Bony Thickness Research Articles

Radiological examinations of the anatomy of the inferior turbinate using digital volume tomography (DVT)

Since the last 120 years there were only few descriptions of the anatomical sizes of the inferior turbinate in the literature. On this background the current study should evaluate the radiological dimensions of the inferior turbinate and the septum using DVT. The latest generation of the Accu-I-tomo was used. The data of 100 adult patients have been evaluated. The bony length was found to be 38.9 mm, the mucosal length 51.0 mm. The findings of the total mucosal thickness at different measuring points were between 8.1 mm and 10.9 mm, those of the bony thickness were between 0.9 mm and 2.3 mm and those of the bony height were between 3.9 mm and 20.8 mm. The results of this radiological study are able to point out the importance of preoperative anatomical evaluation of radiological images. The preoperative focus on the individual anatomy is very important because of the choice of an adequate surgical treatment. Today new radiological techniques can help to find out whether the reason for hypertrophied turbinates is caused by bone, mucosa or both. This knowledge enables a concerted treatment concept.

Three-dimensional Volumetric Measurements and Analysis of the Maxillary Sinus

Multiple chronic rhinosinusitis (CRS) staging systems have been developed in an attempt to correlate symptoms with radiological imaging results. Currently, no perfect system exists. We sought to analyze the maxillary sinus (MS) using three-dimensional volumetric measurements and advanced high-resolution CT imaging. We reviewed MS CT scans from 50 control subjects and 50 subjects with documented CRS involving at least one MS. The following measurements were recorded: (1) volume of MS free air, (2) MS mucosal thickening, and (3) MS lateral wall bony thickness. Average Hounsfield unit (HU) values for mucosal thickening among CRS subjects were also recorded. Values are expressed as mean ± SD and median. Values from the CRS patients were compared with healthy controls using Student's t-tests. Among controls (n = 50), volumes (mL) of right and left MS were 24.1 ± 9.7 and 24.7 ± 9.0, respectively. Among CRS patients (n = 50), the portion of mucosal disease to total sinus volume was 51.8% (right) and 50.7% (left). Mean bony thickness (mm) in controls was 0.98 ± 0.2 (right) and 1.0 ± 0.3 (left). CRS patients had significantly greater bony thickness 1.9 ± 0.8 (right) and 2.0 ± 0.9 (left; p = 0.0001). HU for diseased MS were 30.1 ± 18.7 (right) and 35.7 ± 22.1 (left). Three-dimensional volumetric analysis combined with HU calculations and bony thickness measurements represents a new and unique way to evaluate CT scans in patients with CRS. Additional studies correlating symptoms with imaging findings as well as analysis of all paranasal sinuses is the next step toward a novel staging system.

BMP-2-Mediated Regeneration of Large-Scale Cranial Defects in the Canine: An Examination of Different Carriers

Recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered on an absorbable collagen sponge is a U.S. Food and Drug Administration-approved therapy shown to be an effective means of generating bone formation in multiple clinical settings. However, the optimum dose and delivery of rhBMP-2 to the calvaria are undetermined. The aim of the authors' study was to investigate the use of rhBMP-2 in addressing calvarial defects in a large-animal model through a variety of modifications to this U.S. Food and Drug Administration-approved therapy. Twenty-three adult canines underwent the creation of a standard calvarial defect and received either no treatment, 0.2 mg/ml rhBMP-2 in an absorbable collagen sponge, 0.2 mg/ml rhBMP-2 in an absorbable collagen sponge with corticocancellous chips, 0.2 mg/ml rhBMP-2 in an absorbable collagen sponge with MasterGraft Granules, or 0.4 mg/ml rhBMP-2 in a compression-resistant matrix carrier. Direct comparisons of defect radiopacity were performed at 0, 8, 16, and 24 weeks postoperatively before the animals were euthanized. All specimens were evaluated qualitatively with histology. Surgical control animals had an average defect radiopacity of 32.7 percent at study completion compared with an average of 99.95 percent across all treatment groups. Ectopic bone formation was found consistently in all treatment groups with varying degrees of severity. Regenerated bone thickness, compactness, and organization varied qualitatively between groups. Treatment with 0.2 mg/ml rhBMP-2 in an absorbable collagen sponge with MasterGraft Granules showed the least amount of ectopic bone formation and the most compact bone formation within the defect, and produced reasonably consistent bony thickness across the defect. Future studies should focus on spatial regulation of rhBMP-2 to minimize unwanted bone formation.

