Nasomaxillary Suture Research Articles

An anatomical study of the nasal foramina.

The nasal foramen is located in the nasal bone and for vessels passage to supply the nasal area. This project aimed to establish reliable references for the nasal foramina for future clinical applications. The 72 dried skulls, 46 from the Division of Anatomy, University of Phayao, Thailand, and 26 from the Tulane University School of Medicine, USA, were collected and examined. The location, number, and sizes of nasal foramina were noted. The distances from each nasal foramen to the internasal suture, frontonasal suture, nasomaxillary suture, nasion, and rhinion were also recorded and used in the statistical analytical programs. The most common type of nasal foramen in all skulls was type II (one external opening) at 65.97%, followed by type I (no foramen opening) at 20.83%, type III (two external openings) at 11.11% and type IV at 2.08% (three external openings). Nasal foramen subtypes in many of the Thai and American skulls were type IIb and type IIa. The diameter of a connecting nasal foramen was significantly larger than that of a non-connecting. Results from embalmed confirmed the passage of the external nasal artery through the nasal cavity. The study shows no significant difference in nasal foramen morphometry between Thai and American. It illustrates recent data on type and subtype classifications and the location of a vascular passage through the nasal foramen. This is the first study of NF variations and their respective classifications.

Exit point of the external nasal nerve- cadaveric study

This study aims to confirm how the external nasal nerve exits from the internal surface of the nasal bone to the dorsum of the nose and to determine the exact point of nerve emergence by macroscopic examination. Twenty external nasal nerves of both sexes from the elderly and adult age groups were dissected. The exit point of the external nasal nerve, the width of the nasocartilaginous joint, and the inferior border of the nasal bone from the midline to the nasomaxillary suture were measured. The nerve was classified according to its branching pattern. In this study, in the elderly group, the external nasal nerve enters the dorsum of the nose through the pyriform ligament and exits laterally to the nasocartilaginous joint. But in the adult age group the external nasal nerve exits between the nasal bone and the upper nasal cartilage. We observed mainly three types of nerve but did not find any subtypes or variations in the branching pattern. Among this main classification of nerves, more cases (70%) of type I were observed. However, based on our study, we concluded that the external nasal nerve enters the dorsum of the nose either between the nasal bone and the upper nasal cartilage, or it passes through the pyriform ligament and exits lateral to the nasocartilaginous joint. In rhinoplasty, knowledge about the course, exit point, branching pattern, and variations of the external nasal nerve is unavoidable.

Septic suturitis: A suspected cause of periapical infection in a young horse

SummaryThis case report describes septic suturitis as a likely cause of periapical dental disease in a 3‐year‐old Thoroughbred colt. The horse was presented for a unilateral sinusitis initially managed by a frontal osteotomy and sinus lavage and subsequently developed a septic suturitis. Subsequently, a computed tomography (CT) examination identified a periapical infection of cheek tooth 109 with associated sinusitis of the rostral sinus compartments and an extensive suturitis, with the most severe changes located at the right nasomaxillary suture line. There was an associated local fistulous tract rostral to the mesial periapical region of cheek tooth 107 but unassociated with typical periapical or endodontic dental disease changes on CT. The sinusitis did not respond to oral extraction of cheek tooth 109 and sinus lavage. A repeat head CT 2 weeks later, now revealed buccal alveolar bone loss surrounding cheek tooth 107 with obvious periodontal and endodontic dental disease changes. Oral extraction of cheek tooth 107 was performed and local curettage of the fistulous tract was conducted. We conclude that septic suturitis can become extensive and slow to resolve and its rostral extension can cause periapical infection of the closely associated rostral cheek teeth in young horses.

