Detection of different foreign bodies in the maxillofacial region with spiral computed tomography and cone-beam computed tomography: An in vitro study.

PURPOSE: The detection and exact localization of penetrating foreign bodies are crucial for the appropriate management of patients with dentoalveolar trauma. This study compared the efficacy of cone-beam computed tomography (CBCT) and spiral computed tomography (CT) scans for the detection of different foreign bodies composed of 5 frequently encountered materials in 2 sizes. The effect of the location of the foreign bodies on their visibility was also analyzed. MATERIALS AND METHODS: In this in vitro study, metal, tooth, stone, glass, and plastic particles measuring 1×1×1 mm and 2×2×2 mm were prepared. They were implanted in a sheep's head in the tongue muscle, nasal cavity, and at the interface of the mandibular cortex and soft tissue. CBCT and spiral CT scans were taken and the visibility of foreign bodies was scored by 4 skilled maxillofacial radiologists who were blinded to the location and number of foreign bodies. RESULTS: CT and CBCT were equally accurate in visualizing metal, stone, and tooth particles of both sizes. However, CBCT was better for detecting glass particles in the periosteum. Although both imaging modalities visualized plastic particles poorly, CT was slightly better for detecting plastic particles, especially the smaller ones. CONCLUSION: Considering the lower patient radiation dose and cost, CBCT can be used with almost equal accuracy as CT for detecting foreign bodies of different compositions and sizes in multiple maxillofacial regions. However, CT performed better for detecting plastic particles.

Comparison of Bolton ratio in normal occlusion and different malocclusion groups in Iranian population.

OBJECTIVES: Bolton ratio is used as a method for diagnosis of tooth size discrepancy. Tooth size discrepancy has an important role in the stability of results of final orthodontic treatment. The aim of this study was to determine and compare Bolton ratio in normal occlusion and different malocclusion groups of Iranian population. MATERIALS AND METHODS: This descriptive-analytic study comprises 240 orthodontic patient casts (for every malocclusion group: class I, class II division 1, class II division 2, class III, 30 males and 30 females) which have fully erupted and complete permanent dentitions from first molar to first molar, and also 60 persons (30 male-30 female) with normal occlusion. The mesiodistal tooth sizes were measured using digital caliper two times with a 4-week interval. RESULTS: The average mesiodistal size of all teeth in the malocclusion group was significantly bigger than in the normal occlusion group. Although there was no relationship between anterior ratio and gender or malocclusion groups, but a significant relationship between total ratio in Class II division 1 and normal occlusion was seen. Furthermore, a significant difference between anterior and total ratios in the present study and original Bolton's values was found. CONCLUSIONS: In the normal occlusion group, the anterior and total ratios were bigger than those in Bolton's original study. Also, "class II division 1" showed the lowest values of Bolton ratio among the other normal occlusion and malocclusion groups. Therefore, the original Bolton's values should be used conservatively in Iranian population.

Effects of facemasks versus intraoral appliances in treating maxillary deficiency in growing patients: A systematic review and meta-analysis.

BACKGROUND: Class III malocclusion is one the most challenging types of orthodontic problems. OBJECTIVES: The aim of this study was to compare the dentoskeletal effects of facemasks and intraoral appliances in treating class III maxillary deficiency in growing patients through a systematic review of the available literature. MATERIAL AND METHODS: Electronic and manual searches were performed in the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Database of Systematic Reviews (CDSR), MEDLINE (PubMed), Embase (OVID), and Scopus to find all the relevant studies published by January 2018. All randomized controlled trials (RCTs) recruiting 5-12-year-old patients who received maxillary protraction treatment with any type of facemask and comparing the facemasks with any type of intraoral appliance were included. The primary outcome measure was changes in the A point-nasion-B point angle (ANB), and the secondary outcomes included changes in the overjet, upper-1 (U1) inclination, the mandibular plane angle, and treatment time. The meta-analysis was carried out using the inverse variance-weighted random effects model. RESULTS: Out of 1,629 articles found in the initial search, 5 studies met the inclusion criteria. The meta-analysis showed no differences in the duration of treatment or in any of the cephalometric variables, with the exception of the overjet. CONCLUSIONS: It seems that intraoral appliances and facemasks are similar in terms of dentoskeletal effects in the treatment of class III malocclusion as well as treatment duration. However, due to a lack of a sufficient number of high-quality studies, these results should be viewed with caution. Further high-quality, long-term studies are recommended.

Smile attractiveness perception regarding buccal corridor size among different facial types.

