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1.

Objectives

The present study investigated the position and relationship of the maxillary third molars to the maxillary sinus. These molars were detected to have a close relationship with the maxillary sinus based on panoramic images, using cone-beam computed tomography (CBCT).

Methods

This retrospective study evaluated 162 impacted third molars from 100 patients that showed a superimposed relationship between the maxillary sinus and third molars on panoramic images obtained from CBCT. CBCT images were used to assess the horizontal (buccopalatal) and vertical positions of the maxillary sinus relative to the maxillary third molars, proximity of the roots to the sinus, and angulation and depth of the third molars. The associations among the angulation, depth of third molars, and horizontal and vertical positions of the maxillary sinus relative to the third molar findings were examined using Chi square tests.

Results

Based on the winter classification, the most frequent tooth position was vertical (59.9 %), followed by mesioangular (14.2 %), distoangular (9.9 %), and others. Most impacted teeth were at the level between the occlusal and cervical levels of the adjacent second molar. Regarding the relationships of the maxillary third molars with the maxillary sinus examined on CBCT, vertical type III (buccal root related with maxillary sinus) (34 %) and horizontal type 2 (maxillary sinus located between roots) (64.8 %) were seen most frequently.

Conclusions

The relationship between the maxillary sinus and third molar roots should be considered during extraction. When a risk of sinus perforation is predicted in an extraction, a presurgical CBCT examination could be valuable.
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2.

Objectives

The aim of this study was to evaluate the effect of the relationship between the horizontal position of the maxillary sinus floor and the tooth roots on maxillary sinus pathologies using cone beam computed tomography.

Methods

The patients’ age, sex, presence or absence of apical abscesses, and horizontal relationship between the maxillary sinuses and tooth roots were recorded. In total, 228 maxillary sinuses of 114 patients were divided into case and control groups according to whether pathology was present. The horizontal relationship between the tooth roots and the lower wall of the maxillary sinus was categorized into three types. The variables were analyzed using the Chi-square test.

Results

Of 42 apical abscesses, 13 (31 %) were present in the control group and 29 (69 %) were present in the case group. This difference was statistically significant (p = 0.003). Each of the 228 maxillary sinuses was classified according to its horizontal relationship to the tooth root. The most frequently seen relationship was Type II, followed by Type I and III, respectively. Although the control and case groups showed equilibrium in the distribution of Type II and III relationships, maxillary sinus pathologies were significantly less common in Type I (p < 0.001).

Conclusions

This study shows that positioning of the maxillary sinus toward the buccal side (Type I) poses an obstacle to the spread of odontogenic infection to the sinus and that the presence of apical abscesses is correlated with maxillary sinusitis.
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3.
4.

Objective

The purpose of this study was to investigate the effect of the dental implant penetration into the maxillary sinus cavity in different depths on implant and sinus health in a dog model.

Materials and methods

The study sample included eight titanium dental implant placed in four female dogs immediately after extraction of the first maxillary molar in the palatal socket and assigned into four groups according to the protruding of implant tips (control group A?=?0 mm, and study groups B, C, and D with protrusion of 1, 2, and 3 mm, respectively). The bone blocks of the implants were harvested 5 months postoperatively and evaluated by cone beam computed tomography (CBCT) and histological analysis.

Results

The whole groups showed no signs of inflammation during the 5-month period of the study. The tips of the implants in group B with penetrating depths of 1 mm were found to be fully covered with newly formed bone. The tips of the implants in group C with penetrating depths of 2 mm were exposed in the sinus cavity and showed partially new bone coverage, while depths of 3 mm in group D were found to have no bone formation and the dental implant fixture sites were communicated with the sinus cavity. No significant differences were found among the groups regarding implant stability.

Conclusion

Despite the protrusion extents, penetration of dental implant into the maxillary sinus with membrane perforation does not compromise the sinus health and the implant in canine.
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5.

Objectives

The aim of this study was to evaluate the localization, angulation, and resorption features of maxillary impacted canines on cone-beam computed tomography (CBCT).