Short-term and long-term effects of miniscrew-assisted and conventional rapid palatal expansion on the cranial and circummaxillary sutures

The objective of this study was to analyze the short-term and long-term effects of miniscrew-assisted rapid palatal expansion (MARPE) and conventional rapid palatal expansion (RPE) appliances on cranial and circummaxillary sutures as compared with a matched control group. One hundred and eighty cone-beam computed tomography scans for 60 subjects were evaluated for the 3 groups: (1) MARPE (n= 20; aged 13.7 ± 1.74 years), (2) RPE (n= 21; age 13.9 ± 1.14 years), and (3) control (n= 19; age 13.3 ± 1.49 years) at pretreatment (T1), postexpansion (T2), and posttreatment (T3) (T1 to T3: MARPE, 2 years 8 months; RPE, 2 years 9 months; control, 2 years 7 months). Frontonasal suture, frontomaxillary suture, zygomaticomaxillary suture, zygomaticofrontal suture, intermaxillary suture, pterygomaxillary suture, nasomaxillary suture, and zygomaticotemporal suture were measured on the right and left sides for all 3 time labels. In addition, midpalatal suture was measured at the incisor, canine, and molar levels. Within-group analysis showed that MARPE and RPE led to a significant increase in the widths of frontonasal, frontomaxillary, intermaxillary, nasomaxillary, and midpalatal suture at incisor, canine, and molar levels at T2 compared with T1. Between-group analysis showed that MARPE and RPE significantly increased the width of the intermaxillary and midpalatal suture at the incisor, canine, and molar compared with controls at T2. In the long term, between-group comparisons showed no significant difference among the 3 groups except that MARPE led to a significant increase in the width of midpalatal suture at incisor, canine, and molar levels compared with RPE and controls at T3. MARPE led to a significant increase in the width of the midpalatal suture at incisor, canine, and molar levels compared with RPE and controls in the long term. There was no difference in the width of other cranial and circummaxillary sutures among the 3 groups in the long term.

Effect of reciprocal headgear forces on the calvarium: A finite element study

Orthopedic appliances continue to be used for various sagittal, vertical, and transverse corrections of the maxilla. Although cranial growth can continue to adulthood, no study has drawn attention to the effects of headgear forces on the calvarium, in which anchorage is taken. This study focused on the different biomechanical responses on the calvarium of young children wearing a high-pull headgear of varying forces, using a 3-dimensional finite element analysis and the possible implications of such changes on the human skull. A 3-dimensional finite element model of a 9-year-old child was designed from the computed tomography scan. The material properties of the juvenile skull were assigned. Varying orthopedic forces (400, 500, and 600 g of force) were applied, and the magnitude of displacement and stresses generated on the cranial bones and sutures were interpreted using ANSYS software (version 12.1; Canonsburg, Pa). Maximum displacement was found for the parietal bone in the inferior direction; parietal and temporal bones in the transverse direction; and frontal, parietal, and temporal bones in the sagittal direction. The least displacement was noted for the occipital bone in all the 3-dimensions. The maximum stresses were concentrated over the region of the lateral margins of the piriform aperture and the medial walls of the orbit. Higher stress values were also found on the parietal bone adjacent to the sagittal suture. The highest value of stresses among the sutures of the craniofacial complex was found to be in the region of the frontonasal, frontomaxillary, and nasomaxillary sutures. The effects of displacement and stresses obtained from this study suggest a restriction to the growth of the cranial vault and its normal mobility, in turn altering the intracranial tension and causing altered cranial morphology in young, growing children undergoing high-pull headgear therapy. The human cranial system is dynamic throughout life and may be restricted or altered by hereditary or environmental factors.

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

BackgroundThe objective is 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).MethodsMaxillofacial 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 software. The maxillofacial bone EQV (equivalent) stresses and bone suture EQV strains under occlusal states were obtained in the finite element analysis software.ResultsUnder 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.ConclusionsFor UCCLP, bilateral maxillae, pterygoid processes of sphenoid bones and bilateral 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.