Feasibility and Safety of Superolateral Sphenoidotomy: Radiologic Study by Analyzing Multiplanar Reconstructive CT Scans

Received April 25, 2011 Revised May 26, 2011 Accepted June 1, 2011 Address for correspondence Young-Jun Chung, MD Department of OtolaryngologyHead & Neck Surgery, College of Medicine, Dankook University, San 29 Anseo-dong, Cheonan 330-714, Korea Tel +82-41-550-3974 Fax +82-41-556-1090 E-mail docjung@paran.com Background and ObjectivesZZThe sphenoidotomy removing inferomedial side of anterior sphenoid wall has been the standard procedure to enter the sphenoid sinus. In this paper, we evaluated the feasibility and safety of superolateral sphenoidotomy based on the radiological analysis of the sphenoid sinus. Subjects and MethodZZSeventy-six multiplanar reconstructive computed tomography (CT) scans were reviewed to investigate dimensions of the sphenoid sinus. We measured the length from sphenoid ostium to optic canal and to carotid artery, and also measured the thickness of both upper and lower bony part of sphenoid ostium. The subjects were divided into two groups; one with sphenoid sinusitis and the other without sinusitis and all the measurements were evaluated and were compared between groups. ResultsZZThe mean length from sphenoid ostium to optic canal were 13.8±2.4 mm in control group and 12.9±2.2 mm in sinusitis group. The length from sphenoid ostium to carotid artery were 10.4±1.5 mm and 10.0±1.8 mm in control and sinusitis group, respectively. There were significant differences in both lengths between control and sinusitis group. The bony thickness above and below the ostium were 1.48±0.31 mm and 1.73±0.27 mm respectively and were significantly different from each other (p<0.001). ConclusionZZSince the neurovascular structures was relatively distant from the sphenoid ostium and the bony thickness below the ostium was significantly thicker than that above the ostium, the sphenoidotomy removing superolateral side of anterior sphenoid wall could be an alternative procedure, especially, in patients with a thickened bone around sphenoid ostium. Korean J Otorhinolaryngol-Head Neck Surg 2011;54:399-402

Sphenoid Sinus Pneumatization and Its Relation to Bulging of Surrounding Neurovascular Structures

We investigated the bulging and dehiscence of neurovascular structures in the sphenoid sinus and their relationships to the pneumatization of the sphenoid sinus. One hundred sagittally hemisected cadaveric heads were examined. The degree of pneumatization of the sphenoid sinus was determined. Bulging and dehiscence of the internal carotid artery (ICA), optic nerve, maxillary nerve, and vidian nerve were examined, and the distances between these structures and the anterior or superior wall of the sphenoid sinus were measured. Additionally, the degree of bony thickness over these structures was determined. The prevalences of bulging of the optic nerve, segments 1 and 3 of the ICA, and the maxillary and vidian nerves were 56%, 34%, 65%, 41%, and 52%, respectively. The greater the degree of pneumatization, the more frequently did the structures bulge into the sphenoid sinus. The optic nerve was found to be in close proximity to the anterior and superior walls of the sphenoid sinus. The bone over the surrounding structures was very thin, especially for the complete sellar type. The prevalence of bulging of the optic nerve, the ICA, and the maxillary and vidian nerves increased in proportion to the degree of sphenoid sinus pneumatization.

Mapping the columns of the acetabulum—Implications for percutaneous fixation

Knowledge of the bony thickness of the acetabular columns is one requisite for safe execution of percutaneous fixation of acetabular fractures. We performed a cadaveric study to determine anatomical dimensions of the columns of acetabulum with reference to percutaneous screw fixation. Twenty-two hemipelves (11 pairs) from 6 male and 5 female cadavers were measured and statistically analysed. In the anterior column, the psoas groove displayed the least vertical thickness of 15.1 mm (range, 12.1–18.2 mm), followed by the obturator canal with 15.9 mm (range, 12.2–20.6 mm). The mean thickness of the posterior column wall of the acetabulum along the screw path displayed 21.3 mm (range, 16.5–30.3 mm). This study provides a clinical map for safe passage of both antegrade and retrograde percutaneous screws. Anatomic data suggests that 7.3 mm cannulated screws can be safely accommodated by the anterior and posterior columns of the acetabulum.

