Abnormal Occlusion Research Articles

0317 不正咬合の頭蓋・脊柱筋骨格系に及ぼす内力バランスの最適化計算(OS33:デンタル・バイオメカニクス)

0317 不正咬合の頭蓋・脊柱筋骨格系に及ぼす内力バランスの最適化計算(OS33:デンタル・バイオメカニクス)

713 脊柱系有限要素はりモデルを用いた不正咬合による脊柱変形挙動の解析(GS-2 骨形成(2))

713 脊柱系有限要素はりモデルを用いた不正咬合による脊柱変形挙動の解析(GS-2 骨形成(2))

Root resorption of Primary Teeth Without Permanent Successors

Root resorption of primary teeth usually occurs as the succeeding permanent teeth erupt, which induces differentiation of the hemopoietic cells into osteoclasts. Their root resorption pattern reflects the eruption path of the succeeding permanent teeth, and eventually the primary teeth shed as their succeeding permanent teeth erupt. Even when a permanent tooth germ is congenitally missing, root resorption of the corresponding primary tooth may still occur due to various factors, such as inflammation, traumatic occlusal force, and weakness of periodontium etc. Such congenital missing of permanent teeth is a commonly observed phenomenon in human be ing, and it often accompanies delayed retention of primary teeth. The etiologic factors for congenital missing in elude not only systemic diseases, but also local factors and human evolution process. In the radiographs of the cases in this report, the primary teeth without succeeding permanent teeth show pathologic root resorption. Root resorption progressed about 1/2~3/4 of the roots, and the surfaces of the resorption area were irregular. Considering high susceptibility of the periodontal ligament of primary teeth to root resorption, pathologic root resorption of primary teeth with delayed retention can be explained by the increased masticatory muscle force and abnormal occlusion developed during the mixed dentition. When the primary teeth without succeeding permanent teeth are lost, decision for space maintenance is required and long-term treatment plan for further prosthetic or orthodontic treatment should be establsihed.

Transcervical Approach for Resection of Lateral Skull Base Tumors

ObjectivesConventional approaches for removal of lateral skull base tumors, including transmandibular, infratemporal fossa, preauricular transzygmatic subtemporal approaches, are major invasive procedures that often sacrifice hearing and cause abnormal occlusion and cosmetic defects. Reports of the transcervical approach for resection of skull base tumors are rare, although it was described for resection of clival chordomas in as early as 1966. The purpose of this study is to review our experiences in management of lateral skull base tumors using the transcervical approach. Study DesignRetrospective chart review. MethodsSix lateral skull base tumor cases treated with transcervical approach procedures were reviewed, including the medical records. Results There were 4 males and 2 females. Age ranged from 12 through 52 years. Histopathological diagnoses included malignant schwannoma(n = 1), malignant carotid body tumor(n = 1), heamangioma(n=1), schwannoma (n=2) and pleomorphic adenoma (n=1). Transcervical techniques were used in all cases with the use of microscope in the lateral skull base area. Complete tumor removal was achieved in all cases. Postoperative radiotherapy was implemented in 1 case of malignant schwannoma and 1 case of malignant carotid body tumor. Jugular foramen syndrome occurred as a surgical complication in 1 case of malignant Schwannoma of the vagus nerve. There was no tumor recurrence during the 10 - 42 month follow-up period. ConclusionCompared with conventional approaches, the transcervical approach provides a easy, safe, minimal invasive and effective procedure for removal of selected lateral skull base tumors.

Traumatic Unilateral Temporomandibular Joint Dislocation Overlooked for More Than Two Decades

Forward dislocation of the temporomandibular joint commonly can be easily diagnosed and successfully reduced by manual repositioning. In this report, we discuss a rare case of prolonged temporomandibular dislocation that had persisted for more than 20 years because the otolaryngologist and dentist had missed the dislocation. This patient underwent open reduction and mandibular joint plasty with preoperative orthodontic therapy. It is possible that strong pain and mouth-closing disability may gradually remit and only deviated mandibular prognathism like malocclusion may persist. Therefore, abnormal occlusion warrants careful attention to temporomandibular joint dislocation.

