Deciduous teeth first teeth seen in the mouth are the mandibular centrals and the last are the maxillary second molars. The primary teeth are made up of central incisors, lateral incisors, canines, first molars, and secondary molars; there is one in each quadrant, making a total of four of each tooth. All of these are gradually replaced with a permanent counterpart except for the primary first and second molars; they are replaced by premolars. The replacement of primary teeth begins around age six, when the permanent teeth start to appear in the mouth, resulting in mixed dentition. The erupting permanent teeth cause
Worse is better Rise of Worse is Better", Gabriel claimed that "Worse-is-Better" is a model of software design and implementation which has the following characteristics (in approximately descending order of importance): Gabriel argued that early Unix and C, developed by Bell Labs, are examples of this design approach. Gabriel contrasted his philosophy with what he called the "MIT/Stanford style of design" or "MIT approach" (also known as "the Right Thing"), which he described as follows. Contrasts are in bold: Gabriel argued that "Worse is better" produced more "successful" software than the MIT approach: As long as the initial program is basically good, it