Panoramic Films Research Articles

The Immersive and Interactive Experience in Virtual Reality Games and Films

Virtual reality technology is one of the modern technologies that have been widely concerned in recent year. Its application in the game and film and television industry has produced many works with new experience, especially in immersion and interactivity. Generally, most available resource nowadays focuses on discuss the feasibility of VR application in innovation of traditional works but lack but there is a lack of discussion on VR games and VR movies from the perspective of creating immersion and interactive methods and effects. This essay will discuss the immersive and interactive effects in VR games and VR films separately. In the first part of VR games, it will elaborate how the effects are provided through the VR hardware. Then in the second part, it will discuss the different design techniques used in different styles of game including action games, horror games, exploration games and serious games. As for the discussion on VR films, this essay will take the two most extensive categories of VR movies, panoramic films and VR documentaries, as examples to discuss how VR films achieve the effect and how the performance is. The overview on the immersive and interactive effects in VR games and VR films can provide examples and problems to be solved for creators to produce higher quality work in the future.

Faster Region‐based Convolutional Neural Networks with You Only Look Once multi‐stage caries lesion from oral panoramic X‐ray images

AbstractNeural networks and artificial intelligence find more applications in dentistry. It treats dental caries, the most prevalent type of dental illness worldwide. Even though dental caries can be prevented and treated, they typically cause dental discomfort and tooth loss. For dental caries to be treated quickly and effectively, comprehensive detection may be needed, a combination of techniques that include eye inspection, probing, using a dental probe, and using a hand‐held mirror, and the individual application of each of these techniques, can quickly identify large caries cavities. Long‐established caries detection techniques help to locate only partially hidden but still accessible holes. Deep learning (DL) techniques have produced remarkable diagnostic results in radiology. This study aimed to classify various radiographic extensions on panoramic films using DL techniques, identify caries lesions using these techniques, and compare the results to those of dentists with extensive training. Faster region‐based convolutional neural networks (R‐CNN) is a newly discovered field of medical research that is rapidly expanding and has produced outstanding results in diagnosing and prognosis of pathology and radiology conditions. In this study, dental cavities were detected and analysed using periapical radiographs to evaluate the accuracy of the Faster R‐CNN algorithm. Because these three caries were derived from the oral panoramic images, we designed You Only Look Once Version 3 (YOLOv3) as a U‐shaped network with a large‐scale axial attention module. We also compare the effectiveness of YOLOv3's segmentation to that of other industrial standards. Experiments show that our proposed method, Fast R‐CNN–YOLOv3, achieves higher accuracy in segmenting the three distinct caries level. The proposed model (R‐CNN–YOLOv3) achieved an effective result with a precision of 97.183%.

Evaluation of immediate implant placement with osteotome sinus floor elevation without graft material.

Significant difficulties can be encountered when installing posterior maxillary implants. Osteotome sinus floor elevation (OSFE) enables insertion of implants with insufficient bone height at the posterior maxilla using a special instrument known as the "osteotom." This study aimed to evaluate the implant survival rates and radiographical bone gain data after OSFE with simultaneous implant placement performed without grafting material. Further, we have discussed whether the osteotom tapping distance to sinus floor affects the amount of new bone gain (NBG). Forty dental implants were inserted in 36 patients (20 women and 16 men) aged between 24 and 80 years (mean = 55.7 years). Residual bone height and NBG were analyzed using a commercially available software program on panoramic films. The mean residual bone height at the intended implant sites was 5.4 mm ± 2.2 mm, ranging from 3.5 mm to 6.9 mm. The mean NBG was 1.5 mm ± 0.87 mm, ranging from 0.1 mm to 4 mm. At 64.4 months of follow-up, one implant had been lost in the osseointegration period. The remaining 39 implants were in function, with a survival rate of 97.5%. No significant difference was seen between the osteotome tapping distance to sinus floor and NBG at the implant apex (P = 0.395). OSFE without using bone grafts with simultaneous implant installation is a safe and reliable method with successful long-term results for he rehabilitation of edentulous posterior maxillae.