Occlusal tooth wear in female F344/N rats with aging

Objectives This study was conducted to ascertain whether laboratory rats are an adequate animal model for aging oral cavity research, especially on occlusal tooth wear (OTW), which progresses with aging and causes abnormal occlusions. Mastication has been reported to relate to cognition in the elderly. Thus, it is important to care for the oral cavity, especially in the frail elderly, for the maintenance of all-round quality of life. Adequate and appropriate animal models are essential for basic and clinical research on the oral cavity. Methods Dried maxilla and mandible specimens from 98 young, aging or aged female F344/N rats were used. Results The levels of OTW of all molars were monitored with aging. The molar tooth began to wear at 1-month old (M) and progressed rapidly till 12 M. Subsequently, OTW progressed slowly till 30 M, and then rapidly again after 35 M. Conclusions This study showed that progress of OTW is well correlated with the entire life span of the rat, and suggested that the rat aged over 12 M would be an adequate animal model for research on OTW in middle-aged and elderly people.

Rehabilitation of an irradiated mandible after mandibular resection using implant/tooth-supported fixed prosthesis: a clinical report

Patients undergoing mandibular resection often have facial asymmetry and cosmetic disfigurement, which include a retruded, deviated mandible, motor and sensory deficiencies, and abnormal intermaxillary relationship and occlusion. An implant-supported fixed prosthesis can be an optimal treatment modality. However, there is a problem in creating a repeatable, stable plane of occlusion and maxillomandibular relationship. This report describes the treatment sequence and considerations to rehabilitate a patient undergoing mandibular resection and radiotherapy with an implant-supported fixed prosthesis.

外科的矯正治療前後における前歯部開こう症例の口唇，頬，舌圧の変化

Many anterior openbite cases show the abnormal functions of perioral soft tissues, and these can cause abnormal occlusion and relapse after surgery.The purpose of this study was to investigate the role of perioral soft tissues in the construction of occlusion and dental arches.Female adult Class M anterior open bite cases that had received orthognathic surgery (surgery group), and female adults with normal occlusion, were selected for this study. Materials of the surgery group were corrected at the period of pre-orthognathic surgery (pre-surgery), six months after debonding (short span), and later (middle span).Soft tissuepressures were measured with subminiature pressure sensors at 8 points on teeth and the hard palate. Tongue size, the length and width of the lower dental arch and the lower basal arch, were also measured.The results obtained were as follows. 1) The pressures of the pre-surgery group were lower than those of the middle span group. In the short span group, soft tissue pressures increased at thefrontal area, and decreased at the posterior area. 2) Thepressures of the normalocclusion were higher than the pre-surgery group, and the short span group was equal to or lower than the middle span group. 3) Contact ratios of the short spangroup were higher than those of the pre-surgery group. But, in the middle span group, contact ratios decreased at the frontal area and increased at the posterior area. Otherwise, the contact ratio of the normal group was higher than that ofthe pre-surgery group, and equal to that of middle span group. 4) No differenceswere found regarding measurements of the tongue and the dental arches among the groups. But the length of the tongue at normal occlusion was longer than in the pre-surgery group. The width of the tongue in the short span group was greater than that of the normal occlusion.These results demonstrate that orthognathic surgery would change the pressures and contact ratio of the soft tissues. And it suggests that perioral soft tissues might be adapted functionally to new environments following surgical treatment.

Porous Ceramic Granules of Hydroxyapatite

A ceramic material with a structure featuring narrow intragranular and large intergranular communicating pores with a porosity of 65 vol.% has been developed. The ceramic can be used in surgery for healing bone tissue, for accretion of the alveolar bone, for correction of the abnormal occlusion, and as the vehicle for targeted drug delivery. The large communicating pores facilitate intergrowth of the bone tissue and provide communication between the implant and the surrounding tissues, whereas the narrow pores promote the proliferation of osteogenic cells or serve as the matrix for drug delivery.

