Peri-implant diseases are caused by plaque. Peri-implant diseases are classified into different forms of peri-implant mucositis and peri-implantitis. Non-surgical therapy could be effective in the treatment of peri-implant mucositis, but in peri-implantitis non-surgical therapy was not found to be effective. Thus, a surgical intervention is often needed. As of yet, the most effective intervention for treatment of peri-implantitis has not been identified, and there is no validated treatment protocol available. As surgical treatment may not always resolve a lesion, prevention of peri-implantitis is the best form of treatment. Because poor oral hygiene, cigarette smoking and a history of periodontitis are risk indicators for peri-implantitis, we should modify these factors before the start of implant treatment. Moreover, for long-term implant success, maintenance at regular intervals and patientʼs self-care are essential.

On the one hand a suspicion of the traumatic force damaging the periodontal tissue is often raised, as though it were apparent; on the other hand, the international consensus on the cause of periodontal disease treats the occlusal trauma only as a “modifier". This consensus, howsoever, does not match our clinical intuition and experience. This misfit is due to the fact that the current consensus on the cause of periodontal disease has leaned heavily on findings from the animal testing 40 years ago when research on pathophysiology of periodontal disease, periodontal ligament and dental cement was scarce. Hence, even todayʼs definition of occlusal trauma has not definite place within the classification of periodontal disease. This review article summarizes the research on tooth mobility, periodontal ligament, and dental cement carried out up until 2011 by Kyushu dental university; the research pointed out that the course of development of premature contacts can be classified into 5 different categories. In addition, a functional recovery of periodontal ligament by basic treatment leads to improvement of bite force as well as an increase in cerebral blood flow. This research complements the current concept of the occlusal trauma.

Objective: In the daily clinical dentistry, it is very important to understand the classification of Lytle & Skurow in restorative dentistry and properly apply it to the patients. I would like to reconsider each step through a case of Class III in the said classification, for which full mouth reconstruction seemed necessary. Method: With patient's consent and based on basic dental information I picked out problems. After more detailed examination and assessment, I explained a treatment plan to a patient and decided the treatment policy; then I informed the flow of full mouth reconstruction to the patient. Result: The patient was satisfied esthetically and functionally. From the dentistʼs point of view, no biological and structural problems were apparent. Conclusion: It is very important for a dentist and a patient to have shared understanding of potential risk factors, which cannot be removed (e.g., bad habitude and excessive bite force). It is confirmed that careful step-wise procedures facilitate occlusal reconstruction with long-term stability.

A 58-year-old patient first visited the clinic with chief complaints of esthetic problems including maxillary protrusion and mobility of posterior teeth. Occlusal reconstruction was conducted by the combination of implant, orthodontic, and prosthodontic treatment. The patient presented with moderate to severe periodontal disease; considering patientʼs age, teeth with poor prognosis were strategically extracted for the purpose of esthetic recovery and functional restoration. This is to report the course of treatment and four-year follow-up.

For stability of the denture, controlling the occlusal force is essential. In certain cases such as mandibular protrusion, with normal arrangement of artificial teeth the denture is prone to overturn and often causes pain in the mucosa under the denture base and also other troubles including denture fracture. As deviation of mandibular position due to chewing habits and remaining teeth could root instability of denture in the long term, for the present case the artificial teeth were so arranged to resolve mandibular deviation at the time of occlusion. Recovery of masticatory function was confirmed by measurements of masticatory ability before and after the relevant intervention.

This report is to explain the use of implant overdenture (IOD), which resulted in successful prevention of combination syndrome including flabby gum. Recently, clinical use of IOD for stabilization of complete denture or free-end partial saddled dentures are frequently reported. However, IOD, a remedy for improving quality of life of edentulous patients, has only few long-term observation reports, so its clinical outcomes are not well-known yet. This report of ours it about the case of a patient with the maxillary complete denture and the mandibular free-end saddled denture adjusted to three remaining teeth. For the treatment, 4 implants were placed with support of magnetic attachment for mandibular dentureʼs stability. The patient also has flabby gum symptoms at maxillary anterior region. We utilized IOD for minimization the depression of the mandibular partial denture and for rectification of stabbing of mandibular anterior teeth to the maxillary anterior gum. As the result, five years and seven months of avoidance of combination syndrome was achieved.