Evaluation of treatment changes with rapid maxillary expansion using computed tomography scan: A comprehensive review

The aim of the study was to review in detail, the skeletal, dental and soft-tissue effects of Rapid Maxillary Expansion in young group of patients using Computed Tomographic Scan. The review is conducted through an electronic and manual searches which includes PubMed, Ovid, Cochrane, and Web of Science using the keywords. Searches includes the original studies which were conducted from the January 2000 to May 2020 amongst patients from 6 to 18 years using Hyrax, Haas-type and butterfly-type expanders. Based on the inclusion criteria, 23 relevant articles containing 298 patients were selected to evaluate changes related to skeletal, dental, soft-tissues and airway by assessing Computed Tomography scan. Significant effects have been observed at the mid-palatal suture due to the separation of two hemi-maxillae that led to an increase in the palatal volume, maxillary arch perimeter and correction of posterior crossbite. Changes were also recorded at the circum-maxillary sutures with maximum effects noted in internasal and nasomaxillary sutures. Other observations includes dental changes like buccal tipping of the maxillary posterior anchored teeth, increase in nasal and upper airway dimensions. Few side-effects of Rapid Maxillary Expansion includes recession of alveolar bone and dehiscence in cases of excessive dental tipping, dorsal hump on the nose with flattening of the nasal tip. Interpreting the outcomes with Computed Tomography scan strengthen the orthodontist’s precision in determining the 3-dimension effects with greater specificity. However, more number of Computed Tomography studies on soft-tissue changes and airway effects are required to understand comprehensive mechanics of the procedure.

Dose Reduction for Sinus and Temporal Bone Imaging Using Photon-Counting Detector CT With an Additional Tin Filter.

The aim of this study was to quantitatively demonstrate radiation dose reduction for sinus and temporal bone examinations using high-resolution photon-counting detector (PCD) computed tomography (CT) with an additional tin (Sn) filter. A multienergy CT phantom, an anthropomorphic head phantom, and a cadaver head were scanned on a research PCD-CT scanner using ultra-high-resolution mode at 100-kV tube potential with an additional tin filter (Sn-100 kV) and volume CT dose index of 10 mGy. They were also scanned on a commercial CT scanner with an energy-integrating detector (EID) following standard clinical protocols. Thirty patients referred to clinically indicated sinus examinations, and two patients referred to temporal bone examinations were scanned on the PCD-CT system after their clinical scans on an EID-CT. For the sinus cohort, PCD-CT scans were performed using Sn-100 kV at 4 dose levels at 10 mGy (n = 9), 8 mGy (n = 7), 7 mGy (n = 7), and 6 mGy (n = 7), and the clinical EID-CT was performed at 120 kV and 13.7 mGy (mean CT volume dose index). For the temporal bone scans, PCD-CT was performed using Sn-100 kV (10.1 mGy), and EID-CT was performed at 120 kV and routine clinical dose (52.6 and 66 mGy). For both PCD-CT and EID-CT, sinus images were reconstructed using H70 kernel at 0.75-mm slice thickness, and temporal bone images were reconstructed using a U70 kernel at 0.6-mm slice thickness. In addition, iterative reconstruction with a dedicated sharp kernel (V80) was used to obtain high-resolution PCD-CT images from a sinus patient scan to demonstrate improved anatomic delineation. Improvements in spatial resolution from the dedicated sharp kernel was quantified using modulation transfer function measured with a wire phantom. A neuroradiologist assessed the H70 sinus images for visualization of critical anatomical structures in low-dose PCD-CT images and routine-dose EID-CT images using a 5-point Likert scale (structural detection obscured and poor diagnostic confidence, score = 1; improved anatomic delineation and diagnostic confidence, score = 5). Image contrast and noise were measured in representative regions of interest and compared between PCD-CT and EID-CT, and the noise difference between the 2 acquisitions was used to estimate the dose reduction in the sinus and temporal bone patient cohorts. The multienergy phantom experiment showed a noise reduction of 26% in the Sn-100 kV PCD-CT image, corresponding to a total dose reduction of 56% compared with EID-CT (clinical dose) without compromising image contrast. The PCD-CT images from the head phantom and the cadaver scans demonstrated a dose reduction of 67% and 83%, for sinus and temporal bone examinations, respectively, compared with EID-CT. In the sinus cohort, PCD-CT demonstrated a mean dose reduction of 67%. The 10- and 8-mGy sinus patient images from PCD-CT were significantly superior to clinical EID-CT for visualization of critical sinus structures (median score = 5 ± 0.82 and P = 0.01 for lesser palatine foramina, median score = 4 ± 0.68 and P = 0.039 for nasomaxillary sutures, and median score = 4 ± 0.96 and P = 0.01 for anterior ethmoid artery canal). The 6- and 7-mGy sinus patient images did not show any significant difference between PCD-CT and EID-CT. In addition, V80 (sharp kernel, 10% modulation transfer function = 18.6 cm) PCD-CT images from a sinus patient scan increased the conspicuity of nasomaxillary sutures compared with the clinical EID-CT images. The temporal bone patient images demonstrated a dose reduction of up to 85% compared with clinical EID-CT images, whereas visualization of inner ear structures such as the incudomalleolar joint were similar between EID-CT and PCD-CT. Phantom and cadaver studies demonstrated dose reduction using Sn-100 kV PCD-CT compared with current clinical EID-CT while maintaining the desired image contrast. Dose reduction was further validated in sinus and temporal bone patient studies. The ultra-high resolution capability from PCD-CT allowed improved anatomical delineation for sinus imaging compared with current clinical standard.