Deep learning based dental implant failure prediction from periapical and panoramic films.

Dental implant failure is a critical condition that can seriously compromise therapeutic efficacy. Insufficient bone volume, unfavorable bone quality, periodontal bone loss, and systemic conditions, including osteopenia/osteoporosis and diabetes mellitus, have been associated with implant failure. Early indicators of potential implant failure could help mitigate the risk of severe complications. This study aimed to develop an effective implant outcome prediction model using dental periapical and panoramic films. A total of 248 patients (89 with failed implants and 159 with successful implants) were examined. A total of 529 periapical images and 551 panoramic images were collected from the patients for a deep learning-based model. Based on radiographic peri-implant alveolar bone pattern, implant outcome was divided into three categories: implant failure with marginal bone loss, implant failure without marginal bone loss, and implant success. We extracted features using a deep convolutional neural network (CNN) and built a hybrid model to combine periapical and panoramic images. A comparison among three categories of receiver operating characteristic (ROC) curves was performed. The diagnostic accuracy, precision, recall and F1-score of the dataset were assessed. Our model achieved an AUC (area under the ROC curve) of 0.972 for failure with marginal bone loss, 0.947 for failure without marginal bone loss and 0.975 for success. In all conditions, for periapical images alone, the diagnostic accuracy was 78.6%; the precision was 0.84, recall was 0.73, and F1-score was 0.75. For panoramic images alone, the diagnostic accuracy was 78.7%; the precision was 0.87, recall was 0.63, and F1-score was 0.66. Both periapical and panoramic images were used in our novel method, and the prediction accuracy was 87%. The precision was 0.85, recall was 0.88, and F1-score was 0.85. The deep learning model used features from periapical and panoramic images to effectively predict the occurrence of implant failure and might facilitate early clinical intervention for potential dental implant failures.

Evaluation of Panoramic Radiographs of Totally Edentulous Jaws: A Retrospective Study

Aim: This retrospective study aimed to determine the incidence of random findings in digital panoramic images acquired from edentulous patients presenting for conventional prosthetic rehabilitations or implant-supported dentures. Materials and Methods: In this retrospective study, of the patients aged 16 years and older, 950 of 1100 panoramic films were evaluated by two maxillofacial radiologists (MA and IBY) in ambient light on an LCD monitor. The final classification and radiographic status of each finding were recorded after inter-observer consensus. Radiographs with low image quality and artifacts that did not include the demographic information of the patients were not included in the study. In the present study; impacted teeth, root remnants, radiolucent (RL) lesions, radiopaque (RO) lesions (including idiopathic osteosclerosis), foreign bodies, crest atrophies, soft tissue calcifications, maxillary sinus opacities, and Stafne bone defects were examined. Lesions affecting the alveolar region were divided into three regions as anterior (incisors and canines region), premolars and molars region. Results: Tonsillitis was observed in a total of 55 individuals, 26 men and 29 women. Sialolith was seen in a total of 3 patients, 2 male and 1 female, but phleboliths were not found in any of them. Styloid ligament ossification(SLO) was seen in a total of 125 patients, 69 of these cases were female and 56 were male, however calcified atherosclerotic plaque is the most common calcification with 156 individuals and a rate of 16.4% among calcifications. Laryngeal cartilage calcification, which is seen in 36 female and 23 male individuals. Conclusion: The outcome of this study indicated that the ratio of advantageous findings fixed in digital panoramic images of totally edentulous patients was highly rated. There are indispensable for patients with total edentulism such as routine use and careful examination of panoramic images.

