Recording Natural Head Position Using Cone Beam Computerized Tomography

The purpose of this study was to develop a technique to record the natural head position (NHP) of a subject using the scout images of cone beam computerized tomography (CBCT) scans. The first step was to align a hanging mirror with the vertical (XY) plane of the CBCT field-of-view (FOV) volume. Then, two scout CBCT images, at frontal and at sagittal planes, were taken when the subject exhibited a NHP. A normal CBCT scan on the subject was then taken separately. These scout images were used to correct the orientation of the normal CBCT scan. A phantom head was used for validation and performance analysis of the proposed method. It was found that the orientation detection error was within 0.88°. This enables easy and economic NHP recording for CBCT without additional hardware.

Implant Treatment by Guided Surgery Supporting Overdentures in Edentulous Mandible Patients

Introduction: This study aimed to show the clinical outcomes of implants inserted by guided surgery supporting mandibular overdentures in edentulous patients. Patients and methods: Mandibular edentulous patients were diagnosed with an oral examination, cone-beam computerized tomography, and diagnostic casts for intermaxillary relations and treated with overdentures over two implants by guided surgery. After flapless surgery, implants were early loaded with an overdenture at 6 weeks. Results and discussion: Fourteen patients (nine females and five males) were treated with 28 implants. Four patients (28.6%) had a previous history of periodontitis. Five patients (35.7%) were smokers. Nine patients (64.3%) suffered from systemic diseases (i.e., diabetes, cardiovascular diseases). The clinical follow-up of the study was 44.7 ± 31.4 months. Clinical outcomes showed a global success of 100% of implants. Fourteen overdentures were placed in the patients over the implants. Mean marginal bone loss was 1.25 mm ± 0.95 mm. Four patients (28.6%) showed some kind of mechanical prosthodontic complications. Six implants (21.4%) were associated with peri-implantitis. Conclusions: This study indicates that treatment of mandibular edentulous patients with overdentures by guided surgery and early loading of implants placed appears to be a successful implant protocol.

ASSESSMENT OF MEAN DISTANCE OF MANDIBULAR INCISIVE CANAL USING CONE BEAM COMPUTERIZED TOMOGRAPHY; A CROSS-SECTIONAL STUDY

Objective: To determine the mean distance of mandibular incisive canal from the mental foramen in patients reporting to a tertiary care centre using Cone Beam Computerized Tomography for placement of dental implants in the anterior/interforaminal region. Study Design: Cross-sectional study. Place and Duration of Study: Department of Prosthodontics, Foundation University College of Dentistry Rawalpindi, Jun to Nov 2019. Methodology: A total of 70 patients participated between the age of 20-45 years. Cone Beam Computerized Tomography (the investigation was carried out and measurements of the mandibular incisive canal from mental foramen were recorded with the help of measuring tools in the software and noted down on the proforma. Data were analyzed using SPSS-20. Results: The number of patients selected for this study was 70. Out of these 70 patients, 33 (47.1%) were males and 37 (52.9%) were females. The mean age of patients in this study was 36.31 ± 6.38 years. The mean distance/extension of the mandibular incisive canal from left mental foramen and right mental foramen in all patients was recorded to be 14.49 ± 6.31 mm and 14.97 ± 7.10 mm respectively. Conclusion: Within the limitations of this study, it is concluded that a maximum distance of 22mm of the incisive canal from the mental foramen was observed using cone-beam computerized tomography.

Sinus Augmentation—Expect the Unexpected: Diagnostic Anatomical Study

“Big-nose variant” is an anatomical phenomenon defined as the pneumatization of inferior third of the nasal cavity within the alveolar ridge while simultaneously displacing the maxillary sinus laterally. The purpose of the present study was to assess the prevalence of the big-nose variant phenomenon and suggest a morphology classification system. Diagnostic anatomical evaluation was performed in a tertiary medical center on 321 randomly selected maxillary cone beam computerized tomography scans of patients who presented at an oral and maxillofacial department. Two anatomical categories were defined for anatomical identification: classes for horizontal mesiodistal distribution, and divisions for vertical distribution. Class 2, defined as location of the nasal/sinus border between the distal edge of the canine up to the distal edge of second premolar, was found to be the most prevalent (64.6%). Class 3, defined as location of the nasal/sinus border distal to mesial edge of the first molar, was found in 17.9% of cases. Regarding the divisions category, in 96% and 58.2% of teeth examined, nasal cavity alone was found to be superior to the canine and first premolar, respectively, defined as Division A. In 46.9% and 85.6% of teeth examined, maxillary sinus alone was located above the second premolar and first molar, respectively, defined as Division C. Identifying Class 3 on the paraxial reconstruction is the first step in identifying big-nose variant, with further assurance gained from each determining division. The use of the classes and divisions may enable better maxillary treatment planning, alert surgeons for the unexpected, and avoid complications.

