J. Stomat. Occ. Med. 2008 Hanashima

original article

J. Stomat. Occ. Med. (2008) 1: 27–33
DOI 10.1007/s12548-008-0007-3
Printed in Austria
© Springer-Verlag 2008

A study regarding occlusal plane and posterior
disocclusion
M. Hanashima1 , K. Sakakibara2 , R. Slavicek3 , S. Sato4
1,2

Organ Dental Laboratory, Chigasaki, Japan
Center of Interdisciplinary Dentistry, Department of Environment and Medical Center, DonauUniversity at Krems,
Krems, Austria
4
Division of Orthodontics, Department of Craniofacial Growth and Development Dentistry, Kanagawa Dental Collage,
Yokosuka, Japan
3

Received September, 13; Accepted September 28, 2008

The occlusal plane (OP) is one of the most important elements involved in occlusal reconstruction in restorative,
prosthodontic and orthodontic treatment. The presence orabsence of posterior interferences depends primarily on the
occlusal plane configuration. In powerful grinding movements of the mandible like bruxism, disocclusion of the
posterior teeth is important to prevent the hyperbalance of
masticatory muscle activity. We have investigated the relationship between the inclination of the occlusal plane involving the degree of the curve of Spee and theposterior
disocclusion during forward or retrusive condylar movement. Results indicated that increasing the inclination of
the occlusal plane provides posterior interference during
protrusive mandibular movement, while posterior disocclusion is obtained during retrusive movement. Accentuation of
the curve of Spee provides elimination of posterior contact
during retrusive condylar movements.Therefore, the occlusal plane inclination should be properly and carefully analyzed and must be a part of the diagnosis and treatment
planning prior to any occlusal reconstruction.
Keywords: Posterior disocclusion, curve of Spee, occlusal
plane, retrusive guidance

Introduction
Anatomical features such as the shape of the occlusal surface,
the inclination of the occlusal plane, the facialpattern, and
the functional structure of the temporomandibular joint (TMJ)
are important determinants of occlusion, and we should take
This research is a part of Miwa Hanashima’s Master Thesis of Advance
Dentistry, Donau University, Krems, Austria. The results of this research
were once published in the Journal of Gnathology and Occlusion, Volume
22, 2002 issue, in Japanese. Therefore thisEnglish translation issue is a
secondary publication with copyright permission from Japanese Society of
Gnathology.
Correspondence: Sadao Sato, Research Center of Brain and Oral Science,
Kanagawa Dental College, 82 Inaoka-Cho, Yokosuka 238-8580, Japan.
E-mail: satosada@ca3.so-net.ne.jp

J. Stomat. Occ. Med.

them into consideration when reconstructing occlusion in
dental practice. However, theliterature on occlusion to date
has not provided sufficient information on relationships between such anatomical features.
D’Amico [1] regarded the canine as a stress breaker, as
it reduces the activity of the temporal and masseter muscles
in the lateral mandibular movement, and he has formulated
the occlusion concept known as canine guidance. Goldstein
[2] investigated the relationshipbetween different schema of
occlusion and periodontal diseases and reported that the
canine guidance had a significantly lower rate of periodontal
disease than those with progressive disocclusion or group
function. Subsequently, many investigators have studied the
significance of posterior disocclusion, and the importance
of occlusion schema controlled by the canine is now being
recognized [3,4]. Nevertheless, it appears that confusion
exists over the recognition of canine-guided occlusion or
posterior occlusion. At present, there is no definite measure
to what extent the inclination of canine guidance should be
given or how disocclusion of the posterior teeth should be
determined.
Mchorris [5, 6], in a series of his research, pointed
out that occlusal guidance is important,...