Sulaimani Dent. J. 2014; 1:86-90 Abdulateef et al Introduction: Spacing greater than 0.5 mm between the proximal surfaces of adjacent teeth is described as a “diastema” and if it is in the anterior maxilla in the midline it is known as a “midline diastema”, which is a common aesthetic complaint of people, seeking orthodontic treatment (1) . Maxillary midline diastema (MMD) is a common aesthetic problem in mixed and early permanent dentitions. It may be considered normal for many children during the eruption of the permanent maxillary central incisors (2) . However, if the midline diastema is present after eruption of canines or is more than 2-4mm, there is always an underlying cause (1) . No definite etiology for midline diastema has been identified. Midline diastema can be physiological, dentoalveolar, due to a missing tooth, due to peg shaped lateral, midline supernumerary teeth, procl- ination of the upper labial segment, prominent frenum and due to a self-inflicted pathology by tongue piercing (1) . Angle’s suggestion of abnormal frenum as the cause of midline diastema has been supported by other researches (3-5) . Tooth size discrepancy can be considered as one of the main causes for maxillary midline diastema. The most common discrepancy concerning tooth size is the presence of peg shaped lateral incisors (6) . According to oral habits, any habit such as tongue- thrust, thumb sucking, finger bite and biting the lower lip that results in a long-term force leading to upper anterior teeth separation should be considered as a possible etiological factor (6) . An accurate diagnosis is necessary before treatment can be initiated. No treatment should be initiated if the diastema is physiological and usually if the canines have not erupted (7) . The objectives of this study was to determine the prevalence of maxillary midline diastema among Shorish dental clinic`s patients seeking orthodontic treatment, and to determine the factors associated with maxillary midline Diastema. Materials and Methods: Five hundred and seven patients attending Shorish Dental Clinic, seeking orthodontic treatment during 6 months (October,1 2013 – April,1 2014) were screened randomly to determine the prevalence and etiology of maxillary midline diastema. The age range was between 13 – 40 years to exclude diastema caused by ugly duckling stage or periodontal condition. Patients were excluded if they had previous history of previous orthodontic treatment, any artificial crown or proximal restoration in central incisors, without periapical and/ or periodontal involvement to exclude any factors that may create or change the width of midline diastema. a School of Dentistry, Faculty of Medical Sciences, University of Sulaimani, Kurdistan Region, Iraq. (daroonsaeed@gmail.com) b School of Dentistry, Faculty of Medical Sciences, University of Sulaimani, Kurdistan Region, Iraq . c Sulaimani Polytechnic University, Kurdistan Region, Iraq The prevalence and etiology of maxillary midline diastema among orthodontic patients attending Shorsh Dental Clinic in Sulaimani City Sulaimani Dental Journal SDJ Darwn Saeed Abdulateef a , Azheen Jamil Ali b & Nasih Fatih Othman c Abstract Maxillary midline diastema (MMD) is a common aesthetic problem of people seeking orthodontic problem, which means spacing greater than 0.5 mm between the proximal surfaces of maxillary central incisors. The causes for MMD may be: high frenum attachment; microdontia; macrognathia; supernumerary teeth; peg laterals; missing lateral incisors; midline cysts and unhealthy oral habits. Objectives: The purposes of this study were to determine the prevalence of MMD among Shorish dental clinic`s patients seeking orthodontic treatment and to find the factors associated with this anomaly. Materials and Methods: During 6 months, 507 patients with age (13 – 40) years old attending Shorish Dental Clinic, seeking orthodontic treatment were screened to find the prevalence and etiology of MMD. Result: The MMD was present in 110 patients (21.7%). The frequency of MMD was the same in males and females. It is highest in the young age group and lowest in the older age group (29% vs. 4%). Conclusion: The most frequent factor among the observed etiological factors was oral unhealthy habit which was found in 40% of MMD patients and 8.7% of all cases. Keywords: Maxillary midline diastema, frequency, etiology. Received: May 2014, Accepted: October 2014.