Methods

This retrospective study examined the CBCT scans of 140 maxillary impacted canines in 102 patients (43 males, 59 females; mean age: 16.25 ± 6.31 years). The following impacted canine-related parameters were analyzed on the CBCT images: impaction side; location; root resorption levels of adjacent teeth; occlusal plane and midline distances of impacted canines; and angulations of impacted canines to midline, lateral incisor, and occlusal plane.

Results

Bilateral canine impaction was found in 38 subjects, and unilateral canine impaction was present in 64 subjects. Severe resorption was found in 14 canines. There were no significant differences between the occlusal plane and midline distances to the impacted canine cusp tip and root apex (p > 0.05). The midline angulation of right maxillary impacted canines was significantly higher than that of left maxillary impacted canines (p < 0.05), while the occlusal plane angulation of left maxillary impacted canines was significantly higher than that of right maxillary impacted canines (p < 0.05).

Conclusions

Maxillary canine impaction was more frequently seen in female subjects than in male subjects. Lateral incisors were more frequently affected than first premolars, and slight resorption was more frequently seen in adjacent teeth. CBCT assessment of maxillary impacted canines can provide accurate measurements of angular, linear, and resorption parameters.
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6.

Purpose

Augmentation of the maxillary sinus floor with bone grafting is commonly used for successful treatment of edentulous posterior maxilla with dental implants, and it is essential to maintain good bone volume and quality for long-term success of dental implants. The aim of this experimental study was to investigate the local and systemic effects of boric acid on new bone formation after maxillary sinus floor augmentation (MSFA).

Materials and methods

Twenty-four male, New Zealand rabbits were randomly divided into three groups with eight rabbits each, and bilateral MSFA was performed in each animal. An autogenous bone/xenograft mixture was used to augment the maxillary sinuses in each group. Group 1 was determined as control with no additional materials, whereas 3 mg/kg boric acid (BA) was added to the mixture in group 2, and 3 mg/kg boric acid solution added to drinking water daily in group 3.

Results

The animals were sacrificed and also histologic, histomorphometric, and immunnohistochemical analyses were performed at weeks 4 and 8. At week 4, bone regeneration was better in the local BA group than in the control and systemic BA groups (p?<?0.05). However, no significant difference was found among the groups in terms of bone regeneration at the end of week 8 (p?>?0.05).

Conclusion

Significant higher new bone formation was revealed by BA at early healing especially with local application. BA may be a therapeutic option for improving the bone regeneration.
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7.

Objectives

To examine the dimensions (width, length, and height) of the maxillary tuberosity (MT) and their correlations with age and sex, and to identify different anatomical types for adequate positioning of miniscrews in this area.

Methods

The study enrolled 39 patients attending the University of Valencia. The patients comprised 21 males and 18 females with a mean age of 39.7 ± 8.4 years. The dimensions of all 78 MTs were measured on cone beam computed tomography (CBCT) images using Invivo Dental 5 software.

Results

The intraobserver and interobserver errors were good for all measurements. A total of 858 MT measurements were taken. The widths were greater in men than in women, with significant differences. The MT dimensions showed correlations with patient age, whereby older patients presented with greater widths and lengths, but reduced heights. Three different anatomical types were detected according to patient age.

Conclusions

The dimensions (width, length, and height) of the MT vary according to patient age and sex. The MT dimensions conform to particular anatomical types, which should be taken into account when placing miniscrews in this region.
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8.

Objective

No studies have yet evaluated linear alveolar bone levels and extraction socket dimensions on dry skulls using different techniques. We aimed to investigate the accuracy of cone-beam computed tomography (CBCT), digital radiography, and digital photography.

Methods

Circumferential linear alveolar bone level measurements were performed at six sites on the examined teeth using gutta-percha points placed for reference at the cementoenamel junction and alveolar bone crest. Dimensions of the extraction socket were evaluated by linear measurements in the mesiodistal and buccolingual directions. Groups were formed according to the following imaging and estimation techniques: (1) direct measurement using digital calipers under loupe magnification (gold standard); (2) direct measurement using only digital calipers; (3) digital photographs/ImageJ (Photo/I); (4) digital paralleling long-cone periapical radiographs/ImageJ (Periapical/I); (5) digital panoramic radiographs/digital calipers; (6) digital panoramic radiographs/digital calipers and loupe magnification; (7) digital panoramic radiographs/ImageJ; and (8) CBCT/ImageJ (CBCT/I).