BACKGROUND: The width of the buccal corridor (BC) is one of the factors affecting smile attractiveness. OBJECTIVES: The aim of this study was to determine the effects of the BC size on the smile attractiveness of individuals with short, normal and long faces from the viewpoint of laypersons, general dentists and orthodontists. MATERIAL AND METHODS: Smiling photographs of male and female subjects who met the inclusion criteria were digitally altered to create 3 BC sizes (narrow: 2%; normal: 15%; wide: 28%) and 3 facial types defined by the facial index (FI) (short face: FI ≤ 83.9; normal face: 84.0 ≤ FI ≤ 87.9; long face: FI ≥ 88.0). Nine different combinations were made and the evaluators rated the overall attractiveness and acceptability of each smile on a 10-millimeter visual analog scale (VAS). RESULTS: A total of 53 raters (22 laypersons, 16 general dentists and 15 orthodontists) participated in this study. The orthodontists and general dentists had similar viewpoints and they preferred narrow and normal BCs over the wide ones in all facial types. Laypersons preferred normal BC for normal faces, while they did not distinguish different BCs in short faces. CONCLUSIONS: Variations in the BC size affect smile attractiveness in different facial types and wide BCs are attributed to the least attractive smiles. Due to the different viewpoints of laypersons and professionals in this regard, there is no justification for expanding the maxillary arch to achieve more attractive smiles.

Comparison of Dental Panoramic Radiography and CBCT for Measuring Vertical Bone Height in Different Horizontal Locations of Posterior Mandibular Alveolar Process.

STATEMENT OF THE PROBLEM: Accurate measurement of the available bone height is an essential step in the pre-surgical phase of dental implantation. Panoramic radiography is a unique technique in the pre-surgical phase of dental implantations because of its low cost, relatively low-dose, and availability. PURPOSE: This article aimed to assess the reliability of dental panoramic radiographs in the accurate measurement of the vertical bone height with respect to the horizontal location of the alveolar crest. MATERIALS AND METHOD: 132 cone-beam computed tomography (CBCT) of the edentulous mandibular molar area and dental panoramic radiograph of 508 patients were selected. Exclusion criteria were bone abnormalities and detectable ideal information on each modality. The alveolar ridge morphology was categorized into 7 types according to the relative horizontal location of the alveolar crest to the mandibular canal based on CBCT findings. The available bone height (ABH) was defined as the distance between the upper border of the mandibular canal and alveolar crest. One oral radiologist and one oral surgeon measured the available bone height twice on each modality with a 7-dayinterval. RESULTS: We found a significant correlation between dental panoramic radiographs and cone-beam computed tomography values (ICC=0.992, p< 0.001). A positive correlation between the horizontal distance of the alveolar crest to the mandibular canal and measured differences between two radiographic modalities had been found (r=0.755, p< 0.001). For each single unit of increase in the horizontal distance of the alveolar crest to the mandibular canal, dental panoramic radiographs showed 0.87 unit of overestimation (p< 0.001). CONCLUSION: Dental panoramic radiographs can be employed safely in the pre-surgical phase of dental implantation in posterior alveolus of mandible, especially in routine and simple cases.

Factors Affecting Dental Caries of Preschool Children in Shiraz, 2014.

STATEMENT OF THE PROBLEM: Dental caries, the most common infectious disease, can lead to several consequences, including inflammation and bleeding of the gum, abscess formation, tooth loss, and subsequently loss of available space in the arch. PURPOSE: This study was designed to determine dental caries status of Shiraz preschool children and its related factors. MATERIALS AND METHOD: This cross-sectional study was conducted on the children registered in Shiraz kindergartens in 2014. The study recruited 453 children by randomized cluster sampling. We evaluated the children's demographic and oral hygiene factors, and their dental caries status using decayed, missed, and filled tooth (dmft) index and prevalence of the children with untreated dental caries. Relationship between the children's characteristics and their dental caries status was evaluated. RESULTS: Only 119 children (30.1%) were caries-free. The children's mean dmft index was 3.88(±3.9). After controlling the effect of confounding factors, the children's dental caries status was significantly associated with variables indicating their socioeconomic status such as fathers' job, mothers' education, and number of children in the family. Furthermore, there was a significant association between the children's dental caries status and their oral hygiene habits such as frequency of tooth brushing. CONCLUSION: The dental caries status of the studied preschool children was not desirable which could be indicative of the inadequacy of the current preventive programs. To improve this issue, interventional preventive programs such as tooth brushing are recommended. The programs are more necessary for the children of low socioeconomic families and those with poor oral hygiene habits.

Is Mandibular Fossa Morphology and Articular Eminence Inclination Associated with Temporomandibular Dysfunction?

STATEMENT OF THE PROBLEM: Finding a significant relationship between temporomandibular joint (TMJ) morphology and the incidence of temporomandibular dysfunction (TMD) may help early prediction and prevention of these problems. PURPOSE: The purpose of the present study was to determine the morphology of mandibular fossa and the articular eminence inclination in patients with TMD and in control group using cone beam computed tomography (CBCT). MATERIALS AND METHOD: The CBCT data of bilateral TMJs of 40 patients with TMD and 23 symptom-free cases were evaluated. The articular eminence inclination, as well as the glenoid fossa depth and width of the mandibular fossa were measured. The paired t-test was used to compare these values between two groups. RESULTS: The articular eminence inclination and glenoid fossa width and depth were significantly higher in patients with TMD than in the control group (p < 0.05). CONCLUSION: The articular eminence inclination was steeper in patients with TMD than in the control group. Glenoid fossa width and depth were higher in patients with TMD than that in the control group. This information may shed light on the relationship between TMJ morphology and the incidence of TMD.