dentures and those without were examined to determine whether denture fabrication impacts ridge resorption. Materials and Methods:The study was conducted over a five-year period at the Clinic for Removable Prosthodontics, Faculty of Dentistry, in Skopje. Sixty patients (32 men and 28 women), aged 51 to 70, participated and were divided into two groups: the first received complete dentures after an initial period of post-extraction bone healing, while the second did not receive dentures during this time. Results: Results demonstrated significantly lower resorption in denture-wearing patients, with a 4.3% resorption rate at the masticatory centre and 3.1% at the mental foramen, compared to 8.5% and 6.3% in the non-denture group, respectively (p < 0.01). This difference indicates that patients with complete dentures experience notably reduced mandibular ridge resorption compared to those without dentures. Conclusion: Our findings suggest that timely, well-fitting complete denture fabrication shortly after tooth extraction plays an essential role in slowing alveolar ridge resorption and preserving ridge height, with potential implications for improved patient outcomes based on cultural, social, and economic factors.

Tooth extraction triggers alveolar ridge resorption, and when this resorption is extensive, it can complicate subsequent reconstructive procedures that use dental implants. Clinical data demonstrate that the most significant dimensional changes in the ridge occur soon after tooth extraction. Here, we sought to understand whether a correlation existed between the rate at which an extraction socket heals and the extent of alveolar ridge resorption. Maxillary molars were extracted from young and osteoporotic rodents, and quantitative micro–computed tomographic imaging, histology, and immunohistochemistry were used to simultaneously follow socket repair and alveolar ridge resorption. Extraction sockets rapidly filled with new bone via the proliferation and differentiation of Wnt-responsive osteoprogenitor cells and their progeny. At the same time that new bone was being deposited in the socket, tartrate-resistant acid phosphatase–expressing osteoclasts were resorbing the ridge. Significantly faster socket repair in young animals was associated with significantly more Wnt-responsive osteoprogenitor cells and their progeny as compared with osteoporotic animals. Delivery of WNT3A to the extraction sockets of osteoporotic animals restored the number of Wnt-responsive cells and their progeny back to levels seen in young healthy animals and accelerated socket repair in osteoporotic animals back to rates seen in the young. In cases where the extraction socket was treated with WNT3A, alveolar ridge resorption was significantly reduced. These data demonstrate a causal link between enhancing socket repair via WNT3A and preserving alveolar ridge dimensions following tooth extraction.

Extraction of teeth is followed by resorption of the residual alveolar ridge that continues throughout life resulting in loss of alveolar height and width. Of the numerous techniques that have been used to arrest post extraction alveoloar ridge resorption, the placement of a graft material inside the socket immediately after extraction has been mostly followed. Type 1 collagen is one of the commonly used graft material that prevent resorption by providing dimensional stability to the socket. Bisphosphonates are an anti-osteoclastic drug that prevent resorption by disrupting the membrane ruffling of the osteoclasts. Alendronate a bisphosphonate, is primarily used in diseases with bone loss. It has been used to reduce active bone resorption significantly without interfering with bone mineralization and quality. The need for the study is to examine the inhibitory effect of alendronate on residual ridge resorption when applied locally in combination with type I collagen on alveolar bone immediately following tooth extraction. Twenty patients with age between 30 and 65years were selected from the out patient department of The Oxford Dental College and Hospital. The patients were divided into two groups. In the first group after extraction of teeth from premolar to midline the sockets were irrigated with saline and sutured. On the left side type I collagen sponge was placed and sutured. In the other group the right side was treated the same way after extraction as in first group where as in the left side sockets type I collagen soaked in 20mg/ml of alendronate was placed and sutured. Patients were evaluated clinically for any local irritation as well as radiologically with orthopantomograph X-rays were taken immediately after the extraction, 1month after extraction and 4months after extraction to determine the amount of bone loss prevented. The statistically significant bone loss prevented by the collagen alone was 22.8% and in collagen with alendronate group was 44.38% at the end of 4months. Type I collagen soaked with alendronate when placed in the socket immediately after extraction of teeth prevents post-extraction alveolar ridge resorption.

