Three-dimensional Finite Element Analysis of the Effect of Alveolar Cleft Bone Graft on the Maxillofacial Biomechanical Stabilities of Unilateral Complete Cleft Lip and Palate

Background: The objective was to clarify the effect of alveolar cleft bone graft on maxillofacial biomechanical stabilities, the key areas when bone grafting and in which should be supplemented with bone graft once bone resorption occurred in UCCLP (Unilateral Complete Cleft Lip and Palate).Methods: Maxillofacial CAD (Computer Aided Design) models of non-bone graft and full maxilla cleft, full alveolar cleft bone graft, bone graft in other sites of the alveolar cleft were acquired by processing the UCCLP maxillofacial CT data in three-dimensional modeling softwares. The maxillofacial bone equivalent (EQV) stresses and bone suture EQV strains under occlusal states were obtained in the finite element analysis software.Results: Under corresponding occlusal states, the EQV stresses of maxilla, pterygoid process of sphenoid bone on the corresponding side and anterior alveolar arch on the non-cleft side were higher than other maxillofacial bones, the EQV strains of nasomaxillary, zygomaticomaxillary and pterygomaxillary suture on the corresponding side were higher than other maxillofacial bone sutures. The mean EQV strains of nasal raphe, the maximum EQV stresses of posterior alveolar arch on the non-cleft side, the mean and maximum EQV strains of nasomaxillary suture on the non-cleft side in full alveolar cleft bone graft model were all significantly lower than those in non-bone graft model. The mean EQV stresses of bilateral anterior alveolar arches, the maximum EQV stresses of maxilla and its alveolar arch on the cleft side in the model with bone graft in lower 1/3 of the alveolar cleft were significantly higher than those in full alveolar cleft bone graft model.Conclusions: For UCCLP, bilateral maxillae, pterygoid processes of sphenoid bones and nasomaxillary, zygomaticomaxillary, pterygomaxillary sutures, anterior alveolar arch on the non-cleft side are the main occlusal load bearing structures before and after alveolar cleft bone graft. Alveolar cleft bone graft mainly affects biomechanical stabilities of nasal raphe and posterior alveolar arch, nasomaxillary suture on the non-cleft side. The areas near nasal floor and in the middle of the alveolar cleft are the key sites when bone grafting, and should be supplemented with bone graft when the bone resorbed in these areas.

Successful Management of Cleft Lip and Palate Malformation without Pre-Surgical Infant Orthopedics

Objective: To investigate the effect of lip closure on reduction of cleft palates when no pre-surgical infant orthopedics (PSIO) are used. Study design: Retrospective patient chart-review in our department for Cranio-Maxillofacial Surgery at the University Medical Centre Freiburg, Germany. 19 patients at the age of 5.9 ± 2.1 months with surgical treatment of uni- (UCLP), or bilateral cleft lip and palate (BCLP) without any use of PSIO were included. Results: Early soft tissue correction of the lip leads to an effective reduction of the maxillary arch without any use of PSIO. The presented conventional and digital measurements appeared to be reliable. A successful reduction of the cleft width (UCLP = 3.88 ± 2.42mm, BCLP = 7.33 ± 5.00mm), the width of the alveolar arch (1.91 ± 1.36mm) and the sagittal depth of the alveolar arch (3.07 ± 2.71 mm) could be achieved with the presented workflow. Conclusions: Cleft reduction was obtainable without PSIO when lip closure after Tennison-Randall was performed.

Alveolar arch shapes and its relation to complete denture retention

The alveolar ridge consists of denture bearing mucosa, sub-mucosa and periosteum, and residual alveolar bone. After tooth extraction, the remaining alveolar bone undergoes a remodeling process that leads to morphological reduction and alteration, which results in the change in alveolar ridge forms. However, it does not change alveolar arch shapes. This literature review aimed to analyze the relationship of alveolar arch shapes with complete denture retention. According to House (1958), alveolar arch shapes classified into three classes: Class I-square, Class II-tapering, Class III-ovoid. Those three alveolar arch shapes have a difference in the denture bearing area, with the largest denture bearing site on Class I-Square alveolar arch shape. Some factors that influence complete denture retention are adhesion, cohesion, interfacial force, oral and facial musculature, atmospheric pressure, undercut, rotational insertion path, parallel walls, and gravity. The alveolar arch shapes can affect retention regarding the size of the denture bearing area.The alveolar arch forms with a wider denture bearing area provide more considerable surface contact between the denture and mucous membranes. The forces resulting from those factors of retention might produce more excellent complete denture retention. The square arch shape is the alveolar arch shape with the largest denture bearing area. Hence, the square arch shape is believed to have the best complete denture retention.KEYWORDS: arch shape; retention; complete denture; denture bearing area

A Study of Anatomical Shape of arch projected by Alveolar Process of Maxillary and Mandibular Bone

Introduction: Maxilla and Mandible have an alveolar process that bears socket for root of teeth. When the teeth fall or gets extracted there is resorption of alveolar process. The teeth alignment determines the shape of alveolar process. The objectives of the study was to assess the distribution pattern of anatomical shape of arch projected by alveolar process in Maxilla and Mandible and to compare the anatomy of arch amongst the population of Aryan and Mongoloid communities. Methodology: A total number of 856 people with intact anatomy of alveolar arch were included in the study. Anatomy of alveolar arches were assessed and noted for all. The brass wire was contoured according the shape of alveolar arch of patients and the shape was observed and noted down. Result: The study result showed there was significant difference in frequency distribution of ‘U’, ’V’ and ‘Ovoid’ shape alveolar arch form in maxilla and mandible. There was significant difference in distribution of ‘U’ and ‘V’ shape alveolar arch form in maxilla and ‘U’, ‘V’ and ‘Ovoid’ shape arch form in mandible between mongoloid and Aryan communities. Conclusion: ‘U’shape alveolar arch was seen more frequently in mandible where as “V” shape and ‘Ovoid’ shape arch in maxilla. ‘U’ shape alveolar arch was more frequently seen in Mongoloid communities and ‘V’ shape was more frequently seen in Aryan communities. There was no significant difference in comparison of frequency percentage of various types of arch form between the Male and Female.

