The success of prosthetic treatment for hemi-mandibulectomy patients depends on many clinical factors, such as the extent of the defect site, presence of reconstructive surgery, and number of remaining teeth. Furthermore, displacement of the mandibular segment to the defect side, causing unstable mandibular position and abnormal mandibular movements, is also a critical factor.
The purpose of this study was to observe the clinical aspect of the mandibular movement of mandibulectomy patients to reveal their characteristics. The movements of the condylar point （kinematic axis point） and the incisal point were measured for five mandibulectomy patients by using a mandibular movement analyzer （ARCUSⓇ digma, KaVo, Germany）. Although the paths of the incisal point in opening and closing movements in the frontal plane had obviously drifted to the defect side, the remaining condyle could only slide within a certain limit. Judging from these findings, measurement and analysis of the mandibular movements of such patients are confirmed to be useful for their prosthetic treatment.
There are various problems associated with laboratory and clinical techniques when fabricating hollow maxillary obturator prostheses by the conventional method. This article introduces a new fabrication method that uses three-dimensional （3D） digital technology in order to overcome the problems. The 3D geometric data was obtained by means of 3D optical scanning of a plaster model with a maxillary defect and converted to stereo lithography （STL） data. The hollow obturator part was molded with a 3D printer （DIGITALWAX 020D）. The 3D mold of the obturator with a hollow was returned to the maxillary defect plaster model. The other part of the prostheses was made using the conventional method. The bond strength between the photocoagulation resin for 3D molding and polymerization resin was evaluated using the compressive shear strength test. The result showed enough strength for clinical use. As a result, the proposed method for fabricating hollow maxillary obturator prostheses using a 3D printer is applicable for clinical use.
Although the demand for oral health care for patients at the rehabilitation stage after surgery for head and neck tumors has been increasing, clinical guidelines for such oral health care have not been established. The objective of this study was to investigate the current status of such patients and the problems which dental hygienists faced. According to the medical records, a total of 1,158 patients visited the dental hygienist unit of Tohoku University Hospital in 2013, including 18 patients at the rehabilitation stage after surgery for head and neck tumors. Professional oral health care significantly decreased PCR at the last visits compared to those at the first visits （p＜0.01）. The questionnaire survey of dental hygienists revealed that they were often concerned about insufficient information about care of the surgical field, aspiration prevention, and psychological support. These results suggested that professional oral health care by dental hygienists might motivate the patients to improve their oral health and that clinical guidelines for the oral health care for patients with head and neck tumors are needed.
The patient was an 84-year-old female who visited the Department of Otolaryngology at Kansai Medical University with a chief complaint of some discomfort in one lateral area of her tongue and gingival tissue. She was diagnosed with squamous cell carcinoma. In November 2014, after undergoing marginal mandibulectomy, the patient consulted the Department of Dentistry and Oral Surgery for functional recovery. The patient had scar tissues between the tongue and lower lip. An impression of the surrounding areas including the scar tissues was taken using both the altered cast technique and wax. Both techniques were particularly effective for confirming muscle movements around the scar tissues. A mandibular prosthesis was fabricated based on the findings, and the patient was satisfied with her masticatory function.