This prospective clinical analysis reports on the use of coral granules in alveolar ridge preservation procedures in a population of young, growing patients. The sample consisted of 21 patients, 12 females and 9 males, with a mean age of 13.6 years. These 21 patients had 48 dento-alveolar defects suitable for augmentation with coral granules, and were followed clinically and radiographically for 3-7 years after augmentation. There were two areas of augmentation: 17 defects in the anterior maxilla resulted from traumatic tooth loss, and 31 defects in the posterior maxilla and mandible resulted from the extraction of ankylosed retained primary molars with no permanent succedaneous teeth. Between 1-2 ml of coral granules were implanted into the alveolar bone defects left by the extraction of teeth in both the areas. This was in order to preserve the remaining edentulous ridge from further alveolar ridge resorption. The goal of the procedure was to preserve the alveolus so that in the future, a dental implant could be placed to replace the missing tooth, after jaw growth had stopped, without the need for a bone graft. The coral granules appeared to be totally replaced by the host bone on follow-up clinical and radiographic examinations. The two areas of the jaws behaved quite differently. In the anterior maxilla, where tooth loss was secondary to trauma, the coral granules restored the alveolar ridges temporarily. However, over the years of follow-up in this study, the coral granules failed to provide sufficient bone to support the placement of a dental implant without using a bone graft in 14 of the 17 defects or 82.4% of sites. In the posterior maxilla and mandible, where tooth loss was due to the elective removal of ankylosed primary molars, 29 of the 31 defects or 93.5% of sites were successful as they were able to support the placement of an osseo-integrated dental implant without the use of a bone graft. The alveolar sparing technique was more successful in maintaining an alveolar ridge sufficient for the placement of a dental implant without bone grafting in the posterior maxilla and mandible, where tooth loss was secondary to the elective removal of ankylosed deciduous molars than in the anterior maxilla, where tooth loss was secondary to trauma. Coral granules seem to be more suitable in the posterior maxilla and mandible where there were ankylosed deciduous teeth and congenitally absent permanent teeth than in the traumatized anterior maxilla. In successful sites, coral granules can spare the alveolus from residual ridge atrophy or resorption, obviating the need for a bone graft. This reduces patient morbidity, as a second surgical donor site is avoided because bone graft harvesting is made unnecessary.

Based on literature data it is obvious that there is a connection between smoking and periodontal diseases. Alveolar bone loss increases with smoking. Tobacco smoking affects the proportion of subgingival bacterial flora by influencing oxidoreduction potential of dental plaque and thus making conditions for development of anaerobic bacteria. According to some researchers, smoking affects the mineral component of bone tissue. Orthopantomograms show higher level of alveolar bone loss in smokers than in nonsmokers with the same level of oral hygiene. The aim of this study was to establish if smoking affects alveolar bone loss in complete denture wearers. Our clinical investigation included 60 patients of both sexes (30 smokers and 30 nonsmokers) all complete dentures wearers. All patients met study criteria: jaw relation and smokers who smoke over 20 cigarettes per day. All subjects were interviewed, and after that orthopantomograms were made. They were used to calculate the degree of alveolar bone loss. The examined subjects were approximately of the same age. Mean age of smokers was 59.9 and nonsmokers 61.8. It was established that differences regarding resorption in men were not significant. The degree of resorption in women smokers and women non-smokers was different, but differences were not significant. It has been proven that the number of cigarettes smoked per day is very important. It is considered that the risk of oral epithelial dysplasia increases when smoking more than 20 cigarettes per day. Considering our results regarding resorption of edentulous alveolar ridge in smokers and nonsmokers, we concluded that there were no significant differences. There are opinions in literature that smoking is not an etiological factor in resorption, but there are some opinions that smoking is connected with the degree of resorption in periodontium. The analyses of resorptive changes in edentuolous smokers were done only around implants and it was estimated that smoking has more influence than other clinical risk factors. On the bases of our research we may conclude that smoking does not directly affect the degree of resorption of edentulous alveolar ridge with complete denture wearers.

