Mouth Opening Distance Research Articles

Predictive Factors of Masticatory Performance in Post-maxillectomy Obturator Wearers with Soft Palate Defect That is Either Absent or Limited to the Anterior Part

Purpose: Little objective investigation has been published regarding factors influencing masticatory performance of post-maxillectomy patients with obturator prosthesis. This study aimed to assess the relationship between masticatory performance and sociological and post-surgical factors, and to develop a theoretical equation predicting masticatory performance using significant factors.Methods: In 37 post-maxillectomy patients with obturator prosthesis, their age, gender, resection of hard and soft palate, number of posterior maxillary teeth, occlusal support, and mouth-opening distance on masticatory performance were investigated, and masticatory performance was measured using a gummy jelly. The influence of these items was evaluated quantitatively using multiple regression analysis (Quantification Method type I). The strength of influence of each explanatory factor on the masticatory performance, identified by the category weight and theoretical value of masticatory performance of each subject, was calculated by totaling the category weights and the constant. Pearson correlation coefficient was used to analyze the correlation between actual values and theoretical values of masticatory performance.Results: The order of strength of influence on masticatory performance was identified by the category weights: extent of hard palate resection (1229.9) > occlusal support (1113.0) > mouth-opening distance (280.8) > age (209.0) > resection of soft palate (194.2) > number of posterior maxillary teeth (186.4). There was a high correlation (R2=0.863, P<0.01) between the theoretical values calculated by the predictive equation and the actual values.Conclusion: Masticatory performance of post-maxillectomy patients could be predicted with high accuracy in patients with soft palate defect limited to the anterior part.

Bite Force and Maxillofacial Morphology in Patients With Duchenne-Type Muscular Dystrophy

The purpose of this study is to evaluate maxillofacial morphology and bite force in patients with severe Duchenne-type myodystrophy. The subjects included 24 men (average age, 21.5 years; range, 17 to 30 years) with Duchenne-type muscular dystrophy receiving treatment in National Ioh Hospital. Lateral and axial cephalograms were used to assess the morphology in this study. The maximum bite force on the first molar and the maximum mouth opening distance were measured. The anterior open bite was visualized in most patients on the lateral cephalogram. The upper and lower arch lengths in the patients were significantly smaller than those in the controls (P < .05). In contrast, the upper and lower arch widths in the patients were significantly larger than those in the controls (P < .05). The maximum bite force and maximum mouth opening distance in the patients were significantly lower than those in the controls (P < .05). These results appear to be very useful for improving the care and treatment of patients with Duchenne-type muscular dystrophy.

Factors influencing time of intubation with a lightwand device in patients without known airway abnormality

Study objective To evaluate the correlation between accepted screening tests for difficult tracheal intubation and ease of intubation with a lightwand blind technique. Design Prospective study. Setting Anesthetic rooms of a university hospital. Patients 122 female, ASA physical status I, II, and III patients requiring tracheal intubation for elective surgery. Interventions After receiving a standardized anesthetic induction, patients first underwent direct laryngoscopy to determine Cormack laryngoscopy grade, then tracheal intubation was performed using a transillumination method. Measurements and main results Patient demographics, Mallampati class (MC), mouth opening (MO; cm), and thyromental distance (TMD; cm) were all measured and the values recorded. Body mass index (BMI; kg/m 2) was calculated for each patient. Laryngoscopy grades obtained by laryngoscopy were also recorded. Times to intubation were measured by a chronometer and failures were recorded. Patients were then allocated to groups according to the measured parameters: BMI ≥ 30 kg/m 2, BMI < 30 kg/m 2; TMD ≥ 6 cm, TMD < 6 cm; MO ≥ 3, MO < 3; MC I, MC II, MC III, MC IV, and Laryngoscopy Grade (LG) 1, LG 2, LG 3, LG 4. Intubation times at the first attempt were compared within the groups for each variable. The total results of 119 patients were studied; overall success was 99%, and mean time to intubation at the first attempt was 9.2 ± 4.9 seconds. Although time to intubation was prolonged with increasing Mallampati and laryngoscopy scores, and in the TMD < 6 cm and BMI ≥ 30 kg/m 2 groups, only the MC III and BMI ≥ 30 kg/m 2 groups represented a statistically significant difference of prolongation. Mean time to intubation in the MC III and BMI ≥ 30 kg/m 2 groups were 13.2 ± 5.4 ( p = 0.011) and 14.8 ± 1.7 ( p ≤ 0.001), respectively. Conclusion Mallampati class III airway significantly increases time to intubation when the transillumination technique is used. BMI ≥ 30 kg/m 2 is another factor that interferes with the ease and success of intubation with this technique.

Anaesthetic approach in a case of Goldenhar's syndrome

Anaesthetic approach in a case of Goldenhar's syndrome

下顎運動障害訓練のための３自由度開閉口訓練ロボットの試作

This paper describes the mechanism and real training with the three degrees of freedom (3-DOF) mouth opening and closing training robot WY-2 (Waseda Yamanashi-2) that is developed to train the patients who have problems on their jaw movement. WY-2 consists of a mechanical, actuation, sensor, and control systems. The seesaw mechanism inserted in the patient's mouth opens the mouth by squeezing the master manipulator that is controlled by the doctor. The force sensor measures the patient's biting force. A personal computer integrates and controls the other systems. As a result of therapy with this robot for the real patient, the mouth opening distance increased.

関節鏡視下剥離授動術が奏功した陳旧性顎関節頭骨折の１例

We describe a 56-year-old man who consulted our department because of pain in the left temporomandibular joint (TMJ) on June 15, 1999. The patient had fallen down at work and was injured on May 8. The mouth opening distance was 27 mm, and the pain was present in the left TMJ Radiographic examination showed an oblique fracture in the left condyle, and a small piece of bone was displaced anteromedially.The patient had an old left-condylar fracture, and the remaining articular cavity was detected in the left TMJ by superior articular cavity pumping. We perfomed arthroscopic lysis and lavage operation on July 2. The mouth opening distance improved to 38 mm, and the pain disappeared 12 months after surgery. The patient had no problems in daily life.

The influence of the spring activator on the mobility of the lower jaw in traumatically injured patients.

For functional rehabilitation and improvement of mandibular mobility, 14 patients with dislocated collum or collum fracture dislocations were treated with a spring activator after surgical-conservative treatment. With an interincisal distance of < 12 mm, therapy was started with a loop spring. The average age of the patients was 26.6 years. Eight patients showed additional traumatic injuries, 2 patients were seriously polytraumatically injured. The clinical investigations referring to the maximum mouth opening and maximal interincisal distance resulted in a good to very good functional rehabilitation in all cases. The average maximal interincisal distance of 31.7 mm at the beginning of the spring activator therapy could be increased to 47.3 mm. The largest increase of the maximal interincisal distance was observed after 4 weeks of therapy. The type of reaction, however, differed interindividually. Three patients showed a spontaneous improvement of the interincisal distance within the first 2 to 3 weeks of removal of intermaxillary fixation, whereas 7 patients showed no improvement or only slightly improved values until insertion of the spring activator. An enlargement of the interincisal distance could be achieved in almost every patient within a relatively short period of time despite a drastically reduced mouth opening. Consequently, because of its mode of action in the form of a neuromuscular influence, the spring activator is especially suitable for the functional rehabilitation of patients with fractures of the condylar process.