Morphometric bone assessment of men and women in different age range by cone beam computerized tomography

Osteoporosis corresponds to a decrease in bone mass and micro-architectural deterioration of bone tissue, causing bone fragility and risk of fractures. Although osteoporosis is four times more common in women than in men, they tend to have more complications with a higher risk of mortality after hip fracture. The silent nature of osteoporosis causes delays in early diagnosis, compromising adequate treatment. The objective was to evaluate bone morphometry and correlate morphometric indices between men and women, and between women of different age groups. The sample was divided into: men aged 65 to 75 years (A); women from 45 to 55 years (B1); women from 56 to 65 years (B2) and women from 66 to 75 years (B3). The morphometric indices Computed Tomography Cortical Index (CTCI), the Computerized Tomography Mental Index (MI), the Upper Mandibular Computerized Tomography Index (MCTI-U) and the Lower Mandibular Computed Tomography Index (MCTI-L) were analyzed by through the OnDemand3D software. There were significant differences between the different groups in MI, MCTI-L and MCTI-U and a high correlation between the indices. There was no difference in CTCI when used alone. There are differences in the bone structure of men and women, and between women of different age groups, and the quantitative and qualitative indices can be a useful tool in detecting patients with low bone density when used together for subsequent referral for bone densitometry and specialized medical treatment.

Innovative Non-Irradiating and Non-Invasive Per Fraction Control System in Radiotherapy: Surface-Guided Radiation Therapy Experience of Casablanca Cancer Center

Purpose: Evaluation of the added value of radiotherapy guided by the cutaneous surface in the positioning and monitoring of the radiotherapy Patients and Methods: This study included 21 consecutive patients treated with an accelerator dedicated to "True Beam®" stereotactic radiotherapy whose sessions were monitored by an Optical Surface Monitoring System: "OSMS®". Excluded from our study were treatments controlled exclusively by radiological imaging (IGRT). Positioning variabilities were compared between conventional imaging and skin surface infrared (OSMS) monitoring. Conventional imaging was in the form of standard radiography (KV) performed during the treatment session or three- dimensional by a series of Cone Beam computerized tomography (CBCT) scanned images made at the beginning and end of The total time of the session and the positioning variability’s in the 3 planes were 14 Results: The results of our study show that the cutaneous surface monitoring allowed to obtain a faster alignment of the patient with an improvement in the overall time of the session with a mean at 32% [14.5-49.27%], likewise a sub-millimeter positioning quality for all locations with a median longitudinal distance of 0.02 cm [0-0.66], 01 cm verticality [0-0.32] and laterality 0.02 cm [0-0.77] This benefit is significantly greater for cerebral and Head and neck’s localizations 21 Conclusion: Optical Surface Monitoring System (OSMS®) is a non-invasive and non- irradiating means that allows reliable and fast

A zygomatic bone study using virtual dental implant planning software

This study evaluated the anatomical factors that influence the virtual planning of zygomatic implants by using cone beam computerized tomography (CBCT) scans. CBCT scans of 268 maxilla edentulous patients were transferred to a specialized implant planning software (Galaxis, Sirona) for the following measurements: maxillo-sinus concavity size (small, medium, and large), Zygoma width, implant insertion angle, implant length, and implant apical anchorage. Concavity sizes found were as follows: 34.95% small, 52.30% medium, and 7.35% large. The mean insertion angle was 43.2 degrees and the average implant apical anchorage was 9.1mm. The most frequent implant length was 40mm. Significant differences were found when the different types of concavities in relation to the installation angle, the distance of the apical portion of the implant in contact with the zygomatic bone and the lateral-lateral thickness of the zygomatic bone were compared (p<0.001). Medium-sized maxillary sinus concavity presented greater apical anchorage of the implant (9.7mm) and was the most frequent type (52.30%). The zygomatic bone is a viable site for zygomatic fixtures and the use of specialized implant planning software is an important tool to achieve predictable outcomes for zygomatic implants and allows good visualization of the implant-anatomical structures relation.