Stress and displacement patterns in the craniofacial skeleton with rapid maxillary expansion\u2014a finite element method study

BackgroundRapid maxillary expansion (RME), indicated in the treatment of maxillary deficiency directs high forces to maxillary basal bone and to other adjacent skeletal bones. The aim of this study is to (i) evaluate stress distribution along craniofacial sutures and (ii) study the displacement of various craniofacial structures with rapid maxillary expansion therapy by using a Finite Element model.MethodsAn analytical model was developed from a dried human skull of a 12 year old male. CT scan images of the skull were taken in axial direction parallel to the F-H plane at 1 mm interval, processed using Mimics software, required portion of the skull was exported into stereo-lithography model. ANSYS software was used to solve the mathematical equation. Contour plots of the displacement and stresses were obtained from the results of the analysis performed.ResultsAt Node 47005, maximum X-displacement was 5.073 mm corresponding to the incisal edge of the upper central incisor. At Node 3971, maximum negative Y-displacement was -0.86 mm which corresponds to the anterior zygomatic arch, indicating posterior movement of craniofacial complex. At Node 32324, maximum negative Z-displacement was -0.92 mm representing the anterior and deepest convex portion of the nasal septum; indicating downward displacement of structures medial to the area of force application.ConclusionsPyramidal displacement of maxilla was evident. Apex of pyramid faced the nasal bone and base was located on the oral side. Posterosuperior part of nasal cavity moved minimally in lateral direction and width of nasal cavity at the floor of the nose increased, there was downward and forward movement of maxilla with a tendency toward posterior rotation. Maximum von Mises stresses were found along midpalatal, pterygomaxillary, nasomaxillary and frontomaxillary sutures.

Pyriform aperture enlargement in all aspects.

The pyriform aperture comprises the central area of facial bone structure. It is formed by the free corners of the nasal bone and the frontal processes of the maxillae, which articulate with each other at the nasomaxillary suture lines. Congenital nasal pyriform aperture stenosis might be linked to various craniofacial problems. This review presents all aspects of pyriform aperture stenosis and enlargement. A literature search was conducted. Pyriform aperture definition, nasal development, congenital nasal pyriform aperture stenosis and pyriform aperture enlargement were reviewed. One of the most common abnormalities is holoprosencephaly, which is a midline developmental deficiency that may also be present in combination with facial clefting. The aetiology of nasal pyriform aperture stenosis remains unclear. When diagnosed, the choice of treatment is between non-surgical and operative methods, depending on the seriousness of the problem. Provided the sufferer can maintain a secure air passage with the help of specialised medical procedures and respiratory tract adjuvants, operative therapy may be delayed. The operative outcomes are extremely good, and the prognosis relies mainly on coexisting neural and endocrine problems. This paper evaluates the nasal pyriform aperture in detail.