Efficacy of machine learning assisted dental age assessment in local population

IntroductionAlthough the dental age assessment is commonly applied in forensic and maturity evaluation, the long-standing dilemma from population differences has limited its application. ObjectivesThis study aimed to verify the efficacy of the machine learning (ML) to build up the dental age standard of a local population. MethodsWe retrospectively studied 2052 panoramic films retrieved from healthy Taiwanese children aged 2.6–17.7 years with comparable sizes in each age-group. The recently reported Han population-based standard (H method) served as the control condition. To develop and validate ML models, random divisions of the sample in an 80%–20% ratio repeated 20 times. The model performances were compared with the H method, Demirjian’s method, and Willems’s method. ResultsThe ML-assisted models provided more accurate age prediction than those non-ML-assisted methods. The range of errors was effectively reduced to less than one per year in the ML models. Furthermore, the consistent agreements among the age groups from preschool to adolescence were reported for the first time. The Gaussian process regression was the best ML model; of the non-ML modalities, the H method was the most efficacious, followed by the Demirjian’s method and Willems’s methods. ConclusionThe ML-assisted dental age assessment is helpful to provide customized standards to a local population with more accurate estimations in preschool and adolescent age groups than do studied conventional methods. In addition, the earlier complete tooth developments were also observed in present study. To construct more reliable dental maturity models in the future, additional environment-related factors should be taken into account.

王维诗歌画家视角下的审美观照

When it comes to Wang Wei, it is inevitable to think of “Painting in poetry and poetry in painting”. With the changes of the times and different research perspectives, many scholars have questioned and supplemented this evaluation. It is considered that this evaluation “underestimates” Wang Wei’s achievement sin poetry. His poetry not only achieves a lot in “painting”, but also has fluidity and musicality. It is more like an excellent “panoramic film” integrating landscape and nature. Wang Wei has the perspective of a photographer, the layout of a director, the literary talent of a screen writer and the talent of a sound recorder. Taking Wang Wei’s scenery poetry as the research object, this paper analyzes the unique aesthetic quality embodied in his poetry creation from the painter’sper spective. Wang Wei’s poetry has the composition from the painter’s perspective, with the structure of poetry and ingenious image management, so his creation reflects the aesthetic contemplation with philosophical characteristics. His poetry adequately reflects the artistic conception of emptiness and tranquility created under the aesthetic contemplation of his unique characteristics as well as his attitude towards life as reflected.

Erzincan Bölgesinde Yaşayan Çocuklarda Üçüncü Molar Dişlerin Konjenital Eksikliğinin Araştırılması

Background:In this study, it was planned to retrospectively determine the congenital deficiencies of the third molars in 1460 panoramic films of pediatric patients in the Erzincan region and to examine the distribution according to gender and location in the jaws. Methods:This retrospective study was conducted at Erzincan Binali Yıldırım University, Faculty of Dentistry from June 2018 - January 2020. 1460 patients(752 females and 708 males) between the ages of 10-14 were studied with panoramic radiograph to assess for agenesis of mandibular third molars. Statistical data were analyzed in SPSS 22 program. The Pearson chi-square test was performed for determining the prevalence of congenitally agenesis of the third molar teeth. Results:The prevalence of third molar teeth agenesis was 35.6 %. Total numbers of patients with single third molar missing were 222(15.5 %). The ratio of the prevalence of third molar agenesis for females(38 %) was higher than that for males(33 %). Significantly more third-molar teeth were found to be missing from the maxilla(57 %) than the mandible(43 %). 529 patients(54 %) had agenesis only on the right side and 469 patients(46 %) had agenesis only on the left. Conclusion:The agenesis of the third molars was investigated in pediatric patients living in Erzincan province and its prevalence was found 35.6 %. Congenital deficiency of the third molar teeth is more common in women, while it has been observed more in the maxilla than in the mandible. More comprehensive studies can be done by increasing the number of individuals examined.

The Application of Artificial-Intelligence-Assisted Dental Age Assessment in Children with Growth Delay.

Background: This study aimed to reveal the efficacy of the artificial intelligence (AI)-assisted dental age (DA) assessment in identifying the characteristics of growth delay (GD) in children. Methods: The panoramic films matching the inclusion criteria were collected for the AI model training to establish the population-based DA standard. Subsequently, the DA of the validation dataset of the healthy children and the images of the GD children were assessed by both the conventional methods and the AI-assisted standards. The efficacy of all the studied modalities was compared by the paired sample t-test. Results: The AI-assisted standards can provide much more accurate chronological age (CA) predictions with mean errors of less than 0.05 years, while the traditional methods presented overestimated results in both genders. For the GD children, the convolutional neural network (CNN) revealed the delayed DA in GD children of both genders, while the machine learning models presented so only in the GD boys. Conclusion: The AI-assisted DA assessments help overcome the long-standing populational limitation observed in traditional methods. The image feature extraction of the CNN models provided the best efficacy to reveal the nature of delayed DA in GD children of both genders.

