Intermaxillary Suture Research Articles

Localization of Impacted Maxillary Canines by Panoramic Tomography

In an unselected series of 116 cases of impacted maxillary canines the prevalence of palatally located teeth was 76% and of labially located teeth 9%. The teeth showing a horizontal or or mesio-angular inclination were usually palatally located, while those in vertical position were usually located either in the middle of the alveolar ridge or labially. About 86% of the canines had migrated in the mesial direction. The closer to the intermaxillary suture the crown of an impacted maxillary canine had migrated, the more often was its location palatal. All canines which in the panoramic tomographs were projected at the site of the root of the central incisor were palatally located. Theoretically, a single panoramic tomograph may be used in determining the labio-palatal location of impacted canines. Impacted teeth located palatally are more enlarged in width in the radiograph than are adjacent normally located teeth. Correspondingly, labially situated teeth appear diminished. According to the present study, the panoramic tomography method is not, however, sufficiently reliable for clinical use. The accuracy of determination of the labio-palatal location of impacted maxillary canines on the basis of the magnification in the panoramic tomograph was only about 90%.

Suture development and bony fusion in the fetal rabbit palate

The intermaxillary and the interpalatine regions of the fetal rabbit palate are contiguous areas of suture development and bony fusion, respectively. As these regions must differ regarding the factors responsible for the formation of a suture, the palate was selected as a model for the study of the mechanism of suture development. Palates from 21–25-day rabbit fetuses were classified into developmental stages using cleared and alizarin-stained specimens. The developmental stages of the two areas were compared in paraffin and Epon sections. PAS-staining and autoradiography following [ 3H]-proline injection were used. The difference in development of the two areas resulting in suture formation and fusion, respectively, could not be explained by morphologic differences in the interzonal tissue, but by analysing the osteogenic pattern along the bony rims adjacent to the maxillary and the palatine processes, it was concluded that widening of the bony palate in the maxillary area occurred by displacement and in the palatine area mainly by cortical drift. A lack of separation of the palatine ossification centres is considered to be a possible regulating factor for the fusion of the palatine bones and the continuous spatial movement of the maxillary ossification centres a factor in the formation of the intermaxillary suture.

The maxillary interincisal diastema and its relationship to the superior labial frenum and intermaxillary suture.

From the analysis of histories, dental casts, and cephalograms of 471 children of the Burlington Growth Centre sample, interrelationships between the degree of spacing, crowding, diastema and frenum and suture type were derived and the following conclusions were drawn: 1. Suture type remains more constant through development than frenum type. 2. Frenum type is reasonably constant but may change from low to medium or high attachments, but only to a higher level of attachment. 3. Frenum and suture type are related; frenum types 5 and 6 (low attachment) are associated with spacing and with suture types 3 and 4. 4. The primary factors contributing to maxillary diastema appear to be degree of spacing or crowding in most cases, the specific types of sutures and frenum making a minor contribution.

A lateral radiographic cephalometric study of the maxillae to several anthropological landmarks of the skull: By George W. Cameron, Baylor University College of Dentistry, Houston, Texas

The aim of this study was to determine whether the orthopedic forces of rapid maxillary expansion cause significant quantitative changes in the cranial and the circummaxillary sutures.Twenty patients (mean age, 12.3 ± 1.9 years) who required rapid maxillary expansion as a part of their comprehensive orthodontic treatment had preexpansion and postexpansion computed tomography scans. Ten cranial and circummaxillary sutures were located and measured on one of the axial, coronal, or sagittal sections of each patient's preexpansion and postexpansion computed tomography scans. Quantitative variables between the 2 measurements were compared by using the Wilcoxon signed rank test. A P value less than 0.05 was considered statistically significant.Rapid maxillary expansion produced significant width increases in the intermaxillary, internasal, maxillonasal, frontomaxillary, and frontonasal sutures, whereas the frontozygomatic, zygomaticomaxillary, zygomaticotemporal, and pterygomaxillary sutures showed nonsignificant changes. The greatest increase in width was recorded for the intermaxillary suture (1.7 ± 0.9 mm), followed by the internasal suture (0.6 ± 0.3 mm), and the maxillonasal suture (0.4 ± 0.2 mm). The midpalatal suture showed the greatest increase in width at the central incisor level (1.6 ± 0.8 mm) followed by the increases in width at the canine level (1.5 ± 0.8 mm) and the first molar level (1.2 ± 0.6 mm).Forces elicited by rapid maxillary expansion affect primarily the anterior sutures (intermaxillary and maxillary frontal nasal interfaces) compared with the posterior (zygomatic interface) craniofacial structures.

Endocrines: Their relation to orthodontic diagnosis and treatment planning

The palate is an alternative anchoring site for orthodontic implants and screws. The use of osseointegrated implants in the intermaxillary suture has recently been described as a fast, effective, and low-cost technique for patients with atrophy of the maxillae. The aim of this study was to use cone beam computed tomography (CBCT) to evaluate the thickness of the bone surrounding the intermaxillary suture in relation to the insertion of osseointegrated implants. CBCT images of 144 patients (72 males, 72 females) aged 35–86 years were evaluated. The vertical bone height of the intermaxillary suture was measured using coronal and sagittal Images 5, 10, 15, 20, and 25 mm posterior to the incisive foramen. The mean bone thicknesses from the anterior to the posterior region were 5.59, 4.38, 3.91, 3.95, and 3.94 mm, respectively. Bone thickness was significantly different among the five anteroposterior areas of the suture, but there were no significant differences between males and females, or among age groups. The highest part of the intermaxillary suture was in the anterior region. Three-dimensional imaging is recommended to accurately identify palate bone thickness for implant placement.

Notes on some Fossil Remains of a Gavial-like Saurian from Kimmeridge Bay collected by J. C. Mansel, Esq., establishing its identity with Cuvier's Deuxième Gavial d'Honfleur, Tête à museau plus court (Steneosaurus rostro-minor of Geoffroy St.Hilaire, 1825), and with Quenstedt's Dakosaurus

T he fossils which form the subject of this note consist of part of a lower jaw, with teeth and vertebrae, imbedded in hard pyritic claystone, lent me by J. C. Mansel, Esq., and of parts of the upper and lower jaws, with several teeth in situ and loose, portions of vertebræ and of ribs, a femur, and some other bones, which, owing to their fragmentary and crushed condition, I have not been able to identify, in the British Museum. As received from Mr. Mansel, the bones in the British Museum were nearly hidden in large masses of very hard stone containing, as is usual in Kimmeridge fossils, much pyrites, which made it very diffictflt to extricate them; but this has been successfully accomplished, and the severed pieces have been very skilfully joined by Mr. Davies, to whom I am glad to take this opportunity, of expressing my obligation for much valuable assistance. Description—Upper Jaw .—Of this the British Museum has the extreme end of the snout, comprising the symphysis, with about 4 inches of both intermaxillæ, forming the antero-lateral boundary of an undivided terminal nostril, which has a laterally compressed oval form, and is not swollen at the sides as in the living Gavials and in the extinct Teleosaurs. The oval nostril is indented in front by a slightly overhanging, medial, tubercular production of the symphysis. A thin seam of stone marks the open intermaxillary suture. The outer border of the upper surface of the portions of the intermaxillæ bounding the