Stress and displacement pattern evaluation using two different palatal expanders in unilateral cleft lip and palate: a three-dimensional finite element analysis.

BackgroundIn this finite element (FE) study, the stress distribution and displacement pattern was evaluated in the mid-palatal area and around circum-maxillary sutures exerted by bone-borne palatal expander (BBPE) in comparison with conventional HYRAX rapid palatal expander in unilateral cleft lip and palate.MethodsComputed tomography scan images of a patient with unilateral cleft palate was used to create a FE model of the maxillary bone along with circum-maxillary sutures. A three-dimensional model of the conventional HYRAX (Hygienic Rapid Expander) expander and custom-made BBPE was created by laser scanning and programmed into the FE model.ResultsWith the BBPE, the maximum stress was observed at the implant insertion site, whereas with the conventional HYRAX expander, it was at the dentition level. Among the circum-maxillary sutures, the zygomaticomaxillary suture experienced maximum stress followed by the zygomaticotemporal and nasomaxillary sutures. Displacement in the X-axis (transverse) was highest on the cleft side, and in the Y-axis (antero-posterior), it was highest in the posterior region in the BBPE.ConclusionsThe total displacement was observed maximum in the mid-palatal cleft area in the BBPE, and it produced true skeletal expansion at the alveolar level without any dental tipping when compared with the conventional HYRAX expander.

Facial twist (asymmetry) in isolated unilateral coronal synostosis: does premature facial suture fusion play a role?

Unilateral coronal synostosis (UCS) often causes notable facial twist in affected patients. This condition occurs when the midface deviates toward the synostotic side, and the lower face deviates away from the synostotic side. The exact underlying mechanism for this phenomenon remains unclear. It has been proposed that premature fusion of facial sutures may play a role in the formation of facial twist. The purpose of this study was to determine whether asymmetrical facial suture fusion is present in patients with UCS. A single-center retrospective study was designed. Our study group consisted of 23 patients with a confirmed diagnosis of isolated UCS. Our control group consisted of 17 age-matched patients with deformational plagiocephaly and 11 normocephalic control subjects. The computed tomography scans of the faces were examined for the presence of facial suture fusions on both synostotic and nonsynostotic sides. All results with P < 0.05 were considered statistically significant. We found an increased incidence of fusion of the frontomaxillary, nasofrontal, and nasomaxillary sutures on the side of synostosis in UCS when compared with the nonsynostotic side and when compared with patients with deformational plagiocephaly or normocephalic patients. Asymmetrical premature fusion of facial sutures can potentially be contributing to the facial twist that is seen in patients with UCS.