Evaluation of the clinical efficacy and safety of modified alveolar cleft bone graft with cone-beam CT digital imaging in children.

BackgroundCone-beam computed tomography (CBCT) is used to observe the bone density and bone height in children with modified alveolar bone graft (ABG) at different times after operation. In this study, the changes of labial-palatal bone mass in the stable period of bone union and in the bone graft area were investigated to provide reference for subsequent treatment.MethodsA total of 140 pediatric patients with unilateral complete alveolar cleft were selected and routinely underwent iliac bone grafting. The original data obtained by ProMax 3D (Planmeca) examination were stored in DICOM format at 3 and 6 months postoperatively, and the images were reconstructed by Simplant software (Dentsply Sirona). The bone density of the healthy side was measured at 3 months and 6 months, and the results were expressed as Hounsfield units (HU). The labial and palatal bone height at the bone graft site at 3 and 6 months postoperatively was classified according to the modified Bergland classification method, and was compared with panoramic film classification.ResultsMean bone density at 3 months after surgery (385.4800±78.39770 HU) was not significantly different from that at 6 months (356.1875±73.67164 HU; P>0.05). There were significant differences between the classification of lip and palatal bone height 3 months after operation and that of the classification of panorama film in the same month (P<0.05); between the classification of lip and palatal bone height 6 months after surgery compared with that of panorama film of the same month (P<0.05); and between the classification of bone height degree in labial, palatal, and panoramic slices at 3 months after operation and that at 6 months after operation (P<0.05).ConclusionsThe labial and palatal classification is different, and the bone height classification 6 months after surgery is lower than that 3 months after surgery, indicating the persistence of bone resorption. CBCT can objectively evaluate the bone quality in the bone graft area, which has clinical application value for surgical evaluation value and posttreatment guidance.

The Battle at Lake Changjin: A National Aesthetic Paradigm for Chinese Blockbusters

Abstract The significance of The Battle at Lake Changjin (Changjinhu, 2020) arguably lies in its shaping of a national aesthetic paradigm for Chinese blockbusters. This is mainly reflected in its creation of a panoramic film structure, constructing a solemn yet generous aesthetic style, forming the image of Chinese heroes, casting a consciousness between family and country, and rewriting historical justice through an aestheticized depiction. Behind the film’s latest success at the box office lies the enlightenment in Chinese blockbusters’ exploration of a national aesthetic paradigm: Chinese blockbusters need to firmly progress through this newly developed national-image aesthetic paradigm and continue exploring diverse aesthetic styles.

Farklı Maloklüzyonların Ortodontik Tedavisinde Maksiller Sinüs Boyutlarındaki Değişimin Belirlenmesi

Background: Craniofacial growth-development has a complex and multifactorial structure. According to functional matrix theory, soft tissues change the development direction of hard tissues and affect the sinus cavities within the cranial structure. The objective of this study is to determine the change in the maxillary sinus dimensions after orthodontic treatments according to malocclusion groups. Methods: Our study comprises 51 individuals who have met the admission criteria. Our study was carried out retrospectively. The individuals included in the study have been analyzed in terms of malocclusion groups by comparing their maxillary sinus dimensions on panoramic films. Results: The intended base length, planar length of the maxillary sinus, and the area measurements of the maxillary sinus have been found to be different at pre-treatment and post-treatment in terms of malocclusion. In Class I, the post-treatment maxillary sinus indentation base length has decreased, and the average planar base length and the maxillary sinus area has increased, and in Class II, the post-treatment maxillary sinus indentation base length and the average planar base length has increased, the maxillary sinus area has decreased, and in Class III, The post-treatment maxillary sinus indentation base length and the average planar base length has decreased, and the maxillary sinus area has increased compared to the pre-treatment. Conclusion: There have been changes in the sinus dimensions of Class I, II, and Class III patients who have received orthodontic treatment compared to the pre-treatment. The changes in the possible craniofacial structures before orthodontic treatments should be taken into consideration carefully, and the dental treatments to be applied should be decided after such considerations.