Results

Statistical analyses showed significant differences for all panoramic radiography subgroups in all examined regions compared with the gold standard (p < 0.001). Results of the CBCT/I (r = 0.930, p < 0.01), periapical/I (r = 0.939, p < 0.01), and Photo/I (r = 0.978, p < 0.01) techniques showed high correlation with the gold standard. Reliability of repeated measurements was higher with loupe magnification and the image-processing program.

Conclusions

Periapical/I and CBCT provide promising results in analyses of the dimensions and relations of periodontal tissues. Routine clinical digital photographs can be converted to scaled images and applied to treatment planning and preoperative–postoperative comparisons.
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9.

Purpose

This research is designed to obtain a better understanding and provide more insight of this phenomenon through evaluating the prevalence of congenital absence of maxillary lateral incisors in a Syrian population.

Methods

The method involved clinical examination of 8000 school children with an equal number of males and females (age range 12–15 years) to identify students only affected by bilateral or unilateral congenital absence of maxillary lateral incisors. Agenesis was determined based on radiological evidence.

Results

The results of this study showed that the prevalence of isolated maxillary lateral incisors agenesis was 1.15%. In the sample studied, 66.3% of the patients were female and 33.7% were male (p < 0.05). Absence was bilateral in 47.8% of patients and unilateral in 52.2%. Of the unilateral cases, 48% occurred on the right side and 52% on the left side, and the contralateral maxillary incisor was found to be microdont in 43.75%, right lateral in 47.6%, and left lateral in 52.4%.

Conclusion

The results of this study allow the conclusion that the prevalence of isolated maxillary lateral incisors agenesis in a Syrian population is within the average range with regard to other populations. A significant familial component to the etiology of maxillary lateral incisors agenesis was found.
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10.

Purpose

The relationship between radiographic findings and the occurrence of oroantral perforation is controversial. Few studies have quantitatively analyzed the risk factors contributing to oroantral perforation, and no study has reported multivariate analysis of the relationship(s) between these various factors. This retrospective study aims to fill this void.

Methods

Various risk factors for oroantral perforation during maxillary third molar extraction were investigated by univariate and multivariate analysis. The proximity of the roots to the maxillary sinus floor (root-sinus [RS] classification) was assessed using panoramic radiography and classified as types 1–5. The relationship between the maxillary second and third molars was classified according to a modified version of the Archer classification. The relative depth of the maxillary third molar in the bone was classified as class A–C, and its angulation relative to the long axis of the second molar was also recorded.

Results

Performance of an incision (OR 5.16), mesioangular tooth angulation (OR 6.05), and type 3 RS classification (i.e., significant superimposition of the roots of all posterior maxillary teeth with the sinus floor; OR 10.18) were all identified as risk factors with significant association to an outcome of oroantral perforation.

Conclusion

To our knowledge, this is the first multivariate analysis of the risk factors for oroantral perforation during surgical extraction of the maxillary third molar. This RS classification may offer a new predictive parameter for estimating the risk of oroantral perforation.
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11.

Background

We present a case report of a professional diver who sustained a fracture of the left orbital medial wall as well as floor exceeding 50% with orbital fat herniation blocking the maxillary sinus ostium. This may result in a closed cavity within the maxillary sinus that could potentially result in barotraumas during future diving. The aim of his surgery consists of repairing the orbital fracture and to aerating the sinus at the same sitting.

Method

A transconjunctival approach was used combined with endoscopic sinus surgery approach to the maxillary sinus. The orbital floor fracture was repaired with a titanium plate. A wide middle meatal antrostomy was performed. A size eight Foley’s catheter was inserted into the maxillary sinus and the balloon inflated to elevate and support the displaced inferior orbital floor bone fragment. The balloon was left in situ for 4 weeks to support the mobile inferior orbital fragment till adequate bone healing and stability.

Results

Patient recovered well. At 3 months post-operatively, the maxillary antrostomy remained patent, and a hyperbaric oxygen challenge test was performed with success. A repeat orbital CT scan 1 day after hyperbaric challenge showed no signs of air leakage, and the bony inferior orbital floor fracture has healed completely with the titanium plate in situ.