Location and Tension of the Medial Palpebral Ligament

The aim of this study was to elucidate the precise anatomic location and tension of the medial palpebral ligament (MPL). Eleven hemifaces of 10 fresh Korean adult cadavers were used in this study. Nine specimens were used for measurement of dissection and tension, and 2 were used for histologic study. Measurements of tensile strength of each part of the MPL and Horner muscle were performed using a force gauge.The MPL consisted of 2 layers in all specimens dissected. The superficial layer of the palpebral ligament (SMPL) was observed from the anterior lacrimal crest to the upper and lower tarsal plates. The deep layer of the palpebral ligament (DMPL) lay from the anterior lacrimal crest to the posterior lacrimal crest, covering the lacrimal sac. The Horner muscle was observed at the posterior lacrimal crest just lateral to the attachment of the DMPL and ran laterally to the tarsal plate deep to the SMPL. The SMPL began at 4.5 ± 2.3 mm lateral to the nasomaxillary suture line to the upper and lower tarsal plates. Its transverse length was 9.6 ± 1.5 mm, and vertical width was 2.4 ± 0.7 mm, and its thickness was 4.5 ± 2.3 mm. The transverse length of the DMPL was 3.7 ± 0.4 mm, and its vertical width was 2.9 ± 1.3 mm, with a thickness of 0.3 ± 0.1 mm. The transverse length of the Horner muscle was 7.6 ± 1.9 mm, and its vertical width was 4.06 ± 1.5 mm, with a thickness of 0.4 ± 0.1 mm. The tensile strength of the SMPL was 13.4 ± 3.2 N, that of the DMPL was 4.1 ± 1.7 N, and that for Horner muscle was 9.0 ± 3.1 N. The tensile strength of the SMPL was significantly higher than that of the DMPL (P = 0.003).We reconfirmed that the MPL consisted of 2 layers: superficial layer and deep layer. Our results might be of use in surgeries of the medial canthi.

Combined Flaps for Reconstructing Wide-Range Facial Defects

This report aims to describe the technique of using combined flaps for reconstruction of wide-range facial defects. Two or more flaps were combined to repair wide-range facial wounds, complying with the principle of facial aesthetic subunits to maintain the inherent structural characteristics of the face, to design incision lines conforming to the natural facial contour lines (e.g., nasolabial fold, sulcus alaris, nasomaxillary suture, palpebral margin, vermilion border, hairline) or wrinkles, and to leave hidden incision lines if possible. There were 18 cases with excessively large facial defects requiring the use of a graft with local flaps. From April 1996 to May 2008, 124 patients had their wide-range facial defects repaired by combined flaps. The size of the defects ranged in size from 2.5×4 to 9×10cm. The healing for all the patients was uneventful, and the flap survived completely without complications. After an average of 6months (range, 1-48months), 87 of the patients were available for follow-up evaluation. There was no recurrence of tumor. The repaired tissues were well matched with surrounding tissue in color, texture, and contour. Incision lines were sheltered, and there were no anatomic deformities of the eyelid, upper lip, or nasal ala. Based on the facial aesthetic subregion principle, combined flaps were used to reconstruct wide-range facial defects effectively, obtaining good color, contour, and texture match with the surrounding skin. All in all, the cosmetic results were satisfactory.

Microanatomical Assessment of Nasomaxillary Suture Patency

In addition to acting as a growth site, sutures in the facial skeleton are important for distributing mechanical forces during mastication. In the present study, the extent of fusion of a facial suture is assessed in two samples of adult bushbabies (Galago moholi and Otolemur garnettii). Microanatomical techniques were used to determine the loci of osseous bridges across the nasomaxillary suture (NMS). Histological sections containing sutures with osseous bridging were rated as "fused." One of the specimens was studied using micro-computed tomography before paraffin embedding and serial sectioning. At all ages, O. garnettii shows more advanced fusion of the NMS than G. moholi. The youngest O. garnettii shows multiple foci of fusion of the NMS; however, 13% of the posterior most suture is patent. Throughout the NMS of this animal, sutural fusion is isolated to one or two small osseous bridges, typically of woven bone. These bridges are most often on the external (superficial) surface of the suture, but in numerous sections the site of fusion occurs deep to an external notch. In G. moholi, the youngest adults studied showed little or no fusion across the NMS. However, the nasal and maxillary bones were indirectly tethered at some levels by other bones that were fused to both nasal and maxillary bones. These results indicate that microanatomical evidence is required to fully assess the extent of fusion of facial sutures. These findings also support previous observations of differing magnitude of suture fusion between the two species.