Comparison of Prognostic Indicators of Maxillary Impacted Canine using OPG (Orthopantomogram) with CBCT (Cone Beam Computed Tomography)

OBJECTIVES: The aim of the present study was to compare OPG (orthopantomogram) in locating impacted canines with CBCT (cone beam computed tomography) scans of the same patients. METHODOLOGY: The cross-sectional study was carried out on the OPG (orthopantomogram) and CBCT (Cone-Beam Computed Tomography) of 27 patients (17 females and 10 males) presenting with impacted permanent maxillary canines. Thirty-five impacted canines were subsequently assessed on the four guidelines devised by McSherry and Pitt and applied to the panoramic films and CBCT scans. RESULTS: The results show weak agreement for the canine’s angle to the midline and the canine’s horizontal root apex position (k value=0.55, 0.46, respectively). Moreover, significant differences were found between the OPG (orthopantomogram) and the CBCT (Cone-Beam Computed Tomography) for all the variables using Chi-square and Fisher’s exact test (p=.000) CONCLUSION: The results showed a significant difference in the 2D and 3D images of impacted maxillary canines, which can produce different diagnoses, and therefore treatment plans. OPG (Orthopantomogram) cannot be completely relied upon for the routine diagnosis of impacted canines.

Plaster Panoramic Method: A quintessential approach for beading &amp; boxing of impressions

Reproduction of an error-free cast forms the foundation on which the final restoration is made. Successful rehabilitation of the complete denture (CD) depends on the accurate reproduction of width and depth of the cast including both artistic and anatomic portion. A very important step deciding the success of CD is Beading and Boxing. It is mainly performed to achieve the artistic portion of the cast i.e. land area and base of the cast along with preservation of the details of the final impression particularly the vestibular area. A plethora of techniques for beading & boxing along with their implications have been discussed thoroughly in literature. The present technique involves the modification of the beading & boxing steps i.e. plaster beading and boxing with the help of an old & used panoramic film of a patient. This technique is swift, immaculate, simple, practical, efficient, economical and can be adopted in case of final impressions with both zinc-oxide eugenol as well as elastomeric impression materials to achieve a smooth, accurate, aesthetically pleasing cast with accurate borders.

Treatment of a Class II Hyperdivergent Case with Progressive Condylar Resorption

Condylar resorption can be challenging to orthodontist when encountered during treatment. The clinical characteristics and cephalometric findings of a patient who experienced postoperative skeletal relapse caused by progressive condylar resorption (CR) are presented in this case report. The predisposing factors and treatment protocols of condylar resorption are also discussed. A 17-year-old female patient came to our hospital with chief complaint of no contact of anterior teeth. Cephalometric analysis shows that she is a patient with skeletal Class II hyper-divergent pattern caused by mandibular retrognathism. Flattened left condylar head was found on panoramic film suggesting possible condylar erosion in the past. Before starting her treatment, the superimposition of serial cephalometric films was done, and no active resorption of condyles were found. After four months of pre-surgical orthodontic treatment, a two-jaw surgery was performed. However, an increase in overjet was noticed nine months after that. Cephalometric superimposition revealed a decrease in ramus height indicating a skeletal relapse due to CR. Inter-arch elastics was stopped to eliminate the loading on temporomandibular joint (TMJ), and vitamin D plus calcium supplementation was prescribed. Condyle remained stable throughout the rest of the treatment. Total treatment time is 36 months, and satisfactory facial profile and occlusion have been achieved. CR is attributable to young female, Class II hyperdivergent skeletal pattern, posteriorly inclined condylar neck, estrogen deficiency, and pre-existing TMJ disorder. Mandibular advancement over 10 mm, posteriorly displaced condyles, and counterclockwise rotation of the proximal and distal segment are high-risk surgical factors. Impact of CR can be minimized by making the correct diagnosis, optimal orthodontic or orthodontic-surgical planning, and periodic check up on condylar condition.