Conclusion

This is the first case report of repair of orbital floor fracture with simultaneous aeration of the maxillary sinus in a professional diver using a combined approach. The patient was able to resume his occupation as a professional diver following surgery.
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12.

Objectives

The purpose of this study was to evaluate the prevalence of anatomical variations of the nasal cavity and ethmoid complex on cone-beam computed tomography (CBCT) images.

Methods

The CBCT images of 322 patients were evaluated retrospectively. The anatomical variations of the bilateral nasal cavity and ethmoidal complex were evaluated in four categories, namely nasal septum, turbinates, ethmoid air cells, and crista galli.

Results

The patients comprised 134 males (41.6 %) and 188 females (58.4 %), with an age range of 18–83 years. One or more nasal septum variations were observed in 76.7 % of patients, while variations in the turbinate and ethmoid cell categories were present in 89.4 and 62.1 % of patients, respectively. Overall, 5 % of patients showed pneumatized crista galli.

Conclusions

The detailed radiographic examination of the nasal cavity and ethmoid complex is possible and successful on the CBCT images.
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13.

Objective

The primary aim of our study was to evaluate the efficacy of mineralized bone allograft alone in sinus floor augmentation with simultaneous implant placement in cases with severe atrophy of the residual maxillary bone (bone height <?4 mm).

Methods

Thirty-five dental implants were placed in 29 patients who underwent sinus augmentation via traditional lateral window technique from 2008 to 2013. Patients with residual alveolar height between 1 and 3 mm at the site of implantation were included in the study. The height of residual bone was initially estimated by plain panoramic X-ray and reevaluated intraoperatively by precise micrometric measurement at the site of implantation. Implants of 13 mm height and 3.5 or 4.3 mm in diameter were inserted simultaneously. Mineralized bone allograft was used alone to augment the sinus floor.

Results

No wound dehiscence was recorded. In one case there was a postoperative site infection which subsided with antibiotics without implant failure. One implant migrated during the postoperative period to the maxillary sinus and was removed. One implant failed. The remaining 33 implants were successfully loaded. Follow-up ranged from 3 to 8 years.

Conclusions

Maxillary sinus lift in severely absorbed alveolar ridges with simultaneous implant placement could be safely performed using mineralized allograft alone, rendering the procedure less invasive and less time-consuming.
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14.

Aim

The aim of this case report is to present the trans-sinusoidal pathway used to remove a displaced maxillary third molar from the infratemporal fossa and review the English literature regarding the techniques used.

Case report

A 21-year-old male patient was referred with the findings of an oroantral fistula on the left maxillary vestibular first molar region and slight restriction of mouth opening. The patient underwent a maxillary sinus surgery in order to remove a sinus retention cyst via Caldwell-Luc access in a dental clinic 4 years ago. A computerized tomography scan showed the inverted third molar to be located in the infratemporal fossa, just between zygomatic arch and lateral pterygoid plate. The tooth was accessed through the remaining lateral bone defect from the Caldwell-Luc approach of the lateral sinus wall. The bone defect was extended. The posterior bony wall of the maxillary sinus was removed via a surgical burr. After that, the displaced tooth was exposed. The tooth was mobilized via Warwick James elevator downwards and removed with a forceps.

Conclusion

Access for surgical removal of the tooth from the infratemporal fossa is not only difficult but also has potential for morbidity due to the structures running through it. Wide incision in the maxillary sulcus and blunt dissection are reported with lower success rates and usually necessitate a second intervention via extraoral route. Trans-sinusoidal approach might be an old fashioned but relatively successfully attempt in the removal of the upper third molars from the infratemporal fossa. Considering the time of removal, if no symptoms were present, it is beneficial to wait for a couple of weeks thus facilitating development of fibrous surrounding around the tooth.
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15.

Objectives

Secondary dentine is laid on pulp chamber walls with increasing age, and decreases pulp chamber size. This study aimed to investigate age estimation on cone-beam computed tomography (CBCT) images for forensic science, and the relationship between age and pulp chamber area of maxillary and mandibular molars.