Analysis of the nasal bone and nasal pyramid by three-dimensional computed tomography

Evaluation of the nasal bone and nasal pyramid is essential for the correct osteotomy. The shape of the nasal bone and nasal pyramid of Korean subjects were analyzed using a three-dimensional computed tomography (CT). This study includes 75 patients who visited Inha University Hospital and got a three-dimensional CT from October 2005 to June 2006 (58 males, 17 females, mean age of 33.1 years). The thickness of the bone at the nasomaxillary suture as well as between the rhinion and nasomaxillary suture, on which a lateral osteotomy was performed, was measured. In addition, the length of the nasal bone and the width of pyriform aperture were measured. The morphology of the nasal bone was classified from A to E type, according to Hwang's method. The subjects included 58 males and 17 females with a mean age of 33.1 years. The mean thickness of the lateral osteotomy point is 2.03+/-0.35 mm and that of the medial osteotomy point is 1.75+/-0.37 mm. The mean length of the nasal bone is 20.95+/-5.99 mm. The number of patients with a long nasal bone (more than 25 mm) is 14.7% (11/75). The most common morphology of the nasal bone is A type and there is no D or E type. Since there is no significant difference in the thickness of the nasal bone at the lateral and intermediate osteotomy point, the same strength should be used to perform the correct lateral and intermediate osteotomy. However, the actual lateral osteotomy is performed at a more lateral position than the nasomaxillary suture, which is our standard of measurement. So, using more power in the lateral osteotomy should be considered. There were nine patients with a long nasal bone in this study. For these patients, better results with percutaneous transverse osteotomy could be expected.

High-resolution multislice computerized tomography with multiplanar and 3-dimensional reformation imaging in rapid palatal expansion

The purpose of this study was to evaluate whether high-resolution multislice computerized tomography (CT) with multiplanar reformation and 3-dimensional (3D) imaging is helpful in demonstrating the effects on midfacial sutures induced by rapid palatal expansion (RPE), thereby appraising and corroborating the current state of the art or possibly adding new findings. Two patients in different stages of skeletal maturity (aged 10 and 16 years) underwent CT examinations immediately after active opening with the RPE appliance. The 3D CT imaging method proved to be valuable in visualizing skeletal effects on not only the midpalatal suture, but also adjacent sutures. It allowed precise 3D location of tooth positions. In the 3D CT images of 1 patient, the complete opening of the midpalatal suture was visible. The median dissection of the incisal foramen at the point of unification of the 2 nasopalatine channels could be visualized. Additionally, the positions of severely displaced maxillary canines could be located precisely. In the other patient, apart from the completely open midpalatal suture, the opening or widening of the internasal suture, the nasomaxillary sutures, and the frontomaxillary sutures were visible. The 3D imaging of high-resolution multislice CT opens up a new dimension in orofacial diagnosis. Improvements of the quantity and the exactness of diagnostic parameters were attained. The imaging method is helpful and indicated in RPE patients with additional diagnostic objectives related to the development of occlusion. This imaging method is recommended in borderline cases (juvenile or adult patients with questionable sutural response) to determine whether the suture is completely open or whether surgical support is needed.