Effects of a Dexamethasone-Releasing Stent on Osteoneogenesis in a Rabbit Model

This study is an evaluation of wound healing in an animal model for surgery of frontal sinusitis and treatment effect of topically released dexamethasone using a drug-releasing stent with special emphasis of osteoneogenesis. A prospective, controlled, randomized, double-blinded animal study was performed. Nineteen New Zealand white rabbits were subjected to surgery via an external approach, a 4-mm circular wound was created on the medial side of the maxillary sinus and the underlying bone was denuded of periosteum. The wound was covered in a randomized fashion with either a silicone foil or a new dexamethasone-releasing stent system. Twelve to 30 days later, the animals were killed and a histological examination was performed. In comparison with the baseline bony thickness (40 micrometer) obtained in one animal, osteoneogenesis occurred on both paranasal sides but was significantly less if a dexamethasone-releasing stent was applied (117 [95% CI, 116-128]; 52 [95% CI, 43-64]; p < 0.001). Maximal bony thickness was observed in both treatment groups between days 20 and 25 with a tendency toward a higher percentage decrease in the dexamethasone-treated sides (p < 0.08). Using a visual analog scale (0-5) a significantly smoother bony surface was observed for dexamethasone (2 [95% CI, 1.1-1.9]; 2 [95% CI, 1.8-2.2]; p < 0.01). Using a new drug-releasing stent system, dexamethasone efficiently decreases postoperative osteoneogenesis in a standardized animal wound model for endoscopic sinus surgery. Therefore, the use of this system may be of value to decrease restenosis rates using corticosteroids in selected patients after frontal sinus surgery, especially the endoscopic modified Lothrop procedure.

Clinical Implications of Anthropometric Patellar Dimensions for TKA in Asians

Anthropometric patellar dimensions can influence implant design and surgical techniques in patellar resurfacing for TKA. We measured anthropometric patellar dimensions in 752 osteoarthritic knees (713 in females and 39 in males) treated with TKA in 466 Korean patients and compared them with reported dimensions for Western patients. We investigated the effects of postoperative overall thickness deviations, residual bony thickness after bone resection, and postoperative deviations of component center positions from median ridge positions versus clinical and radiographic outcomes evaluated 1 year after surgery. Korean patients undergoing TKA had thinner and smaller patellae than Western patients. We found no associations between preoperative to postoperative overall thickness differences and clinical and radiographic outcomes and no differences between knees with a residual bony thickness 12 mm or greater and knees with a residual thickness less than 12 mm, with the exception of WOMAC pain scores. We found no associations between postoperative deviations of component center position and clinical or radiographic outcomes. Our findings indicate bone resection for patellar resurfacing can be flexible without jeopardizing clinical outcome. Level IV, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Changes of maxillary sinus volume and bony thickness of the paranasal sinuses in longstanding pediatric chronic rhinosinusitis

To evaluate the chronic bony changes in the paranasal sinuses of longstanding chronic rhinosinusitis (CRS) in pediatric patients and to compare them with normal controls. A single-institution retrospective analysis. Thirty 15- and 16-year-old children with longstanding CRS, for more than 2 years, despite maximal medical treatment and had a Lund CT score over 20 were enrolled as the CRS group. They were compared with 45 age and gender matched randomly selected normal controls without CRS. No enrolled patient had a history of nasal or adenoid surgery. The volume of the maxillary sinus was measured using a three-dimensional CT reconstruction program (V-works 4.0). The bony thickness of the maxillary (MS) and ethmoid sinuses (ES) and the middle turbinate (MT) was measured and compared. In addition, we evaluated the effect of disease duration on the sinus volume and bony thickness. The mean volume of the MS was 22.5+/-4.4 cm(3) in the normal group and 20.0+/-4.1 cm(3) in the CRS group; this difference was statistically significant (p=0.02). However, there was no correlation found between the disease duration and maxillary sinus volume (r=-0.07, p=0.69). The mean thicknesses of the bony walls were 1.0+/-0.4 mm (MS), 0.8+/-0.4 mm (ES) and 1.8+/-0.5 mm (MT) in the normal group and 1.2+/-0.3 mm (MS), 1.2+/-0.4 mm (ES) and 2.4+/-0.5 mm (MT) in the CRS group; these differences were significant (p<0.01). In addition, the bony thickness of the ES was significantly correlated with the duration of symptoms (r=0.44, p=0.03). The volume of the maxillary sinuses decreased and the bony thickness of the paranasal sinuses increased with longstanding pediatric CRS.

