An introduction to ultrasonography in oral surgery

Ultrasound evaluation of intra-osseous cavity: A preliminary study in pig mandibles

AIMS

To assess the role of ultrasonography as a possible tool for diagnosis of intra-osseous lesions.

METHODS

Our sample comprised five macerated pig jaws. The regions of bony crypts of third molars were examined on both sides, totaling 10 examinations. The degrees of difficulty for both ultrasound image visualization and bone translucency were rated by two groups of evaluators (i.e. dental radiologists and physician ultrasonographers).

RESULTS

Our results showed that it is possible to detect images of the intra-osseous cavity at a low-degree difficulty by using both radiographic and ultrasonic techniques (46.6% and 43.3%, respectively). However, the crypts were not fully detected by both groups (16.6% and 13.3%, respectively).

CONCLUSIONS

We concluded that ultrasonography is a useful method for evaluation of intra-osseous lesions in jaws, provided that the cortical bone is thin enough to allow ultrasound waves to pass through.

The role of diagnostic ultrasound as a new diagnostic aid in oral and maxillofacial surgery

Only very few studies have been done in the past to evaluate the usefulness and limitations of ultrasonography in oral and maxillofacial surgery. This study, though in an embryonic stage, has been done to bring this technique to limelight and to put forth the importance of its use and limitations in the branch of oral surgery. The purpose of this study was to investigate and study the characteristic pattern of the oral tissues on gray scale ultrasonography and to assess the practical applicability of this new diagnostic technique in diagnosing various tissue pathologies in the field of oral and maxillofacial surgery.

The use of ultrasound in the investigation of the muscles of mastication

The aim of this article was to review the literature concerning ultrasonography imaging (US) of the muscles of mastication and to discuss its use, advantages and disadvantages and the findings of the authors. A web search was performed using the terms "ultrasound" and "muscles". US has been shown to be a reliable method of great utility in the field of diagnosis of alterations in the muscles of mastication and for the study of changes during growth and aging. It should be preferred in comparison to computerized axial tomography (CT) and magnetic resonance imaging (MRI) because of its safety and cost advantages since it is as reliable and precise as these other techniques. Although various techniques have been used in ultrasonographic scanning, this article discusses those techniques most commonly adopted by the authors.

Effect of treatment of dentofacial deformity on masseter muscle thickness

OBJECTIVE

The objective of the present study was to determine the modifications in masseter muscle thickness before and after interdisciplinary orthodontic, oromyofunctional and surgical treatment of class III dentofacial skeletal deformities (DFSD).

DESIGN

Fifteen patients with class III DFSD participated in the study, denoted P1 group before the interdisciplinary treatment and P2 group (same patients) 6-8 months after surgery. Fifteen individuals with no DFSD were used as the control group. Bilateral ultrasonography (US) of the masseter muscle under resting and biting conditions was performed in the three groups.

RESULTS

There was a significant difference (P<0.01) for all muscles tested between the control, P1 and P2 groups, with greater thickness for controls, intermediate thickness for P2, and the lowest thickness for P1 in all situations evaluated.

CONCLUSION

We conclude that there was an increase in masseter muscle thickness after surgical correction of DFSD accompanied by interdisciplinary treatment, although the values were still lower than those observed in the control group.

Determination of the anti-inflammatory effects of methylprednisolone on the sequelae of third molar surgery

PURPOSE

The anti-inflammatory effect and adrenal suppressive side effect of methylprednisolone sodium succinate (MP) on the postoperative sequelae of third molar surgery were evaluated using objective methods in a double-blind, crossover study.

PATIENTS AND METHODS

Twenty patients who were to undergo surgical removal of bilateral, symmetrically placed lower third molars were studied. Each patient was given 125 mg MP intravenously before surgery on one side, and a placebo before surgery on the opposite side on a random basis. Ultrasonographic and computed tomographic examinations were performed to determine the amount of facial edema. Trismus was evaluated by measuring maximal interincisal opening, and pain was evaluated by recording the number of standard analgesic tablets used on the day of surgery and the first postoperative day. Hypothalamic-pituitary-adrenal (HPA) axis function was tested by measuring basal plasma cortisol (hydrocortisone) levels preoperatively and postoperatively. The adrenocorticotropic hormone (ACTH) stimulation test also was performed before and after administration of MP, to evaluate adrenal function.

