ABSTRACT: The aim of this study was to evaluate the sensation of each tooth type at the cortical level. The tactical sensation from teeth plays an important role in controlling the masticatory system. However, the role of each tooth type has not been determined. Functional near-infrared spectroscopy (fNIRS) was used to detect changes in cerebral blood flow in the somatosensory cortex of 12 healthy volunteers. Painless vibrotactile stimuli were applied to 8 teeth (left maxillary and mandibular incisors, canines, 1(st) premolars, or 1(st) molars). The somatosensory cortex was activated during stimulation of all teeth. A comparison of cortical activation revealed significantly greater activation during stimulation of the maxillary and mandibular first molars. However, no significant differences were seen between any other teeth. These results indicate that the first molar is the most sensitive tooth type at the cortical level, and provide basic data on the relationship between input from individual tooth type and brain activation. These data could be useful for understanding the neural mechanisms of individual tooth types.
Journal of dental research 06/2012; 91(8):759-63. · 3.46 Impact Factor
ABSTRACT: In this case report, crowding malocclusion with TMJ (temporomandibular joint) closed lock was treated with modified offset
archwire (MOAW) and multi-loop edgewise archwire (MEAW). Owing to the TMD (temporomandibular disorder) problems, we decided
to extract the lower third and upper second molars. Crowding in the upper and lower arches was successfully treated with the
improvement of TMD. Condylar movement was improved by orthodontic treatment with ΔY shift noted on condylographic evaluation.
Two years after the treatment, the occlusion was fairly stable.
international journal of stomatology & occlusion medicine 04/2012; 3(1):49-60.
ABSTRACT: INTRODUCTION: The mandibular fossa (MF) connects the mandible to the cranium through a bilateral articulation. It is suggested
that the mandible and the temporal bones have a reciprocal effect on their position and movement, acting as a temporo-mandibular
unit. The purpose of this study was to analyze the possible role of the mandibular fossa in the development of malocclusion
by comparing its three-dimensional (3D) position in different dentoskeletal frames in caucasic European human skulls. METHOD:
Several 3D angular and linear measurements obtained from Cone Beam Computerized Tomography scanning images of 101 skulls from
the Weisbach collection at the Vienna Natural History Museum were analyzed. RESULTS: The position of MF varied in different
dentoskeletal frames. The sagittal position measured from the Nasion or Sella landmark was significantly smaller in Class
III compared with the other two groups. The vertical position of MF did not differ significantly amongst groups. Two effective
ways of evaluating the MF sagittal position are to measure the 3D distance from MF mean landmark to the fronto-nasal suture
(Nasion) or to the Sella landmark. CONCLUSION: The MF position is suggested to be considered an important factor in the development
of malocclusions. Its influence on the position of the mandible supports the idea of a temporo-mandibular unit. Analysis of
the position of MF should be included in the diagnostic process.
KeywordsMandibular fossa-Glenoid fossa-Temporal bone-Cranial base-Mandible-Skull-Human-3DCT-Craniofacial-Vertical dimension
international journal of stomatology & occlusion medicine 04/2012; 2(4):179-190.
ABSTRACT: PURPOSE: Mandibular growth rotation is an important phenomenon in human facial growth. However, changes in the vertical height
of the dentition, the inclination of the occlusal plane, and subsequent mandibular rotation during growth, are only poorly
established. This study was designed to examine the inter-relation among occlusal plane rotation, mandibular growth rotation,
and the establishment of tooth axis during growth and development. MATERIALS AND METHODS: The materials used consisted of
351 lateral cephalograms from 39 children who belonged to a longitudinal growth study. We observed their growth changes in
the developmental stages from first molar eruption (Initial stage) until the completion of permanent dentition (Final stage).
We measured values regarding the posture of the lower face, including mandibular rotation, occlusal plane, and tooth axis.
The tangent law was applied for the sagittal organization of the mandibular teeth by geometrical analyses. RESULTS: Results
showed that mandibular growth rotation is associated with occlusal plane rotation, which is caused by greater vertical height
increase in the molars than in the anterior incisors. It was also shown that the mandibular incisors followed the tangent
law, but the long axis of the posterior mandibular teeth exhibited almost the same angle, approximately 15° with the direction
of the tangent. This tooth axis arrangement was very much dependent upon occlusal plane rotation and mandibular rotation during
growth. CONCLUSION: The results of this cephalometric study could help dentists to determine a more suitable organization
of occlusion in the sagittal plane, as required in orthodontics, prosthodontics, and implant dentistry.
international journal of stomatology & occlusion medicine 04/2012; 2(3):122-130.
ABSTRACT: PURPOSE: The aim of the present study was to investigate whether there is any association between occlusal contact patterns
during sleep bruxism and signs of temporomandibular disorders (TMD). MATERIALS AND METHODS: The association of occlusion pattern
and symptoms of TMD was assessed in 240 Japanese participants. Participants completed a questionnaire to report pain and other
symptoms regarding TMD and their self-awareness of sleep bruxism. A simple device (BruxChecker) custom fitted to each participant
was applied to evaluate the occlusal contact pattern during sleep. Condylograph was also applied to examine the function of
temporomandibular joint (TMJ). RESULTS: Participants with a major increment in the mediotrusive side occlusal contact areas
on BruxChecker reported significant impact on the high prevalence of TMD signs and self-awareness of sleep bruxism. CONCLUSION:
The positive relationship between a certain classification of occlusal grinding during sleep bruxism and signs of TMD constitutes
a key point to consider the possible role of occlusal factors during sleeping as risk indicators in the genesis of TMD.
international journal of stomatology & occlusion medicine 02/2009; 2(1):11-15.
ABSTRACT: The dentist must have a broader perspective in treating occlusion and consider the masticatory organ in terms of dynamic function
and not in a static manner. Speech function is very complex and thus it is thought to be one of the contributors to the development
of temporomandibular joint dysfunction. In this study, we have examined the condylar movement pattern during speaking in different
skeletal frame, Class I, Class II-1, Class II-2 and Class III, in order to establish the foundation or baseline information
involving phonetic function for the diagnosis of craniomandibular function and dysfunction. In conclusion, subjects with Class
II skeletal frame showed a relatively long and forward position of phonetic movement, while the Class III skeletal showed
a short and close to RP working position. These results indicated that the craniomandibular system has a capacity for functional
compensation to the skeletal discrepancy. It is necessary and important to evaluate the pattern of condylar movement during
phonation in establishing a proper diagnosis of the stomatognathic function.
Stomatologie 02/2008; 105(1):7-12.