conservative treatment mand. crowding

Resident’s Name: Joanne Lewis Date: April 3, 2009
Article title: Conservative treatment for malaligned permanent mandibular incisors in the early mixed dentition.
Author(s): Milton E. Gellin, DDS
Journal: Journal of Dentistry for Children
Volume (number):
Month, Year: July/August 1989
Major topic: extraction of mandibular primary incisors during the early mixed dentition.
Type of Article: literature review
Main Purpose: to point out that extraction of the mandibular primary incisors during the early mixed dentition can prevent this area from reaching maximum intercanine dimensional growth.
Overview of method of research: The author observed 44 children who had 57 lingually erupted permanent mandibular incisors to determine the outcome of lingual eruption. For cases involving crowding and rotation, the author reviewed the current literature to determine proper treatment and outcomes.
Findings: In all cases the author observed involving lingual eruption, labial migration and acceptable alignment occurred without the need to extract a primary incisor. The data suggests that removal of retained primary incisors should not be considered until 8.4 years of age. For crowding and rotation, research shows that the initial crowding is normal (1.6 mm in males and 1.8 mm in females), transitory and is improved by normal developmental processes. Proper alignment occurs with the transverse widening of the mandibular anterior arch when the permanent incisors begin their eruption. The strongest impulse for lateral growth of the mandibular alveolar process occurs with the eruption of the lateral incisors. When the lateral incisors are fully erupted, the intercanine width is complete. No data exists to indicate that the rotations of permanent mandibular incisors are signs of crowding; they can spontaneous self-correct. One study found that the best predictor of spacing or crowding in the permanent dentition is the sum of the spaces between the primary teeth at three to four years of age. The presence of the primary incisors and canines contribute to the optimal development of the mandibular intercanine width sufficient enough to accommodate the initial crowding of the mandibular permanent incisors.
Key points/Summary: When a mandibular permanent incisor has erupted to the lingual of a primary incisor, the dentist should reassure the parent that the primary incisor should exfoliate by 8 years of age. If it does not, it should be considered overretained and extraction is indicated. When the mandibular permanent incisors first erupt, some degree of crowding occurs. The alleviation of this crowding is brought about by many factors, including the increase of intercanine width and growth of the alveolar process. The continued presence of the mandibular primary incisors and canines insures that these increases do occur.
Assessment of article: The author makes a good case for not removing “shark teeth”…..but of course parents will still want it.