The aim of this study was to investigate the factors influencing the masticatory function of oral cancer patients who had undergone segmental mandibular resection.
The subjects were 70 patients whose masticatory function could be examined among those who had undergone segmental mandibular resection under a diagnosis of oral cancer or osteoradionecrosis at our hospital since 1992. Masticatory function was evaluated based on total biting force and chewing function score, and then statistically analyzed. Multiple linear regression and logistic regression analyses were performed. In all analyses, the following 10 clinical variables were used as independent variables: 1） age, 2） gender, 3） duration after surgery, 4） performance or nonperformance of mandibular bone reconstruction, 5） the number of residual teeth of the mandible, 6） number of occlusal supports, 7） presence or absence of lower dentures, 8） performance or nonperformance of tongue resection, 9） radiation dosage, and 10） mandibulectomy area.
Among the 10 clinical variables, the number of residual teeth of the mandible had the greatest influence on masticatory function.
This study identified the factors that can be used to estimate the masticatory function of oral cancer patients who had undergone segmental mandibular resection.

View full abstract

The rehabilitation of oral functions in patients with maxillofacial defects is often required in order to use dento-maxillary prostheses. Preservation of abutment teeth is also important for long-term maintenance of those functions. However, the mechanical and biological stresses on the abutments are generally greater than those on other parts, so various types of abutments have been used to disperse the stress. This study focused on detecting periodontopathic bacteria around the sulcus of abutment teeth by the polymerase chain reaction method. We collected samples from periodontal pockets of three kinds of partial denture abutment: magnetic keepers, implant abutments and konus telescopic crowns. The samples were divided into two groups depending on the clinical symptom of inflammation. The results revealed that bacteria detection ratios were significantly higher in the inflammation abutments than those of non-inflammation abutments. Comparing the abutments, the ratio of magnetic keepers with inflammation was lower than that of other abutments and the control natural teeth. These results indicate that this method is useful for maintaining oral hygiene. Further study is needed for standardizing oral care around the abutments and increasing the number of samples to confirm the conditions of periodontopathic bacteria in various abutments.

View full abstract

Formulating the color of a facial prosthesis requires not only coordinating with the surrounding facial skin tone but also reflecting the underlying dermis. Intrinsic coloring pigment is often too concentrated to reproduce the translucency of skin. Clinically, a nylon fiber called “flocking” is used to obtain the nuance of skin tone. The purpose of this study was to examine the effect of adding color flocking to facial silicone on the color tone of facial skin using a spectrophotometer.
Ten subjects participated in this study. Four types of silicone sample were fabricated with only color pigment, or with 110 mg, 220 mg, or 440 mg flocking added to the color pigment in each subject. Melanin index （MI）, Hb （hemoglobin） index （HbI）, and hemoglobin oxygen saturation （HbSO₂） index were evaluated as well as spectral reflectance and colorimetric values of the sample silicone formulated for the 10 subjects. a^＊, b^＊ and MI were not significantly different between each sample. HbI increased according to the amount of flocking added while HbSO₂ index decreased. The results in this study suggest that flocking is effective for fabricating natural facial prosthesis.

View full abstract

The patient was a 76-year-old man, who visit the Department of Oral Surgery, Iwate Medical University Hospital for a checkup. The clinical diagnosis of the patient was tongue carcinoma of the right-side edge （T2N0M0） in July 2002．A subtotal glossectomy, radical neck dissection on the right side, and immediate reconstruction using an outside femur flap were performed in August. In January 2005, the patient consulted the Department of Maxillofacial Prosthetic to achieve functional recovery.
A complete maxillary denture with a form of palatal augmentation prosthesis and mandibular prosthetic appliance were provided in December 2005. The patient was evaluated by palatogram, repetitive saliva swallowing test, modified water swallowing test，and questionnaire survey of dietary intake. These tests revealed improved mastication, swallowing, and articulation function. The palatal augmentation prosthesis was confirmed to be effective for this case reconstructed by vascularized free flap after subtotal glossectomy.

View full abstract

Mandibular tumor resections require removal of surrounding tissues to ensure clear margins. Reconstructive procedures should be performed based on surgical and prosthetic coordination. Social and psychological issues relating to the impact of successful surgical and prosthetic procedures are important for improving quality of life. This paper presents a case report of prosthetic reconstruction following large resection in the mandible, using an unique prosthetic design. The design of the prosthesis and its procedure are described, and patients’ evaluation of oral function is also reported using the visual analog scale method.

View full abstract