Effects of Gender and Age in Mandibular Leeway Space for Taiwanese Children.

Purpose: Leeway space is clinically crucial in pediatric dentistry because it is utilized to resolve tooth crowding and allow the first molars to drift mesially to establish a Class I molar relationship in the later stages of mixed dentition. This study investigated leeway space in the mixed dentition of Taiwanese children of different sexes and ages. Materials and Methods: The digital panoramic dental films of 182 lower arches of 119 boys and 63 girls aged 5–10 years were analyzed in this retrospective study. The mesiodistal crown widths of the primary canines and first and second molars and the permanent canines and first and second premolars were measured using medical imaging software. Differences in leeway space were statistically analyzed. Results: The average leeway space was 1.29 ± 1.48 mm on each side of the lower arch. The leeway space of children aged 5–6 years was significantly greater than that of children aged 7–8 years. No gender difference in crown width was discovered, except with regard to the primary first molar. Although no gender difference in leeway space was observed, permanent teeth affected leeway space more for girls than for boys. Conclusion: In Taiwanese children, although leeway space does not differ by sex, age affects leeway space. However, permanent tooth size has an influence on the leeway space of girls.

Effects of removable functional orthodontic apparatus on mandibular condyle bone quality

Aim: This study aims to compare the impact of dynamic functional orthodontic appliances on mandibular condyle bone density in patients with Class I, Class II, and Class III malocclusion during their growth and development phases.&#x0D; Methodology: The histories of patients with three separate malocclusions who received dynamic functional orthodontic appliance treatment were analyzed in this retrospective study. Twenty-eight patients met the inclusion criteria and were divided into four groups: maxillary expansion devices (Group A), twinblock/monoblock devices (Group B), face masks (Group C), and chincups (Group D). The fractal analysis approach was used to determine the mandibular condyle bone density by analyzing panoramic films taken from the patients at the beginning (T0) and end (T1) of treatment.&#x0D; Results: In Groups A and B, the results of the mandibular condyle bone fractal analysis decreased at the end of treatment compared with the pre-treatment results (p &lt; 0.05). In Groups C and D, the post-treatment results were better than the pre-treatment ones (p &lt; 0.05).&#x0D; Conclusion: Among the different malocclusion groups, some dynamic functional orthodontic appliances (maxillary expansion and twinblock/monoblock devices) enabled an increase in bone density in the mandibular condyle, while some (face masks and chincups) decreased the density. It is important to conduct orthodontic treatment by analyzing the results obtained with the use of these appliances.&#x0D; &#x0D; How to cite this article: Yüzbaşıoğlu Ertuğrul B. Effects of removable functional orthodontic apparatus on mandibular condyle bone quality. Int Dent Res 2021;11(Suppl.1):7-11. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.2&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Deep Learning for Caries Detection and Classification.