Drug-induced gingival hyperplasia is a side effect symptom caused by anticonvulsant, antihypertensive or immunosuppressant. Many clinical reports suggest that such symptoms are controllable with appropriate oral hygiene instruction and periodontal treatment as gingival hyperplasia is usually not caused by medication alone, but caused or exacerbated by gingivitis due to poor oral hygiene. Presented here is a case of a 53-year-old male patient with chief complaints of tooth mobility of lower anterior teeth and right-upper molars along with gingival bleeding. At the initial visit, he was diagnosed as generalized moderate-to-severe chronic periodontitis and gingival hyperplasia in the lower anterior region. History taking revealed systemic conditions he suffered including after-effect of cerebral hemorrhage, peripheral nerve disorder and high blood pressure. For these, the patient was prescribed several medications including calcium antagonists whose known side effects include gingiva hypertrophy. As a result of basic periodontal treatment and oral hygiene instruction in consideration for the systemic diseases, the patientʼs periodontal environment has improved and the post-treatment course uneventful.

In occlusal reconstruction determining the occlusal plane is one of the most important steps. The cant of occlusal plane affects the posterior teeth in relation with condylar path and anterior guidance upon mandibular movement. The cant of the occlusal plane also affects the esthetic smile line. In determining the occlusal plane for edentulous jaws it is common to set the occlusal plane on the wax bite rim according to the anatomical landmark. In case of dentulous jaws, there is a method to determine the occlusal plane according to Broadrick occlusal plane analysis. In this paper proposed is a method to determine the occlusal plane of mandible using self-made "Occlusal Plane Analyzer" (OPA). With this method it becomes possible to set the occlusal plane accurately and simply against the referential plane on the articulator with face-bow registration, and the position of the occlusal plane can be recorded. This OPA can be used for the examination of almost all types of dental casts, because it has a five-axes adjustable plane.

This case report describes the treatment of a woman who lost mandibular posterior teeth. The bilateral alveolar ridges showed severe tissue defects. She complained of the discomfort of a partial denture connected by a lingual bar and wished for fixed prostheses. However, the height of the alveolar bone was insufficient to place standard-length implants. In addition, she rejected bone augmentation and the usage of biomaterials. Therefore, short implants were placed in both sides of atrophic alveolar ridges without tissue augmentation. Conventional crowns were placed on the right side on three short implants, and a unilateral distal-extension partial implantretained partial denture (IRPD) using magnetic attachment was placed on the left side using the two available short implants. The patient was satisfied with the outcome of this treatment for 12 years even though a clasp was added to the removable partial denture at 11 years due to the wear of the magnet keepers. The combination of short implants and an IRPD using magnetic attachment is effective for patients with a severely atrophic posterior mandibular from the aspect of minimal intervention.

The position of the mandible is often discussed within the context of contact of teeth in the opposing dental arches, but the upper and lower teeth normally do not touch to each other except during mastication and swallowing. In other words, at the rest position of the mandible there should be some space between upper and lower teeth; in orthodontic treatment and designing prostheses, therefore, two different mandibular positions, namely, the rest position and the intercuspal position have to be taken into consideration. It is important to check and treat with sufficient attention to the tongue position and the stable relationship between upper and lower teeth. On the articulator, the contact of upper and lower teeth are examined by surface sliding, with fixed condyle; whereas, in human mastication upper and lower teeth come in contact with lateral translation of the mandible. Despite the crucial role of tongue position and movement during mastication, articulators cannot simulate such functions. Intraoral occlusal adjustment is important in occlusal treatment for dentulous jaws.