Cranial Parameters Assessment of Open Bite with Short Upper Anterior Facial Height

Aims: The aims of this study are planned to evaluate the cranial base parameters of the short upper anterior facial height of open bite occlusion and compare them with the normal occlusion. Materials and Methods: The total sample of this study was 48 cases, divided into 12 case for each male and female of the normal class 1 molar occlusion and short upper facial height with open bite cases. The age of the patients was ranged between 13-15 years. A lateral cephalometric radiograph film was taken. All the cephalometric x-rays were analyzed to evaluate the cranial parameters and the upper anterior facial height. The data subjected to statistical analysis by using student t-test to distinguish the significant differences at 0.05 level for the short upper anterior facial height and to record the cranial parameters of the sample. Results: The comparison of the cranial parameters between the normal and open bite occlusions , the male expressed no significant difference ( at 0.05 level ) in the parameters except the liner (S-Ar) and the angular (N-S-Ba, N-S-Po and N-S-Co).While the female displayed no significant difference (at 0.05 level) in parameters except (N-S-Ba and N-S-Po angles). Conclusions: The short upper anterior facial height with anterior open bite case has influences on the cranial base development especially on (S-Ar, N-S-Ba, N-S-Po and N-S-Co). Key word: Open bite, Facial height, Cranial parameters. Obaidi HA, Al-Sarraf HA. Cranial Parameters Assessment of Open Bite with Short Upper Anterior Facial Height. Al–Rafidain Dent J. 2013; 13(3): 501-507. Received: 17/6/2012 Sent to Referees: 17/6/2012 Accepted for Publication: 16/9/2012 INTRODUCTION Anterior open bite is a malocclusion characterized by a deviation in the vertical relationship between the maxillary and mandibular dental arches, with absence of contact between the incisal edges of the maxillary and mandibular teeth in the vertical plane. (1-3) It may be a disturbance in skeletal development, (4) or only malpositioning of the anterior teeth, caused by thumb or pacifier sucking, infantile swallowing, speech disturbances and/or tongue thrusting. (5-8) Open bite is a multifactorial phenomenon and no single factor can account for this malocclusion. (9) Etiology plays an important role in diagnosis, (10) it can be broadly described as being either dental or skeletal in origin. (11-12) Skeletal anterior open bite is a complicated malocclusion characterized mainly by overgrowth of the maxillary, (13) and mandibular posterior dentoalveolar heights, resulting in a longer vertical facial dimension and a steeper mandibular plane. (14) Anterior open bite is a complex clinical entity that entails a combination of different 3-dimensional dental and skeletal components. (15) There is a possible association between a large cranial base angle and open bite. (16) Any change in flexure could affect the relationships of the maxilla and mandible and inCranial Parameters Assessment of Open Bite with Short Upper Anterior Facial Height ISSN: 1812–1217 Al – Rafidain Dent J Vol. 13, No3, 2013 www.rafidaindentj.net 502 fluence the type of malocclusion. (17) Growth studies have generally shown that an increased angulation of the cranial base is associated with increased vertical dimension. (18) The aims of this study were to evaluate the cranial base parameters of the short upper anterior facial height with open bite occlusion and compare them with the normal occlusion. MATERIALS AND METHODS The sample of the control group included 24 cases of normal Class l molar occlusion, divided into 12 case for each gender. The dental criteria of the normal Class 1 molar occlusion are: has no crowding or spacing with overbit and overjet (2-4mm) .The sample of open bite cases was 42 case, only 24 case of short upper anterior facial height was selected after achieving the comparison with the normal occlusion depending upon the linear length N-ANS (nasionanterior nasal spine), using student ttest at 0.05 significant level. (Table 1, Figures 1 and 2). Table (1): Explore the significant difference between the upper anterior facial height of the normal occlusion and open bite cases. Variable Sex Occlusion No Mean* SD t-test Significance