Background: Denture treatment is crucial for edentulous patients to maintain a long and healthy life, as well as restore their chewing function. After complete dentures are fitted, it is not uncommon for them to become ill-fitting due to ridge resorption over time, requiring adjustments or relining procedures. Residual ridge resorption results from the combined influence of various local and systemic factors. There have been no reported cases of patients who have worn complete dentures for an extended period without experiencing significant alveolar ridge resorption. I report a case of a patient who had not visited a dentist or had any adjustments for 28 years after being fitted with complete dentures. Case presentation: The patient, a 56-year-old woman, visited the general dentistry of the Nippon Dental University Hospital in Tokyo in March 1994. The diagnosis was masticatory dysfunction caused by ill-fitting upper and lower complete dentures. The treatment plan aimed to improve oral hygiene, restore the health of the alveolar ridge, and achieve proper occlusal contact with a final prosthetic device. The upper and lower dentures were fitted in May 1994. In November 2022, her artificial tooth broke, and she visited the clinic requesting denture repair for the first time in 28 years. A medical interview revealed that the patient had never visited another dental clinic since having dentures fitted 28 years ago. Although wear of the artificial teeth was observed, when the fitting condition of the upper and lower dentures was checked using fitting test materials, it was confirmed that there were no problems with the fitting condition and that there was almost no alveolar ridge resorption. Conclusion: I report on a patient who has worn the same dentures for 28 years. Although wear of the artificial teeth was observed due to bilateral balanced occlusion, the occlusal balance was appropriately maintained. It has been found that metal-based dentures, when fabricated using proper methods, do not promote alveolar ridge resorption.

Alveolar bone undergoes volumetric changes after extraction due to physiologic bone remodeling. The amount of alveolar bone available during prosthodontic treatment can affect the esthetic outcome of the treatment and make implant placement challenging. Socket preservation techniques are advocated postextraction to maintain the bone's vertical and horizontal alveolar bone dimensions and prevent its atrophy. This review is oriented toward a clinician, describing the different materials and techniques in practice today for socket preservation. A variety of methods have been studied as a means to stop alveolar ridge resorption. While immediate implant placement was recommended as a socket preservation technique, clinical trials have not demonstrated favorable results. The main techniques favored by clinicians today involve bone grafts, bone substitutes, barrier membranes, and combinations thereof. As with periodontal defects, these materials show favorable outcomes in alveolar bone regeneration and ridge preservation. Tooth bone grafts, both autogenous and allogenous, have been recommended recently for ridge preservation as they are chemically similar to bone and can induce osteogenesis. The use of autologous platelet concentrates has yielded contradictory results in studies. Cutting-edge approaches entail using growth factors and tissue engineering concepts. While these strategies are still in the development stages, it has peerless potential in preserving and regenerating alveolar bone. Alveolar ridge resorption is an unavoidable physiological process after extraction and leads to severe bone deficiencies, affecting esthetics. These changes in alveolar ridge dimensions make implant placement difficult and affect the longevity of the implant. Clinical intervention can prevent alveolar bone resorption and preserve the ridge. Bone grafts and substitutes including concentrates remain the best choices in ride preservation. The use of growth factors and tissue engineering concepts requires further clinical trials before widespread use in clinical practice.

INTRODUCTION: The aim of the study was to observe the relationship between alveolar ridge resorption in mandible and masticatory performance based on gender in complete denture wearers. MATERIALS AND METHODS: The subjects included were those wearing complete denture between the ages of 45-69 years-old, treated at the Dental and Oral Hospital of University Sumatera Utara. Alveolar ridge resorption in mandible was analysed using the panoramic radiograph and masticatory performance was evaluated clinically using the colour-changeable chewing gum. RESULT: 40 patients were included in this study. 50% were women in which 15 women (37.5%) had mild alveolar ridge resorption whilst 5 (12.5%) had severe alveolar ridge resorption. For masticatory performance, 14 women (35%) had good masticatory performance and 6 (15%) had poor masticatory performance. For the men; 17 (42.5%) had mild alveolar ridge resorption whilst 3 (7.5%) had severe alveolar ridge resorption. For masticatory performance, 16 men (40%) had a good masticatory performance and 4 (10%) had a poor masticatory performance. There was a significant correlation between alveolar ridge resorption in mandible and masticatory performance amongst women (p=0.014). However, there was no significant correlation found between gender and alveolar ridge resorption in mandible (p=0.695), between gender and masticatory performance (p=0.716), and between alveolar ridge resorption in mandible and masticatory performance amongst men (p=0.088). CONCLUSION: The alveolar ridge resorption in mandible is associated with masticatory performance amongst women.