Objectives: Deep learning methods have achieved impressive diagnostic performance in the field of radiology. The current study aimed to use deep learning methods to detect caries lesions, classify different radiographic extensions on panoramic films, and compare the classification results with those of expert dentists. Methods: A total of 1160 dental panoramic films were evaluated by three expert dentists. All caries lesions in the films were marked with circles, whose combination was defined as the reference dataset. A training and validation dataset (1071) and a test dataset (89) were then established from the reference dataset. A convolutional neural network, called nnU-Net, was applied to detect caries lesions, and DenseNet121 was applied to classify the lesions according to their depths (dentin lesions in the outer, middle, or inner third D1/2/3 of dentin). The performance of the test dataset in the trained nnU-Net and DenseNet121 models was compared with the results of six expert dentists in terms of the intersection over union (IoU), Dice coefficient, accuracy, precision, recall, negative predictive value (NPV), and F1-score metrics. Results: nnU-Net yielded caries lesion segmentation IoU and Dice coefficient values of 0.785 and 0.663, respectively, and the accuracy and recall rate of nnU-Net were 0.986 and 0.821, respectively. The results of the expert dentists and the neural network were shown to be no different in terms of accuracy, precision, recall, NPV, and F1-score. For caries depth classification, DenseNet121 showed an overall accuracy of 0.957 for D1 lesions, 0.832 for D2 lesions, and 0.863 for D3 lesions. The recall results of the D1/D2/D3 lesions were 0.765, 0.652, and 0.918, respectively. All metric values, including accuracy, precision, recall, NPV, and F1-score values, were proven to be no different from those of the experienced dentists. Conclusion: In detecting and classifying caries lesions on dental panoramic radiographs, the performance of deep learning methods was similar to that of expert dentists. The impact of applying these well-trained neural networks for disease diagnosis and treatment decision making should be explored.

Evaluation of apical root resorption in Class III patients who received one- or two-phase orthodontic treatment

Objectives: The aim of this study was to compare the incidence root resorption and dilaceration between the patients with and without previous orthopedic treatment after the fixed orthodontic treatment. Materials and Methods: The pre- and post-treatment digitized panoramic films of 40 Class III adult patients meeting the inclusion criteria were selected from patient population of the orthodontic department. Half of the patients were treated with two-phase treatment (orthopedic therapy followed by fixed appliance treatment; Group 1), while the others wore only fixed appliances (Group 2). Root resorption was evaluated from the first molar to the first molar for each arch using the ImageJ software (Bethesda, Maryland, USA). The presence of root dilacerations was also recorded on the pre-treatment panoramic radiographs. Paired samples t-test and Mann– Whitney U-test were used to compare root length. Results: Intragroup comparisons for each tooth indicated that the upper and lower incisors, first molars and upper left second premolars presented a significant decrease in Group 1 (P &lt; 0.05). In contrast, in Group 2, a significant decrease in tooth length was found only in the upper incisors (P &lt; 0.05). Intergroup comparisons for root length change indicated statistically significant differences for the lower incisors, upper second premolars, and all first molars except for the upper left molars (P &lt; 0.05). Nevertheless, the prevalence of root dilaceration in Group 1 was higher than that in Group 2. Conclusion: Class III patients who received two-phase treatments experienced more root resorption and dilaceration compared with patients who received one-phase treatments. It should be remembered that early orthopedic forces may have potential adverse effects on a dental root in the long-term.

Prevalence of Radiographic Anomalies and Abnormalities on Panoramic Films in the Pakistani Population

OBJECTIVES: Orthopantomogram (OPG) is a dental radiograph that captures the maxillofacial region in a single image for quick assessment of the dental arches and their surrounding structures. It can be used for treatment planning and analysis of jaw-related pathologies. Prior studies have demonstrated geographical variations in radiographic anomalies and pathologies, our purpose was to establish baseline statistics for the Pakistani population, so the Pakistani dentists are able to distinguish between anomalies and pathologies and provide appropriate care when needed. METHODOLOGY: A cross-sectional study design was used to analyze de-identified 2411 OPGs taken for routine dental care at the dental clinics of Riphah International University. These were broadly classified according to site. Data was documented on SPSS version 22 and presented as frequencies. RESULTS: From a total of 2,411 OPGs, 2326 met the inclusion criteria. The mean age of the patients was 29.06±17.99 years. Our findings included pneumatization of the maxillary sinus in 9.8%, pathological findings in the sinus in 3.9%, deflected nasal septum in 7.5%, alveolar bone loss in 32.7%, elongated styloid process in 12.1%, pathological finding associated with maxillary bone in 1.4% and mandibular bone in 2.1%. CONCLUSIONS: Our results were somewhat unique when compared with studies from other geographical locations. We established baseline statistics about the common anomalies and abnormalities noted in dental radiographs for the Pakistani population. KEY WORDS: Orthopantomogram, anomalies, mandible, maxilla