Relationship between pattern of intracranial artery abnormalities on transcranial doppler and Oxfordshire Community Stroke Project clinical classification of ischemic stroke.

The Oxfordshire Community Stroke Project (OCSP) devised a simple classification for acute stroke based on clinical features only, which is of value in predicting prognosis. We investigated whether the pattern of intracranial vascular abnormalities is related to the clinical syndrome. Patients with acute ischemic stroke were classified by a stroke physician as having total or partial anterior circulation infarct (TACI or PACI, respectively), lacunar infarct (LACI), or posterior circulation infarct (POCI). Color-coded power transcranial Doppler was done whenever possible. Intracranial arterial velocities were compared in the 4 subtypes of ischemic stroke after adjustment for age and time to transcranial Doppler. Middle cerebral artery velocity was abnormal (hyperemia, reduced velocity, occlusion, or focal stenosis) in 38 of 69 TACIs (55%), 50 of 171 PACIs (29%), and 20 of 236 LACIs or POCIs (8%) (P<0.001). Velocity in the A1 segment of the anterior cerebral artery was reversed in 12 of 69 TACIs (17%), 20 of 171 PACIs (12%), and 8 of 236 LACIs or POCIs (3%) (P<0.001). Basilar artery velocity was abnormal in 8 of 121 POCIs (7%) compared with 5 of 355 (1%) of the other subtypes (P=0.005). Vertebral artery velocity was abnormal (reduced velocity, occlusion, stenosis) in 20 of 121 POCIs (17%) compared with 20 of 355 others (6%) (P=0.01). Intracranial arterial abnormalities were related to OCSP clinical subtype. Therefore, it is possible to stratify patients according to OCSP classification in trials of new treatments in which treatment effectiveness may depend on the underlying pattern of arterial pathology and before any arterial imaging is available.

Effects of Malocclusion on Physical Growth and Development

In this paper, the relationship between occlusion and physical function and physique of female students was examined. The abnormal occlusion group was inferior to normal occlusion group in some indexes of physical function, above all, in grip strength and lean body mass significantly (p<0.10). In physique, anterior cross-bite group was inferior in body weight, skinfold thickness, arm girth and thigh girth.

Screening for von Willebrand Disease With a New Analyzer Using High Shear Stress: A Study of 60 Cases

AbstractWe have evaluated the performance of a new analyzer using high shear stress, the PFA-100 (Platelet Function Analyzer, Dade International, Massy, France), for screening of patients with von Willebrand disease (vWD). Whole citrated blood is aspirated through a capillary to the central aperture of a membrane coated with collagen and with a platelet agonist (either epinephrine or adenosine diphosphate [ADP]). The time required to obtain occlusion of the aperture by a platelet plug is defined as the closure time (CT). We studied 60 patients with different types of vWD and 96 normal subjects. Fourteen subjects with hemophilia and 15 patients with a platelet disorder were also analyzed. When omitting results from two patients with type 2N, the 58 other patients with type 1, type 2A, type 2B, type 3, or acquired vWD all exhibited an abnormal occlusion with collagen-ADP (sensitivity, 100%) and 56 of 58 had an abnormal CT with collagen-epinephrine (sensitivity, 96.5%). Only two patients with mild type 1 were not detected with collagen-epinephrine. In comparison, the bleeding time (BT) was normal in 20 patients: 17 with type 1, two with type 2A, and one with acquired vWD (sensitivity, 65.5%). The specificity of the PFA-100 was over 95% with both types of cartridges. Thus, the analyzer is well adapted to routine testing, as it has the advantages of simplicity and ease of execution, and demonstrates a high sensitivity, clearly superior to that of BT, for the screening of patients with vWD.