Methods

We reviewed the CBCT images of 316 first molars in 87 patients with dental lesions. The 87 patients were classified into three groups: younger, 11–28 years; middle-aged, 34–59 years; and older, 60–74 years. The relationship between age and pulp chamber area of maxillary and mandibular molars was evaluated.

Results

The mean pulp chamber area of maxillary molars was 8.4 ± 2.0, 4.4 ± 1.7, and 2.9 ± 0.9 mm2 in the younger, middle-aged, and older groups, respectively, (p = 0.028). The mean pulp chamber area of mandibular molars was 10.5 ± 2.3, 6.7 ± 2.2, and 3.7 ± 1.5 mm2 in the younger, middle-aged, and older groups, respectively, (p = 0.000). The mean pulp chamber area of mandibular molars was larger than that of maxillary molars in the younger (p = 0.000), middle-aged (p = 0.000), and older (p = 0.094) groups. The mean pulp chamber area of maxillary and mandibular molars was significantly correlated with age [Y = ?0.142X + 11.582 (R 2 = 0.586, p = 0.000) and Y = ?0.163X + 14.249 (R 2 = 0.609, p = 0.000), respectively].

Conclusions

These findings should be useful for diagnosis and treatment planning in dental practice and age estimation in forensic science.
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16.

Objectives

We investigated and compared the errors generated by multislice computed tomography (MSCT), cone-beam computed tomography (CBCT), and digital dental casts when used to provide digital data about dental structures.

Methods

Ten A20 skull models were scanned with MSCT and CBCT, and dental plaster cast models were optically scanned in three dimensions. The maxillary dental area was then compared. The distance between the three-dimensional scan data of the skull and each set of digital dental data were measured. Reference data were then overlapped with the experimental digital model using surface-based registration. The distance of errors was measured with the shortest distance measurement function. The distances between each experimental digital model and the reference scan data were measured, and error values were determined for all maxillary teeth and each tooth surface area. Errors were measured for all teeth from the central incisors to the second molar on both the left and right sides. Errors were measured from the mesial, distal, and labial surfaces and the tooth cusp tip area for each tooth.

Results

The digital dental casts had the smallest error (p < 0.001). The error in the digital dental casts (mean ± standard deviation) was 0.10 ± 0.12 mm. The CBCT error was 0.34 ± 0.38 mm, which was significantly greater than the MSCT error (0.19 ± 0.16 mm) (p < 0.001).

Conclusions

We recommend the use of digital dental casts with digital dental imaging for three-dimensional measurement of the dental area because this technique had the smallest errors.
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17.

Objectives

Radiographic examinations have clinical validation/relevance in dental practice. Dentists pay strong attention to absorbed doses to the eye lens, which is located near or inside the irradiation field. Recently, the ICRP recommended a new threshold dose for the eye lens. Therefore, we carried out eye lens dose measurements using a head phantom.

Methods

We affixed fluorescence glass dosimeters to a head phantom and measured the absorbed doses during intraoral radiography, panoramic radiography, cephalography, helical scan computed tomography (helical CT), and dental cone beam computed tomography (dental CBCT).

Results

The mean absorbed dose to the eye lens in intraoral radiography examinations for maxillary incisor teeth and molar teeth was 0.11 ± 0.09 and 0.08 ± 0.04 mGy, respectively. Corresponding values in occlusal method examinations for the maxillary (craniocaudal angulation 70° parallel to the occlusal plane) and mandibular (craniocaudal angulation 90°) regions were 0.19 ± 0.01 and 0.19 ± 0.07 mGy, respectively. The mean value for panoramic radiography examinations was 0.07 ± 0.02 mGy, while that for cephalography examinations in the posteroanterior projection and left lateral projection was 0.02 ± 0.00 and 0.18 ± 0.02 mGy, respectively. The corresponding value for helical CT was 11.87 ± 1.12 mGy, while those for dental CBCT of the front teeth and molar teeth were 0.07 ± 0.02 and 0.12 ± 0.09 mGy, respectively.

Conclusions

Eye lens doses ranged between 0.02 and 0.19 mGy in individual radiographic examinations, including CBCT. Although helical CT recorded 11.87 mGy, it was still lower than the recent ICRP-recommended threshold (500 mGy).
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18.

