Changes of the posterior airway space following orthognathic surgery in class III

Objective: Adaptation of the pharyngeal airway space does occur after different surgical strategies of class III patients including mandibular setback, maxillary advancement and bimaxillary surgery. The aim of this study is to conduct a detailed cephalometric evaluation of the alterations taking place in the morphology of the pharyngeal airway space after treatment of class III skeletal deformity via different surgical procedures [i.e. mandibular setback, maxillary advancement, bimaxillary surgery] in both males and females

Methods: This study is a before-after cross sectional retrospective research. One hundred and twenty consecutive patients who were diagnosed as having skeletal class III deformity. All patients included in this study were adults who had completed their growth and had cephalograms within a month prior to operation [T1] and 1 month to 9 months post-surgery [T2] taken in the natural head position. Patients were divided according to the type of surgery undertaken in three groups: group 1 [bimaxillary], group 2 [mandibular setback] and group 3 [maxillary advancement] surgeries. Posterior airway size was evaluated at both T1 and T2 in each group. The results were compared by paired t and one-way ANOVA tests

Results: Airway size decreased significantly in group 1 and 2 [p<0.05] but increased in group 3[p<0.05]

Conclusion: Airway dimension and morphology as well as head and neck posture changed significantly in different surgical treatments of class III deformity

feasibility of ultrasonography in defining the size of jaw osseous lesions

Statement of the Problem: Jaw bone lesions are common pathologic conditions. The role of ultrasonography in evaluation of the extra-osseous lesions is confirmed, however, this imaging modality is not the diagnostic routine for the intraosseous jaw lesions

Purpose: The purpose of this study was to evaluate the efficiency of ultrasonography in diagnosis of intra-osseous jaw lesions concerning their size and content and also to study its correlation with the histopathological findings

Materials and Method: For this study, 15 patients with intra-osseous jaw lesions in the maxilla and mandible were selected from those referred to the Department of Oral Surgery. Panoramic imaging, computed tomography [CT] or cone beam computed tomography [CBCT] and ultrasonography [USG] were performed for all the lesions. The size of the lesions was measured by USG and then compared with CT or CBCT. Moreover, the correlation amongst the echographic patterns and histopathologic results was evaluated

Results: In 12 cases, size values were in complete agreement with CT or CBCT. The size of 3 lesions could not be measured by the radiologist due to the thickness of buccal cortical plate

Conclusion: Findings of this study suggested that USG might be feasible in estimating the size of intra-osseous jaw lesions with little underestimation. This study also confirmed that ultrasound imaging was a very useful imaging technique which could provide significant diagnostic information regarding the content of jaw bone lesions where the buccal bone thickness was thin enough

Comparison of panoramic radiography with cone beam CT in predicting the relationship of the mandibular third molar roots to the alveolar canal

PURPOSE: Preoperative radiographic assessment of the mandibular third molars is essential to prevent inferior alveolar nerve damage during extraction. The purpose of this study was to assess the reliability of panoramic signs of association between the roots of teeth and the canal, and to compare the panoramic signs with cone beam computed tomography (CBCT) findings. MATERIALS AND METHODS: CBCT images of 132 impacted mandibular third molars were evaluated to determine the association of the root to the canal. The CBCT findings were compared with the corresponding panoramic images. Logistic regression analysis was used to define the diagnostic criteria of the panoramic images. RESULTS: Among the panoramic signs, loss of the cortical line was the most frequent radiographic sign predicting association (sensitivity: 79.31). Contact of the tooth with the canal was observed in all cases in which the loss of cortical line of the canal or darkening of the roots was found on the panoramic radiographs. CONCLUSION: Darkening of the roots and loss of the cortical line on panoramic radiographs might be highly suggestive of the risk of nerve injury.

Ultrasonographic findings of mesenchymal chondrosarcoma of the mandible: report of a case

Today, ultrasound imaging is being widely used to assess soft tissue lesions in the maxillofacial region. However, ultrasound investigations of intra-osseous lesions are rare, especially for tumors of the jaws. This report emphasized the capability of this useful imaging modality in identification of the characteristics of malignant conditions involving the bone. Mesenchymal chondrosarcoama, one of the unusual malignant conditions of the jaw, was presented in a young male with significant facial swelling. Different imaging modalities parallel with the histopathologic investigation confirmed the diagnosis. Interestingly, destruction of the bony cortex and new bone formation with a characteristic "sun ray appearance", highly suggestive of sarcomas, was manifested on the ultrasonograph. Thus, this report presented the ultrasonographic features of chondrosarcoma of mandible and considered the ultrasonography to be a useful imaging modality to evaluate intra-osseous jaw lesions.

[Comparative study of facial soft tissue profile changes following bilateral sagittal split and subcondylar osteotomies in patients with mandibular prognathism]

Programming for a successful operation and accurate prediction of the outcome of orthognathic surgery result in correction of occlusal and skeletal relations and improve the facial esthetics and function of patients. This retrospective study sought to assess the soft tissue changes following subcondylar and bilateral sagittal split osteotomy [BSSO] to retrude mandible in patients with mandibular prognathism. This retrospective experimental study evaluated 35 patients with mandibular prognathism and a mean age of 25.5 years [range 18.8 to 30.9 yrs]. Cephalometric variables were measured on lateral cephalograms of patients before and after surgery and recorded. A total of 12 patients had undergone BSSO while 23 subjects had received subcondylar surgery. Cephalometric variables were analyzed using paired t- and independent t-tests. The study results demonstrated that the mean changes in cephalometric soft tissue variables of Ls-Pr [P<0.05], Li-Id [P<0.01] and G-Sn/Sn-Me [P<0.05] after BSSO were significantly higher that the rates in Subcondylar surgery group. However, the mean changes in soft tissue variables of SLs-A [P<0.05], a2 facial angle [P<0.05] and LFH [P<0.001] in subcondylar surgery group were significantly higher than the rates in BSSO group. In patients that had undergone subcondylar surgery, the lower facial height and the mentocervical angle had increased which is indicative of a shift towards a straight facial profile after this type of surgery. This study showed that a greater improvement in profile is achieved after BSSO compared to subcondylar surgery according to the current esthetic parameters