Habitos De Postura

Journal of Oral Rehabilitation 2007 34; 663–670

Head posture and dental wear evaluation of bruxist children with primary teeth
´ ´ A . L . V E L E Z * , C . C . R E S T R E P O * , †, A . P E L A E Z - V A R G A S * , †, ‡, G . J . G A L L E G O * , †, †, § ´ & M . T A M A Y O * , † *CES University, Medellın, Colombia, †CES-LPH Research E. ALVAREZ*, V. TAMAYO
´ ´ ´ Group, Medellın, Colombia,‡Universidad Nacional de Colombia – Sede Medellın, Colombia, §FUMC, Medellın, Colombia

SUMMARY The aim of the present study was to compare the head position and dental wear of bruxist and non-bruxist children with primary dentition. Methods: All the subjects had complete primary dentition, dental and skeletal class I occlusion and were classified as bruxist or non-bruxist according to theiranxiety level, bruxism described by their parents and signs of temporomandibular disorders. The dental wear was drawn in dental casts and processed in digital format. Physiotherapeutic evaluation and a cephalometric radiograph with natural head position were also performed for each child to evaluate the cranio-cervical position for the bruxist group (n = 33) and the control

group (n = 20). Thevariables of the two groups were compared, using the Student t-test and Mann–Whitney U-test. Results: A more anterior and downward head tilt was found in the bruxist group, with statistically significant differences compared with the controls. More significant dental wear was observed in the bruxist children. Conclusions: Bruxism seems to be related to altered natural head posture and more intensedental wear. Further studies are necessary to explore bruxism mechanisms. KEYWORDS: bruxism, head, posture, dental wear Accepted for publication 4 February 2007

Introduction
The aetiology of bruxism has been defined as multifactorial (1). It is mainly regulated centrally, not peripherally (2). This fact means that oral habits (3), temporomandibular disorders (TMD) (4–7), malocclusions (8, 9),hypopnoea (10), high-anxiety levels (11) and stress (12), among others (13) could influence the peripheral occurrence of bruxism. These factors act as a molar stimulus to the central nervous system, which reacts with an alteration in the neurotransmission of dopamine (14, 15) and the result is the clenching or grinding of the teeth. During early infancy, children react to the habits of their parents,such as smoking, alcohol and the use of psychoactive drugs among others (16). These habits are risk factors involved in acquiring bruxism (17), thus they have to be evaluated to make a reliable diagnosis of the parafunction.

Bruxism not only affects the masticatory muscles, but also all the muscles of the cranio-facial complex, shoulders and neck (18). These structures share innervations throughthe trigemino-cervical complex, which is conformed by the upper cervical and trigeminal nerves (18). Also, anatomically, the axes for the excentric movements of the mandible and cervical column concur in the occiput (19). These connections cause the jaw position to influence the activity of the cervical muscles (20) and the neck inclination to influence the bilateral sternocleidomastoid activity(21). If the masticatory system, neck and shoulders are anatomically and physiologically connected and bruxism affects all the above described structures, it might be possible that the head position and the homeostasis of the cranio-cervical system could be affected when a parafunction occurs, so the head posture could be different between bruxist and non-bruxist subjects.
doi:10.1111/j.1365-2842.2007.01742.x

ª 2007 The Authors. Journal compilation ª 2007 Blackwell Publishing Ltd

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´ A . L . V E L E Z et al.
The head posture could be affected by the skeletal (22) and dental occlusion (23, 24). During the mixed dentition, the dental occlusion changes (25), so the head posture could be affected (26). In the primary teeth period, the arch dimensions seem to be stable (27, 28),...