Bony eminence on the middle cranial fossa corresponding to the temporomandibular joint

We report a nameless bony eminence over the temporomandibular joint (TMJ) and its possible clinical significance. Forty-two half heads of 21 UK Caucasian cadavers (61-95 years old, mean 84.3 +/- 8.2 years, male:female = 11:10) were used to investigate the surface of the middle cranial fossa (MCF) over the TMJ. The thickness of the bony roof of the glenoid fossa was also measured. A bony eminence over the glenoid fossa was observed in half of the specimens. Some showed a complete oval bulge, which completely reflected the contour of the glenoid fossa. The others showed a bony bulge, which partially reflected that contour. The mean (+/-SD) thickness of the bone in the roof of glenoid fossa was 1.5 +/- 1.2 mm. The mean bony thickness of specimens showing the eminence was 0.8 +/- 0.5 mm, whereas it was 2.3 +/- 1.2 mm in specimens without an eminence. These differences were statistically significant (P < 0.01). The osteological features we describe may be relevant to certain clinical problems. Traumatic dislocation of mandibular condyle, for example, might relate to a weakness of the glenoid fossa.

Morphologic Analyses of Mandible and Upper Airway Soft Tissue by MRI of Patients With Obstructive Sleep Apnea Hypopnea Syndrome

To evaluate the morphological features of the mandible and the volume of the upper airway soft tissues in determining the anatomical risk factors for the upper airway in Japanese male patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Five morphological parameters of the mandible at the mandibular base plane and three volumetric parameters of the upper airway soft tissue were analyzed using three-dimensional (3D) magnetic resonance imaging software in 31 OSAHS and 20 controls. There were no significant differences between the two groups in mandibular internal width (the distance between the internal right and left gonia [IRG and ILG]) and mandibular bony thickness. However, the patients with OSAHS had a significantly wider mandibular divergence (the angle between the spina mentalis (SM)- IRG line and SM- ILG line), a smaller mandibular internal length (the perpendicular distance from SM to the RG- LG line), and a smaller area than the normal subjects at the mandibular base plane. There were no significant differences in these morphological parameters for the mandible between obese and nonobese OSAHS patients. The volumes of the tongue, soft palate, and lateral pharyngeal walls were not significantly different between the OSAHS and the control groups. Japanese male OSAHS patients had specific anatomical features in the bottom part of the mandible; however, obesity seemed to be a less significant risk factor. Investigators and clinicians must realize that ethnicity may modify the effects of obesity and abnormal craniofacial anatomy as risk factors for the pathogenesis of OSAHS.

Relationship between Tinnitus Loudness Level and Internal Jugular Venous Flow Rate Measured by Coloured Doppler Ultrasonography in Patients with a High Jugular Bulb

The aim of this study was to investigate the relationship between tinnitus loudness level (TLL) and internal jugular venous flow rate (IJVFR) in tinnitus patients with a unilateral high jugular bulb detected by temporal bone high-resolution computed tomography (HRCT). The study group consisted of 24 adult patients (13 male, 11 female) with a unilateral high jugular bulb. One ear suffered from tinnitus with a high jugular bulb was included into the study group. The ears without tinnitus and no high jugular bulb on temporal bone HRCT comprised the control group. All patients were evaluated with a history and physical and otolaryngologic examinations, and, using a questionnaire, TLLs were detected. The patency and flow rates in the internal jugular veins were measured by right and left internal jugular venous Doppler ultrasonography. The TLLs were "very quiet" in 1 (4.1%) patient, "intermediate loud" in 17 (70.9%) patients, and "very loud" in 6 (25.0%) patients. IJVFRs were not different in the study and control groups. In the study group, IJVFRs were not correlated with age. There was no relationship among TLLs and IJVFRs, dominance, dehiscence, and bony septum thickness between the high jugular bulb and the middle ear. TLLs were not affected by IJVFRs, dominance, dehiscence, and bony septum thickness in patients with a high jugular bulb. More detailed studies should be undertaken to determine the reason for the different TLLs in patients with a high jugular bulb.

Rationale for osteotome selection in rhinoplasty.

