Analysis of 154 Cases of Teeth with Cracks
Roh BD, Lee YE. Dent Traumatol. 2006;22(3):118-123.
It is well known that cracked teeth occur most frequently in the mandibular molars with large or poor restorations in those over 50 years of age. However, with increasing knowledge and experience with cracks of teeth, cracks appear to be found frequently in intact teeth without restorations. The aim of this study is to analyze the cases of tooth cracks in a dental hospital in a year, and to find out the characteristic features of cracks of teeth. For 1 year, each tooth that was identified as a cracked tooth was recorded and analyzed in terms of the classification of cavity and restorative material, the nature of opposing tooth, the location in the arch, the age and gender, and the clinical signs and symptoms, and treatment result. Cracked teeth were observed most frequently in the teeth with no restorations (60.4%) and with class I restorations (29.2%). The most prevalent age was in those over 40 years of age (31.2% in their 40s, 26.6% in their 50s) and the prevalence was similar in men (53.9%) and women (46.1%). Cracked teeth were found most frequently in the maxillary molars (33.8% in first molar, 23.4% in second molar) than in the mandibular molars (20.1% in first molar, 16.2% in second molar). 96.1% of the cracked teeth responded to the bite test, and 81.1% of the cracked teeth were observed in the mesiodistal direction. The prevalence of cracked tooth was highest in the intact teeth with no restoration, in maxillary molars, and in those over 40 years of age. When examining an intact maxillary posterior tooth that is sensitive to a bite and thermal change, crack in the mesiodistal direction need to be considered one of the causes.
Who has not had a patient complain that a tooth hurts when they chew? Cracked tooth syndrome usually exhibits discomfort to chewing pressures and in some cases an abnormal sensitivity to thermal changes in otherwise normal teeth. The authors of this study provide an update of and agreement with previous studies on the diagnosis of and the clinical circumstances in which teeth demonstrate cracked tooth syndrome. This study also provides clinicians with insight concerning what teeth and what clinical conditions put a tooth at risk for this condition. Of interest, while previous studies have described the presence of existing intracoronal restorations in mandibular molars,1,2 this study presents data that does not agree with previous studies. In this study, more than 60% of the teeth exhibiting cracked tooth syndrome were restoration-free, with almost 30% having a Class 1 restoration. Diagnosis using a bite test was reliable more than 96% of the time. While the data is scattered compared to past studies, the conclusions are consistent. When a patient has a chief complaint of a posterior tooth being sensitive to biting and thermal changes, in all likelihood a crack in the mesiodistal direction needs to be considered as the cause. Treatment may require an onlay or full-coverage restoration to protect the tooth from fracture.
1. Bader JD, Martin JA, Shugars DA. Preliminary estimates of the incidence and consequences of tooth fracture. J Am Dent Assoc. 1995;126(12): 1650-1654.
2. Fennis WM, Kuijs RH, Kreulen CM, et al. A survey of cusp fractures in a population of general dental practices. Int J Prosthodont. 2002;15(6): 559-563.
Howard E. Strassler, DMD