GENDER FEATURES OF THE ALVEOLAR PROCESS OF THE UPPER JAW

The individual face shape, the ratio of its proportions, the articulation capabilities of each person to a significant extent depend on the characteristics of occlusion and occlusion, in turn, are determined by the size, shape and ratio of dental, alveolar and basal arches. Two of them - alveolar and basal - pass at the corresponding levels of the alveolar areas of the jaws, which means that it is almost impossible to correct them, therefore they play the role of landmarks for setting the dental arch during dental prosthetics. A full-fledged aesthetic and functional restoration of the maxillofacial region after prosthetics largely depends on the dentist taking into account the individual morphological characteristics of the jaws, their cellular areas and specifically the morphometric parameters of the collar and basal arches. In order to determine the possible variants of the shape of the alveolar and basal arches of the upper jaw and the patterns of their ratio during the routine dental examination, 55 people (27 men and 28 women) aged 21-60 years with preserved maxillary dentition were examined. It has been established that the alveolar and basal arches of the upper jaw can have the shape of five geometric shapes: an oval, a semicircle, an ellipse, a trapezoid or a square. In this case, the shape of the collar and basal arches can coincide or be combined in various combinations. The analysis of the obtained results showed that in men the alveolar arch most often had the shape of an oval (70%), in women - an oval or semicircle (43%, respectively). With the aim of possible variants of the alveolar and basal arches form determination and peculiarities of their correlation 55 individuals (27 men and 28 women) in age of 21-60 years with the preserved teeth row were examined during planned dental examination. All examined were patients of the “Dental clinic of dr. Dakhno” (Kyiv). Computer tomographic investigation was made to these patients according to medical indications, scanning was made parallely to the occlusal plane. Image reconstruction was conducted with the use of highly dimentional bone algorithm. Alveolar and basal arch form of the upper jaw were determined on the images. It was established that alveolar and basal arches of the upper jaw can have a form of five geometrical figures: oval, semicircle, ellipse, trapeze or square. Form of the alveolar and basal arches can match or can combine in different combinations. Received results analysis testified that alveolar arch has a form of the oval in men and oval or semicircle – in women. Basal arch in men also most frequently has a form of oval, less often – semicircle, square and trapeze. In women basal arch more often has a form of trapeze or semicircle, less often – oval or square. In men alveolar and basal arches form matched in 41% of cases, in women – only in 31% of cases among total amount of all examined individuals. Most often alveolar and basal arches matched in the form of oval and semicircle, only in one case arches of the trapeze form matched in man, in woman – square form. Maxillary alveolar and basal arches form variants analysis let to determine areas, where distance between alveolar crests was maximal. Most variable this index was in individuals with the oval form of the alveolar arch on the level of 16-26, 17-27 or 18-28 teeth. Peculiarities of the alveolar and basal arches form of the alveolar process of the upper jaw in male and female individuals are characterized with expressed individual variability. These peculiarities consideration during dental prosthesis let avoid series of complications connected with the pressure redistribution on the osseous tissue of the jaws during articulation.

Research on the Related Factors of the Second Molar Dislocation and Orthodontic Erect Method

The second molar dislocation is more common clinically. To investigate the related factors of the second permanent molar dislocation, and provide reference for the clinical diagnosis and treatment of orthodontics. From the current clinical research, the clinical methods of orthodontic erect secondary molars are also diverse and clinical.The narrower first molar alveolar arch width, smaller ANB angle, and crowded maxillary posterior segment arch are the factors that cause the maxillary second permanent molar dislocation. The narrow alveolar arch width, the smaller SNB angle, the larger ANB angle, and the crowded lower mandibular arch are the factors leading to the dislocation of the mandibular second permanent molar. In addition, for the second mandibular molar malposition, it is particularly important to select the corrective treatment plan. It is especially important to improve the treatment.

Evaluation in Arch Width Variations among Different Skeletal Patterns in District Solan Population

Introduction The facial growth pattern differs from individual to individual, and the variations in it are quite high. The assessment of relationship of dental arch dimensions with the facial growth pattern is essential for proper diagnosis and treatment planning. Aim The purpose of this study was to evaluate and compare the dental and alveolar arch widths in patients with varying facial growth patterns in Distt. Solan population. Materials and Methods Pretreatment lateral cephalograms and dental study models of 45 patients with age group between 16 and 30 years were included in the study. Patients were divided into three groups: group I (normodivergent), group II (hypodivergent), and group III (hyperdivergent) on the basis of y-axis, Jarabak ratio, and SN-MP (Sella-Nasion–mandibular plane) angle. Interpremolar and intermolar dental and alveolar arch widths were measured and compared for all the three groups. Results The results showed that the dental and alveolar arch widths were increased in hypodivergent patients and decreased in hyperdivergent patients, which was not statistically significant. Conclusion It was concluded that the dental and alveolar arch dimensions increased as the facial pattern became horizontal.