Background: In dental prosthetics many advances have been achieved, but the great problem is still having with us: that is the resorption of the residual alveolar ridge and managing or preventing the secondary soft tissue changes brought on by bone loss. Objective: To evaluate the rate of resorption of alveolar ridge height of maxillary anterior arch in patients treated with immediate partial denture. Materials and Methods: This observational comparative study was conducted in the Department of Prosthodontics, Bangabandhu Sheikh Mujib Medical University for the duration of one year. On the basis of inclusion criteria patients were initially included in the study. A written informed consent was obtained from every patient. Study sample divided equally into two groups, Group A and Group B. Each group consists of 15 patients. Group A patients were treated with extraction of teeth followed by immediate denture prosthesis and group B patients were treated with extraction of teeth, but not provided by any prosthesis. Data were collected on the basis of alveolar bone resorption in the period of 1 month, 3 months and 6 months of extraction on a predesigned data collection sheet. Results: Mean vertical height at one month follow up was 25.48 (±2.41) mm in group A and 23.43 (±2.85) mm in group B which was statistically significant. Mean vertical height at three month follow up was 23 (±1.33) mm in group A and 22 (±2.99) mm in group B which was statistically significant. Mean vertical height of alveolar bone at six month follow up was 22.5 (±2.71) mm in group A and 21.5 (±3.18) mm in group B which was also statistically significant. Conclusion: Patient treated with immediate partial denture following extraction of teeth shows less alveolar bone resorption than patients treated without immediate partial denture.

When tooth is extracted because of deep caries, severe periodontal disease, trauma etc., alveolar ridge resorption happen inevitably. Alveolar ridge resorption after tooth extraction makes implant placement difficult. To overcome these alveolar bone deficiencies, additional procedures such as GBR, Block bone graft, Ridge splitting or Distraction osteogenesis is needed. In case of severe horizontal bone loss (Seibert classification, Class I), implant placement is usually done with Block bone graft or GBR procedure. Unlike these two procedures, the ridge splitting converts non-contained defect to contained defect that are favorable to be healed. Also ridge splitting have advantages such as the maintenance of buccal plate and rapid healing by the strong local metabolism. In these two cases, it is ascertained that implant placement with ridge splitting procedure is effective in the severely atrophied alveolar ridge.

This study evaluated reconstruction of the alveolar ridge after molar extraction in rats with bioabsorbable bone repair scaffolds. The material was prepared from the unsaturated polyester poly(propylene glycol-co-fumaric acid) (PPF), which may be cured in situ to form a porous scaffold. The intention is to use this material either as a stand-alone bone graft substitute or as an extender to autograft harvested from mandibular reconstruction sites. The bioactivity of the graft substitute was investigated in a rat residual ridge resorption model. PPF bone repair material was injected into the defect site, where it cross-linked in situ in the presence of a hydroxyapatite (HA) filler and effervescent agents. The PPF-based material develops porosity during an in situ cure by generating carbon dioxide during the effervescent reaction of citric acid and sodium bicarbonate. The incorporation of HA promotes osteoconduction within the bone repair scaffold. In this study, bioactivity of the porous scaffold was evaluated as a function of HA particle size (micrometer-sized vs nanometer-sized particles). The maxillary or mandibular molars on the right side were extracted from 96 adult Sprague-Dawley rats. A 2-mm round bur was used to create a uniform trench defect measuring 2 mm in diameter, 2 mm in depth, and 4 mm in length at each extraction site. The defect site was (1) treated with PPF bone repair material containing nanometer-sized HA, (2) treated with PPF material containing micrometer-sized HA, (3) treated with demineralized freeze-dried bone allograft, or (4) left untreated. Rats were sacrificed at 2, 4, 7, and 12 weeks postoperative. Resorption of the residual alveolar ridge was assessed by radiographic outcomes. Bone ingrowth through the defect site was measured by histomorphometric outcomes. Mandibular and maxillary ridge heights increased for all treatments used in this study. There were no clinical indications that addition of either of the PPF bone repair materials retarded hard- or soft-tissue healing of the extraction sites. Although not statistically significant, the mandibular defects treated with PPF containing nanometer-sized HA healed at a faster rate as determined by ridge height and new bone formation measurements when compared with the other treatments. These findings suggest the feasibility of using PPF bone graft substitutes for oral-maxillofacial applications.