Prospective Randomized Trial of a Metallic Intravascular Stent in Hemodialysis Graft Maintenance

To evaluate percutaneous transluminal angioplasty (PTA) alone versus PTA and flexible self-expanding stent placement for the management of hemodialysis access graft stenoses. Thirty-seven grafts in 34 patients were evaluated for abnormal intradialytic parameters (n = 27) or occlusion (n = 10). Angiography identified stenoses (mean, 69%; range, 50%-95%) at or within 3 cm of the vein-graft junction (70%) or in the peripheral outflow vein (30%) that had recurred within a 6-month period after previous PTA. They were randomized to PTA alone (n = 20) or PTA with Wallstent (n = 17). Additional lesions were treated by PTA alone, and a mean of 1.4 (range, 1-3) lesions were treated per patient. Significant differences existed in the mean number of previous accesses (1.8 and 0.8 in the PTA and stent groups, respectively) and in the mean number of previous interventions in the current access (1.8 and 2.9, respectively). End points were subsequent radiologic or surgical intervention, transplantation, and death. Technical success was 100% (mean residual stenosis, 12%; range, 0%-30%). The primary patency of 128 days and secondary patency of 431 days were similar for both groups. Secondary patency required a mean of 1.8 and 1.6 additional interventions for the PTA and stent groups, respectively. The adjunctive stent placement increased the cost of the procedure by 90%. Despite significant added costs, there was no advantage to stent placement for recurrent peripheral hemodialysis graft stenoses that were already adequately dilated with balloon angioplasty.

Ｏｓｓｅｏｉｎｔｅｇｒａｔｅｄ ｉｍｐｌａｎｔ症例におけるそしゃく運動経路の特徴に関する臨床的観察

The purpose of this study was to investigate the characteristics of the path of chewing movement in patients with osseointegrated implants.Chewing movement was recorded and analyzed by Sirognathograph Analyzing System III. Seventy patients with osseointegrated implants and 100 subjects with natural teeth were selected for this study.The results were as follows:1. Distribution of the patterns of chewing movement1) Distribution of the patterns of chewing movement in patients with osseointegrated implants were different from those in subjects with natural teeth, but both groups had many of the same patterns of chewing movement.2) Distribution of the patterns of chewing movement in patients with osseointegrated implant of full bridges, over dentures, and partial bridges differed.2. The causes of the abnormal patterns of chewing movementAbnormal patterns of chewing movement were mainly caused by access holes in osseointegrated implant of full bridges, abnormal occlusal planes in over dentures, and abnormal natural teeth in partial bridges.

ABNORMAL OCCLUSAL CONDITIONS: A FORGOTTEN PART OF DENTISTRY

ABNORMAL OCCLUSAL CONDITIONS: A FORGOTTEN PART OF DENTISTRY

The Correlation of Cavernous Systolic Occlusion Pressure With Peak Velocity Flow Using Color Duplex Doppler Ultrasound

This prospective study involved 27 patients who underwent dynamic infusion cavernosometry/cavernosography and color duplex Doppler ultrasound. Phase III dynamic infusion cavernosometry/cavernosography determination of cavernous artery systolic occlusion pressure and color duplex Doppler measurements of peak velocity flow were performed. Four subpopulations were defined: 1) normal cavernous artery systolic occlusion pressure and peak velocity flow, 2) abnormal systolic occlusion pressure and normal peak velocity flow, 3) normal systolic occlusion pressure and abnormal peak velocity flow, and 4) abnormal systolic occlusion pressure and peak velocity flow. Peak velocity flow significantly correlated with cavernous artery systolic occlusion pressure and, using a normal value of greater than 25 cm. per second, resulted in a sensitivity and specificity of 95%. The positive predictive value of an abnormal peak velocity flow was calculated to be 95%. We conclude that peak velocity flow is an effective, reliable and noninvasive means of evaluating corporeal arterial function in an office setting.

