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5/29/2016 Influence of Functional Head Postures on the Dynamic Functional Occlusal Parameters
Introduction Go to:
The efficiency of the masticatory system largely depends on alignment and occlusion of dentition. Pattern of teeth
occlusion greatly influence the human vital function such as chewing, swallowing and phonetics. More than static
occlusal contacts, dynamic contacts affect the mastication and all other physiological activities. Occlusal contacts
are controlled by temporomandibular joint (TMJ), dentition and muscles of mastication. The tooth contact should
be along its long axis for the optimum health of the tooth and supporting periodontal structures. Bilateral
harmonious contacts will help in the development of orthopedically stable TMJ and maintains the joint health. The
mandibular path during the mastication should be devoid of occlusal interferences. Presence of occlusal interference
during mastication will result in occlusal instability, increased activity in muscle of mastication.[1] Majority Dental
researchers still believe improper occlusal contacts are one of the main etiological factors for the initiation of TMJ
disorder.[2]
Head posture is varied according to the physiological and functional activity of the human. These head postures can
be divided into an active feeding position posture, upward posture and extended head posture. Incorrect forward
head posture is also known to cause the neck, head, shoulder tension and pain along with occlusal changes.[3]
Skeletal radiographs, occlusograms were used by the early researchers to establish the positive correlation between
head posture and occlusion. Change in head postures will result in a change of mandible position due to stretching
and elongation of the muscles attached to it. Routine functional activities such as eating and drinking alter the head
posture. The head extends forward by approximately 30° during food consumption; this head posture is known as
active feeding posture.[4] This posture shifts the mandible and its closure path anteriorly. The head is extended
around 45° during drinking; this will result in the mandible shift posteriorly.[5] All the dental therapeutic
procedure's eventual success depends on its harmony with occlusion. The clinicians most commonly use supine
position during restorative procedures, occlusion evaluation and correction. Allimportant functional occlusal
contact during appropriate head position is usually ignored. Existent dental literature on the influence of the
functional head posture on the dynamic occlusal contact is minimal. The knowledge of the change in tooth contact
during functional head posture will help the dentist during occlusal evaluation and therapeutic procedures. It is
critical for dentists to incorporate these changes in occlusion analysis to eliminate the iatrogenic interferences,
improve longevity of the restoration and health of all parts of the masticatory system.[6] Therefore, this
experimental study was planned with the objective to evaluate the influence of different functional head posture on
dynamic occlusal contacts.
Subjects and Methods Go to:
Sample 2/7
The institutional ethical committee approval was obtained for the study before the initiation. The study
methodology was explained, and written consent was obtained from all participants prior to their inclusion in the
study. The study sample consisted of 50 students from College of Dentistry, King Khalid University. This study
took place in the dental clinics of college of Dentistry, King Khalid University during the first semester of 2013.
The King Khalid university college of Dentistry is situated in the southern part of Saudi Arabia. It is one of the
largest dental colleges in the kingdom and consists of an undergraduate students ranging from first semester to
twelve semester and intern dentists. The student body included the students from all parts of the Kingdom of Saudi
Arabia. The student body consisted of 240 students; eighteen students were not interested in participating in the
study. The students agreed to participate in the study were screened to the satisfaction of inclusion criteria
mentioned in the study. A total of 62 were students identified suitable for study. The simple random sampling
procedure was used to select the 50study sample. All the 62 students university registration numbers were written
on the piece of paper in a container, mixed up, randomly selected in the lottery system. This will construct a 95%
confidence interval with a Margin of Error of about five. The age group of the subjects included in the study were
1825 years. The inclusion criteria for the study subjects were: Class I dental occlusion, no posterior missing teeth
other than third molars, no previous history of orthodontic treatment or maxillo facial surgery, normal overbite (24
mm) and overjet (03 mm), no posterior cross bite and no crown/fixed partial dentures. Exclusion criteria was the
http://www.stva.ncbi.nlm.nih.gov/pmc/articles/PMC4160681/