Objectives

The pulpal anesthetic and cardiovascular parameters obtained by 2 % lidocaine with epinephrine (LE; 1:80,000) or clonidine (LC; 15 mcg/ml) were studied in diabetes mellitus (DM) type 2 and healthy volunteers (72), after maxillary infiltration anesthesia.

Materials and methods

Onset and duration of pulpal anesthesia were measured by electric pulp tester; vasoconstrictive effect of used local anesthetic mixtures by laser Doppler flowmetry (LDF) through pulpal blood flow (PBF); systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were registered by electrocardiogram monitoring.

Results

Onset of pulpal anesthesia was shorter for LC than for LE in healthy, while it was not different in diabetic participants; duration of pulpal anesthesia was significantly longer in type 2 diabetic participants, regardless of used anesthetic mixture. Significant reduction of PBF with LE was observed during 45 min in healthy and 60 min in diabetic participants, while with LC such reduction was observed during 45 min in both groups. LE caused a significant increase of SBP in the 5th and 15th minutes in diabetic versus healthy participants, while LC decreased SBP from the 10th to 60th minutes in healthy versus diabetic participants.

Conclusions

DM type 2 influences duration of maxillary infiltration anesthesia obtained with LE and LC, and systolic blood pressure during LE anesthesia.

Clinical relevance

The obtained results provide elements for future protocols concerning intraoral local anesthesia in DM type 2 patients.
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19.

Objectives

The purpose of the present study was to radiographically evaluate the prevalence and characteristics of palatogingival grooves (PGs) in maxillary anterior teeth on cone-beam computed tomography (CBCT) to better understand the nature of these defects.

Methods

The CBCT examinations of 993 teeth (330 canines, 315 lateral incisors, 348 central incisors) in 191 patients (87 males, 104 females; age range 16–80 years) were evaluated retrospectively. The diagnosis and radiographic condition of PGs were obtained by consensus among all observers. Verification of PGs was achieved from the patients’ clinical records, which were stored in a database after their clinical evaluation. Differences in age, sex, occurrence, and location were evaluated by the Chi-square test. The level of significance was set at p < 0.05.

Results

Among the 993 teeth examined, nine PGs were observed in seven lateral incisors and two central incisors in eight patients (four males and four females). There was one bilateral case in the lateral incisors. The frequencies of PG occurrence and affected patients were 0.90 and 4.18%, respectively, without significance for sex and location (p > 0.05).

Conclusions

PGs were a relatively infrequent anomaly of teeth in this population, but when present, clinicians should understand the clinical features of these root variations.
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20.

Objectives

The main aim of this study was to investigate whether Hounsfield unit derived from computed tomography (HU/CT) and gray value derived from cone beam computed tomography (GV/CBCT) can predict the amount of new bone formation (NBF) in the defects after bone reconstruction surgeries.

Materials and methods

Thirty calvaria defects created in 5 rabbits and grafted with both radiolucent (RL, n = 15) and radiopaque (RO, n = 15) bone substitute materials were evaluated, 8 weeks postoperatively. The defects were scanned by multislice computed tomography (Somatom®, Siemens Healthineers, Erlangen, Germany) and CBCT (NewTom VG®, Qualitative Radiology, Verona, Italy). MSCT and CBCT scans were matched to select the exact region of interest (ROI, diameter = 5 mm and height = 1 mm). HU/CT and GV/CBCT of each ROI were obtained. Mean amount of NBF in whole of the defects was measured using serial histomorphometric assessment. We investigated the correlation between HU/CT and GV/CBCT, HU/CT and NBF, and GV/CBCT and NBF generally, and separately among the RL or RO grafted defects, by linear generalized estimating equation modeling. Receiver operation characteristic analysis was performed to check the accuracy of HU/CT and GV/CBCT in diagnosing more than 10% NBF in the samples.

Results

There were linear correlations between HU/CT and GV/CBCT, HU/CT and NBF, and GV/CBCT and NBF.

Conclusion

According to the results, both HU/CT and GV/CBCT can be considered as fairly good predictors for assessment of the amount of NBF following bone reconstruction surgeries.
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