CDEN0110

06 I I MICD _ diastema closure _Midline diastemata (MD) are spaces of varying magnitude between the crowns of fully erupted maxillary and mandibular central incisors. Keene describes MD as anterior midline spacing greater than 0.5 mm between the proximal sur- faces of adjacent teeth. Incidences of maxillary and mandibular MD are 14.8 and 1.6 %, respec- tively.1 MD can occur in temporary, mixed or perma- nent dentition and may be considered normal for many children during the eruption of the perma- nent maxillary central incisors. When incisors first erupt, they may be separated by bone and the crowns incline distally because of the crowding of the roots. With the eruption of the laterals and permanent canines, the MD reduces or even closes completely. Etiologicalfactors The etiological factors of MD are described by various researchers. Angle concludes the presence of an abnormal frenum to be the cause of MD,2 a view that has been supported by other re- searchers.3–5 According to Tait, the frenum is the effect and not the cause of the incidence of di- astemata.6 He reports causes such as ankylosed central incisors, flared or rotated central incisors, anodontia, macroglossia, dento-alvolar dispropor- tion, localised spacing, closed bite, facial type, eth- nic and genetic characteristics, inter-premaxillary sutureandmidlinepathology.Weberliststhecauses for spacing between maxillary incisors as the result of high frenum attachment, microdontia, macro- gnathia,supernumeraryteeth,peglaterals,missing lateralincisors,midlinecysts,habitssuchasthumb- sucking, mouth breathing and tongue thrusting.7 Therefore, the etiological factors can be sum- marised as follows: 1. developmental: microdontia, missing laterals, mesiodens, macroglossia, macro-hypertrophic fibrous frenum; 2. pathological: midline cysts, tumours and peri- odontitis; 3. neuromuscular: oral habits, such as tongue thrustingduringspeech,swallowingorabnormal pressure during rest. cosmeticdentistry 1_2010 Midline diastema closure with direct-bonding restorations Author_ Dr Sushil Koirala, Nepal Fig. 2 Fig. 3 Fig. 1_MICD TP. Fig. 2_Placement of plastic strip. Fig. 3_Plastic strip is supported with index finger. Fig. 1