Proper selection of an osteotome for nasal osteotomy is important for minimizing soft tissue trauma. Radiographic analysis of the facial bony lateral wall thickness was performed to suggest a guideline for an appropriate osteotome size for Asians. Facial bone computed tomography (CT) of 100 patients (50 male, 50 female) were studied. The thickness of the facial bony lateral wall at three points along the track of a lateral osteotomy, and two points along the track of a medial osteotomy and intermediate osteotomy were measured. The average bony thickness along the track of a lateral osteotomy was 2.61 +/- 0.66 mm at the low level, 2.75 +/- 0.76 mm at the middle level, and 2.72 +/- 0.53 mm at the high level in subjects. The average bony thickness along the track of an intermediate osteotomy were 1.26 +/- 0.34 mm at the low level, and 1.31 +/- 0.32 mm at the high level in the subjects. The average bony thickness along the track of the medial osteotomy were 2.54 +/- 0.31 mm at the low level, and 2.77 +/- 0.30 mm at the high level in subjects. These results may provide a guideline for choosing an osteotome of appropriate size for the Asian population.

Influence of patellar thickness on results of total knee arthroplasty: Does a residual bony patellar thickness of [le ]12 mm lead to poorer clinical outcome and increased complication rates?

With patellar thickness averaging 24.0 mm and 21.9 mm in Singapore men and women undergoing total knee arthroplasty, achievement of precut thickness is difficult if the recommended residual bony thickness of 15 mm is maintained. We retrospectively compared the clinical outcome of 56 patellae resurfaced [le ]12 mm (mean residual thickness, 10.4 mm) with 56 patellae resurfaced [gt ]12 mm (mean residual thickness, 13.7 mm). Both groups were comparable in terms of demographic characteristics, presentation, precut patellar thickness, and operative details (P[gt ].05). Knee scores (P=.627), extensor mechanism function (P=.625), and postoperative range of motion (P=.344) were comparable.Differences in the overall (P=.167) and patellar (P=.061) complication rates as determined by chi-square test on the SPSS 10.0 program were not significant, although there were 4 patella-related complications in group 2. Increased patella-related complications may be associated with an excessive patellar composite of the patellofemoral articulation. A residual patellar thickness of [lt ]12 mm did not appear to affect the clinical outcome in this series.

Morphologic and radiologic anatomy of the occipital bone.

Several diseases may cause craniovertebral instability warranting occiput-cervical fusion. As occipital screw and rod constructs are becoming more popular, requiring that screws be placed either medially or laterally in the occipital bone, the need for clearer anatomical and computed tomography (CT)-confirmed data regarding the relative thickness of the occiput in its various localities has become more critical. In 18 cadaveric specimens, the occipital bone was divided into 35 measurable segments. Transversely, the occipital bone was divided into five lines starting at the level of the inion; horizontal lines then proceeded inferiorly in 1-cm segments, 1, 2, 3, and 4 cm below the level of inion. In a comparable fashion, the occipital bone was divided vertically, starting at the midline, and proceeding laterally also in 1-, 2-, and 3-cm segments. Anatomical measurements of thickness were directly performed using a Vernier caliper. Results were directly correlated with axial CT measurements of bony thickness. Anatomical and CT measurements closely correlated within the same specimen, but there was significant interspecimen variability. The marked differences in the occipital bone anatomy noted between specimens indicates that patients undergoing occipital screw placement for cranial-cervical instability would benefit from preoperative occipital CT evaluations.

Non-invasive aspergillosis of the paranasal sinuses: CT and MRI findings

Aspergillosis is the most common fungal infection of the paranasal sinuses, and needs to be recognized because it requires surgical removal. Twenty proven cases of aspergillosis of the paranasal sinuses are reported here. CT was performed in all the cases and MRI in 2 cases. The maxillary sinus was affected in 19 patients and the sphenoid sinus in 1. Mycosis was unilateral in all but 1 of the cases. Foci of increased attenuation at CT were observed in 18 cases, with calcification in 10 cases and/or dental material in 13 cases. An increased bony wall thickness was observed in 16 cases. All the patients but 1 had at least one of the signs. At MRI the fungal mass displayed a hypointense signal on T1- and T2-weighted images. No enhancement was noted on post-contrast T1-weighted images. The diagnosis of paranasal sinus aspergillosis is suggested by the CT findings, when a hyperdense mass with calcifications and/or dental material is noted with thickening of the sinus wall. MRI may have a complementary diagnostic role in doubtful cases.