Newly Concept of the Limited Mouth Opening Disorder: Clinical Characteristics and Diagnosis of Patients With Masticatory Muscle Tendon-Aponeurosis Hyperplasia

Kenji Kakudo DDS, PhD, Second Department of Oral and Maxillofacial Surgery, OSAKA DENTAL UNIVERSITY, OSAKA, Japan
Hirohito Kubo DDS, PhD, 2nd Department of Oral and Maxillofacial Surgery, OSAKA DENTAL UNIVERSITY, OSAKA, Japan
Tomoko Fujii DDS,PhD, Second Department of Oral and Maxillofacial Surgery, Osaka Dental University, Osaka, Japan
Statement‚“ of the problem:Masticatory muscle tendon-aponeurosis hyperplasia is a new disease entity characterized by chronic, severe mandibular hypomobility with a square mandible caused by contracture of the masticatory muscles resulting from hyperplasia of tendons and aponeurosis. The aim of this study was to investigate the skeletal and kinesiological features of the mandible in this disease using cephalometric analysis and mandibular kinesiography.

Materials and Methods:This study group comprised 19patients (0 male, 19 female) with masticatory muscle tendon-aponeurosis hyperplasia. 8patients (8 female) were selected for cephalometric analysis and 11patients (0male, 11female) were selected for analysis of mandibular movement. The control group consisted of 9 volunteers ( 0male, 9female) without limited mouth opening or TMD symptoms showing a skeletal morphology resembling masticatory muscle tendon-aponeurosis hyperplasia.

Results:Cephalometric analysis showed that the gonial angle (p<0.01), FMA (p< 0.05), cant of the occlusal plane (p<0.01), and Y-axis (p<0.001) were significantly lower than the standard values. The saddle angle (p<0.05) and facial angle (p<0.001) were significantly greater than the standard values. Linear analysis showed that S-Go/N-Me was significantly lower than the standard value (p<0.05). Analysis of mandibular movement showed a significantly shorter mouth opening distance in the patient group than that in the control group (p < 0.01), but no significant difference in the amount of left and right lateral movement between the two groups.

Conclusion:This study showed the skeletal and kinesiological features of the mandible in this disease using cephalometric analysis and mandibular kinesiography.

References:

1)Yoda, T. et.al:Long-term results of surgical therapy for masticatory muscle tendon-aponeurosis hyperplasia accompanied by limited mouth opening. Int J Oral Maxillofac Surg 2009;38(11).1143-1147.

2)Sato,T.etal:Proteomicanalysisofmasticatorymuscletendon-aponeurosishyperplasia:Apreliminary study using a 2D-DIGE system. J Oral Maxillofac Surg Med Patho 2012;24.185-188.

See more of: Poster Session
See more of: Abstract/Poster Sessions
<< Previous Abstract | Next Abstract >>