Tomographic analysis of nasomaxillary and zygomaticomaxillary buttress bone thickness for the fixation of miniplates

Variability in human tooth cementum thickness reflecting functional processes

OBJECTIVE

The aim of this study was to investigate the thickness of acellular extrinsic fibre cementum (AEFC) at four root positions of anterior and posterior teeth with special focus on functional aspects. Furthermore, the correlations between cementum thickness and chronological age and sex are investigated.

BACKGROUND

While numerous studies confirm continuous cementum apposition with age, masticatory forces as well as physiological and orthodontically induced tooth movements also have the potential to affect tooth cementum thickness.

MATERIALS AND METHODS

Undecalcified teeth were embedded in resin and transverse-sectioned in the cervical third of the root. Two sections per root were selected, and digital images at four positions were obtained (mesial, distal, oral, and vestibular) using light microscopy. The AEFC thickness of 99 teeth (anterior = 66, posterior = 33, male = 54, female = 45) were measured in both sections. The differences in mean values between root positions and the association of root position variation with tooth type, age, sex, and subject as well as the overall effects of age and sex were analysed using a mixed model.

RESULTS

First incisors and canines showed the greatest mean AFEC thickness, in contrast to premolars which had the lowest values. Differences were found across the four root positions, with a pattern varying considerably between anterior and posterior teeth and between maxilla and mandible in the anterior teeth. An interaction between root position and subject pointed to the existence of an individual component in the variation of AEFC thickness across the four root positions. There was an age trend with an almost linear increase in cementum thickness of 1 μm per year. Overall, females tended to exhibit a significantly lesser AEFC thickness compared to males.

CONCLUSIONS

Distinct differences in the pattern of thickness values across the four root positions in anterior and posterior teeth support the assumption that the AEFC is strongly affected by functional processes. In addition to sex-specific differences and age-related trends, the root position variation of AEFC thickness varies from individual to individual.

Reconstruction of the anterior maxillary defect using a vascularized bone flap with residual teeth in the posterior maxilla

BACKGROUND

Microsurgical bone reconstruction is challenging in cases of anterior maxillary defects because of the presence of residual teeth. The study analyzed the method and feasibility of using vascularized bone flaps to reconstruct anterior maxillary defects.

METHODS

We retrospectively analyzed 15 patients treated at the Department of Oral and Maxillofacial Surgery, Peking University School, and Hospital of Stomatology between November 2017 and January 2023.

RESULTS

A total of 14 patients were successfully reconstructed using the digital technique: 6 deep circumflex iliac artery (DCIA) flaps and 8 fibular free flaps. Palatal and buccal pedicle paths were used in 4 and 10 cases, respectively, for vascular anastomosis. The implant coverage rates of the DCIA and fibular free flaps were 87.2% and 92.6%, respectively (p > 0.05).

CONCLUSION

Anterior maxillary defects reconstructed with the DCIA and fibular free flaps are reliable methods. Furthermore, the palatal and buccal paths are recommended for vascular anastomosis.