RESULTS

Statistical analysis of the data indicated a significant decrease in edema, trismus, and pain in the MP group. Plasma cortisol levels showed a nonsignificant decrease in both the MP- and placebo-treated groups. The ACTH stimulation test indicated normal HPA axis function before and after MP administration. No clinically apparent infection, disturbance of wound healing, or other corticosteroid-related complications were noted. Eighteen patients (90%) indicated a preference for the overall postoperative course when MP was used.

CONCLUSION

In the absence of contraindications for corticosteroid administration, preoperative use of MP appears to be a safe and effective method of reducing postoperative complications in third molar surgery.

The ultrasonic value of local muscle hypertrophy in patients with temporomandibular joint disorders

Muscle pain and tenderness on palpation are two common symptoms in patients with temporomandibular joint disorders. Examination of the masticatory muscles is largely restricted to the use of electromyography. The technique of ultrasonography in the diagnosis of muscle hypertrophy in patients with temporomandibular joint disorders was investigated. The results of the study indicate that ultrasonography may be beneficial to locate affected muscles that do not exhibit symptoms of tenderness on palpation and thereby give hints for treatment planning.

The use of ultrasound to determine the position of the mandibular condyle

A randomized, single blind study of 20 patients examined the accuracy of ultrasound in establishing the position of the mandibular condyle in relation to the glenoid fossa. The sonographic technique is described. The temporomandibular joint was imaged sonographically with the patients in an open- and a closed-mouth position as a model for condylar sag and proper condylar seating, respectively, during mandibular ramus osteotomy procedures. One radiologist identified condylar position correctly in 38 of 40 still ultrasound images, with a sensitivity and a specificity of 95%. During real time ultrasound examination, it is possible to visualize varying degrees of condylar movement in relation to the glenoid fossa. The results of this study support the potential use of ultrasound as an adjunct to mandibular orthognathic surgery.

Combined use of Doppler and conventional ultrasound for the diagnosis of vascular and other lesions in the head and neck

Twenty-three patients with swellings of the head and neck were prospectively investigated by Doppler ultrasound and ultrasound imaging to determine the type and vascularity of the lesions and thereby aid pre-operative diagnosis. Four vascular lesions were correctly identified while vascularity was not found in patients with lipoma, cysts, abscess, or muscular hypertrophy. Increased vascularity was found in or near some tumours and lymphangiomas, but by careful comparison of findings these lesions were not confused with true vascular lesions. The value of the investigations was demonstrated by a change in the treatment in 6 of the cases in this series.

An evaluation of the clinical applications of diagnostic ultrasonography in oral surgery

This article reviews the available literature on the ultrasonographic examination of the head and neck as related to oral and maxillofacial surgery, presents clinical case summaries illustrating these applications, and evaluates the role of ultrasonography in current clinical practice.

The diagnostic limitations of ultrasonography in maxillofacial surgery

The records of 63 patients having had ultrasound examinations with grey-scale B-mode scanners have been reviewed, to determine what contribution ultrasound made to the diagnosis of superficial maxillofacial masses, when compared with clinical examination and other methods of investigation. Most of the ultrasound parameters described in the literature are found in the cases we have examined. Despite the fact that the ultrasound image is often compatible with the disease, diagnosis using ultrasound was much less accurate than expected. From this series, it is concluded that ultrasound examination is not recommended for the diagnosis of all maxillofacial pathology, especially when the echographist has no special experience in this field of pathology, when ultrasound findings are not correlated with clinical ones, and when the ultrasound report is not precise and exhaustive.

Ultrasonography of inflammatory soft tissue swellings of the head and neck

Experience with 107 B-scan sonographs of inflammatory soft tissue swellings of the head and neck is described, and an echomorphologic classification is proposed which consists of the following five types: edema, infiltrate, preabscess, echo-poor, and echo-free abscess. Because the clinical course of the symptoms differs significantly between the last three types, it was concluded that they represent different stages of abscess formation. A comparison of all the physical and sonographic diagnoses showed only slightly higher sensitivity for sonography. However, with regard to the specific diagnosis of abscess, the sonographic examination seemed to be superior to the clinical diagnosis.