A Case of Jaw Deformity with Various Physical Symptoms Due to Abnormal Habitual Occlusion

We treated a case of jaw deformity with pernicious biting habit and other symptoms.The patient was a 48-year-old female, who had been attempting to improve prognathism with conscious edge-to-edge occlusion. Consequently, she had some physical symptoms, that is unstable occlusion, mandibular malposition, headache and pain of the lingual margin. Analysis of the integration of electromyogram (tapping and clenching) had shown that she could bite stronger with the anterior position of the mandible than with edge-to-edge occlusion. She used a modified, inclined bite plate which guided the mandible forward. After one month, she acquired stable occlusion and lingual pain was cured. After that, 44 were extracted and anterior segmental osteotomy by modified Kole's method was performed. The integration of electromyogram was similar to controls, at three months after operation. Now, she has been followed up without symptoms for10months since operation.

The individuality of the patient and the temporomandibular joints. Part I

T h i s clinical report uses the individual case 9 eport method of clinical research. It is directed toward he-individual variations in growth of the mandibular :ondyle and the behavior and pattern of growth of the 'acial skeleton, focusing on the influences on ortholontic treatment and temporomandibular joint dys'unction. 9 Faulty intercuspation of the teeth and dental intru;ions into the freeway space are two of the many eti)logic factors that may lead to joint dysfunction and its ;equelae. lntercuspation of the teeth, which operate hrough the proprioceptive functions of the periodonium, can be a major influence on mandibular position n closure after initial contact. Faulty intercuspation can )verload a joint in various ways. Dysfunction of the oints and musculature may occur before orthodontic reatment, during treatment, or anytime after treatment aas been completed. Whether related directly to treatnent or not, the orthodontist must be alert to recognize ;uch dysfunction and intervene whenever it may occur. The primary team for management and treatment ffthese conditions is the orthodontist and the restorative tentist. One or the other or both, combining their ef:'orts, can correct a majority of these problems related :o abnormal occlusal function. On some occasions, sur;ical intervention may be required to reposition the naxilla or correct other skeletal deformities, but surgical revision of the joint itself is seldom required in ldults and never in young persons. The role of the orthodontist in correcting a mal9cclusion is a complex one that requires moving teeth :o a desired dental occlusion in harmony with normal :elations of the joint structures, and this is best accomalished in a growing face where relationships among ill of the components are in a continual state of flux. rhe ultimate goal is optimal intercuspation of the teeth tnd normal temporomandibular joint (TMJ) function

Early orthodontic treatment of the deciduous dentition. The therapeutic potentials and indications

The purpose of orthodontic treatment of the deciduous dentition is to prevent the skeletal manifestation of anomalies. Anterior open bites, abnormal posterior occlusions, lateral cross-bites and negative (reverse) overjets, may be preserved in the permanent dentition. Early recognition of the anomalies and their aetiology makes it possible, by eliminating bad habits and through the use of simple appliances, to normalise occlusion and ensure physiological development of the permanent dentition.

そしゃく運動の終末位（中心こう合位）に関する臨床的研究 第１報 こう頭かん合位との比較

The terminal position of mastication (centricocclusion: CO) has been reported to coincide with the intercuspal position (ICP), which is defined as the mandibular position where the maximum intercuspation occurs. However, the relationship between the ICP and the CO still remains unclear.The purpose of this study is to investigate the relationship between the ICP and the CO.Recording and analysis of the three-dimensional relationship between the ICP and the CO were performed in fourty subjects with normal occlusion, fifty subjects with abnormal occlusion, and sixty subjects with craniomandibular disorders by using the Sirognathograph Analyzing System.As a result, the non-coincidence of the ICP and the CO was characteristically observed in subjects with abnormal occlusion and craniomandibular disorders.From the results obtained, it is suggested that the terminal position of mastication does not always coincide with the ICP.