Restricting facial bone growth with skeletal fixation: A preliminary study

Conventional orthodontic treatment of vertical or anterior maxillary excess by growth modification can be problematic in children because of the high levels of patient compliance required. The purpose of this preliminary study was to investigate the use of rigid skeletal fixation to modify facial bone growth without compliance. Three 30-day old female pigs from the same litter were included in phase I. Pediatric miniplates were rigidly fixated with monocortical screws in the experimental pig to bridge the zygomaticomaxillary suture and both the frontonasal and nasomaxillary sutures, bilaterally. In the sham experimental pig, the same surgical protocol was followed, but miniplates were omitted (ie, screw placement only). In the control pig, surgery was not performed. All 3 pigs were housed and fed a normal diet under identical conditions postoperatively for 63 days; then they were killed, their right hemi-skulls were prepared for and underwent 3-dimensional coordinate landmark analysis, and en-bloc specimens from the zygomaticomaxillary, frontonasal, and nasomaxillary sutures of the left hemi-skulls underwent histologic analysis. Two 50-day-old female pigs from the same litter were used in phase II. The same experimental protocol was followed as before for the experimental pig and the sham experimental pig. Both pigs were fed a normal diet for 105 days; then they were killed, and their skulls were prepared for and underwent 3-dimensional coordinate landmark analysis. Rigid plating restricted zygomaticolacrimal suture length, maxillary bone length, nasal bone length, midfacial breadth, and frontal bone length by an average of -14% to -15% (range, -4% to -36%). No growth differences were noted between the animals in maxillary height, mid-premaxillary length, bregma-lambda length, palatal lengths, or mandibular length. Also, plating the sutures produced a clear depressed concavity in the infraorbital region, altered the alignment of the infraorbital plane lateral to the concavity, inhibited the anterior migration of the maxillary tuberosity, and resulted in raised folding on the bony surface adjacent to the zygomaticomaxillary suture. Rigidly fixating frontonasomaxillary and zygomaticomaxillary sutures inhibits growth of facial bones and might provide a means of restricting excess growth without having to rely on patient compliance. In addition, these altered growth patterns in the plated pig model produced similar and potentially homologous infraorbital features shared by living humans in comparison with ancestral fossil forms.

Morphometry of the nasal bones and piriform apertures in Koreans

In order to understand the morphological characteristics of Korean noses, the nasal bones and piriform apertures were measured and classified in the dried skulls of Korean adults. The shapes of the nasal bones were classified into five types (Type A-E). Among the types of the nasal bone, Type A, in which the nasomaxillary sutures initially descended vertically and then obliquely, was present in 43.2% and Type B, in which the nasomaxillary sutures were concave in the middle part, was present in 52.3% of the noses examined. The height of the nasal bone was 25.9 +/- 3.8 mm in males, 24.5 +/- 3.7 mm in females; the width was 9.2 +/- 2.4 mm in males, 8.8 +/- 2.6 mm in females. The height of the piriform aperture was 30.1 +/- 2.6 mm in males, 28.0 +/- 2.8 mm in females; the upper width was 16.8+2.6 mm in males, 17.0 +/- 2.0 mm in females; the lower width was 25.7 +/- 1.7 mm in males, 25.4 +/- 2.1 mm in females. Each measurement was compared with those carried out in other populations.

Computer-aided assessment of bony nasal pyramid dimensions.

To develop a computer-enabled paradigm for assessment of bony nasal pyramid dimensions. Retrospective review of archived computed tomographic data. Tertiary level academic center. Patients who had undergone computed tomographic scans for computer-aided transsphenoidal hypophysectomy were included. Previous nasal surgery, inflammatory sinus disease, and documented maxillofacial trauma were exclusion criteria. Archived computed tomographic scan images were reviewed using the software tools on a computer-aided surgical (CAS) system (StealthStation; Sofamor Danek, Memphis, Tenn). Standardized methods for the measurement of nasal bone thickness and bony nasal pyramid projection were established. Bony nasal pyramid projection and nasal bone thickness were determined. Computed tomographic scans from 8 patients were reviewed. Nasal bone thickness at the level of lateral osteotomy was 2.39 +/- 0.68 (mean + SD) mm, while nasal bone thickness at the level of intermediate osteotomy was 1.18 + 0.30 mm. Nasal projection from the nasomaxillary suture to the rhinion in the axial plane was 19.20 + 3. 10 (mean + SD) mm, while the corresponding nasal projection at the nasion was 20.61 + 3.52 mm. This brief report presents a new paradigm for the assessment of the bony nasal pyramid. Additional normative data are necessary. This information has important implications for rhinoplasty instrument design, surgical planning, and aesthetic assessment. It is likely that computer-enabled review of archived computed tomographic images for maxillofacial assessment will become increasingly accepted. Of course, further modifications of computer technology and its specific applications are expected.